Fetal hemoglobin response to hydroxyurea in Yemeni sickle cell disease patients.

To assess the Hb F response to hydroxyurea (HU) in Yemeni sickle cell disease, 86 patients attending hospitals in Sana'a City, Yemen, were studied. Group I (short-term follow-up, n = 21) were treated with 500 mg/day HU for 3-6 months; group II (long-term, n = 26) were treated with 500 mg/day HU for 8-48 months; group III were untreated (n = 39). Hb F levels were monitored using cation exchange high performance liquid chromatography (HPLC).