Glomerular pathology of allograft kidneys

Abstract

Background: To review glomerular diseases diagnosed in allograft kidneys and to correlate them with clinical parameters. Methods: Eight hundred and ninety-one renal graft biopsies and 43 graft nephrectomies filed in Queen Mary Hospital from 1980 to 2004 were studied. They came from 442 allografts transplanted to 425 patients. Results: Glomerular diseases were diagnosed in 33.0% of kidney grafts. Indications for biopsy were baseline assessment (23 biopsies, 2.5%), renal dysfunction (790 biopsies, 88.7%), proteinuria (154 biopsies, 17.3%), hematuria (11 biopsies, 1.2%), and by protocol (4 biopsies, 0.4%). The median time post-transplant when the biopsies were procured was less than 8 months. The mean time posttransplant for diagnosing IgA nephropathy (IgAN), transplant glomerulopathy (TG), focal segmental glomerulosclerosis (FSG), mesangiocapillary glomerulonephritis (MCGN), membranous GN, mesangial proliferative GN, and diabetic nephropathy was 70, 66, 65, 55, 45, 49, and 101 months, respectively. Specific glomerular diseases were diagnosed by biopsies in 106 of 119 (89.1%) proteinuric allografts. Recurrent glomerular disease was documented in 31 (7.0%) grafts. Conclusion: Glomerulopathy was common in allograft biopsies. IgAN, TG, FSG, mesangial proliferative GN, and membranous GN comprised the majority. A higher proportion of grafts from donors related to the recipients than from unrelated donors had IgAN (p < 0.05), and there was no difference in the time to diagnose IgAN post-transplant between the two groups, suggesting that genetic factors might play a role in its pathogenesis. Recurrence of glomerulopathy underlying endstage renal disease was frequent for IgAN, FSG, and MCGN, but this was rare for membranous GN.