Successful Remission of Nephrotic Syndrome Caused by IgA Nephropathy with Membranoproliferative Glomerulonephritis-pattern Lesion Treated by Cyclosporine and Oral Corticosteroids.

Immunoglobulin A nephropathy (IgAN) is a common glomerular renal disease presenting with mesangial cell proliferation and mesangial matrix hyperplasia and is typically treated with oral glucocorticoids. However, the clinical presentations and treatment strategies for certain cases of oral glucocorticoid-resistant IgA nephropathy have not been established. We herein report a case of recurrent IgA nephropathy presenting with nephrotic syndrome and membranoproliferative glomerulonephritis-pattern lesions. A 42-year-old woman presented to our clinic 22 years ago after urinary occult blood was detected during a health examination, leading to a diagnosis of IgA nephropathy based on a renal biopsy. Although temporary remission was achieved with oral glucocorticoid therapy, the relapse occurred repeatedly. Eight years ago, she underwent a third renal biopsy, which revealed grade II (C) and Oxford classification M1E0S1T0 findings. Temporary remission was achieved following tonsillectomy and steroid pulse therapy. Subsequently, she presented with nephrotic syndrome and rapidly increasing urinary protein levels. A fourth renal biopsy revealed membranoproliferative glomerulonephritis (MPGN) pattern lesions that were not previously observed. The administration of cyclosporine and corticosteroids after steroid pulse therapy led to complete remission. In cases of recurrent IgA nephropathy complicated by nephrotic syndrome, MPGN-pattern lesions may underlie this condition. In these cases, both corticosteroids and additional cyclosporine may be effective.