Abstract
Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is an immune-mediated disorder of small and medium-sized vessels, characterized by the production of autoantibodies that target the neutrophilic antigens leading to mononuclear cell infiltration and destruction of blood vessels in lungs, skin, and kidneys. Although rare, the coronavirus disease 2019 (COVID-19) vaccine may trigger autoimmune vasculitis. We report a rare case of ANCA-associated renal vasculitis following COVID-19 vaccination in a 59-year-old male who presented with flu-like symptoms and deranged renal function tests. He received his second dose of the Pfizer COVID-19 vaccine 17 days ago. His clinical picture, serological testing, and radiological imaging were concerned with glomerular disease. His serum was positive for ANCAs, and the renal biopsy specimen revealed pauci-immune glomerulonephritis. He was diagnosed with AAV-associated renal vasculitis following COVID-19 vaccination because no other etiology was identified. His clinical improvement after starting rituximab and steroids reinforced the diagnosis.