Balancing Efficacy, Health Status, and Cost-Effectiveness: A Comparative Study of Desidustat and Erythropoietin in Chronic Kidney Disease Patients on Hemodialysis

Abstract

Background. Anemia is a common problem that greatly affects the quality of life and prognosis of those with CKD (chronic kidney disease). The conventional course of treatment has traditionally used ESAs (erythropoiesis-stimulating agents) such as erythropoietin; however, more recent medications, such as Desidustat, a hypoxia-inducible factor prolyl hydroxylase inhibitor (HIF-PHI), may be more advantageous in terms of both efficacy and cost. In this study, CKD patients receiving hemodialysis are compared for efficacy, safety, and cost-effectiveness between Desidustat and erythropoietin treatment.
Methods. This prospective, single-center, open-label study with parallel groups was carried out at Saveetha Institute of Medical Sciences in Chennai. A total of 60 patients with CKD on maintenance hemodialysis were randomized to receive either Desidustat (100 mg orally, 3 times a week) or Erythropoietin (subcutaneous injections) for 12 weeks. At baseline, four weeks, eight weeks, and 12 weeks, hemoglobin levels, biomarkers (TSAT, ferritin, and hepcidin), and status of physical and mental health had been noted. The key finding was the proportion of hemoglobin responders (defined as a rise from baseline of ≥1g/dL). Secondary outcomes included predictors of hemoglobin response, adverse effects, and cost-effectiveness.
Results. The proportion of hemoglobin responders was 83.33% in the Desidustat compared to 73.33% in the Erythropoietin group (p = 0.530), indicating no significant difference in efficacy. Hemoglobin levels increased gradually in both groups over 12 weeks. Higher serum albumin (OR = 3.32, 95% CI: 1.54-7.16, p = 0.008) and lower iPTH levels (OR = 0.98, 95% CI: 0.97-0.99, p = 0.004) have been important indicators of hemoglobin response. Hepcidin levels decreased significantly in the Desidustat group in contrast to Erythropoietin (p = 0.038), suggesting improved iron metabolism with Desidustat. No significant differences were noted in TSAT or ferritin levels. Adverse effects were comparable between the groups, with similar hospitalization and infection rates. Desidustat demonstrated better cost-effectiveness, with a lower monthly cost compared to Erythropoietin.
Conclusions. When treating anemia in individuals with CKD receiving hemodialysis, Desidustat is a safe and efficient substitute for erythropoietin, with the added advantage of cost-effectiveness. Serum albumin and iPTH were significant predictors of hemoglobin response. To validate these results larger multicentric studies are necessary.
Keywords: Chronic kidney disease, anemia, Desidustat, Erythropoietin, hemodialysis, hemoglobin response, biomarkers, cost-effectiveness, hepcidin, iron metabolism

Introduction

Chronic kidney disease (CKD) affects millions of people globally and is often accompanied by anemia, which significantly impacts the quality of life and contributes to increased morbidity and mortality [1]. Anemia prevalence can reach up to 90% in patients with ESRD (end-stage renal disease) [2]. The management of anemia in CKD changed dramatically with the introduction of recombinant human erythropoietin (EPO) in the late 1980s, which effectively increased hemoglobin levels and reduced the need for blood transfusions [3, 4]. In 1989, the FDA approved EPO for anemia treatment in CKD patients [3].

However, ESAs (erythropoiesis-stimulating agents) like EPO present challenges, including risks of cardiovascular events [5], the burden of regular injections, and significant healthcare costs. Additionally, some patients’ responses to ESA therapy are insufficient, highlighting the need for alternative treatments [6].

The high prevalence of anemia in CKD, combined with the limitations of current therapies, necessitates exploring new options that improve patient outcomes and reduce costs [2, 5, 7]. Desidustat, an oral HIF-PHI (hypoxia-inducible factor prolyl hydroxylase inhibitor), is emerging as a promising alternative. By stabilizing hypoxia-inducible factors, Desidustat stimulates endogenous erythropoietin production and enhances iron metabolism [8]. Its oral administration and potential for a better safety profile compared to ESAs make it appealing [8]. Furthermore, Desidustat may offer a more cost-effective solution for anemia management in CKD patients, especially when considering long-term ESA therapy costs [9].

While early trials show that Desidustat effectively raises hemoglobin levels, more studies are needed to compare it directly with traditional ESAs, especially regarding clinical outcomes, health status, and cost-effectiveness [10]. Currently, few studies have been conducted in India [11]. This study aims to compare Desidustat and EPO in CKD patients, focusing on hemoglobin response, health status, predictors of response, and cost-effectiveness, offering a comprehensive evaluation of Desidustat as an alternative to ESA treatment.

 

Materials and Methods

Study Design

This single-center, prospective, open-label, parallel-group trial was conducted at Saveetha Institute of Medical Sciences & Research, Chennai, to compare the efficacy, health status, and cost-effectiveness of Desidustat with erythropoietin in treating anemia in CKD patients on hemodialysis. This study was conducted from June 2023 to July 2024 in patients aged 18 to 75 years. The inclusion criteria werepatients undergoing maintenance hemodialysis for at least three months with hemoglobin levels between 8.0 and 10.0 g/dL, TSAT greater than 20%, and no deficiencies in folate, vitamin B12, or iron [12]. Patients had to be off erythropoiesis-stimulating agents or iron therapy for four weeks, provide informed consent, and meet the exclusion criteria, including recent or active malignancy, uncontrolled hypertension, or liver disease. All participants granted written in formed consent, and the Institutional Ethics Committee (No.012 /06/2023/IEC) authorized the research.

Sixty patients were randomized into 2 groups using a computer-generated sequence. One group (30 patients) received Desidustat, and the other group (30 patients) received Erythropoietin-epoetin alfa. Desidustat was administered orally (100 mg three times weekly), whereas Erythropoietin was given subcutaneously following standard protocols. Hemoglobin levels were closely monitored throughout the study, and dosages were adjusted based on individual responses.

Enrollment and Screening

Baseline data collected included demographic information, medical history, and current medications. There were no substantial differences in current medications between the Desidustat and Erythropoietin groups. Patients in both groups were not on vitamin B12 or folic acid tablets during this period. Laboratory tests were administered to measure hemoglobin, MCV (mean corpuscular volume), PCV (packed cell volume), ferritin, TSAT, hepcidin, MCH (mean corpuscular hemoglobin), erythrocyte sedimentation rate (ESR), serum albumin, body mass index (BMI), Kt/V (a measure of dialysis adequacy), URR (urea reduction ratio), and intact PTH (parathyroid hormone) levels.

Treatment and Follow-Up

Following a 12-week course of treatment, follow-up evaluations were carried out at baseline, four, eight, and twelve weeks. Clinical evaluations included physical examination and laboratory tests to monitor hemoglobin, PCV, MCV, MCH, MCHC, ferritin, TSAT, and hepcidin. ESR, serum albumin, BMI, Kt/V, URR, and intact PTH were also measured. Hemoglobin responders were defined as those achieving hemoglobin levels between 10 to 12 g/dL, increasing by at least 1 g/dL [13] by week twelve.

The “medical outcome study questionnaire SF-36”, was used to measure the overall physical and mental health status at baseline and twelve weeks [14].

Monitoring and Dose Adjustments

Dosages were adjusted based on hemoglobin levels and other clinical parameters to ensure patient safety and optimize treatment efficacy. Adverse events were documented and managed throughout the study. The primary focus was maintaining patient safety while ensuring effective treatment.

Data Collection and Statistical Analysis

Data collected during the study, including baseline characteristics, laboratory results, status of heath scores, and adverse events, were securely documented for comparison between treatment groups.

Baseline Characteristics

Baseline characteristics, such as hemoglobin, PCV, MCV, MCH, MCHC, TSAT, ferritin, hepcidin levels, markers of dialysis efficacy like URR, Kt/V and ESR were assessed. Comparisons between Desidustat and Erythropoietin groups were made using separate t-tests at baseline and twelve weeks. Statistical significance has been established as a p-value of less than 0.05.

Hemoglobin Responders

The proportion of hemoglobin responders (patients with hemoglobin levels between 10-12 g/dL and an increase of ≥1 g/dL) was compared using a chi-square test, with odds ratios and 95% confidence intervals calculated. To determine the effects of both duration and treatment, levels of hemoglobin were computed at baseline, 4 weeks, 8 weeks, and12 weeks using repeated-measures ANOVA.

Multivariate Logistic Regression

Multivariate logistic regression was used to identify predictors of hemoglobin response, including ESR, serum albumin, BMI, Kt/V, URR, intact PTH, age, and comorbidities such as hypertension and diabetes. After setting the significance level at p < 0.05, odds ratios with confidence intervals of 95% were computed.

Hemoglobin Rise Over Time

Repeated-measures ANOVA was used to examine hemoglobin levels at four, eight, and twelve weeks. Line graphs were used to depict trends and compare the Desidustat and Erythropoietin groups.

Ferritin, TSAT, and Hepcidin Levels

Ferritin, TSAT, and hepcidin levels have been assessed at baseline, four, eight, and twelve weeks. and compared between the two groups using repeated-measures ANOVA. Line graphs illustrated these trends.

Health status

The SF-36 survey [14, 15] was used to measure physical and mental health changes, and paired t-tests within groups and independent t-tests across groups were utilised to compare the results. Results have been summarized as mean scores and standard deviations.

Cost-Effectiveness

Cost-effectiveness was evaluated by comparing total costs (drugs, administration, monitoring, and adverse events) and QALYs (Quality-Adjusted Life Years) gained. The ICER (Incremental Cost-Effectiveness Ratio) [16] has been computed to assess the cost per QALY gained by switching from Erythropoietin to Desidustat.

Safety Outcomes

The incidence of treatment-related events, including hospitalization rates, infections, volume overload, nausea, abdominal pain, headache, fatigue, and insomnia, was assessed using chi-square or Fisher’s exact tests based on expected frequencies. Results were summarized as the number of patients experiencing each event in both groups, with p-values  used to identify significant differences. Hospitalization rates were specifically analyzed using chi-square tests, with relative risks calculated to compare the frequency of hospitalizations between Desidustat and Erythropoietin groups.

 

Results

The baseline characteristics of patients in the Desidustat and Erythropoietin groups were generally comparable, with no significant differences seen in the majority of variables which have been outlined in Table 1. The average age was around 52 years in both groups, and the BMI (body mass index) was slightly elevated in the Desidustat group, though this difference approached statistical significance (p = 0.059). Hemoglobin (Hb) levels were similar between groups (p = 0.335). However, the Desidustat group had significantly higher MCV and MCH compared to the Erythropoietin group, with p-values of 0.001 and 0.005, respectively. There were no discernible variations in other measures, including albumin, packed cell volume (PCV), ESR, and markers of dialysis efficacy (Kt/Vand URR). The gender distribution in this study demonstrated a significant imbalance between the two treatment groups. In the Desidustat group, 86.67% of participants were male, compared to 43.33% in the Erythropoietin group (p = 0.001). Despite this disparity, no gender-related analyses were conducted, as gender was not hypothesized to influence the outcomes. There were no appreciable variations in the prevalence of heart failure between the two groups, and both had comparable rates of diabetes and hypertension.

