[Case Report: MPO-ANCA Associated Vasculitis After Pfizer-BioNTech COVID-19 mRNA Vaccination].

We report a case of MPO-anti-neutrophil cytoplasmic antibody ANCA-associated vasculitis, with pulmonary-renal syndrome, after the mRNA booster third dose vaccine Pfizer BioNTech against COVID-19 in 71-year-old Caucasian man with no specific past medical history. A kidney biopsy diagnosed ANCA-associated pauci-immune crescentic glomerulonephritis. Renal function and constitutional symptoms have been partially improved with treatment with dialysis, intravenous rituximab and steroid pulse therapy. No disease following either infection or vaccination with fourth dose against COVID-19.