Hematologic response to hydroxyurea therapy in children with beta-thalassemia major.

beta-thalassemia major is the most common monogenic hereditary blood disease in children. beta+-thalassemia major gene frequency in Georgia averages 0,019 (3,79% gene carriers). Hydroxyurea (HU) has been known to cause induction of fetal hemoglobin (HbF), but the efficacy of this treatment in beta-thalassemia patients is still unclear. This study was undertaken to evaluate the clinical and hematologic responses in patients with beta+-thalassemia to treatment with HU during 5 years in Georgia. Six children, aged 8 years to 13 years with transfusion-dependent beta+-thalassemia phenotype were enrolled in a trial to assess the response to HU therapy. Hemoglobin, reticulocyte count, HbF and ferritin were evaluated. The starting dose of HU was 5 mg/kg per day (5 days week) given orally once a day. Response to therapy was evaluated at 1, 2, and 5 years of treatment. Clinical improvement and rise in the HbF levels was observed in all patients. We report three cases of a remarkable response to treatment with HU in which the red cell transfusion was stopped after 1 year of treatment, and the patients became completely transfusion-free for more than 5 years. A moderate response was seen in two patients, who remained transfusion-dependent, but at longer intervals. There was no serious complication of treatment with HU. Long-term HU therapy may correct the anemia and can eliminate or minimize the transfusional needs in children with beta+-thalassemia major in cases, when the patient's baseline HbF level is > or =15% and its increase during the treatment is up to 20%.