RESUMEN
Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis is a class of autoimmune diseases that can cause kidney failure because of mononuclear cell infiltration and the destruction of small and medium-sized blood vessels. Coronavirus disease 2019 (COVID-19) may trigger or exacerbate autoimmune diseases. We present a case of ANCA-associated vasculitis in a patient with rheumatoid arthritis after a COVID-19 infection, who presented with intermittent hemoptysis and dyspnea and was diagnosed with COVID-19 pneumonia three weeks ago. Her clinical, radiological, and serological picture was concerned with pulmonary-renal syndrome. Her serum was positive for antinuclear antibody and ANCAs, and renal biopsy showed pauci-immune crescentic glomerulonephritis. She was diagnosed clinicopathologically with pauci-immune glomerulonephritis in the setting of rheumatoid arthritis (RA) after a COVID-19 infection. Her condition improved after she was treated with rituximab and pulse dose methylprednisolone.