Variable DESIDUSTAT ERYTHROPOIETIN p-value
Mean SD mean SD
Age in years 52.30 11.83 52.70 10.52 0.935
BMI 22.60 2.39 21.54 1.83 0.059
Hb 8.89 0.43 8.98 0.36 0.335
PCV 27.56 3.73 26.36 4.42 0.260
MCV 92.66 5.69 87.68 5.82 0.001
MCH 30.57 10.64 27.12 1.96 0.005
MCHC 33.56 1.23 32.80 1.16 0.813
HEPCIDIN 200.07 67.30 199.10 61.86 0.954
ESR 27.73 12.85 28.73 12.17 0.758
ALBUMIN 3.70 0.44 3.63 0.39 0.517
kt/v 1.25 0.15 1.22 0.20 0.519
URR 64.3 4.7 63.1 4.56 0.318
iPTH 314.57 142.31 316.13 113.93 0.963
Count n=30 Frequency Count n=30 Frequency  
Male 26 86.67% 13 43.33% 0.001
Female 4 13.33% 15 50.00% 0.006
HTN 30 100% 30 100% 1.000
DM 12 40% 13 43% 1.000
Heart failure 7 23.33% 8 26.67% 1.000
Table 1. Baseline characteristics of the study participants.

The proportion of hemoglobin responders was 83.33% (n=25) in the Desidustat group and 73.33% (n=22) in the Erythropoietin group, p=0.530 indicates that there is no statistically significant variation among the groups, indicating similar efficacy in achieving a hemoglobin rise of ≥1 g/dL by week 12as given in Figure 1.

Comparison of responders and non-responders to treatment between the Desidustat and the Erythropoietin groups
Figure 1. Comparison of responders and non-responders to treatment between the Desidustat and the Erythropoietin groups.

At baseline, four weeks, eight weeks, and twelve weeks, hemoglobin levels were assessed. Both Desidustat and Erythropoietin groups demonstrated a gradual increase in haemoglobin levels over time, with no significant variation among groups at any time point(p>0.05). At baseline, there was no significant variation among groups(p=0.795). At 4 weeks, the mean hemoglobin levels were nearly identical (p=0.967), and similar trends were observed at eight weeks(p=0.642) and twelve weeks(p=0.724). These results suggest that both treatments are equally effective in raising hemoglobin levels over the 12-weeksas explained in Figure 2.

Comparison of the increase in hemoglobin levels between the Desidustat and the Erythropoietin groups.
Figure 2. Comparison of the increase in hemoglobin levels between the Desidustat and the Erythropoietin groups.

The hemoglobin levels and biomarkers (TSAT, Ferritin, and Hepcidin) were assessed at baseline, four weeks, eight weeks, and twelve weeks in both Erythropoietin and Desidustat groups.

The study also measured changes in several biomarkers, including transferrin saturation (TSAT), ferritin, and hepcidin. TSAT scores indicated a marginally significant increase in both groups over the 12 weeks (p = 0.715) as outlined in figures 3, 4 and 5 respectively. Ferritin levels decreased in both groups without statistical significance (p = 0.544). In contrast, Hepcidin levels decreased significantly in the Desidustat group compared to the Erythropoietin group (p = 0.038), recommending a potential advantage of Desidustat in enhancing iron metabolism.

The study examined several cytological parameters, including total leukocyte count (TLC), PCV, MCV, mean corpuscular hemoglobin (MCH), and RBC count given in Table 2. Baseline values for RBC and PCV were similar between the groups, and changes at 12 weeks were also comparable, with no significant differences. The MCV was noticeably greater in the Desidustat group at baseline (p=0.001), but the difference decreased by 12 weeks (p=0.281). MCH was also higher in the Desidustat group at baseline(p=0.005), but at 12 weeks, this change was not statistically significant (p = 0.725). At any given moment, there were no discernible variations between the groups’ MCHC or TLC.

Parameter DESIDUSTAT ERYTHROPOIETIN p-value
mean SD mean SD
Baseline RBC 2.99 0.57 3.01 0.51 0.813
RBC at 12 weeks 3.22 0.43 3.21 0.57 0.921
Baseline PCV 27.56 3.73 26.36 4.42 0.26
PCV at 12 weeks 29.82 3.52 29.04 5.52 0.516
Baseline MCV 92.66 5.69 87.68 5.82 0.001
MCV at 12 weeks 91.5 5.35 89.99 5.43 0.281
Baseline MCH 30.57 10.64 27.12 1.96 0.005
MCH at 12 weeks 28.4 2.31 28.2 1.91 0.725
Baseline MCHC 30.57 1.23 32.80 1.16 0.813
MCHC at 12 weeks 30.24 3.41 31.13 1.36 0.652
Baseline TLC 8434.67 2318.02 8625.47 3903.85 0.579
TLC at 12 weeks 8121.33 2431.05 8036.23 2225.63 0.739
Table 2. Comparison of Increase in Hematological parameters between the two groups.
Comparison of TSAT between the Desidustat and the Erythropoietin groups.
Figure 3. Comparison of TSAT between the Desidustat and the Erythropoietin groups.
Comparison of ferritin between the Desidustat and the Erythropoietin groups.
Figure 4. Comparison of ferritin between the Desidustat and the Erythropoietin groups.
Comparison of hepcidin between the Desidustat and the Erythropoietin groups.
Figure 5. Comparison of hepcidin between the Desidustat and the Erythropoietin groups.

Multivariate logistic regression identified higher serum albumin (OR = 3.32, 95% CI: 1.54-7.16, p = 0.008) and lower iPTH levels (OR = 0.98, 95% CI: 0.97-0.99, p = 0.004) as significant predictors of hemoglobin response. Reduced ESR (p = 0.051) also trended toward significance. These results suggest that favorable baseline nutritional and inflammatory profiles enhance treatment outcomes. While Kt/V showed a positive but nonsignificant association with hemoglobin response (OR = 2.50, p = 0.179), URR displayed a significant negative association (OR = 0.741, p = 0.003). This indicates that higher URR values may decrease the likelihood of achieving hemoglobin response, despite dialysis adequacy (Table 3).

Variable Coefficient Standard Error z p-value Odds Ratio
ESR -0.101 0.051 -1.955 0.051 0.904
ALBUMIN 1.2 0.45 2.667 0.008 3.32
BMI 0.165 0.194 0.85 0.395 1.18
Kt/V 5.354 3.984 1.344 0.179 2.5
URR -0.3 0.1 -3 0.003 0.741
IPTH -0.02 0.007 -2.857 0.004 0.98
Age 0.055 0.039 1.417 0.156 1.057
DIABETES -0.374 0.904 -0.413 0.68 0.688
HYPERTENSION -2.308 9.27 -0.249 0.803 0.099
Heart failure -0.289 0.916 -0.315 0.753 0.749
Table 3. Multivariate logistic regression analysis with hemoglobin responders.

In this study, both the Desidustat and Erythropoietin groups showed improvements in overall health status over the course of three months, as determined by the SF-36 survey (Table 4).Although both groups exhibited increased scores in domains like physical functioning, role physical, and mental health, among the groups, there were no statistically significant differences (p > 0.05).

Domain Time Point Desidustat Group Erythropoietin Group P-values
Physical Functioning (PF) Baseline 55.8 ±22.6 56.2 ± 23.1 0.946
3 months 68.3 ± 18.2 65.8 ± 19.7 0.612
Role Physical (RP) Baseline 56.7 ± 32.4 54.9 ± 31.8 0.829
3 months 66.5 ± 27.8 61.3 ± 30.6 0.494
Bodily Pain (BP) Baseline 47.8 ± 23.5 48.3 ± 24.1 0.935
3 months 59.2 ± 20.7 58.7 ± 20.8 0.926
General Health (GH) Baseline 47.3 ± 13.4 48.1 ± 14.1 0.823
3 months 58.4 ± 12.4 56.7 ± 12.9 0.605
Vitality (VT) Baseline 42.6 ± 15.3 41.9 ± 15.6 0.861
3 months 55.8 ± 14.2 57.4 ± 16.8 0.692
Social Functioning (SF) Baseline 57.8 ± 18.5 56.4 ± 19.3 0.775
3 months 64.7 ± 17.4 65.5 ± 18.7 0.864
Role Emotional (RE) Baseline 42.6 ± 33.7 41.8 ± 34.1 0.927
3 months 58.7 ± 30.3 56.6 ± 32.7 0.797
Mental Health (MH) Baseline 46.9 ± 13.9 46.8 ± 14.2 0.978
3 months 56.3 ± 12.8 54.5 ± 13.4 0.597
Table 4. Comparison of Physical and Mental health status using SF-36 between the two groups.

Desidustat’s monthly cost totals $51.61, offering 0.025 QALYs over three months, while Erythropoietin costs $58.43 monthly, yielding 0.020 QALYs. Both treatments share $11.45 administration and monitoring costs, with $8.43 per treatment related event. Desidustat’s lower costs and higher QALYs lead to an ICER of $-1,493.98, indicating greater cost-effectiveness (Table 5).

Category Desidustat Erythropoietin
Drug Costs $2.65 per dose, thrice a week ($31.81 /month) $4.82 per dose, twice a week ($38.55 /month)
Administration Costs similar similar
Monitoring Costs $11.45/month $11.45/month
Treatment Related Event Management Costs $8.43 per event $8.43 per event
Total Cost (Monthly) $51.61 $58.43
Incremental Cost-Effectiveness Ratio (ICER) $-1,493.98
Table 5. Comparison of cost-effectiveness between the two groups.

Safety outcomes have been comparable among the groups, with no significant differences in hospitalization rates (11 vs 13, p=0.782), infections (11 vs 8, p=0.631), or volume overload (p=0.650).Gastrointestinal symptoms, like nausea and vomiting, were more common (3 vs1, p=1.0) in the Desidustat group; nevertheless, the differences did not reach statistical significance. Other adverse effects, such as headache, fatigue, and insomnia, occurred at similar rates across both groups (Table 6).

Safety outcomes Desidustat Erythropoietin p-value
Number of Hospitalizations 11 13 0.782
Infections 8 11 0.631
Volume Overload 3 2 0.650
Nausea and Vomiting 3 1 1
Abdominal Pain 1 0 1
Headache 0 1 0.462
Fatigue 3 2 1
Insomnia 0 1 0.462
Table 6. Comparison of safety outcomes between the Desidustat and the Erythropoietin groups.

 

Discussion

The findings of this study demonstrate that Desidustat is a viable alternative to Erythropoietin in controlling anemia in patients with CKD. Both drugs showed similar efficacy in raising hemoglobin levels over 12 weeks, with no significant difference in hemoglobin response rates. These results are consistent with those reported by Gang et al., who found Desidustat to be equally effective as Erythropoietin in increasing hemoglobin levels in CKD patients [17].

