Hydroxyurea increases hemoglobin F levels and improves the effectiveness of erythropoiesis in β-thalassemia/hemoglobin E disease

Abstract

Hydroxyurea (HU) is one of several agents that have been shown to enhance hemoglobin (Hb) F levels in patients with sickle cell disease and may be useful as e therapy for β-globinopathies. However, limited information exists on the effects of HU in patients with thalassemia. Accordingly, we examined the hematologic effects of orally administered HU in 13 patients with β-thalassemia/Hb E, including four patients who had been splenectomized. These patients were treated with escalating doses (final range, 10 to 20 mg/kg/d) for 5 months and were observed in the outpatient hematology clinic every 2 to 4 weeks. Complete blood counts including reticulocyte counts, amounts of Hb E and Hb F, (G)γ:(A)γ and α:non-α globin biosynthetic ratios were evaluated before and during treatment. Almost all patients responded with an average increase of 33% in Hb F levels, from a mean (±SD) of 42% ± 11% to 66% ± 8% (P < .0001), and a reciprocal decline in the percentage of Hb E from 59% ± 9% to 49% ± 8% (P < .001). Reticulocytosis was decreased from a mean (±SD) of 18.0% ± 15.6% to 11.7% ± 9.1% (P