# A Series of Glomerular Diseases That Developed After COVID-19 Vaccination

## TL;DR

This paper reports cases of kidney diseases that developed after receiving mRNA-based COVID-19 vaccines, highlighting the need for long-term monitoring.

## Contribution

The study presents 30 cases of glomerular diseases following mRNA vaccination, adding to the understanding of vaccine-related adverse effects.

## Key findings

- Twenty patients were diagnosed with IgA nephropathy after vaccination.
- Some patients experienced a relapse of pre-existing IgAN following vaccination.
- Short-term outcomes were generally favorable, but some patients had severe kidney function decline.

## Abstract

Background

Although the coronavirus disease 2019 (COVID-19) vaccine has been shown to be effective in preventing severe COVID-19 infection, many vaccine-related adverse events have been reported with the increasing use of COVID-19 vaccines based on messenger RNA (mRNA). Cases of new-onset and relapsing vaccine-related glomerular diseases, including minimal change disease (MCD), antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis, immunoglobulin (Ig)G4-related disease, and IgA nephropathy (IgAN), have been reported.

Methods

We present 30 patients who developed glomerular diseases after COVID-19 mRNA vaccination. We evaluated the clinical characteristics, vaccine types, and outcomes of 30 patients whose urinalysis results indicated proteinuria and/or occult blood after COVID-19 mRNA vaccination. For a definitive diagnosis, we performed a renal biopsy and evaluated their histological findings.

Results

Out of 30 patients, 19 (63.3%) were female, and 11 (36.7%) were male. The median age of the patient was 42.5 years (range, 24-66 years). Seventy-three percent of the patients received BioNTech Pfizer vaccines, and 26.7% received Moderna vaccines (mRNA-1273). Gross hematuria was observed in 83.3% of the patients, and 13.3% had nephrotic syndrome. Twenty patients with IgAN were diagnosed by renal biopsy, while the remaining were diagnosed with MCD (n=3), proliferative glomerulonephritis with monoclonal Ig deposits (PGNMID) (n=1), TAFRO syndrome (characterized by thrombocytopenia, anasarca (edema, pleural effusion, and ascites), fever, reticulin fibrosis/renal dysfunction, and organomegaly; n=1), and anti-glomerular basement membrane (GBM) disease (n=1). Four patients who previously underwent treatment for IgAN experienced exacerbation of urinary abnormalities and disease relapse.

Conclusion

In conclusion, various glomerular diseases were newly diagnosed after COVID-19 mRNA vaccination. Although their short-term outcomes seem favorable, some patients developed serious worsening renal function and nephrotic range proteinuria. Patients with vaccine-related glomerular disease should be monitored long-term to predict prognosis in the future.