Although this study lacked gender-specific analyses, a significant imbalance was observed, favoring males in the Desidustat group (p = 0.001). Hemoglobin response and secondary outcomes were unaffected, consistent with standardized dialysis protocols minimizing gender-related differences. Joharapurkar et al. (2024) reported similar findings [13]. The results support the applicability of both drugs and highlight the importance of representative sampling in future research.

A notable observation from this study was the significant decrease in hepcidin levels in the Desidustat group. One important regulator of iron metabolism is hepcidin, which saw a reduction that likely enhanced iron availability for erythropoiesis, contributing to Desidustat’s efficacy. Chen et al. (2019) similarly observed a reduction in hepcidin levels, which was linked to improved iron mobilization in patients treated with Roxadustat [8], while Gang et al. (2022) reported similar findings for Desidustat in dialysis-dependent CKD patients [17]. Both groups showed slight increases in TSAT levels, with no significant difference (p = 0.715), as well as a non-significant reduction in ferritin levels (p = 0.544), consistent with the DREAM-D trial findings, where Desidustat had a minimal effect on iron metabolism markers during anemia treatment in CKD patients [17].

The multivariate logistic regression analysis revealed that higher serum albumin, lower iPTH levels, and reduced ESR were significant predictors of hemoglobin response. This aligns with literature suggesting that inflammation, indicated by elevated ESR, can impair erythropoiesis and diminish the efficacy of anemia treatments [18]. Higher albumin levels, reflecting better nutritional status, were also associated with improved responses to anemia therapy [19].

In this study, multivariate regression analysis showed that dialysis adequacy, as measured by Kt/V, was not significantly associated with hemoglobin response (p = 0.179), possibly due to the influence of nutritional status and inflammation. In contrast, a significant negative association was found between URR and hemoglobin response (p = 0.003), suggesting that higher URR might reflect more aggressive dialysis or underlying conditions, such as malnutrition or inflammation, that impair erythropoiesis [20]. This underscores the complex interplay between dialysis and anemia, as highlighted by Owen et al. [20] and Liu et al. [21], and suggests the need for further research on how dialysis metrics interact with nutritional and inflammatory factors in CKD.

Regarding safety, the safety outcomes of Desidustat and Erythropoietin were comparable, with no significant differences in hospitalization rates, infections, or other complications. This safety profile aligns with previous clinical trials, which found Roxadustat (a HIF-PHI) to be well-tolerated and similar in safety to Erythropoietin [22].

Physical, emotional and mental health improvements have been noted in both groups, as measured by the SF-36 survey. Significant enhancements across all domains suggested that effective anemia management, regardless of the drug, improved patients’ well-being. These results mirror those reported by Provenzano et al. (2021), who also found significant quality of life improvements in individuals receiving Roxadustat (HIF-PHI) treatment [6].

One of the study’s most significant findings was the cost-effectiveness of Desidustat. The lower monthly costs, combined with slightly better QALY outcomes, produced a favorable ICER. This economic advantage is especially important in resource-limited settings where the high cost of Erythropoietin poses a barrier to treatment. Desidustat’s cost-effectiveness has also been highlighted in other studies, which identified it as a key benefit over traditional erythropoiesis-stimulating agents (ESAs) [13].

Similar cost advantages were noted with Roxadustat, another HIF-PHI. Dhillon et al. (2019) reviewed Roxadustat and found that it improved iron metabolism by lowering hepcidin and reducing the need for iron supplements, which contributed to its lower treatment costs compared to ESAs [10]. This suggests that Desidustat, a similar HIF-PHI, may offer comparable economic benefits. Provenzano et al. (2016) further demonstrated that Roxadustat effectively increased hemoglobin in non-dialysis CKD patients with good safety, reinforcing Desidustat’s potential as a cost-effective alternative for anemia management [7].

These studies collectively support the potential of Desidustat as a cost-effective and efficacious treatment option for anemia in CKD patients. The ability of HIF-PHIs like Desidustat to manage anemia while improving iron metabolism and reducing treatment costs makes them valuable alternatives to traditional therapies, particularly in settings where cost-effectiveness is crucial. While this study provides valuable insights into cost-effectiveness, future research should consider indirect costs and other health-economic factors.

Overall, the results suggest that Desidustat is not only an effective and safe alternative to Erythropoietin but also a more cost-effective option for anemia management in CKD patients, aligning with existing literature on the potential benefits of Desidustat.

 

Conclusion

This study demonstrated that Desidustat is not only comparable to Erythropoietin in terms of improving hemoglobin levels and enhancing health status but also offers significant advantages in cost-effectiveness. Desidustat’s unique mechanism of action, which positively influences iron metabolism, alongside its lower treatment costs, positions it as a promising alternative to traditional erythropoiesis-stimulating agents.

 

Limitations

The study’s limitations include its relatively short duration, specific population and small sample size, as it was conducted in a single centre. Longitudinal multicentric studies with more diverse populations are required to thoroughly evaluate the long-term effectiveness and safety of Desidustat compared to Erythropoietin.

 

Future implications

The study findings suggest that Desidustat could be a valuable option for anemia management in CKD on hemodialysis, particularly in settings where cost considerations are paramount. It paves the way for conduction of longitudinal multicentric studies to assess Desidustat’s wider relevance in a variety of patient demographics.

 

Ethical issues

The study was initiated after obtaining institutional ethics approval (No.012 /06/2023/IEC) and informed consent of participants and undertaken following the revised Declaration of Helsinki (2008) guidelines.

 

Data availability

The data regarding study findings are available with the corresponding author and is accessible on request.

 

Abbreviations

CKD: Chronic Kidney Disease

ESA: Erythropoiesis Stimulating Agent

HIF-PHI: Hypoxia-inducible factor prolyl hydroxylase inhibitor

ESRD: End-stage Renal Disease

EPO: Erythropoietin

TSAT: Transferrin Saturation

QALYs: Quality-Adjusted Life Years

ICER: Incremental Cost-Effectiveness Ratio

 

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  9. Parmar DV, Kansagra KA, Patel JC, Joshi SN, Sharma NS, Shelat AD, Patel NB, Nakrani VB, Shaikh FA, Patel HV; on behalf of the ZYAN1 Trial Investigators. Outcomes of Desidustat Treatment in People with Anemia and Chronic Kidney Disease: A Phase 2 Study. Am J Nephrol. 2019;49(6):470-478. https://doi.org/10.1159/000500232. Epub 2019 May 21. PMID: 31112954.
  10. Dhillon S. Roxadustat: First Global Approval. Drugs. 2019 Apr;79(5):563-572. https://doi.org/10.1007/s40265-019-01077-1. PMID: 30805897.
  11. Zydus to launch Desidustat breakthrough treatment for anemia in CKD patients under brand name Oxemia. Medical Dialogues. Available from: https://www.medicaldialogues.in. (last accessed on 20 September 2024)
  12. KDOQI. Clinical practice guidelines and clinical practice recommendations for anemia in chronic kidney disease. Am J Kidney Dis. 2006;47(5 Suppl 3)
  13. Joharapurkar A, Pandya V, Patel H, et al. Desidustat: a novel PHD inhibitor for the treatment of CKD-induced anemia. Front Nephrol. 2024;4:1459425. https://doi.org/10.3389/fneph.2024.1459425.
  14. Ware JE, Snow KK, Kosinski M, Gandek B. SF-36® Health Survey Manual and Interpretation Guide. Boston, MA: New England Medical Center, The Health Institute, 1993. 15.
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Comparison Among Potassium Binders on the Management of Hyperkalemia on Chronic Dialysis Patients: A Protocol for Systematic Review

Abstract

Introduction. Treating hyperkalemia is one of the main goals of supportive care in patients on hemodialysis. In this context, therapy with new potassium binders is a promising resource.
Objective. The main aim is to evaluate the difference in serum potassium concentration after treatment with sodium zirconium cyclosilicate or patiromer compared to placebo/sodium polystyrene sulfonate/calcium polystyrene sulfonate.
Methods. We will perform systematic research in PubMed, EMBASE, CINAHLE, and grey literature will be screened. We will screen RCTs on patients treated with SZC or patiromer in chronic hemodialysis, without sex or age restriction, which include the differences in serum potassium concentration, adverse events (AEs), and mortality as outcomes.
Expected results. This systematic review is expected to provide a comprehensive evaluation of the efficacy and adverse effects of new potassium binders, compared to sodium polystyrene sulfonate or calcium polystyrene sulfonate or placebo, on serum potassium concentration, in a sample of hemodialysis patients. Furthermore, possible gaps in actual knowledge can be highlighted, suggesting new research.
Conclusions. The present protocol for a systematic review will consider all existing evidence from published RCTs about the efficacy of potassium binders on hemodialysis patients.

Keywords: Potassium binders, sodium zirconium cyclosilicate, patiromer, hyperkalemia, CKD, Hemodialysis

Introduction

The incidence of Hyperkalemia is common in kidney diseases, and its incidence increases in patients who previously experienced hyperkalemia, similarly to patients with diabetes or assuming RAASIs, with successively shorter time between the episodes [1].

Patiromer and Sodium Zirconium Cyclosilicate (SZC), an ion-exchange polymer resin and an ion-exchange microporous resin, were developed in the second decades of the third millennium, reducing adverse events [24].

The increased risk of mortality and morbidity in hyperkalemia is well-known [5, 6], as well as their increased incidence in patients treated with RAASIs.  It occurs because RAASIs reduce the aldosterone-related potassium excretion that physiologically occurs in the distal and collecting tubule. Despite this, RAASIs showed nephroprotective and cardioprotective action, and it makes RAASIs useful to use. For this, new potassium binders, also aimed to better manage hyperkalemia in patients treated with RAASIs, managing pre-dialysis serum potassium that is considered a risk factor of cardiovascular mortality [7].

 

Aims and scope

The main objective is to evaluate the difference in serum potassium levels at different time points after treatment with SZC and patiromer compared to placebo, sodium polystyrene sulfonate or calcium polystyrene sulfonate.  The rationale for using potassium binders is to reduce pre-HD serum potassium, allowing a mitigation of interdialytic potassium changes and reducing the risk of arrhythmia.

Furthermore, the safety needs to be evaluated among these potassium binders in this population, due to the different pharmacokinetics that improve them.

Methods

Design and registration

This systematic review protocol follows the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA-P) guidelines [8]. This review protocol will also be registered in the PROSPERO database.

Search strategy

We will perform systematic research in MEDLINE, EMBASE, and CINAHLE, looking for published randomized controlled trials (RCTs). Grey literature will be screened through Google Scholar, Scopus and ClinicalTrials.gov. Only RCTs will be included in the study.

