Collapsing glomerulopathy in renal allograft biopsies: A study of nine cases

Collapsing glomerulopathy (CG) is considered to be a distinct clinicopathologic pattern of proliferative podocyte injury. The clinical significance of CG in renal allograft biopsies is yet not clear due to the scant data on the occurrence of CG in renal transplant recipients. We identified nine cases of CG in allograft biopsies over a period of 2 years. Detailed clinical information, including follow-up data, was collected and histopathological analysis performed. All the nine patients were males with a mean age at diagnosis of 32.4±11.2 years. The median posttransplantation duration at diagnosis of CG as 52 (range 12–98) months. All the patients presented with severe proteinuria and graft dysfunction. Histological analysis showed a median number of 8 glomeruli. The collapse of the glomerular tuft with visceral epithelial cell hyperplasia involved median of 2 glomeruli (range 1–4). At the last follow-up (mean duration 6 months), four patients had graft failure (return to dialysis) while four had functioning grafts. One patient was lost to follow-up. This series emphasizes the importance of this rare glomerular pathology as an important cause of graft dysfunction that may lead to allograft failure.