Development and relapse of nephrotic syndrome with thrombotic microangiopathy following repeated COVID-19 vaccination: A case report

Here, we report the development and relapse of nephrotic syndrome, complicated by thrombotic microangiopathy (TMA), after repeated injections of the mRNA-1273 (Moderna) coronavirus disease 2019 (COVID-19) vaccine. A 50-year-old male patient was admitted for further examination and treatment 28 days after receiving the second dose of the vaccine. Laboratory tests revealed nephrotic-range proteinuria, microscopic hematuria, low platelet count, and mild anemia with decreased haptoglobin levels. Renal biopsy revealed subendothelial swelling, double contours of the glomerular basement membrane, and mesangiolysis, which suggested glomerular endothelial injury. Further immunohistochemical analysis revealed the presence of platelet thrombi by CD42b staining and glomerular endothelial injury with proliferation by CD34 staining with periodic acid-Schiff counterstaining or Ki67 staining. The patient was, therefore, clinically diagnosed with TMA. Angiotensin receptor blocker treatment gradually resulted in the resolution of the patient’s clinical symptoms. However, the patient relapsed with full nephrotic syndrome. His clinical manifestations even worsened 20 days after the third vaccine injection. The close association between repeated vaccinations and development and relapse of nephrotic syndrome with TMA strongly suggests a causal relationship between these conditions. Clinicians and pathologists should be aware that this vaccine could induce not only simple minimal change disease but also nephrotic syndrome with TMA.