We will search for papers in the English language, and we will include only European and American countries, to avoid heterogeneity in the population. Reference lists from eligible trials and related reviews will also be reviewed, in order to find additional potential eligible studies. Ongoing, unpublished trials or further data from published trials will be researched on ClinicalTrials.gov. Finally, where needed, we will contact the experts in the field.

Search details are summarized in Table 1.

MEDLINE 127
((Potassium binders) OR (lokelma) OR (sodium zirconium cyclosilicate) OR (Veltassa) OR (patiromer)) AND ((Placebo) OR (Kayexalate) OR (sodium polystyrene sulfonate) OR (sorbisterit) OR (calcium polystyrene sulfonate)) AND ((dialysis) OR (Hemodialysis) OR (peritoneal dialysis) OR (CKD) OR (Chronic Kidney Disease)) AND ((Potassium) OR (hyperkalemia)) ‘Filters: Clinical Trial, Randomized Controlled Trial’
CINAHL 8
#1 Potassium Binders

#2 Lokelma

#3 Sodium zirconium cyclosilicate

#4 Veltassa

#5 Patiromer

#6 Placebo

#7 Kayexalate

#8 Sodium polystyrene sulfonate

#9 Sorbisterit

#10 Calcium polystyrene sulfonate

#11 Dialysis

#12 hemodialysis

#13 Peritoneal dialysis

#14 CKD

#15 Chronic Kidney Disease

#16 Potassium

#17 Hyperkalemia

#18 #1 OR #2 OR #3 OR #4 OR #5 OR #6 OR #7 OR #8 OR #9 OR #10

#19 #11 OR #12 OR #13 OR # 14 OR #15

#20 # 16 OR #17

#21 #18 AND #19 AND #20 in Trials

EMBASE 87
((‘Potassium binders/exp’ OR ‘lokelma’ OR ‘sodium zirconium cyclosilicate’ OR ‘Veltassa’ OR ‘patiromer’) AND (‘Placebo’ OR ‘Kayexalate’ OR ‘sodium polystyrene sulfonate’ OR ‘sorbisterit’ OR ‘calcium polystyrene sulfonate’) AND (‘dialysis’/exp OR ‘hemodialysis’/exp OR ‘peritoneal dialysis’/exp OR ‘chronic kidney disease’ OR ‘CKD’/exp) AND (‘potassium’ OR ‘hyperkalemia’/exp)) AND (‘Clinical Trial’ OR ‘Randomized Controlled Trial’)
Table 1. Search strategy PubMed and EMBASE.

Eligibility criteria 

PICO strategy will be applied as follows:

– Population: we will compare the efficacy and the adverse effects in patients treated with SZC or patiromer. Eligible RCTs will consider subjects with chronic hemodialysis, without sex or age restriction. Exclusion criteria correspond to CKD in conservative treatment, acute hemodialysis, and oncological disorders.

– Intervention: SZC or Patiromer

– Comparator: placebo, sodium polystyrene sulfonate or calcium polystyrene sulfonate.

– Outcome: differences in serum potassium concentration, Adverse events (AEs), and mortality.

– Study design: Randomized clinical trials (RCTs)

Literature screening and study selection

The summary will be shown using the PRISMA flow diagram [9]. Duplicate will be removed.

Studies will be screened first by title and abstracts by two independent authors and any disagreement will be discussed with a third author. All abstracts will be screened using Rayyan software, whereas all full-text articles will be screened using the Mendeley software desktop.

Data extraction

Studies will be screened first by title and abstracts by two independent authors and any disagreement will be discussed with a third author with Rayyan software. Subsequently, the full texts of the selected studies will be read and assessed by two independent authors and any disagreement will be discussed with a third author. Reasons for the exclusion will be reported for each study. The selection process will be described through the PRISMA flow diagram.

The following data will be extracted through a standardized extraction Excel sheet by two independent authors:

  1. General characteristics of the study (design, settings, sample size)
  2. Participant characteristics: inclusion and exclusion criteria; number of participants screened and included; average age; comorbidities; sex; area of recruitment
  3. Intervention characteristics: type and duration of the treatment and the follow-up
  4. Adverse events: number of participants affected by adverse events, description of the adverse events and number of dropouts.

Missing data will be obtained by contacting the included studies’ authors. We will send emails three times in three months.

We will include RCTs to allow a high-grade validity of this systematic review. If needed for insufficient data, we will include non-RCTs and observational studies.

Data items

Identification of the study: this will include the name of the journal, article DOI, article title, authors, publication year, short citation, and country.

Methods: study objectives, study design, inclusion and exclusion criteria, intervention, comparator characteristics, population details and results will be included.

For intervention and comparator will be specified type, dose, duration, frequency, and mode of administration.

For population, detail will be detailed mean age, sex, and number of participants. Results will describe summary statistics, effect estimates, confidence intervals, p-values, subgroup analyses, sensitivity analyses, risk of bias, and GRADE.

We plan to perform subgroup analyses based on age (< or > 18 years), hemodialysis or peritoneal dialysis, and a network analysis for different potassium binders will be performed.

Main findings: this will include patient characteristics and other relevant clinical outcome measures.

Methodological quality assessment 

For the systematic review, the method of assessing the risk of bias or study quality, and for the data extraction will be structured as follows: studies will be screened first by title and abstracts by two independent authors and any disagreement will be discussed with a third author with Rayyan software.

Blinding: the study selection, data extraction, and risk of bias assessment will be performed without blinding the assessors to the study authors or the journal of publication.

Strategy for data synthesis: qualitative synthesis of the results based on risk of bias will be performed. If applicable, quantitative synthesis through a meta-analysis will follow. The risk of bias will be assessed independently by two authors, using the ROB 2.0 Tool for each outcome of interest. Any disagreement will be discussed with a third reviewer. RobVis visualization tool will be used to create the RoB graph.

 

Meta-analysis

Primary analysis will compute serum potassium differences between SZC/Patiromer and placebo/sodium polystyrene sulfonate or calcium polystyrene sulfonate. Secondary analysis will consist on a network metanalysis comparing each potassium binder/placebo. All data will be analyzed with fixed-effect model or random-effect model based on the heterogeneity of the studies. Mean differences, and 95% confidence interval (CI), will be calculated for continuous outcomes. For dummy outcomes, the Odds Ratio (OR), computing 95% confidence interval (CI), will be computed. Data were pooled using the fixed-effects model and also analyzed with the random-effects method to guarantee the strength of the model. We plan to test for heterogeneity using the χ² statistic related to freedom degrees, with a P value of 0.05 used as the cut-off value to determine statistical significance. In addition, the degree of heterogeneity will be investigated by calculating the l² statistics. We will consider l² low if <25%, moderate if 25-50%, moderate-high if 50-75% and very high if >75%. In case of high heterogeneity, we will perform sensitivity analyses to explore sources of heterogeneity, such as study quality, year of publication, intervention or control variables, participants characteristics, and risk of bias. In addition, sub-group analyses will be conducted. We will use RevMan 5.4 software to perform the meta-analysis of all outcomes, and R4.4.0 software to perform the Network meta-analysis of all outcomes.

We will assess funnel plot asymmetry and the contour-enhanced funnel plot to explore publication bias. GRADE System will be used to evaluate the certainty of the evidence and to summarize the study conclusions.

 

Ethics

This is a systematic review that will use published data and does not require ethical approval, but each included study have to enrol patients after written consent and approval ethical code.

 

Status of the study and dissemination plan

We are starting the literature search, but the selection has not already started. We expect to complete the project and report it in 12 months. We will follow the updated PRISMA guideline to report the final paper and we will upload the progress on the PROSPERO website. Furthermore, we hope to publish a systematic review in a Nephrological journal.

 

Discussion

Serum potassium levels deviation from the normal range increases morbidity and mortality, both in conservative CKD [10, 11] and dialysis patients [12].

Considering that levels both lower or upper normal range are related to increased mortality and morbidity, hyperkalemia seems to significantly increase mortality and morbidity [5, 6]. This can be explained by the higher risk of arrhythmia in patients with rapid potassium intradialytic oscillations. About this, guaranteeing normal serum potassium on interdialytic days is needed to avoid rapid intradialytic oscillation [13].

The hyperkalemic effect of RAASIs can be physiologically explained, by a reduced urinary potassium excretion in the distal and collecting tubule, as well as by an increased potassium movement through the extracellular space [14].

It is well known that RAASIs are able to reduce fibrosis [15] and that they can reduce mortality and hospitalization [16], for this is needed to find a solution to manage hyperkalemia RAASIs-related.

Indeed, new potassium binders allow for better management of RAASI treatment in CKD patients, as well as reduced hypokalemia as an adverse effect compared to old potassium binders. For these reasons, an inclusive systematic review is needed to evaluate the efficacy and safety of each potassium binder.

 

Conclusion

This protocol deeply describes the methods and criteria used to perform a systematic review of the literature, including selection, extraction, biases evaluation, and synthesis of data from published RCTs evaluating the efficacy and safety of various potassium binders. We hope that this systematic review will increase the current knowledge and will hypothesize possible future research to overpass current gaps.

 

