Minimal Change Disease Complicated by IgG4-related Kidney DiseaseDeveloping Acute Kidney Injury: A Case Report and Literature Review

The coexistence of IgG4-related kidney disease (IgG4-RKD) and minimal change disease (MCD) is extremely rare. A 60-year-old woman with bilateral submandibular gland swelling and high serum IgG4 levels was admitted to our hospital because of massive proteinuria. Renal biopsy revealed MCD concurrent with IgG4-related tubulointerstitial nephritis. She rapidly developed acute kidney injury requiring transient hemodialysis. Subsequently, her renal function and proteinuria improved with immunosuppressive therapy using prednisolone and cyclosporine, achieving partial remission This case highlights the diverse manifestations of IgG4-related kidney disease and suggests that the coexistence of two renal disorders may contribute to disease severity.