Hematologic Effects of Hydroxyurea Treatment in Children with Hb SC and SB+ Thalassemia

Background: The effects of hydroxyurea in clinically severe hemoglobin SC (Hb SC) and hemoglobin Sβ+ thalassemia patients (Hb Sβ+) are not well defined. The largest previous report reviewed 15 children with Hb SC treated with hydroxyurea (Yates, et al: Pediatr Blood Cancer 2013;60: 323-325). Prior studies describe a mixed hematologic pattern of response, but all pediatric reports show an increase in fetal hemoglobin and MCV in Hb SC. To further evaluate the hematologic effect of hydroxyurea in these compound heterozygous conditions, we reviewed 27 patients with Hb SC and 7 with Hb Sβ+ treated to date at our institution