Bibliography

  1. Thomsen RW, Nicolaisen SK, Hasvold P, Sanchez RG, Pedersen L, Adelborg K, Egstrup K, Egfjord M, Sørensen HT. Elevated potassium levels in patients with chronic kidney disease: occurrence, risk factors and clinical outcomes-a Danish population-based cohort study. Nephrol Dial Transplant. 2018 Sep 1;33(9):1610-1620. https://doi.org/10.1093/ndt/gfx312. PMID: 29177463.
  2. Vifor Pharma. Patiromer US Prescribing Information 2016.
  3. PubChem. Sodium zirconium cyclosilicate. Available at: https://pubchem.ncbi.nlm.nih.gov/compound/91799284#section=Top (Accessed October 2019);
  4. Stavros F, Yang A, Leon A, Nuttall M, Rasmussen HS. Characterization of structure and function of ZS-9, a K+ selective ion trap. PLoS One. 2014 Dec 22;9(12):e114686. https://doi.org/10.1371/journal.pone.0114686. PMID: 25531770; PMCID: PMC4273971.
  5. Luo J, Brunelli SM, Jensen DE, Yang A. Association between Serum Potassium and Outcomes in Patients with Reduced Kidney Function. Clin J Am Soc Nephrol. 2016 Jan 7;11(1):90-100. doi: https://doi.org/10.2215/CJN.01730215. Epub 2015 Oct 23. PMID: 26500246; PMCID: PMC4702219.
  6. Collins AJ, Pitt B, Reaven N, et al.  Association of serum potassium with all-cause mortality in patients with and without heart failure, chronic kidney disease, and/or diabetes. Am J Nephrol. 2017;46:213–221. https://doi.org/10.1159/000479802.
  7. Palmer BF, Carrero JJ, Clegg DJ, Colbert GB, et al. Clinical Management of Hyperkalemia. Mayo Clin Proc. 2021 Mar;96(3):744-762. https://doi.org/10.1016/j.mayocp.2020.06.014. Epub 2020 Nov 5. PMID: 33160639.
  8. Moher D, Shamseer L, Clarke M, Ghersi D, Liberati A, Petticrew M, et al. Preferred reporting items for systematic review and meta-analysis protocols (PRISMA-P) 2015 statement. Syst Rev. 2015;4: 1. https://doi.org/10.1186/2046-4053-4-1.
  9. Page MJ, McKenzie JE, Bossuyt PM, Boutron I, Hoffmann TC, Mulrow CD, et al. The PRISMA 2020 statement: An updated guideline for reporting systematic reviews. The BMJ. 2021. https://doi.org/10.1136/bmj.n71.
  10. Borrelli S, De Nicola L, Minutolo R, Conte G, Chiodini P, Cupisti A, Santoro D, Calabrese V, Giannese D, Garofalo C, Provenzano M, Bellizzi V, Apicella L, Piccoli GB, Torreggiani M, Di Iorio BR. Current Management of Hyperkalemia in Non-Dialysis CKD: Longitudinal Study of Patients Receiving Stable Nephrology Care. Nutrients. 2021 Mar 15;13(3):942. https://doi.org/10.3390/nu13030942. PMID: 33804015; PMCID: PMC8000881.
  11. Calabrese V, Cernaro V, Battaglia V, Gembillo G, Longhitano E, Siligato R, Sposito G, Ferlazzo G, Santoro D. Correlation between Hyperkalemia and the Duration of Several Hospitalizations in Patients with Chronic Kidney Disease. J Clin Med. 2022 Jan 4;11(1):244. https://doi.org/10.3390/jcm11010244. PMID: 35011985; PMCID: PMC8746076.
  12. Calabrese V, Tripepi GL, Santoro D. Impact of hyperkalemia in length of hospital stay in dialysis-dependent patients. Ther Apher Dial. 2022 Oct;26(5):1050-1051. https://doi.org/10.1111/1744-9987.13847. Epub 2022 Apr 11. PMID: 35366057.
  13. Ferraro PM, Bolignano D, Aucella F, et al. Hyperkalemia excursions and risk of mortality and hospitalizations in hemodialysis patients: results from DOPPS-Italy. J Nephrol. 2022;35(2):707-709. https://doi.org/10.1007/s40620-021-01209-5.
  14. Palmer BF, Clegg DJ. Physiology and Pathophysiology of Potassium Homeostasis: Core Curriculum 2019. Am J Kidney Dis. 2019 Nov;74(5):682-695. https://doi.org/10.1053/j.ajkd.2019.03.427. Epub 2019 Jun 19. Erratum in: Am J Kidney Dis. 2022 Nov;80(5):690. PMID: 31227226.
  15. Koszegi S, Molnar A, Lenart L, et al. RAAS inhibitors directly reduce diabetes-induced renal fibrosis via growth factor inhibition. J Physiol. 2019;597(1):193-209. https://doi.org/10.1113/JP277002.
  16. Beusekamp JC, Tromp J, Cleland JGF, et al. Hyperkalemia and Treatment With RAAS Inhibitors During Acute Heart Failure Hospitalizations and Their Association With Mortality. JACC Heart Fail. 2019;7(11):970-979. https://doi.org/10.1016/j.jchf.2019.07.010.

Platelet-To-Lymphocyte Ratio and Arteriovenous Fistula for Hemodialysis: An Early Marker to Identify AVF Dysfunction

Abstract

The KDOQI guidelines (Kidney Disease Outcomes Quality Initiative) recommend autologous arteriovenous fistula (AVF) as the primary vascular access in hemodialysis patients because of the higher quality of life and lower complication rates if compared to arteriovenous grafts (AVGs) or central venous catheter (CVC). Several studies used various inflammatory biomarkers to evaluate the association between systemic inflammation and AVF dysfunction. A novel inflammatory biomarker, the platelet–lymphocyte ratio (PLR), is a useful and easy laboratory parameter that can reveal systemic inflammation. Our study aimed to evaluate the relationship between PLR value changes over time and AVF dysfunction. The impact of PLR on our outcome showed a trend close to the significance (OR: 4,9; 95%CI: [0.84-28.5]; p = 0.08) but the slope was not linear. Therefore, we performed the same analysis splitting the patients by the median PLR value and we highlighted a significant relationship between our outcome and the PLR (log-transformed) for PLR-value under the median value (OR: 9.97; 95%CI: [2.53-39.25]; p = 0.001). Furthermore, in patients with PLR above the median value, the interaction visit-PLR showed an impact close to the statistical significance (OR: 7.7; 95%CI: [0.81-72.97]; p = 0.07). PLR (log-transformed) was positively correlated with AVF age (Rho: 0.254, p = 0.002).

Keywords: AVF, chronic kidney disease, hemodialysis, platelet-lymphocite ratio, thrombosis

Introduction

The KDOQI guidelines (Kidney Disease Outcomes Quality Initiative) recommend autologous arteriovenous fistula (AVF) as the primary vascular access in hemodialysis patients because of the higher quality of life and lower complication rates if compared to arteriovenous grafts (AVGs) or central venous catheter (CVC) [13]. Several studies evaluated the association between systemic inflammation and AVF dysfunction using various inflammatory biomarkers [4, 5, 10].

A novel inflammatory biomarker, the platelet-lymphocyte ratio (PLR), is a useful and easy laboratory parameter that can reveal systemic inflammation [1]. Various studies showed how the PLR values are linked to chronic inflammation in different clinical conditions [8, 12]. Our study aimed to evaluate the relationship between PLR value changes over time and AVF dysfunction (both stenotic and/or thrombotic complications) in our group of patients undergoing chronic hemodialysis (HD) at our center.

Assessment of Hemodialysis Adequacy by Online Clearance Monitoring

Abstract

Measuring the uremic solute clearance is an important factor in analyzing the adequacy of maintenance hemodialysis (MHD) therapy. Conventionally hemodialysis (HD) adequacy was measured by urea removal through the Daugirdas single pool kt/V (spKt/V) formula. We aimed in our study to correlate online clearance monitoring (OCM) spKt/V to the Urea Reduction Ratio (URR) and Daugirdas spKt/V in maintenance hemodialysis patients. This single-center cross-sectional study, conducted at the hemodialysis unit in the nephrology department of SRM Medical College Hospital and Research Center, involved 100 participants undergoing maintenance hemodialysis (MHD) therapy for 200 sessions. The OCM with URR and Daugirdas spKt/V values were obtained from each session and the results were analyzed using SPSS software with p <0.05 significance. In the results, we found that the OCM spKt/V, Daugirdas spKt/V, and URR showed positive correlations. These results emphasize that OCM can be an alternative method to assess dialysis adequacy for every session without the need for repeated blood sampling. Keywords: Hemodialysis, Adequacy, Online clearance monitoring, spKt/V

Introduction

Hemodialysis (HD) is the most common form of renal replacement therapy (RRT). Measuring the dialysis-delivered dose is an important factor in analyzing the adequacy of patients undergoing maintenance hemodialysis (MHD) therapy. Conventionally, HD adequacy was measured by sampling blood at pre- and post-hemodialysis therapy to calculate the urea removal through the Daugirdas spKt/V formula spKt/V = −ln(R-0.008×t) + (4-3.5×R) 0.55×UF/V. However, the drawback of conventional HD adequacy measurement is the requirement for blood sample collection during HD sessions [1].

An alternative non-invasive method named Online Clearance Monitoring (OCM) has evolved and uses a UV absorbance mechanism to measure the urea removal value at the dialysate outlet which calculates the spKt/V in the machine itself and provides the delivered dialysis dose at each dialysis session without the need of the blood urea samples [2].

The Educational Programs in Home Hemodialysis: Scoping Review

Abstract

Introduction. Home hemodialysis is an effective therapeutic option for patients with chronic kidney disease. As highlighted in the literature, its management requires good self-care abilities from the patient and adequate support for self-care from the caregiver. Therefore, the development of educational programs plays a fundamental role in patient care.
Aim. The goal of this study is to map the educational programs aimed at caregivers and patients undergoing home hemodialysis treatment, in order to identify gaps in the literature regarding this focus.
Methods. A Scoping Review was conducted following the Joanna Briggs Institute guidelines. Potentially relevant articles were identified through a selection process on major databases (PubMed, Scopus, CINAHL, EMBASE, Web of Science, and Google Scholar), without applying any time limits.
Results. The educational programs available in the literature for home hemodialysis patients focus on both clinical and psychological aspects; training through a “practical” approach is the most commonly used strategy.
Discussion and conclusions. The review highlights the crucial role that a multidisciplinary and multidimensional educational approach can provide to home hemodialysis patients. It is necessary to optimize educational strategies for this population to improve patient outcomes.

Keywords: home nursing, nephrology nursing, hemodialysis, self-care, renal dialysis, patient education

Sorry, this entry is only available in Italiano.

Introduzione

La malattia renale cronica (Chronic Kidney Disease – CKD) è una patologia cronica con andamento progressivo definita dalle linee guida “Kidney disease improving global outcome” (KDIGO) come “un’anomalia della struttura o della funzione renale, presenti per 3 mesi, con implicazioni per la salute” (KDIGO 2024) [1]. Nell’ambito della gestione della malattia renale cronica vengono definite diverse strategie terapeutiche partendo dall’approccio conservativo fino ad arrivare al trattamento renale sostitutivo o al trapianto [2]. Il trattamento renale sostitutivo è rappresentato dalla dialisi, un procedimento fisico che mediante la presenza di una membrana semipermeabile e una soluzione di lavaggio, detta dializzato, determina l’eliminazione delle sostanze tossiche dall’organismo [3]. Attualmente sono disponibili due metodiche di svolgimento della dialisi, ovvero l’emodialisi e la dialisi peritoneale domiciliare [4]. Nonostante l’emodialisi in centro comporti diversi vantaggi, tra cui l’assistenza diretta e un gruppo multidisciplinare a completa disposizione che fornisce supporto, l’elevata frequenza delle sedute in ospedale può determinare un impatto notevole sulla qualità di vita del paziente [5]; pertanto l’emodialisi domiciliare rappresenta una valida alternativa. La letteratura definisce che, negli ultimi anni i tassi di ospedalizzazione e mortalità̀ dei pazienti gestiti in emodialisi in struttura risultano elevati rispetto ai dati provenienti dai pazienti gestiti in emodialisi domiciliare [6]. Il trattamento emodialitico domiciliare presenta diversi benefici in quanto mantiene l’autonomia del paziente e diminuisce il rischio di contrarre infezioni ospedaliere [7]; tuttavia, esistono dei fattori ostacolanti l’inizio di tale trattamento che possono essere di varia natura [7]: tecnica, legate alla difficoltà di gestione della fistola; psicosociale, legata a sentimenti di paura del paziente e della famiglia; clinica, legata alle complicanze relative alla malattia e al trattamento. Questi rischi possono essere ridotti da un appropriato processo di preparazione e educazione del paziente e del caregiver [7].

