Introduction:
Collapsing glomerulopathy (CG) is a distinct and aggressive variant of focal and segmental glomerulosclerosis (FSGS), characterized clinically by heavy proteinuria, rapid decline in renal function, and progression to end-stage renal disease (ESRD). Histologically, CG is defined by segmental or global collapse of glomerular capillaries, hypertrophy and hyperplasia of visceral epithelial cells, and marked tubulointerstitial injury, including microcystic tubular dilatation. The clinical impact of CG in renal allograft biopsies is not fully elucidated, with limited data on its incidence and outcomes in transplant recipients.This study aimed to determine the prevalence, clinicopathological characteristics, and outcomes of CG in renal transplant recipients, based on allograft biopsy findings.
Methods:
This retrospective, single-center, observational study reviewed 160 renal allograft biopsies conducted over a 50-month period. A diagnosis of CG was made when at least one glomerulus exhibited global or segmental collapse of the glomerular capillary tufts, accompanied by prominent hypertrophy and hyperplasia of visceral epithelial cells. Data were retrieved from hospital records to assess the clinicopathological impact of CG on allograft function and patient outcomes.
Results:
CG was identified in 6.25% (10/160) of allograft biopsies. Two patients had undergone native kidney biopsies, which revealed the presence of DGGS. The mean time to CG diagnosis was 25 months post-transplant (range 4–50 months). At the time of biopsy, the mean proteinuria was 1.9 grams/day, and the average serum creatinine was 2.25 mg/dL. Rituximab was administered to three patients alongside standard therapy, with a follow-up duration ranging from 3 to 24 months. Graft failure occurred in three patients, while two others succumbed to infections despite functioning grafts. The remaining four patients maintained functioning grafts, with a mean serum creatinine of 3.25 mg/dL (range 1.17–5.24 mg/dL).
Conclusions:
The development of CG in renal allograft biopsies is associated with significant proteinuria, declining graft function, and a high risk of graft loss. These findings underscore the need for early identification and aggressive management to potentially mitigate poor outcomes in affected patients.
I have no potential conflict of interest to disclose.
I did not use generative AI and AI-assisted technologies in the writing process.