Immunoglobulin A nephropathy (IgAN) is the most common primary glomerulonephritis worldwide with heterogeneous histopathological phenotypes. Although IgAN with membranoproliferative glomerulonephritis (MPGN)-like features has been reported in children and adults, treatment strategies for this rare IgAN subtype have not been established. Here, we present the case of a 56-year-old man with no history of kidney disease who initially presented with nephrotic syndrome. Renal biopsy revealed MPGN-like features with a negative serological workup for secondary causes. Immunofluorescent staining was predominantly positive for IgA in the glomerular mesangial and capillary walls. Galactose-deficient IgA1 staining showed a distribution pattern similar to IgA staining. Electron microscopy revealed disorganized structural deposits in the mesangial and subendothelial regions. Based on clinical and histopathological findings, the patient was diagnosed with primary IgAN. The nephrotic syndrome resolved completely after six months of combined corticosteroids and cyclosporine A (CsA) therapy. Although corticosteroids and CsA were tapered off, hematuria and proteinuria remained in complete remission for years of follow-up. This case demonstrates the importance of recognizing IgAN with MPGN-like features as a histopathological subtype that may benefit from intensive immunosuppressive therapy.
Keywords: Corticosteroids; Cyclosporine A; Galactose-deficient IgA1; IgA nephropathy; Membranoproliferative glomerulonephritis; Nephrotic syndrome.
© 2024. The Author(s), under exclusive licence to Japanese Society of Nephrology.