Reactive Perforating Collagenosis in Hemodialysis Patients

Abstract

Chronic Kidney Disease associated Pruritus (CKD-aP) in hemodialysis affects approximately 38% of our patients. It is not associated with any dermatological lesion other than the common scratching lesions, a consequence of the symptom itself. The causes associated with itching have been studied in various treatments. However, there is a relatively rare condition that involves 10% of hemodialysis patients, known as reactive perforating collagenosis. This is a pathological condition secondary to chronic hemodialysis therapy, where widespread itching develops, associated with a peculiar reactive dermatosis with perforation of the dermis and development of dermal-epidermal continuity solutions with extrusion of matrix components dermal. In this work we report our experience with a diagnosed case of this condition.

Keywords: Pruritus, Chronic Kidney Disease, Perforating Dermatosis, Reactive Perforating Collagenosis, Hemodialysis, Hemodiafiltration with Endogenic Reinfusion

Sorry, this entry is only available in Italiano.

Epidemiologia e patogenesi del CKD-aP

Il prurito associato alla malattia renale cronica (CKD-aP) è definito come una sintomatologia pruriginosa direttamente correlata alla malattia renale cronica, non causato da altre eventuali condizioni patologiche concomitanti. Il CKD-aP possiede un’elevata variabilità clinica, rendendo la sua diagnosi difficoltosa. La severità di questa condizione può essere tale da compromettere notevolmente lo stile di vita dei pazienti affetti. Il sintomo potrà essere intermittente o persistente [1]. Questa è una caratteristica dei pazienti con Malattia renale cronica end-stage (ESRD) e tende a manifestarsi nei pazienti sia in terapia conservativa, indicando la progressiva necessità di ricorrere ad un trattamento sostitutivo, sia in terapia sostitutiva, legata ad una ridotta efficienza dialitica. Tuttavia, la persistenza del sintomo, nonostante il potenziamento della capacità depurativa dei trattamenti sostitutivi in alcuni pazienti, ha dimostrato la presenza di meccanismi patogenetici peculiari, determinati dalle alterazioni fisiopatologiche della malattia renale cronica.

In considerazione della vasta eterogeneità della sintomatologia pruriginosa e del mancato riferimento del sintomo da parte dei pazienti, l’epidemiologia del CKD-aP è in corso di definizione ed in costante aggiornamento.

Nei pazienti in terapia conservativa è stata valutata la prevalenza di tale condizione tramite uno studio osservazionale internazionale, il CKDopps (Chronic Kidney Disease  Outcomes and Practice Patterns Study), con un arruolamento di circa 3780 pazienti con malattia renale cronica (G3-G4-G5),  e successiva valutazione del sintomo tramite questionari multidimensionali autosomministrati per la valutazione della qualità di vita nella CKD, con riscontro di una prevalenza complessiva del 24% per pazienti affetti da prurito ad intensità moderata-severa, maggiormente presente nei pazienti con malattia renale cronica G5 [2-4].

Thrombosis in Hemodialysis Tunnelled Central Venous Catheters: From Pathogenesis to Therapeutic Strategies

Abstract

Central venous catheter-related thrombosis is a frequent non-infectious complication, typically associated with catheter dysfunction and hemodialysis inadequacy. Central venous catheters (CVCs) are categorized into non-tunnelled and tunnelled types, wherein the choice depends on patient’s clinical conditions and the diagnostic and therapeutic workup. Tunnelled CVCs (tCVCs) are sought whenever an arteriovenous fistula is unfeasible or as primary access in patients with poor prognosis.
Dysfunction is defined as the inability to maintain adequate blood flow within the prescribed dialytic session.
Amongst non-infectious complications causing tCVC malfunctioning, thrombosis is the most frequent, and it is further classified into intrinsic (being endoluminal, pericatheter or fibrin sleeve-associated thrombosis) and extrinsic forms (including mural and atrial thrombosis).
Diagnosis requires imaging tests like chest X-ray or abdominal X-ray, echocardiography, dynamic catheterography and computed tomography.
Pharmacological treatment involves use of local thrombolytic agents. In case of extrinsic thrombosis, systemic anticoagulation is mandatory, occasionally requiring tCVC replacement.
Prevention of thrombotic complications includes adequate positioning and appropriate use of the tCVC, with anticoagulant/antimicrobial-based locking solutions playing a crucial role in this context. In cases of extrinsic thrombosis, treatment options vary based on thrombus size, ranging from a conservative approach availing of systemic anticoagulation to surgical interventions like thrombectomy or thrombus aspiration, possibly associated with tCVC removal.
In conclusion, late dysfunction of tCVCs is primarily due to thrombosis, thus requiring diagnostic imaging and specific drug therapies. Prevention is crucial to minimize complications.

Keywords: Central venous catheter, thrombosis vascular accesses, hemodialysis

Sorry, this entry is only available in Italiano.

Introduzione

La trombosi del catetere venoso centrale (CVC), insieme alla stenosi venosa e alla disfunzione meccanica, rientra tra le complicanze non infettive, il più delle volte tardive, del CVC ed è associata a malfunzionamento, bassi flussi ematici e inadeguatezza dialitica [1]. Si tratta di una complicanza tra le più frequenti nella comune pratica clinica di emodialisi. Pertanto, compito essenziale del team degli accessi vascolari è quello di prevenire, riconoscere e trattare tempestivamente le cause del malfunzionamento, in particolare la trombosi del CVC, spesso associata ad eventi fatali. Il nefrologo utilizza due tipologie di CVC: i non tunnellizzati (ntCVC), detti anche cateteri temporanei, non cuffiati, il cui utilizzo è limitato a un massimo di 15 giorni dal posizionamento e i cateteri tunnellizzati (tCVC), cuffiati, adatti a un uso più prolungato in assenza di accessi vascolari alternativi. La scelta del tipo di catetere è determinata dalle condizioni cliniche generali del paziente e dalla valutazione prognostica effettuata in prima istanza. Generalmente, si ricorre al tCVC come accesso vascolare (AV) di scelta qualora non vi sia un patrimonio vascolare adeguato all’allestimento di una fistola arterovenosa (FAV) nativa o protesica, oppure come prima opzione in presenza di controindicazioni al confezionamento di un AV alternativo (e.g. scompenso cardiaco di grado severo) o nei casi in cui l’aspettativa di vita sia inferiore a un anno. Il ntCVC, invece, viene prevalentemente utilizzato nell’ambito del trattamento dell’insufficienza renale acuta, nei pazienti late referral in caso di urgenza all’avvio a terapia dialitica o, per brevi periodi, come bridge in attesa della maturazione dell’AV definitivo. Occorre ricordare che, come suggerito dalle linee guida KDOQI, i ntCVC devono essere tenuti in situ per un periodo di tempo non superiore alle due settimane a causa dell’elevato rischio di infezioni, specialmente se posizionati in vena femorale e in soggetti obesi [2]. In questa Review metteremo a fuoco gli aspetti patogenetici, clinici e terapeutici peculiari della trombosi correlata al tCVC per emodialisi.

Convective Methods versus Diffusive Methods: Defined Superiority?

Abstract

The technique of dialysis has seen enormous advancements over the past fifty years, evolving from an initial phase,primarily based on diffusion through a semipermeable membrane to the current preference for high-efficiency convection, involving the removal of several liters of ultrafiltrate. Diffusive dialysis, due to its relative simplicity in execution, has allowed the treatment of millions of individuals with ESRD, ensuring them a certain quality of life. However, it is not considered optimal in terms of survival and has some complications inherent to the uremic state. Convection, by removing toxic substances through solvent drag, has enabled the purification of not only small molecules but also medium-to-large molecular weight molecules. As a result, hemodiafiltration techniques have shown improvements in both mortality and intradialytic complications such as cramps and intradialytic hypotension. These results, however, involve fluid exchanges that far exceed 20 liters per session, thus increasing technical complexity and not being applicable to all patients, particularly those with vascular access problems. The recent discovery of so-called medium cut-off (MCO) membranes appears to maintain the benefits of hemodiafiltration techniques without the need for high convective flows. Therefore, the debate between convection and diffusion seems far from over and may hold more surprises in the near future.

Keywords: diffusion, convection, hemodialysis, hemodiafiltration, medium cut-off membranes

Sorry, this entry is only available in Italiano.

Introduzione

La diatriba sulla superiorità di una tecnica dialitica rispetto ad un’altra nei riguardi della depurazione renale, nasce sin dai primi anni di applicazione della dialisi cronica a pazienti con ESRD. Nel 1965, Beldin Scribner [1] osservò che i pazienti sottoposti a dialisi peritoneale, nonostante avessero livelli più elevati di urea e creatinina rispetto ai pazienti in emodialisi, spesso “si sentivano meglio” ed avevano una neuropatia più sopportabile. Scribner ipotizzò che il peritoneo fosse più permeabile alle molecole di peso molecolare più elevato rispetto all’emodialisi e quindi ne favorisse la rimozione. Nacque allora l’ipotesi che, nell’uremia si accumulavano anche molecole di medio peso molecolare, le così dette “medie molecole” con un impatto sulla fisiopatologia dell’uremia. A causa delle loro dimensioni, queste molecole venivano rimosse più lentamente dell’urea e le membrane cellulosiche, in uso all’epoca, mostravano un’elevata resistenza diffusiva alle medie molecole. Di conseguenza, per purificare l’organismo da queste tossine era necessario un numero minimo di ore di dialisi a settimana, non inferiore alle 30 ore settimanali. Negli anni successivi con l’introduzione di nuove membrane di sintesi, al di là delle cellulosiche, il concetto della sola durata, è stato sostituito da ipotesi meccanicistiche che si basavano sulla dose di dialisi ricavata dall’indice KT/Vurea proposto da Gotch e Sargent [2].

Il Kt/V è un rapporto adimensionale che si basa sulla valutazione della clearance dell’urea, del tempo di trattamento e del volume dell’acqua corporea totale. Per anni questo indice con un valore di cut-off ottimale sull’ordine di 1,2-1,4 è stato considerato espressione di adeguatezza dialitica. In realtà si è sempre trascurato che il Kt/V riguardava solo l’urea e quindi una molecola di basso peso molecolare, dimenticandosi dell’insegnamento di un padre della dialisi come Beldin Scribner che aveva posto l’accento sulla importanza delle medie molecole.

Solo negli anni ’80 con lo sviluppo delle membrane semi-permeabili, la convezione è stata riconosciuta come un processo potenzialmente vantaggioso per la rimozione di soluti di dimensioni maggiori rispetto a quelli che possono essere eliminati attraverso la sola diffusione. La dialisi convettiva, in particolare l’emofiltrazione (HF), venne utilizzata in ambito clinico con sistemi pionieristici che permettevano la rimozione di grandi quantità di acqua corporea e la sua sostituzione con un liquido sterile reinfuso attraverso un circuito addizionale [3].

