Investigation of the relationship with disease and disease complications in thalassemia cases

Aim: Thalassemia is an autosomal recessively inherited hematological disorder characterized by defective synthesis of hemoglobin chains. Patients present with different disease phenotypes depending on the underlying genetic mutation and exhibit variable clinical courses depending on the severity of anemia and the need for transfusions. Regulatory T cells (TREG), a subset of T cells, play a key role in ensuring immune tolerance in the body. The relationship between TREG and clinical outcomes has been demonstrated in various diseases such as autoimmune diseases and malignancies. On the other hand, studies on the relationship between TREG and thalassemic cases are quite limited. Our study aimed to evaluate TREG levels in adult beta thalassemic cases and investigate their relationship with clinical complications. Material and Methods: The study was designed as a cross-sectional study and was conducted with the participation of beta thalassemia patients followed up at the Department of Adult Hematology, Faculty of Medicine, Çukurova University. Transfusion-dependent beta thalassemia major cases and healthy volunteers as a control group were included in the study. Informed written consent was obtained from all participants. The demographic and clinical characteristics of the patients (age, gender, education, chronic disease, transfusion frequency, chelator use, history of complications, etc.) were obtained from the electronic database (Enlil v3.25.09.1) used for patient follow-up at our hospital. Laboratory data included hemogram, biochemical tests, ferritin, parathyroid hormone, TSH, FSH, LH, hormone levels such as estradiol and testosterone, and 25-OH-vitamin D. Cardiac, hepatic, endocrine, and bone-metabolic complications were evaluated according to the ''Thalassaemia International Federation's Guidelines for the Management of Transfusion-Dependent β-Thalassaemia 2025." Blood samples collected for TREG analysis were processed within 12 hours of collection at our hospital's Central Laboratory, and the analyses were performed using Kaluza software (Beckman Coulter, Miami, FL). Since the required lymphocyte activation level could not be sufficiently achieved prior to the planned studies to determine the Th 17 cell level, these studies could not be completed, and only TREG levels were included in the statistical analyses. Data were analyzed using the SPSS 20.0 program. Results: A total of 54 cases were included in the study, comprising 27 beta thalassemia patients and 27 healthy volunteers. Regulatory T cells were found to be at lower levels in the thalassemia group compared to the control group, and this difference was found to be significant in the Helios+TREG group. When examining the relationship between TREG levels and complications, TREG levels were found to be lower in beta thalassemia cases with endocrinopathy and cardiac complications compared to cases without complications, and this decrease was seen to originate from the Helios+TREG subgroup. No statistically significant difference in TREG levels was observed for cases with hepatic and bone-metabolic complications. Additionally, no correlation was found between TREG levels and hemoglobin, ferritin, and 25-OH vitamin D levels. Conclusion: Our findings indicate that TREG levels are reduced in patients with beta thalassemia, but this change is not associated with complications other than endocrinopathy and cardiopathy. While our study contributes to the limited literature on the subject, larger-scale and more comprehensive studies are needed to obtain definitive results.