Gross haematuria after mRNA COVID‐19 vaccination in two patients with histological and clinical diagnosis of IgA nephropathy

A 28 years old lady with history of microscopic haematuria for 5 years underwent a pre-scheduled kidney biopsy for suspected IgA nephropathy. Her renal function was normal with proteinuria 0.11 g/day. 3 weeks prior to biopsy, she received her second dose of mRNA COVID-19 vaccine (Pfizer-BioNTech BNT162b2) and developed painless gross hematuria 3 h later. Serum creatinine level was mildly elevated from 58 to 72 μmol/L. Urine protein creatinine...