Pretransplant Vitamin D Deficiency Is Associated With Higher Relapse Rates in Patients Allografted for Myeloid Malignancies.

Purpose Vitamin D (VitD) deficiency is common in patients with hematologic malignancies undergoing allogeneic transplantation (alloSCT), but its prognostic relevance is unclear. Patients and Methods The impact of pretransplant VitD status on overall survival, relapse mortality, and nonrelapse mortality was investigated retrospectively in a cohort of 492 patients undergoing alloSCT at our center from 2002 to 2013. VitD deficiency was defined as a serum level of 25-hydroxyvitamin D3 < 20 ng/mL (equivalent to < 50 nM) before alloSCT and was assessed using accredited laboratory methods and a standard chemiluminescent immunoassay. Results were validated in an independent cohort of 398 patients diagnosed with myeloid malignancies. Results A total of 396 (80%) and 348 (87%) patients had VitD deficiency before alloSCT in the training and validation cohort, respectively. In the training cohort, VitD deficiency was significantly associated with inferior overall survival (hazard ratio [HR], 1.78; P = .007) in multivariable analysis. This was due to a higher risk of relapse (HR, 1.96; P = .006) rather than nonrelapse mortality. A significant association of pretransplant VitD deficiency with higher relapse rates was observed only in patients diagnosed with myeloid (HR, 2.55; P = .014) but not with lymphatic diseases (HR, 1.60; P = .147). A similar impact of pretransplant VitD deficiency on relapse risk in myeloid diseases was also observed in an independent patient cohort (HR, 2.60; P = .017). Validation of the effect of VitD deficiency on relapse in patients with myeloid malignancies was successful. Conclusion Pretransplant VitD deficiency was associated with a higher risk of relapse in patients allografted for myeloid malignancies. Prospective studies on VitD status and correction of VitD deficiency in the setting of alloSCT are highly warranted.