Clinical and hematological responses to hydroxyurea in sicilian patients with Hb S/β-thalassemia

Although, several reports have detailed that hydroxyurea can ameliorate the clinical course of adult and pediatric patients with sickle cell anemia (Hb S or betaS), few clinical studies have been carried out in patients with beta (S)/beta -thalassemia. In a two-year clinical study, we evaluated the efficacy of hydroxyurea in a group of 22 adult Sicilian patients with beta (S)/beta -thaiassemia with severe phenotypes. Among the 20 patients evaluated during 2 years of treatment, we observed a very good clinical response with a 93% reduction of the annual number of crises (median 7 versus 0.5 crises per year; P < 0.001) and of days in hospital (mean 22 +/- 21.9 versus 1.2 +/-2.3; P < 0.001), a significant increase in Hb F (7.5 +/-5.3% versus 25.2 +/-5.2%; P < 0.001) and in MCV (73.1 +/-4.8 f L versus 96.4 +/-7.2 f L; P < 0.001), and no significant modifications in Hb (9.6 +/-1.3 g/dL versus 10.0 +/-1.5 g/dL; P > 0.05) and in WBC (11.4 +/-3.9 x 10(9)/L versus 10.2 +/-3.9 x 10(9)/L; P > 0.05). Twelve patients had no crises from the first month of treatment; 16 patients showed a 2-3-fold increase over baseline in Hb F During the study no severe complications and no important side effects of hydroxyurea were observed. Our data suggest that hydroxyurea efficacy in patients with beta (S)/beta -thalassemial may be greater than that described in patients with sickle cell disease. This pattern and durability of response will need to be confirmed ill a larger, randomized, clinical trial.