Pre-transplantation vitamin D deficiency increases acute graft-versus-host disease after hematopoietic stem cell transplantation in thalassemia major patients.

BACKGROUND: Although there are many studies on the role of vitamin D deficiency (VDD) in hematopoetic stem cell transplantation (HSCT), outcomes have often reported conflicting results because of the heterogeneity of the patients in the studies. METHODS: We investigated the association between VDD prior to HSCT and outcomes after HSCT in a relatively homogenous group of patients with thalassemia major (TM) who received identical treatment for TM before transplantation, and the same conditioning regimen and GVHD prophylaxis during and after transplantation. All patients, including the patients with normal vitamin D3 levels received 400 to 800 IU per day of vitamin D for the first 6 months after HSCT. RESULTS: Pre-HSCT VDD increased the frequency of aGVHD after transplantation, particularly in HSCTs performed with PBSC for the stem cell source. Pre-transplant low vitamin D3 levels had no association with transplant outcomes such as engraftment, viral infections, alloimmunization, chronic GvHD, total days of hospitalization, and success in terms of transfusion independence. CONCLUSIONS: Low vitamin D3 levels before HSCT carry a significant risk for aGVHD. All patients with TM should be screened for VDD before HSCT, and every effort should be made to supplement vitamin D before the transplant in VDD patients.

Iron-chelation therapy with oral chelators in patients with thalassemia major.

In thalassemia major (TM), without iron chelation therapy, iron-mediated free radical damage causes liver, endocrine, and myocardial toxicities. Deferoxamine has universally been the standard therapeutic option for iron chelation therapy; however, its usage is troublesome, leading to suboptimal patient compliance. In order to maximize the effectiveness of iron chelation therapy, oral iron chelators deferiprone and deferasirox constitute an important development, offering a potential to improve compliance. Although both oral drugs are effective, they have differences including different pharmacokinetics and side-effect profiles. Our retrospective evaluation of TM patients using oral chelators showed that oral chelators are effective in reducing iron overload regarding ferritin level and partially in cardiac T2* value. However, in our study side effects and discontinuation rates were unexpectedly high and close follow-up of TM patients using oral chelators should be carefully done. The variability in rate of side effects and drug discontinuation in spelenectomized patients using oral chelators suggests that spleen may have a role in pharmacokinetics of these drugs, as well.