A First Step toward a New Approach to Treating Membranous Nephropathy

Membranous nephropathy, the leading cause of nephrotic syndrome in adults (approximate incidence among white adults without diabetes, 8 to 10 cases per million population per year), is the result of IgG deposition in the subepithelial space of glomerular capillaries.1,2 Strategies for treating patients with membranous nephropathy have engendered major controversy in nephrology for several decades. A few trials, most of which have been underpowered, have shown that glucocorticoids do not affect outcomes. Other studies indicate that alkylating agents are useful in patients with membranous nephropathy who have nephrotic syndrome but serum creatinine levels below 1.1 mg per deciliter (100 μmol . . .