Case Report of Spontaneous Remission of Biopsy-Proven Idiopathic Immune Complex-Mediated Membranoproliferative Glomerulonephritis

Membranoproliferative glomerulonephritis (MPGN) is a histopathologic diagnosis causing microscopic hematuria, nephrotic range proteinuria, and chronic renal failure. Current understanding divides pathogenesis into two broad categories: immune complex mediated and complement mediated (now termed C3 glomerulopathy). The term idiopathic immune complex-mediated MPGN would apply to a patient without an identifiable source of immune complex production and no evidence of C3 glomerulopathy. Presented is a patient with idiopathic immune complex mediated MPGN and her clinical course. The patient opted for conservative therapy with losartan, carvedilol, chlorthalidone, and atorvastatin. Nephrotic range proteinuria of 8.7 g per day resolved over 5 months, with improvement of serum from 3.3 to 1.2 mg/dL. Remission continues at follow-up 21 months after biopsy. For idiopathic immune complex-mediated MPGN, resorting to empiric immunosuppression therapy may not be the best option. As this patient demonstrates, a conservative approach of blood pressure control with anti-renin-angiotensin agents, control of lipids, and watchful follow-up can be successful.