ABSTRACT
BACKGROUND AND AIMS: Antineutrophil cytoplasmatic antibody (ANCA) associated vasculitis (AAV) is a small vessel vasculitis hallmarked by the presence of antibodies against antigens in cytoplasmic granules of neutrophils. Vaccines per se stimulate the immune system, including the innate and the adaptive immune response. Therefore, it is possible that an excess of autoimmunity is observed after vaccine administration. Vaccination (notably influenza) is a recognized trigger for the relapse of ANCA-associated vasculitis. ANCA associated vasculitis and autoimmune reactions have been reported with COVID-19 infection and following vaccination. We report the case of a Caucasian, 62-year-old-man, with a previous history of type 2 diabetes mellitus, hypertension and atrial fibrillation. Blood analysis 1 year before presentation showed preserved renal function and normal urinalysis. He received the first dose of Pfizer-BioNTech COVID-19 vaccine and 2 weeks later routine blood analysis showed acute kidney injury with serum Creatinine 1.75 mg/dL with De novo hematuria, a protein-to-creatinine ratio (RPC) 1.1 mg/g and candersartan (4 mg twice daily) was started. The patient received the second dose of COVID-19 vaccine 21 days after the first injection. Two weeks later, he developed anorexia, nausea and De novo hematuria. He was admitted at the emergency department with deteriorating renal function with a sCr of 5.5 mg/dL, worsening hematuria with dysmorphic red blood cells and proteinuria (RPC 2.9 mg/g). Renal ultrasound was normal. Immunological studies revealed an elevated ANCA-MPO titer of 561. A kidney biopsy was performed and showed a crescentic necrotizing glomerulonephritis. Immunofluorescence confirmed pauci-immune glomerulonephritis. He was diagnosed with renal limited myeloperoxidase (MPO) ANCA AAV. He started three pulses of 500 mg I.V methylprednisolone followed by prednisolone 1 mg/kg/day after that. He also started rituximab (four doses of 500 mg I.V. once a week apart). Despite the immunosuppression, the patient never recovered renal function and remained dialysis dependent. CONCLUSION: Whether autoimmune diseases can be triggered after vaccination remains a matter of discussion among experts. ANCA-associated vasculitis and autoimmune reactions have been reported with COVID-19 infection and following vaccination, which prompts the question whether this response could be a direct reaction to the RNA present in the vaccine. While an association with De novo ANCA vasculitis and COVID-19 vaccine may be possible, further investigation is necessary.