Outcome of kidney allograft in patients with adulthood-onset focal segmental glomerulosclerosis: comparison with childhood-onset FSGS.

BACKGROUND Idiopathic focal segmental glomerulosclerosis (FSGS) occurring at young age is known to predispose to poor graft outcome, but the outcome of adulthood-onset FSGS (A-FSGS) has not been thoroughly investigated. Here, we compared the graft outcomes between kidney recipients with A-FSGS and childhood-onset FSGS (C-FSGS). METHODS We enrolled 47 A-FSGS recipients and 60 C-FSGS recipients with an onset age of ≤ 15, from four of the largest transplant centers in Korea. RESULTS The baseline characteristics were similar between two groups. The 1- and 3-year cumulative recurrence rates were 20.0 and 22.1%, respectively. FSGS was recurrent in 19 C-FSGS patients [median duration, 2 months (interquartile range, IQR, 1-35)], and 11 patients had recurrent disease in A-FSGS [5 months (IQR, 3-37)]. The recurrence rate was similar between two groups (P = 0.126). The 5- and 10-year graft survival rates were 90.0 and 78.5%, respectively. The overall graft survival rates were not different between two groups. After adjusting baseline characteristics, the development of major outcomes was similar between two groups except acute rejection that was more frequent in A-FSGS. The age of disease onset did not affect recurrence in both groups. While grafts with recurrence had poorer graft survival in the A-FSGS group (P = 0.005), the recurrence was not associated with graft loss in the C-FSGS group (P = 0.558). CONCLUSIONS The onset age did not affect the graft outcome in patients with FSGS, and the recurrence significantly affected graft survival in A-FSGS. Therefore, the main focus should aim for the management of recurrence.