Response to hydroxyurea in β thalassemia major and intermedia: Experience in western India

Background: The clinical and hematological response to hydroxyurea was evaluated in beta thalassemia patients in western India with variable clinical severity and correlated with genetic factors. Materials and methods: Seventy-nine patients-[38-beta thalassemia intermedia-(group I), 41-beta thalassemia major-(group II)] on hydroxyurea therapy were followed-up for 20-24 months. Results: Among the frequently transfused patients in group I, 58% became transfusion independent and 16% showed a 50% reduction in transfusions after therapy which correlated with a higher mean fold increase in HbF and gamma mRNA expression levels. Forty-one percent of patients in group I had associated alpha-thalassemia and 72.7% were XmnI (+/+). beta thalassemia chromosomes among the responders of group I (41%) were linked to haplotype (- + + - + + - - +) as against haplotype ( + - - - - - - - + ) being more common among the non-responders. Response was not linked to the beta thalassemia mutations. Thirty-two percent of group II patients showed a 50% reduction in their transfusion requirements after therapy which also correlated with a higher mean fold increase in HbF and gamma mRNA expression levels. A significant decrease in serum ferritin was seen in both groups. 19% of patients could not tolerate the drug. Conclusions: In group I, clinical response to hydroxyurea was better in patients with alpha-thalassemia, XmnI (+/+) and a higher mean fold increase in gamma mRNA expression. In group II, only one-third of patients showed a partial response. (c) 2009 Elsevier B.V. All rights reserved.