A Rare Case of Proliferative Glomerulonephritis with Monoclonal IgG Deposits in an Adolescent Female; Mimicking Immune Complex Glomerulonephritis

Proliferative glomerulonephritis with monoclonal IgG deposits (PGNMID) is a rare renal disease under the spectrum of monoclonal gammopathy of renal significance (MGRS). Majority of the cases have been diagnosed in adult population, especially after the age of 40 years. We report a rare case of PGNMID in a 16 years old female, presented with nephrotic syndrome and active urine sediment. She had normal serum creatinine, low C3 and negative infective and autoimmune markers. Renal biopsy revealed membranoproliferative glomerulonephritis (MPGN) with monoclonal IgG3 kappa deposits. Our adolescent patient was treated with standard antiproteinuric therapy and steroid. Though C3 became normal on follow up, but proteinuria was increased and rituximab was added. Our case emphasizes the awareness by nephrologist and renal pathologist about this rare disorder even in adolescent population for accurate diagnosis, prognostication and treatment.