Induction of fetal hemoglobin synthesis in children with sickle cell anemia on low-dose oral sodium phenylbutyrate therapy.

This study was designed to determine if low doses of oral sodium phenylbutyrate (SPB) induce hemoglobin F (HbF) synthesis in children with hemoglobin SS (HbSS). We treated 8 children with HbSS over a period of 5-30 weeks. The initial dose (1.0 g/d) was increased weekly (by 1.0 g/d) until F-reticulocytes doubled. All patients showed an increase in F-reticulocytes (P = 0.002) that was dose-dependent (P = 0.001). Three of 5 patients who continued oral SPB for more than 10 weeks had substantial increases in HbF. We conclude that lower dose SPB is effective in inducing HbF synthesis in some children with HbSS. Further trials are warranted to determine the optimal treatment regimen.