glomerulonefrite Archivi - GIN

ANCA-Associated Glomerulonephritis Following SARS-CoV2 Infection: A Case Report

Abstract

Antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV) primarily affects small- and medium-sized arteries, including kidney vessels, thus causing rapidly progressive glomerulonephritis. The pathogenesis of AAV is intricate and several factors, including infections, are known to possibly trigger the autoimmune process. Numerous studies have reported that SARS-CoV-2 might cause acute kidney injury (AKI). To date, a modest number of AAV with COVID-19 cases has been reported. Herein, we discuss the case of a 61-year-old man with new-onset of diffuse proliferative ANCA-associated glomerulonephritis after COVID-19.

Keywords: Vasculitis, ANCA, Acute Kidney Injury, Glomerulonephritis, COVID

Introduction

Antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV) is a systemic autoimmune disease that affects primarily small- and medium-sized arteries, including kidney vessels, thus causing rapidly progressive glomerulonephritis (GN) [1, 2]. The pathogenesis of AAV is intricate. Several factors (i.e. specific drugs, infectious agents, environmental exposures, etc.) are known to possibly trigger the autoimmune process in genetically susceptible patients [3, 4]. Numerous studies have reported that severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), responsible for the respiratory disease called Coronavirus disease-19 (COVID-19), may cause acute kidney damage (AKI) [5, 6]. To date, a modest number of AAV with COVID-19 cases have been reported [7]. Herein, we discuss the case of a 61-year-old man with new-onset of diffuse proliferative ANCA-associated glomerulonephritis (GN) after COVID-19.

State of art and new perspectives in the induction regimen of ANCA-associated vasculitis with renal involvement: from histopathology to therapy

Abstract

Anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV) are rare autoimmune diseases characterised by medium and small vessels inflammation. Renal vasculitic involvement is one of the most severe manifestations, with high mortality in case of a delayed diagnosis and a significant impact on patients’ long-term prognosis. Histological classifications and scores for the definition of renal involvement in AAV exist and correlate with the renal outcome. Current induction regimen consists of a high dose of glucocorticoids and immunosuppressive drugs: cyclophosphamide (CYC), rituximab (RTX) or a combination of both. RTX use is expanding thanks to randomised control trials suggesting its non-inferiority compared to the standard CYC therapy in general AAV and a better safety profile; its cost has also reduced thanks to the availability of biosimilars. However, the equivalence of RTX and CYC in patients with severe renal involvement is still debated.

The quest for the ideal induction regimen in AAV is moving towards a more personalized approach: on the one hand, efforts are made to use already existing therapies in the most appropriate way; on the other, new insights into AAV pathogenesis has allowed the discovery of new targets, such as the complement factor C5a.

Thanks to this new AAV management, renal outcome and overall survival has visibly improved. New studies are needed to reach a more personalized approach in the induction regimen of ANCA-associated glomerulonephritis and AAV in general.

 

Keywords: ANCA, vasculitis, glomerulonephritis, rituximab, cyclophosphamide, renal biopsy

Sorry, this entry is only available in Italian.

Introduzione

Le AAV, vasculiti ANCA-associate (anticorpi anti-citoplasma dei neutrofili), sono rare vasculiti necrotizzanti autoimmuni che coinvolgono i vasi di medio e piccolo calibro. Le AAV includono tre patologie differenti: la granulomatosi con poliangioite (GPA, in passato nota come malattia di Wegener), la poliangioite microscopica (MPA) e la granulomatosi eosinofila con poliangioite (EGPA, in passato nota come sindrome di Churg Strauss) [1]. L’incidenza in Europa è rispettivamente di 2.1-14.4, 2.4-10.1 e 0.5-3.7 per milione e la prevalenza di 46-184 per milione. La sopravvivenza a 5 anni è intorno al 74-91% per la GPA, 45-76% per l’MPA e 60-76% per l’EGPA [2]. Il picco di incidenza si colloca fra i 65-75 anni, con una lieve prevalenza maschile.

Nel corso della malattia, circa il 90% dei pazienti sviluppa anticorpi ANCA, rivolti contro proteine contenute nel citoplasma dei neutrofili: sebbene esistano degli overlap, gli ANCA anti PR3 (anti-proteinasi 3) sono più frequenti nella GPA, mentre gli ANCA anti MPO (anti-mieloperossidasi) nella MPA; il 40% dei pazienti con EGPA sviluppa positività agli ANCA, in prevalenza MPO, spesso associata a forme con coinvolgimento vasculitico. Esistono alcune eccezioni: il 10% dei pazienti è ANCA negativo ed è possibile sviluppare entrambi gli anticorpi, prevalentemente nelle forme secondarie [3,4].