title: Genotype-phenotype relationship of patients with β-thalassemia taking hydroxyurea: a 13-year experience in Iran.
abstract: We evaluated the clinical responses to hydroxyurea (HU), adverse effects, and β-globin gene variants in a large series of β-thalassemic patients over a 13-year period in Iran. The patients (n = 232) were divided into two groups: transfusion-dependent β-thalassemia patients 2 years of age and older (n = 126; Group 1), and β-thalassemia intermedia (βTI) patients without any history of blood transfusion or with a long-interval transfusion (n = 106; Group 2). In Group 1, 86 patients became transfusion-free, and 25 patients needed 1-2 transfusions per year at the end of study. All except three patients in Group 2 were completely transfusion free with a significant increase in Hb level after 1 year compared to the baseline Hb value (P < 0.0001). We did not find a significant correlation of response to HU with XmnI polymorphism or IVS II-I (G > A) mutation (P > 0.05). In our study, HU at a dose of 8-15 mg/kg/day was effective in decreasing or effecting cessation of the need for regular blood transfusion, as well as in increasing Hb levels in β-thalassemia patients, without any major side effects. Hydroxyurea may thus represent a safe alternative to blood transfusion in transfusion-dependent β-thalassemia patients, or help to increase Hb level in untransfused βTI patients.
authors.affiliation: Hematology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran. Karimim@sums.ac.ir
authors.forename: Mehran
authors.initials: M
authors.lastname: Karimi
authors.forename: Sezaneh
authors.initials: S
authors.lastname: Haghpanah
authors.forename: Ali
authors.initials: A
authors.lastname: Farhadi
authors.forename: Majid
authors.initials: M
authors.lastname: Yavarian
mesh_terms: D000293:Adolescent; D000328:Adult; D000963:Antimetabolites / Q000009:adverse effects / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D004305:Dose-Response Relationship, Drug; D004351:Drug Resistance; D005260:Female; D005500:Follow-Up Studies; D056726:Genetic Association Studies; D006801:Humans; D006918:Hydroxyurea / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D007492:Iran; D008297:Male; D008875:Middle Aged; D009154:Mutation; D011110:Polymorphism, Genetic; D012189:Retrospective Studies; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific) / Q000235:genetics*; D065227:Transfusion Reaction; D055815:Young Adult; D055544:beta-Globins / Q000235:genetics*; D017086:beta-Thalassemia / Q000188:drug therapy* / Q000235:genetics* / Q000503:physiopathology / Q000628:therapy
chemical_list: D000963:Antimetabolites; D055544:beta-Globins; C101716:DNA modification methylase XmnI; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific); D006918:Hydroxyurea