The effect of transfusion on immune responses in thalassemia

Abstract

Background: Regular transfusions are the gold standard therapy for β-thalassemia and are often complicated by secondary-iron overload and alloimmunization. We assessed the frequency of regulatory T cells (Tregs) and the levels of cytokines implicated in Th-responses in 49 patients 33 TDT and 16 NTDT in order to investigate the contribution of transfusion and its complications on immune responses.

Materials and methods: Tregs were characterized with flow cytometry. Soluble IL-4, IL-6, IL-10, IL-17A, and TGF-β1 were assessed by ELISA. Clinical data including alloimmunization, age of onset of transfusion splenectomy hepatitis B and C infection, iron overload assessment with MRI T2* (liver and heart) were recorded from the patients' files.

Results: Tregs levels, IL-6, IL-10, TGFβ and serum ferritin were higher in the TDT compared to the NTDT group (all p < 0.05). There was no difference of Tregs and circulating cytokines in patients in correlation with the extend of iron overload (assessed by T2*liver), the type of chelator or the development of alloantibodies.

Discussion: Tregs levels are higher in TDT patients compared to NTDT, a difference which could be ascribed to transfusion. Tregs levels and the cytokines analyzed may play little role in alloimmunization and are not impacted by the extend of iron overload.

Keywords: Iron-overload; Thalassemia transfusion; Tregs alloimmunization.