Negli anni ’90, la tecnologia delle macchine per dialisi progredisce velocemente, permettendo una migliore gestione dei volumi di ultrafiltrazione ed una efficiente diffusione. Nasce l’emodiafiltrazione (HDF), tecnica mista convettivo-diffusiva, che negli anni 2000 si diffonde in tutto il mondo dialitico affiancandosi alla HD tradizionale.

Da allora si continua a discutere se sia preferibile la diffusione o la convezione o anche la combinazione delle due, in termini di depurazione, effetti collaterali e benefici del paziente.

 

Le tecniche di dialisi diffusive

Le tecniche diffusive che comprendono anche la dialisi peritoneale che sfrutta la membrana peritoneale (e quindi non è una tecnica extra-corporea), hanno alcuni vantaggi:

  • Efficienza nella rimozione delle piccole molecole: eccellente per eliminare urea, creatinina e altre piccole tossine. La peritoneale inoltre permette di rimuovere una certa quota di medie molecole
  • A concentrazioni più alte di piccole molecole aumenta il gradiente con il liquido di dialisi e quindi l’efficienza della tecnica
  • Le caratteristiche della membrana, in particolare la porosità, influenzano i trasporti diffusivi
  • Tecnologia ben consolidata ampiamente disponibile e supportata da una vasta esperienza clinica
  • Flessibilità nelle opzioni: possibilità di scegliere tra emodialisi e dialisi peritoneale in base alle esigenze del paziente

Accanto ai vantaggi vi sono anche alcune limitazioni:

  • Tempo e Frequenza: le sessioni di emodialisi richiedono diverse ore e devono essere effettuate più volte alla settimana
  • La peritoneale richiede lunghi scambi e ultrafiltrazione non eccessiva
  • Tolleranza cardio-vascolare in emodialisi: non ottimale, tanto che spesso le sedute, in particolare nei pazienti fragili, sono gravate da episodi ipotensivi
  • Meno efficace per la rimozione di molecole più grandi: la diffusione è meno efficace nel rimuovere tossine di dimensioni maggiori e legate alle proteine.

La dialisi diffusiva, detta anche tradizionale, pur con questi limiti ha permesso, a milioni di persone di vivere con una discreta qualità di vita, anche in assenza di funzione renale. Nell’emodialisi diffusiva (HD), i dati degli studi clinici supportano che il raggiungimento di valori Kt/V dell’urea in single pool (non equilibrato) superiori a 1,2 possono essere sufficienti per una larga schiera di pazienti [4]. Il valore soglia maggiore di 1,2 del Kt/V può essere ottenuto aumentando le dimensioni del dializzatore o la velocità del flusso sangue. Per aumentare la Kurea, si può anche allungare la durata della sessione di dialisi (ovvero, aumento del tempo di trattamento, la t nell’indice Kt/V).

Sulla base di diversi studi clinici, è opinione diffusa che un tempo di trattamento più lungo delle classiche 4 ore per seduta, conferisca benefici clinici che vanno oltre Kt/Vurea, inclusa l’eliminazione delle tossine sostanzialmente più grandi dell’urea (le cosiddette molecole medie) e una adeguata rimozione del volume di fluido target (raggiungimento del peso secco) riducendo al contempo l’instabilità emodinamica.  I dati osservazionali indicano che un tempo di trattamento più lungo è associato a una sopravvivenza più lunga, a una migliore gestione dei liquidi corporei, a un migliore controllo della pressione sanguigna, a un migliore controllo del fosforo e a meno eventi cardiovascolari gravi rispetto a sessioni di dialisi più brevi [5]. In questo contesto, il tempo medio di trattamento dialitico nei pazienti che ricevono dialisi in centro tre volte alla settimana è ora di 4 ore (per un totale di 12 ore settimana) [6]. In alcuni paesi come il Giappone nel 2008 e in Germania nel 2009, le sessioni di dialisi sono tra le più lunghe dei paesi DOPPS [6]. Al contrario negli Stati Uniti le misurazioni delle prestazioni non sono legate alla durata della sessione, ma piuttosto al Kt/Vurea  che viene raggiunto. Per questo sono favorite sessioni dialisi brevi, con flussi sangue elevati e dializzatori di ampia superficie. Sessioni di dialisi più brevi offrono molti vantaggi operativi ed incrementi del flusso di pazienti su tre turni giornalieri, a scapito però di una maggiore incidenza di effetti collaterali come l’ipotensione intradialitica (IDH) ed i crampi. Le linee guida giapponesi [6] sottolineano l’importanza di una dialisi più lunga e più “morbida” (con flussi sangue ed ultrafiltrazioni orarie ridotti), al fine di garantire al meglio la stabilità emodinamica, nonostante una maggiore probabilità di avere valori di Kt/Vurea inferiori a 1,2.

Resta a tutt’oggi l’incertezza sulla durata ottimale della sessione di dialisi e sui parametri di adeguatezza e sulla gestione del volume dei liquidi e dell’ultrafiltrazione oraria. Tematiche che però non si fermano alla dialisi diffusiva e che sono presenti anche nelle tecniche di tipo convettivo.

 

Le tecniche di dialisi convettive

Nonostante gli indubbi vantaggi dell’emodialisi tradizionale, sia la mortalità che la morbilità rimangono inaccettabilmente elevate nei pazienti in emodialisi (HD) [7]. La ritenzione di molecole tossiche di peso molecolare medio (5–40 kDa) e di molecole legate alle proteine è chiamata in causa nella patogenesi della sindrome uremica e nella precoce mortalità in dialisi cronica [8]. Per questo negli anni 2000 vi è stata un grande attenzione verso le dialisi ad alto flusso che potrebbero favorire la rimozione di medie molecole. Tuttavia, nessuno dei due grandi studi, l’HEMO study [9] e l’MPO [10], hanno dimostrato un chiaro vantaggio delle membrane ad alto flusso rispetto a quelle a basso flusso. Entrambi gli studi hanno però suggerito che era preferibile incrementare i flussi convettivi per accrescere la rimozione di molecole di grosse dimensioni (Figura 1). Di qua la maggiore diffusione delle tecniche convettive.

Nelle tecniche convettive:

  • La drive force principale non è il gradiente di concentrazione ma la differenza di pressione trai due lati della membrana
  • Il maggior fattore di impatto nel trasporto lo hanno le dimensioni delle molecole nei riguardi dei pori della membrana
  • Importante è il coefficiente di sieving della membrana che per l’acqua è pari a 1
  • Il coefficiente di sieving influenza sia il passaggio di acqua che quello dei soluti

La tecnologia delle membrane insieme all’evoluzione delle macchine da dialisi ed accanto ad una buona dose di inventiva dei nefrologi, in particolare degli italiani, ha permesso lo sviluppo negli ultimi anni di numerose tecniche di tipo misto convettivo-diffusivo (Figura 2).

Tra le tante tecniche di tipo misto, quella che più si è affermata e diffusa è la HDF. In HDF la diffusione, che è il principale meccanismo di rimozione in emodialisi a basso flusso, è combinata con la convezione. Considerando che la quantità stimata di trasporto convettivo durante l’HD ad alto flusso è <10 litri/sessione, nell’HDF in post-diluizione, possono essere 25 litri o più, i litri scambiati. Accanto alla HDF, per un certo periodo, ha preso piede una tecnica convettiva pura e cioè l’HF proposta da Lee Henderson [3] e che si basa esclusivamente sui trasporti convettivi senza diffusione. L’HF ha uno scarso impatto depurativo per le piccole molecole come l’urea, mentre privilegia le medie e le grandi molecole. Utilizzando questa tecnica, in pre-diluzione con scambi del 120% del peso corporeo e per sfatare il mito del KT/Vurea riguardo alla mortalità nei pazienti in dialisi cronica, noi abbiamo realizzato uno studio policentrico randomizzato a due bracci tra HD tradizionale ed HF in pre-diluizione [11]. Partecipavano allo studio pazienti con alto grado di mortalità (indice di Charlson > 6) e veniva valutata la mortalità a tre anni come obiettivo primario. A fine studio si è riscontrato un miglioramento significativo della sopravvivenza con HF rispetto a HD (78%, HF contro 57%, HD). Il Kt/V di fine trattamento era significativamente più alto con HD (1,42 ± 0,06 contro 1,07 ± 0,06 con HF), mentre i livelli di beta(2)-microglobulina sono rimasti costanti nei pazienti HD (33,90 ± 2,94 mg/dL al basale e 36,90 ± 5,06 mg/dL a 3 anni), ma sono diminuiti significativamente nei pazienti in HF (30,02 ± 3,54 mg/dL al basale contro 23,9 ± 1,77 mg/dL; p < 0,05). In pratica lo studio dimostrava che nell’influenzare la mortalità era meno rilevante il KT/Vurea rispetto alla riduzione di medie molecole rappresentate dalla beta2-microglobilina. Quindi una ulteriore prova del minor valore prognostico nel rischio di morte, della rimozione dell’urea rispetto a quella delle medie molecole.

L’HF però è più complicata della HDF e, alla lunga, penalizza molto la rimozione delle piccole molecole, che un certo impatto lo hanno sulla sindrome uremica.  Negli ultimi anni due studi randomizzati controllati con disegno molto simile, lo studio CONTRAST [12] e lo studio turco OL-HDF [13], non hanno trovato una differenza significativa tra HDF post-diluizione e HD. Tuttavia, le analisi post hoc di entrambi gli studi, hanno evidenziato rischi di mortalità più bassi nei pazienti con i volumi di convezione più elevati per sessione (in media >22,0 litri nel CONTRAST e >19,7 litri nello studio turco.

Un terzo grande studio randomizzato e controllato ESHOL [14] ha dimostrato che il rischio di mortalità complessivo nei pazienti con HDF era inferiore del 30% rispetto ai pazienti con HD. In questo studio, il volume medio di convezione era di 23,7 litri. Una sotto-analisi dello studio ESHOL ha confermato la relazione tra convezione (volume) e rischio di mortalità. Nel complesso, questi risultati supportano il concetto di una relazione dose-risposta tra volume di convezione e sopravvivenza.  In realtà il volume convettivo non va visto come una grandezza assoluta (con un cut-off di 23 litri), ma andrebbe messo in relazione con la superficie corporea del paziente e con il suo peso corporeo [15].

Nel 2023 viene pubblicato sul New England Journal Medicine lo studio CONVINCE [16], studio multinazionale, randomizzato e controllato che ha coinvolto pazienti con insufficienza renale sottoposti a emodialisi ad alto flusso da almeno 3 mesi. Tutti i pazienti sono stati considerati candidati per un volume di convezione di almeno 23 litri per sessione e hanno mantenuto questi volumi di scambio per tutta la durata dello studio. Ogni paziente veniva assegnato a ricevere HDF ad alte dosi o continuare la terapia HD convenzionale ad alto flusso. L’outcome primario era la morte per qualsiasi causa. Un totale di 1.360 pazienti è stato sottoposto a randomizzazione: 683 a ricevere HDF ad alte dosi e 677 per ricevere emodialisi ad alto flusso. Il follow-up mediano è stato di 30 mesi.  La morte per qualsiasi causa si è verificata in 118 pazienti (17,3%) nel gruppo HDF e in 148 pazienti (21,9%) nel gruppo HD (rapporto di rischio: 0,77; confidenza al 95%, intervallo, da 0,65 a 0,93.

