Risk Factors Associated with Kidney Injury and the Impact of Kidney Injury on Overall Survival in Pediatric Recipients Following Allogeneic Stem Cell Transplant

Pediatric allogeneic stem cell transplant (AlloSCT) patients are at substantial risk of developing kidney injury (KI), and KI contributes to transplant-related morbidity and mortality. We compared the estimated creatinine clearance (eCrCl) at 1, 3, 6, 9, and 12 months post-AlloSCT in 170 patients following reduced toxicity conditioning (RTC) versus myeloablative conditioning (MAC) to baseline. eCrCl was calculated using the Schwartz equation. Patients with ≥50% drop in eCrCl from the baseline were considered to have KI. Patients received tacrolimus and mycophenolate mofetil (MMF) for graft-versus-host disease (GVHD) prophylaxis. The logistic regression model was used for assessing risk factors for KI. Seventy-six patients (median age = 10.6 years) received RTC AlloSCT; 94 patients (median age = 8.5 years) received MAC AlloSCT. The incidence of KI at 1 month post-AlloSCT was significantly higher in MAC versus RTC AlloSCT (43/94 [45.7%] versus 13/76 [17.1%] P < .0001). There was no statistical difference in KI at 3, 6, 9, and 12 months post-AlloSCT between the 2 conditioning groups. On multivariate analysis, only MAC was a significant risk factor for KI (odds radio [OR] 3.44, 95% confidence interval [CI] 1.59-7.42, P = .002). In multivariate analysis for risk factors affecting overall survival (OS), the following were statistically significant: MAC versus RTC (hazard ratio [HR] 2.66, P = .0008), average versus poor-risk disease status (HR 2.09, P = .004), matched sibling donor (MSD) and matched unrelated donor (MUD) versus umbilical cord blood (UCB) (HR 2.31, P = .013), no KI versus KI (HR 2.00, P = .005). In children, MAC is associated with significant risk of KI in the first month after transplant, and KI in the first month post-AlloSCT is associated with a significantly decreased OS.