De novo membranous nephropathy in human renal allografts: report of nine patients.

Nine new patients with de novo membranous nephropathy (MN) are reported. The onset of MN, as defined by onset of nephrotic-range proteinuria, ranged from 11 to 30 months after transplantation. Five of the nine patients returned to hemodialysis within 4 to 26 months after the onset of nephrotic syndrome. No known exogenous (for example, ALS or HBsAg) or endogenous antigens could be demonstrated as the cause in any of the nine patients. The possibility that excellent tissue compatibility might increase the risk of subsequent de novo MN is suggested by the finding of four patients with "full house" HLA-A,B mismatch. This phenomenon occurs in approximately one in 100 to 200 transplants. It is suggested that de novo MN is not as unusual as heretofore believed and that its prognosis is poor.