Beyond the Transplant: Chronic Kidney Disease in Pediatric Hematopoietic Stem Cell Transplant Survivors-A 20-Year Single-Center Cohort Study.

BACKGROUND: Pediatric hematopoietic stem cell transplantation (HSCT) is curative for malignant and non-malignant diseases, yet survivors remain at substantial risk for late renal complications. Data on chronic kidney disease (CKD) incidence and its determinants in pediatric HSCT recipients are limited. METHODS: We conducted a single-center retrospective cohort study of 261 pediatric patients (aged 0-21 years) who underwent HSCT at Schneider Children's Medical Center, Israel, between 2000 and 2020. Acute kidney injury (AKI) was defined per KDIGO creatinine criteria. CKD was defined as eGFR < 90 mL/min/1.73 m2 sustained ≥ 3 months and/or proteinuria or hypertension. Given the limited number of CKD events, multivariable logistic regression identifying factors associated with CKD was treated as exploratory. Overall survival was analyzed using Kaplan-Meier methodology. RESULTS: AKI episodes occurred in 20.5% of patients during the first three months post-HSCT. CKD incidence increased progressively: 6.0% at one year, 8.6% at three years, and 16.5% at five years-substantially exceeding the ~5% background prevalence reported in the general Israeli pediatric population. Older age at transplantation was the only variable significantly associated with CKD in this exploratory model (mean 11.96 vs. 7.12 years in the CKD and non-CKD groups, respectively; p = 0.008). A higher proportion of patients who developed CKD had undergone four or more transplantations compared with those who did not (31.6% vs. 3.7%), though this difference did not reach statistical significance (p = 0.22) and should be regarded as hypothesis-generating. Patients with a borderline baseline creatinine in the early post-transplant period had lower overall survival than those with a normal baseline creatinine (log-rank p = 0.05), an association whose biological basis requires further study. CONCLUSIONS: CKD affects a substantial and growing proportion of pediatric HSCT survivors in this cohort, particularly those transplanted at older ages. These findings are associative rather than causal, given the retrospective, single-center design and limited number of CKD events. They nonetheless support systematic long-term renal surveillance and nephrology referral as part of post-HSCT survivorship care, with prospective, adequately powered studies needed to confirm risk factors and clarify mechanisms.