Prevalence and Timing of AKI in Pediatric Hematopoietic Stem Cell Transplantation

Background: Acute kidney injury (AKI) is a commonly recognized complication of hematopoietic stem cell transplant HSCT with impact on morbidity and mortality. As the use of HSCT increases, the impact of AKI on patient centered outcomes gains more importance. While the incidence of AKI in pediatric HSCT recipients ranges from 21%- 84%, there is a paucity of data describing the timing of AKI following HSCT. We aimed to evaluate point prevalence and timing of AKI in the first 21 days following transplant in the pediatric HSCT population. Methods: This is a retrospective cohort study from 2010-2019 at Texas Children’s Hospital. Patients less than 24 years of age who underwent allogeneic or autologous HSCT were included. AKI was defined using Kidney Disease Improving Global Outcomes (KDIGO) creatinine criteria. Baseline creatinine was the lowest creatinine in the past 90 days. AKI incidence and prevalence was evaluated over the first 21 days post-HSCT. Primary outcome was point prevalence of AKI over the first 21 days following HSCT. Results: 654 patients were evaluated with a median of 22 creatinine levels per patient (IQR 15-22) over a 21-day period. Median age was 8 years old (IQR 3-13) and 63% were female. 82% underwent an allogeneic HSCT with the most common indication being malignancy (63%). 22% (145/654) of patients had AKI on day of transplant (prevalent AKI). Incident AKI after day 0 was 63% (414/654). Most patients (51%) developed their first episode of AKI during days 1-7. Peak point prevalence of any AKI occurred on day 16 at 50%. Peak prevalence for severe AKI was on day 21 at 26%. Conclusion: Prevalent and incident AKI was very common in pediatric HSCT recipients. Understanding AKI burden for this population can provide clinicians valuable insight to mitigate modifiable risk factors and provide appropriate anticipatory guidance. Risk stratification of patients to identify those at highest risk for adverse renal outcomes is needed to optimize resource utilization and improve outcomes.