Abstract
BACKGROUND AND OBJECTIVES: AKI is associated with progression of CKD. Little is known about AKI after kidney transplantation in pediatric recipients. We aim to describe the epidemiology, risk factors, consequences, and outcomes of AKI in this population. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We performed a retrospective longitudinal analysis of pediatric kidney transplant recipients followed at The Hospital for Sick Children (Toronto, Canada) from 2001 to 2012. AKI was defined as an increase in serum creatinine ≥1.5 times baseline, and a rise of serum creatinine ≥1.25 but <1.5 times baseline defined subacute AKI. RESULTS: Of 179 children, 122 were eligible for analysis. At baseline (3 months post-transplant), median age of the children was 13 years old (interquartile range, 9-16 years old), and 53% had CKD stage 2. Congenital anomalies of the kidney and urinary tract accounted for 46% of children. Over the study period (12 years), the incidence of AKI was 37% (n=45 children), and 65% (79 children) experienced subacute AKI. Twenty-seven percent (33 children) did not develop AKI or subacute AKI. The main causes of AKI were infections other than urinary tract infections, rejection, and urinary tract infections. In a multivariable Poisson regression analysis, independent risk factors for AKI included younger age, girls, grafts from deceased donors, and lower baseline eGFR. AKI was significantly associated with lower long-term GFR and graft loss independent of rejection episodes. Moreover, subacute AKI was associated with progression of CKD. CONCLUSIONS: AKI and subacute AKI were common after pediatric kidney transplantation, and they were associated with graft loss, lower eGFR, and more rapid progression of CKD.