Rapidly Progressive Glomerulonephritis: A COVID-19 Case Report

Abstract

Anti-neutrophil cytoplasmic antibody (ANCA) associated vasculitis is a systemic autoimmune disease that typically presents as a multi-organ manifesting disease of unclear etiology that can predispose to rapidly progressive glomerulonephritis (RPGN). If left untreated, ANCA-associated vasculitis can be fatal, and RPGN can progress to irreversible renal failure. Environmental and genetic factors have been implicated in the pathogenesis of this vasculitis. Coronavirus disease (COVID-19) has been noted to have various physiologic impacts on the body, with literature indicating possible autoimmune effects. We present a rare case of ANCA-associated vasculitis in an elderly male with no known autoimmune history after a recent illness with COVID-19. The patient had been seen as an outpatient with progressively declining renal function until he presented to the hospital with acute renal failure and pericarditis. Workup revealed elevated anti-myeloperoxidase antibody (MPO-AB) and perinuclear ANCA (p-ANCA) antibodies with a biopsy confirming focal cresenteric glomerulonephritis, and the patient was initiated on steroid therapy with notable improvement and a return to baseline kidney function.

Keywords: antineutrophil cytoplasmic antibody (anca) associated vasculitis (aav); covid 19; pauci-immune glomerulonephritis (gn); pericarditis; rapidly progressive renal failure; renal failure.

Figure 1. Single glomerulus with foci of fibrinoid necrosis.

Figure 2. Core biopsy revealed some intimal fibrosis with signs of tubulointerstitial inflammation and collections of inflammatory cells. Hypercellularity is noted throughout, and moderate interstitial fibrosis and tubular atrophy can be appreciated.

Figure 3. Immunofluorescent staining shows a glomerulus with crescentic fibrin deposition. A segmental glomerular reaction for fibrinogen within Bowman's space, representing areas of necrosis and crescent formation, is present. No significant reaction for IgG, IgA, IgM, C3, C1q, kappa, or lambda was noted.

Figure 4. Core biopsy with trichrome staining on low power demonstrating dense collagenous deposition.

Figure 5. Vessel seen showing mild arterial intimal fibrosis and no significant arteriolar hyalinosis or arteritis.