MO208: De Novo Glomerulonephritides Following BNT162B2 COVID-19 Vaccine: A Case Series

Abstract

BACKGROUND AND AIMS: The development and massive use of mRNA COVID- 19 vaccine BNT162b2 has raised new concerns on triggering De novo immunemediated diseases, in particular rare diseases as glomerulonephritis (GN), even if the security profile is excellent and severe reactions have been rare. In literature few similar cases were recently described [1, 2]. We report six cases of newly diagnosed GN after a two-dose regimen of SARS-CoV-2 vaccine, from a single tertiary care institution in Northern Italy. METHOD(S): We described six cases of De novo GN occurring after massive use of Pfizer-BioNTech BNT162b2 COVID-19 vaccine from March 2021 to December 2021. All cases were biopsy proven. Baseline characteristics and laboratory findings, treatments and outcomes were based on review of medical records. RESULT(S): From April 2021, we observed two IgA nephropathies (IgA-N), one membranous nephropathy (MN), one membranoprolipherative GN (MPGN), one acute interstitial nephritis (aTIN) and one minimal change disease (MCD). Of note, one IgA-N presented with diffuse purpura as in IgA-vasculitis. The median age at vaccination was 52.8 years (min-max 18-67) and three (50%) were female; arterial hypertension was the most common comorbidity (50%). Only one subject contracted COVID-19 before vaccine (16.6%). None of the points showed any sign of renal disease before vaccine; at the time of disease onset, the median creatinine was 1.49 mg/dL (min-max 0.6-10.5 mg/dL) and proteinuria 3.0 g/24 h (min-max 0.9-13.8 g/24 h). All cases presented after the second dose (1 day to 6 months thereafter) and three (50%) were within 3 weeks from the vaccine. Of note, the aTIN developed after the vaccine during a long-time therapy with statins and relapsed after a rechallenge with a statin few months later. All the nephropathies were treated as per center practice, with an overall good response (four partial remissions and one complete remission). Given a target population of about 100 000-200 000 residents in our area, we could estimate an incidence rate of 4-8 cases/100 000 patient-years. CONCLUSION(S): This small series has a lot of limitations including the small number of patients and we probably missed some cases in our area. Furthermore, we could not investigate a causal association, even if the timing of disease onset might be suspicious in three cases and the incidence seemed to be almost twice as the expected in Europe (about 2-4/100.000 patient-years). As for SARS-CoV-2 vaccines, it is likely that the mRNA vaccine will result in a more potent inflammatory stimulus than the one observed after inactivated virus-vaccine: maybe some patients had already a subclinical GN and the vaccine constituted a flare leading to the full-blown disease [3].