Rapidly Progressive Glomerulonephritis: A COVID-19 Case Report.

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.