Unraveling Impact of Hemoglobin F and A2 Levels: Correlation With Disease Severity and Treatment Response in Transfusion-Dependent Beta-Thalassemia.

Abstract

Fetal hemoglobin (HbF) has been reported to be associated with disease severity and treatment response to HbF-inducing therapies like Hydroxyurea and thalidomide in patients suffering from transfusion-dependent beta-thalassemia (TDT). However, the role of hemoglobin A2 (HbA2) remains less clear in TDT, therefore this study aims to determine the impact of both HbF and HbA2 levels on disease severity and treatment response. A prospective observational study was conducted at the Peshawar Institute of Medical Sciences and Fatimid Foundation Peshawar from May 2023 to October 2023. A total of 232 TDT-diagnosed patients were enrolled using a convenient sampling technique, whereas coinheritance of beta-thalassemia with other hemoglobinopathies was excluded. This study reveals a significant impact of HbF on disease severity (p<0.05) but finds no substantial correlation (p>0.05) between HbA2 levels and disease severity. Additionally, HbF and HbA2 levels exhibit no association with treatment response categories in patients receiving HbF induction therapy, and various mutations do not significantly alter HbF and HbA2 levels or disease severity parameters in TDT patients. The study established a significant association between HbF and disease severity. However, regarding treatment response, neither HbF nor HbA2 levels impact response categories. Combinatorial treatment with hydroxyurea and thalidomide showed superior efficacy compared to monotherapy. A larger sample size and extended follow-up are recommended to further explore the impact of HbF, HbA2, and various mutations on disease severity and treatment response.