Le conclusioni dello studio sono state molto laconiche: nei pazienti con insufficienza renale, che richiedono terapia sostitutiva renale, l’uso di HDF ad alte dosi ha comportato un rischio inferiore di morte per qualsiasi causa rispetto alla HD convenzionale ad alto flusso.

Tuttavia, andando a guardare nelle pieghe dello studio si scopre che tra i pazienti del gruppo HDF, il vantaggio assoluto di sopravvivenza sembrerebbe riguardare i pazienti più giovani, che non avevano il diabete o problemi cardiovascolari rilevanti. Quindi la superiorità della HDF in termini di mortalità andrebbe circostanziata a determinate categorie di pazienti.

L’HDF a parte un vantaggio diretto sulla mortalità ha anche una superiorità nei riguardi della HD su uno degli effetti collaterali della dialisi extracorporea, la ipotensione intradialitica (IHD), che, a sua volta è un importante determinante della sopravvivenza in dialisi. Diversi studi, tra cui il FRENCHIE study, confrontando la tolleranza cardio-vascolare in HDF ed in HD, hanno dimostrato una significativa ridotta incidenza di IDH e di crampi in 11.981 sessioni di HDF [17]. Quindi migliore tolleranza cardiovascolare in HDF e di conseguenza ci sarebbe da aspettarsi una ridotta mortalità nel lungo periodo per il forte legame che esiste tra IDH e mortalità.

Mettendo insieme tutti questi dati sarebbe lecito affermare che la partita tra diffusione e convezione, la ha largamente vinta la convezione associata alla diffusione.

In realtà, negli ultimi anni sono state sviluppate membrane permeabili alle medie molecole, le così dette membrane a medio cut-off, che hanno riproposto il tema della diffusione semplice in HD.

 

La diffusione con le membrane a medio cut-off (MCO)

Recentemente, grazie ai processi ottimizzati di formazione delle membrane e all’uso simultaneo di additivi particolari, sono state generate membrane di dialisi con nuove caratteristiche di profilo diffusivo e proprietà di separazione. Le nuove membrane per dialisi hanno un’eccellente selettività e gradualità nella separazione delle molecole, rispetto a quelle polimeriche classiche. Ora si è giunti ad una classe di membrane, le così dette MCO, che hanno capacità di rimozione di molecole di larghe dimensioni comparabili a quelle della HDF, però con il vantaggio di una rimozione ridotta e controllata di albumina [18]. Si è quindi configurata una tecnica di dialisi definita Expanded Hemodialysis (HDx) che dovrebbe esporre a minori rischi i pazienti con denutrizione proteico-calorica, che possono soffrire elevate perdite di albumina. Inoltre, le membrane MCO possono essere utilizzate anche con flussi di sangue non così elevati come richiesto dalle tecniche convettive.

Quindi la diatriba tra convezione e diffusione si è recentemente riaperta e non possiamo dare per certo la superiorità della convezione come sembrava sino a qualche anno fa.

Va però detto che la HDF, sia pure con qualche distinguo, ha dimostrato, in studi randomizzati e controllati di vaste dimensioni, un certo grado di superiorità, almeno per quel che riguarda il rischio di morte e di IDH, rispetto alla HD [16, 17]. Le membrane MCO pur avendo mostrato eccellenti capacità di rimozione delle medie molecole, devono ancora validare, in studi RCT, una loro superiorità riguardo gli hard endpoint clinici come la mortalità. Molto recentemente in Spagna è stato iniziato lo studio MOTHER [19], che confronta l’HDF con una membrana MCO nei riguardi della mortalità e morbilità in un ampio gruppo (700) di pazienti in dialisi cronica.

I risultati preliminari di questo studio supportano il dato che l’HDx non è inferiore a OL-HDF nel ridurre l’esito di mortalità per tutte le cause. Naturalmente dovremo attendere i risultati definitivi di questo studio [19], come anche di altri studi RCT, che affrontino lo stesso tema, per capire il reale valore di queste nuove metodiche nel panorama delle tecniche dialitiche, che vedono come protagonisti, la diffusione e la convezione.

Figura 1. Rimozione di molecole a diverso peso molecolare a seconda della tecnica dialitica ( membrana) e della entità del flusso convettivo.
Figura 1. Rimozione di molecole a diverso peso molecolare a seconda della tecnica dialitica ( membrana) e della entità del flusso convettivo.
Figura 2. Evoluzione nel tempo delle tecniche emodiafiltrative , partendo dalla biofiltrazione ad arrivando alla emodiafiltrazione on-line con almeno 23 litri di liquido di scambio.
Figura 2. Evoluzione nel tempo delle tecniche emodiafiltrative , partendo dalla biofiltrazione ad arrivando alla emodiafiltrazione on-line con almeno 23 litri di liquido di scambio.
Curve di sopravvivenza riguardanti pazienti con alto grado di co-morbidità
Figura 3. Curve di sopravvivenza riguardanti pazienti con alto grado di co-morbidità e trattati per 36 mesi o con emodialisi classica low-flux o con emofiltrazione in pre-diluizione ( con scambio di liquido di sostituzione del 120% del peso corporeo). Significativa differenza in mortalità, nonostante in emodialisi sia stato mantenuto un alto KT/V di circa 1,42 contro un basso Kt/V di 1,07 in emofiltrazione. I livelli di beta2 microglobulina sono però significativamente ridotti in emofiltrazione, mentre restano elevati e non si modificano in emodialisi. ( voce bibliografica n.11)

 

Bibliografia

  1. Oxford Academic – “Belding Scribner and the Development of Hemodialysis”URL: Oxford Academic (Oxford Academic) 1965.
  2. Gotch FA, Sargent JA.A mechanistic analysis of the National Cooperative Dialysis Study (NCDS).Kidney Int. 1985 Sep;28(3):526-34.
  3. Henderson LW. The beginning of clinical hemofiltration: a personal account.ASAIO J. 2003 Sep-Oct;49(5):513-7
  4. Clinical practice guidelines for hemodialysis adequacy 2006
  5. Nauman Q.Mortality and Duration of Hemodialysis Treatment. JAMA. 1991;265(22):2958
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Stenotic FAV: Success of the Collaboration Between Spoke and HUB

Abstract

The arteriovenous fistula constitutes the vascular access of first choice in hemodialysis. We present three clinical cases that highlight the resolution in interventional radiology of venous stenosis, one of the major complications.
Clinical monitoring and instrumental diagnostics with color Doppler ultrasound have prevented the failure of the AVF due to high risk of thrombosis.
The angiographic interventions, thanks to the collaboration between Spoke and Hub, were completed without complications.

Keywords: hemodialysis, stenosis, AVF, interventional radiology, color Doppler ultrasound, PTA

Sorry, this entry is only available in Italiano.

Introduzione

La fistola artero-venosa (FAV) per il paziente in dialisi costituisce l’accesso vascolare di prima scelta, in quanto meno gravato da complicanze a medio-lungo termine e per la maggiore sopravvivenza rispetto alla protesi e al catetere venoso centrale permanente [1]. L’Ecocolordoppler (ECD) ormai da anni rappresenta l’esame diagnostico meno invasivo per il mapping dei vasi pre-confezionamento FAV e per il monitoraggio delle complicanze (stenosi, trombosi, ematomi, aneurismi e pseudoaneurismi) venose e arteriose [26]. Sono più frequenti le stenosi venose che le stenosi arteriose [7, 8]; si distingue poi ulteriormente tra stenosi dell’inflow (vaso afferente) e stenosi dell’outflow (vaso efferente). Tra le stenosi venose, le stenosi iuxta-anastomotiche (entro i 2 cm dall’anastomosi) sono più frequenti rispetto alle stenosi distali [7, 8].

Il primum movens della stenosi venosa è l’iperplasia neointimale. Costituiscono fattori concomitanti lo stress chirurgico, lo stato pro-infiammatorio legato alla malattia renale cronica, la predisposizione genetica, le venipunture ripetute. Il processo che si determina è un’anomala proliferazione e migrazione delle cellule muscolari lisce, con espressione di citochine, chemochine, e mediatori come l’endotelina, il TGFβ, l’ossido nitrico, l’osteopontina e l’apolipoproteina. Spiegherebbe la riduzione del lume vascolare anche la migrazione di fibroblasti dall’avventizia all’intima [911].

Lactobacillemia: A Rare Entity in Immunocompromised Patients. Description of a Clinical Case and Literature Review

Abstract

Bacteremia caused by Lactobacillus is rare, data on its clinical significance are based only on case reports and a limited number of studies, often difficult to interpret.
Lactobacillus species is a commensal colonizer of the mouth, gastrointestinal and genitourinary tract. Its significance as a pathogen is overlooked frequently.  The diagnosis of these infections requires a mutual relationship between the physician and the microbiologist to rule out contamination risk.
Most patients with Lactobacillus bacteremia are immunosuppressed or patients at increased risk of symptomatic bacteremia with comorbidities, treated with broad-spectrum antibiotics and have indwelling venous catheters.
Risk factors related to Lactobacillus bacteremia include impaired host defenses and severe underlying diseases, as well as prior surgery and prolonged antibiotic therapy ineffective for lactobacilli.
We describe an unusual case of a woman, on chronic hemodialysis treatment, with a sepsis due to Lactobacillus casei and review the literature.

Keywords: Lactobacillus, bacteremia, hemodialysis, immunocompromised patients

Sorry, this entry is only available in Italiano.

Introduzione

Il Lactobacillus è un batterio gram-positivo, anaerobico facoltativo, a forma di bastoncello. È un comune commensale dei tessuti della mucosa umana (cavità orale, tratto gastrointestinale e tratto genitale femminile) e non fa parte della flora cutanea. È ampiamente distribuito anche nell’acqua, nelle acque reflue e negli alimenti quali latticini, carne, pesce e cereali. La sua presenza, come commensale del tratto gastrointestinale, è associata alla protezione contro gli agenti patogeni e alla stimolazione del sistema immunitario. Per questo è utilizzato in tutto il mondo come probiotico [1, 2].

La batteriemia causata da lattobacilli è rara e i dati sul suo significato clinico si basano solo su casi clinici e su un numero limitato di studi [3, 4].

Essendo i lattobacilli comuni commensali è verosimile che l’incidenza reale possa essere sottostimata e, talora, può essere difficile interpretarne la presenza in sedi abitualmente sterili. Pertanto, il significato clinico è ancora argomento di discussione. Infatti alcuni Autori [5] ritengono che questo batterio non dovrebbe mai essere considerato un contaminante, mentre altri Autori [6] lo considerano un contaminante occasionale.