Back to the Basics: Improving Vitamin D Levels in Early Post-Transplant Period Positively Impacts HCT Outcomes in Children

Background: We previously reported significant vitamin D (VD) deficiency in pediatric hematopoietic cell transplant (HCT) recipients with 70% of children starting the HCT process with blood 25-OH VD levels <20 ng/mL that resulted in inferior overall survival at 100 days after HCT (Wallace, BBMT 2016). In 2015 we instituted clinical practices for rigorous VD level monitoring and replacement for all HCT recipients to achieve and maintain 25-OH VD level 30-60 ng/ml during first 100 days after HCT. The goal of this quality improvement project was to evaluate if rigorous VD supplementation in the early HCT period has an influence on HCT outcomes as compared to our published historical controls. Method: We reviewed all HCT recipients' transplanted from 2015-2016. All patients received clinical monitoring and supplementation for VD during the first 100 days of transplant (intervention cohort) and compared VD levels and HCT outcomes with patients who received HCT from 2011 (historical controls). Results: We reviewed 131 patients in our intervention cohort and 134 patients in our historical cohort. Patient demographics and disease characteristics were similar in both groups with the exception of more patient receiving myeloablative conditioning regimen in the intervention cohort (P = .02). Patients in both cohorts received similar HCT supportive care. 41.5% of patients in the intervention cohort were VD deficient prior to HCT. 71% of these patients had documented therapeutic VD level at 60 days and 81% at 100 days post HCT (Table 1). In the historical cohort 70% of patients were VD deficient and only 31% had a documented therapeutic VD level at 60 days post HSCT. Overall survival after HCT was significantly better in the intervention cohort at 89% as compared to the historical cohort at 77% at 100 days after HCT (P < .0135, Table 1) with an overall risk of .49 in the intervention cohort after multi- variate analysis (P = .03). The other notable difference was significantly lower incidence of TMA in intervention cohort supplemented with VD, 10% as compared to 19% (P = .03) in the historical group (Table 2).Table 1Overall Survival by CohortTable 2Multivariable Analysis of SurvivalTable 2Multivariable Analysis of Survival Discussion: We improved VD levels in the majority of HCT recipients by rigorous monitoring and blood level-based VD supplementation in the early post-transplant period. We noted significant improvement in overall transplant outcomes and reduction of the HCT-related complication of TMA in our intervention cohort receiving targeted VD supplementation, as compared to our historical control receiving only standard VD doses in parenteral nutrition and enteral feeds. Our experience indicates that a straightforward intervention such as adequate supplementation of the essential vitamin, vitamin D, can significantly impact overall HCT results. Future prospective studies are needed to better understand the impact of VD on HCT outcomes.