Mortality and Allograft Loss Trends Among US Pediatric Kidney Transplant Recipients With and Without Focal Segmental Glomerulosclerosis.

BACKGROUND: Pediatric patients with focal segmental glomerulosclerosis (FSGS) have high rates of disease recurrence and allograft failure after kidney transplantation, but there are few data for long-term survival posttransplantation.

STUDY DESIGN: Retrospective cohort study.

SETTING & PARTICIPANTS: 12,303 pediatric patients (aged <18 years), including 1,408 (11%) patients with FSGS, who received a first kidney transplant in 1990 through 2009 and were followed up through June 2015 were identified from the US Renal Data System database.

PREDICTORS: Primary cause of end-stage renal disease, FSGS or other.

OUTCOMES: All-cause patient mortality and allograft loss.

RESULTS: All-cause mortality significantly improved for patients with FSGS who underwent transplantation in the 2000s versus the 1990s (6.72 vs 12.24 deaths/1,000 patient-years; HR, 0.55; 95% CI, 0.39-0.78; P<0.001). Reductions in allograft loss were less dramatic (75.91 vs 89.05 events/1,000 patient-years; HR, 0.85; 95% CI, 0.74-0.98; P=0.02). After adjusting for baseline characteristics at the time of transplantation, patients with FSGS had similar rates of death compared with patients without FSGS (HRs of 0.81 [P=0.6] and 1.06 [P=0.2] among those who underwent transplantation in the 2000s and 1990s, respectively) despite higher rates of allograft loss (HRs of 1.17 [P=0.03] and 1.27 [P<0.001], respectively). Among patients who underwent transplantation in the 2000s, further adjustment for allograft failure as a time-varying covariate demonstrated a lower rate of death among patients with FSGS compared with those without FSGS (HR, 0.70; P=0.02).

LIMITATIONS: Lack of information about certain risk factors for mortality, including duration of chronic kidney disease; missing data; and potential primary disease misclassification.

CONCLUSIONS: Survival of pediatric kidney transplant recipients with FSGS improved between the 1990s and 2000s and was similar to that of recipients without FSGS. Interestingly, adjustment for allograft failure showed greater survival for pediatric patients with FSGS who underwent transplantation in the 2000s as compared with others, suggesting that effective interventions to decrease allograft loss due to disease recurrence may improve patient survival.