COVID-19 Vaccination and Glomerulonephritis.

Introduction: mRNA COVID-19 vaccine is more effective than traditional vaccines owing to superior immune activation. Nevertheless, the impact of mRNA COVID-19 vaccine on triggering /relapsing glomerulonephritis (GN) is limited. We report a case series of patients who developed new or relapsing GN postvaccination.

Methods: We evaluated baseline characteristics, vaccine type, and clinical outcomes of 13 patients from our institution who had a new diagnosis or relapse of their GN post-mRNA COVID-19 vaccination.

Results: Of 13 patients, 8 patients were newly diagnosed with having GN and 5 patients had relapse. Median age was 62 years (range 19-83 years). Autoimmune disease (38%) was the most prevalent underlying disease followed by cancer (23%). Most patients were White males. IgA nephropathy (IgAN) was the most common GN in our series (5 patients, 38%) followed by membranous nephropathy (MN) (3 patients, 23%). There was 1 patient with IgAN who had evidence of IgA deposits before vaccination suggesting the immune activation after vaccination triggered a flare of the disease. Our case series also included the first case report of tip-variant focal segmental glomerulosclerosis (FSGS), NELL-1-associated MN, and atypical anti-glomerular basement membrane (GBM) nephritis. A total of 77% developed acute kidney injury (AKI) with most being Kidney Disease: Improving Global Outcomes stage 1 (67%). Outcomes are favorable with 80% responding to therapy.

Conclusion: New cases and relapse of GN can present shortly after mRNA COVID-19 vaccination. New cases of IgAN may result from unmasking of undiagnosed IgAN owing to robust immune activation rather than development of new deposits.