COVID-19 vaccination and glomerulonephritis

Background MRNA COVID-19 vaccine is more effective than traditional vaccines due to superior immune activation. However, the impact of mRNA COVID-19 vaccine on triggering de novo/relapsing glomerulonephritis (GN) is limited. We report a case series of patients who developed new or relapsing GN post vaccination. Method 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 GNs 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%). Majority of patients were white male. IgA nephropathy (IgAN) was the most common GN in our series (5 patients, 38%) followed by membranous nephropathy (MN) (3 patients, 23%). One patient with IgAN had evidence of IgA deposits prior to vaccination suggesting that the immune activation following vaccination triggered a flare of the disease. Our case series also included the first case report of tip-variant focal segmental glomerulosclerosis, NELL-1 associated MN, and atypical anti-GBM nephritis. Seventy seven percent developed acute kidney injury with the majority being KDIGO stage 1 (67%). Outcome are favorable with 80% responding to therapy. Conclusions 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 due to robust immune activation rather than development of new deposits.