Clinical and hematological effects of hydroxyurea therapy in sickle cell patients: a single-center experience in Brazil

Efeitos clínicos e hematológicos do tratamento com hidroxiureia em pacientes falciformes: experiência de um centro no Brasil

Ana Cristina Silva-Pinto Ivan Lucena Angulo Denise Menezes Brunetta Fabia Idalina Rodrigues Neves Sarah Cristina Bassi Gil Cunha De Santis Dimas Tadeu Covas About the authors


Sickle cell disease (SCD) is the most common genetic disorder among people of African descent, affecting approximately 3,500 newborns each year in Brazil. Hydroxyurea (HU) is the only effective drug to treating patients with SCD, thereby reducing morbidity and mortality. The objective was to analyze the effects of HU on SCD patients at our institution.


Retrospective study conducted at a sickle cell centre in Ribeirão Preto, São Paulo, Brazil.


We analyzed clinical and laboratory data on 37 patients. The hematological parameters and clinical events that occurred during the year before and the first year of treatment with HU were analyzed. The mean dose of HU was 24.5 ± 5.5 mg/kg/day.


There were rises in three parameters: hemoglobin (8.3 g/dl to 9.0 g/dl, P = 0.0003), fetal hemoglobin (HbF) (2.6% to 19.8%, P < 0.0001) and mean cell volume MCV (89 to 105 fl, P = 0.001); and reductions in the numbers of leukocytes (10,050/µl to 5,700/µl, P < 0.0001), neutrophils (6,200/µl to 3,400/µl, P = 0.001), platelets (459,000/µl to 373,000/µl, P = 0.0002), painful crises (1.86 to 0.81, P = 0.0014), acute chest syndromes (0.35 to 0.08, P = 0.0045), infections (1.03 to 0.5, P = 0.047), hospitalizations (1.63 to 0.53, P = 0.0013) and transfusions (1.23 to 0.1, P = 0.0051).


The patients presented clinical and hematological improvements, with an increase in HbF and a reduction in the infection rate, which had not been addressed in most previous studies.

Anemia, sickle cell; Hydroxyurea; Fetal hemoglobin; Acute chest syndrome; Erythrocyte indices

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