[Cooperative study of de novo extramembranous glomerulonephritis in renal allografts in humans: report of 19 new cases in 1550 renal transplant patients of the transplantation group of the Ile de France].

A collaborative study including seven kidney transplant centers in Paris recorded 19 new cases of "de novo" membranous glomerulonephritis (MGN) in a series of 1000 kidney graft biopsies over 1550 renal transplantations. This study represents the largest series "de novo" MGN in the literature. The mean time for the onset of the proteinuria was 26 months post-transplantation (extremes 2-58 months). None of the following factors seemed to be linked with the presence of MGN: age, sex, donor-recipient HLA phenotype, 1st graft vs 2nd graft, cadaver vs related graft, HLA matching, recipient treatment, number of transfused blood units, lymphocytotoxins, number of rejection episodes, number and length of acute tubular necrosis, viral or bacterial infections. These 19 new cases of MGN were compared to the other previously published 42 cases. They generally do not appear to be deleterious for the graft function.