An Unusual Case of ANCA Associated Vasculitis (AAV) After a COVID-19 Vaccine

ABSTRACT

Introduction: COVID-19 vaccines have been related to immune mediated adverse events and recently some case reports of AAV precipitated after either RNA or viral vector vaccines have been reported. Case Description A 83 year old woman with past records of polymyalgia rheumatica (2017) treated with low dose prednisone, was admitted to our hospital because of malaise, hyporexia and weight loss in the context of urinary symptoms. These started since the second COVID-19 Pfizer- BioNTech vaccine dose administred 3 months ago. Initial blood test revealed anemia, acute kidney injury (serum creatinine 1.7mg/dl), leucocytosis and elevated CRP. Urinalysis showed microhematuria and mild proteinuria in the context of a positive urine culture. She had normal kidneys on ultrasonography. Diuretics and antibiotics were started, but few days after renal function continued worsening (sCr 4,3 mg/dl) with an active sediment. For this reason, immunology tests were ordered with positive high MPO-ANCA antibodies. Hence, a kidney biopsy was performed showing 11 normal glomeruli but severe arteritis in two small-middle sized arterioles with fibrinoid necrosis. Steroids and Rituximab were given as induction therapy with good renal response. Discussion(s) AAV after COVID-19 vaccine administration has been reported previously, and it could be related to its molecular mimicry and immune crossreaction. Most of them were typical forms of pauci-immune crescentic glomerulonephritis, but none with isolated vascular damage. Although cases reported appeared shorter time after vaccine administration, our patient was on low dose prednisone which may explain a subacute onset of the disease. Moreover, she clearly presented constitutional sypmtoms ever since the second vaccine dose was administred. Finally, although the efficacy and safety of the COVID-19 vaccines have been demonstrated, particular attention should be paid to patients with known or suspected autoimmune diseases.