Recurrent and De Novo Focal Segmental Glomerulosclerosis After Kidney Transplantation: Comparison of Clinical Features and Transplant Outcomes

Background: Focal segmental glomerulosclerosis (FSGS) is a notable subtype of glomerulonephritis in kidney transplantation, often resulting in graft failure. Yet, research comparing transplant outcomes between de novo and recurrent FSGS is scarce. This study aims to compare clinical features and transplant outcomes between these two categories. Methods: This retrospective study enrolled 773 kidney transplant recipients from two centers between January 2008 and October 2021. Patients diagnosed with FSGS through graft kidney biopsy were included. They were categorized into two groups based on the time of FSGS occurrence and results of native kidney biopsy: the recurrent FSGS group and the de novo FSGS group. Results: Of 773 kidney transplant patients, 24 had primary FSGS-causing end-stage renal disease. During a median 65-month follow-up, 5 of these patients developed recurrent FSGS (incidence: 26.3%). Among 749 patients with other kidney diseases causing end-stage renal disease, 9 had de novo FSGS (incidence: 1.2%). In the recurrent FSGS group, 2 out of 5 patients experienced graft failure, with no deaths or acute rejections. Similarly, in the de novo FSGS group, 3 out of 9 patients experienced graft failure, with no deaths or acute rejections. Kaplan-Meier analysis showed slower graft loss in de novo FSGS, resulting in a higher graft survival rate compared to recurrent FSGS (probability of graft survival, 60% vs 33.3%, P = .036). Conclusions: Graft loss progresses more slowly in de novo FSGS compared to recurrent FSGS, resulting in a higher long-term graft survival rate in de novo FSGS than in recurrent FSGS.