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

Pretransplant Vitamin D Deficiency Is Associated With Higher Relapse Rates in Patients Allografted for Myeloid Malignancies
Vitamin D has been shown to affect multiple signalling pathways and immune responses. It has been identified that Vitamin D deficiency is common in patients with hematologic malignancy. This is a retrospective cohort study to evaluate the impact of pre-transplant Vitamin D status on outcomes.
Patients undergoing allogeneic hematopoietic stem cell transplantation (alloHSCT) for myeloid and lymphoid malignancies between 2002-2013 at one centre formed the training cohort. The following data was collected: OS, relapse, NRM, disease stage, conditioning, patient age, donor type, recipient/donor sex match, GVHD information. Vitamin D deficiency was defined as 25-hydroxyvitamin D less than 320ng/mL. Validation was performed in a cohort of patients with alloHSCT for AML/MDS between 2009-2013 at different centres (independent cohort).
In the training cohort, 492 patients (age range 17 -75) were assessed and 80% Had Vitamin D deficiency before alloHSCT. Vitamin D deficiency was significantly associated with a higher risk of relapse and inferior overall survival. For ALL, Vitamin D deficiency was associated with significantly inferior OS. For AML, pre-transplant Vitamin D deficiency was only significantly associated with higher risk of relapse. A higher relapse risk was also observed in myeloid diseases in the independent patient cohort.
Retrospective study with risk of confounding bias, such as information about treatment prior to HSCT including length of stay in hospital, infections, complications. Adult study and therefore not directly transferrable to pediatrics. The independent cohort only included patients with AML, thus ALL findings not validated in separate cohort. There was no data providing insight on possible mechanisms leading to the effect on outcome.
In adult patients with hematologic malignancies, Vitamin D deficiency seems to be associated with worse outcomes (OS and/or relapse). Due to minimal risk, vitamin D supplementation seems reasonable to try and prevent deficiency in all patients that will need allo-HSCT.