title: Clinical and hematological effects of hydroxyurea therapy in sickle cell patients: a single-center experience in Brazil.
abstract: CONTEXT AND OBJECTIVES 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. DESIGN AND SETTING Retrospective study conducted at a sickle cell centre in Ribeirão Preto, São Paulo, Brazil. METHODS 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. RESULTS 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). CONCLUSION 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.
authors.affiliation: Centro Regional de Hemoterapia de Ribeirão Preto, Department of Internal Medicine, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil.
authors.forename: Ana Cristina
authors.initials: AC
authors.lastname: Silva-Pinto
authors.forename: Ivan Lucena
authors.initials: IL
authors.lastname: Angulo
authors.forename: Denise Menezes
authors.initials: DM
authors.lastname: Brunetta
authors.forename: Fabia Idalina Rodrigues
authors.initials: FI
authors.lastname: Neves
authors.forename: Sarah Cristina
authors.initials: SC
authors.lastname: Bassi
authors.forename: Gil Cunha De
authors.initials: GC
authors.lastname: Santis
authors.forename: Dimas Tadeu
authors.initials: DT
authors.lastname: Covas
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D000755:Anemia, Sickle Cell / Q000097:blood / Q000188:drug therapy*; D000986:Antisickling Agents / Q000494:pharmacology / Q000627:therapeutic use*; D001803:Blood Transfusion; D001938:Brazil; D002648:Child; D004909:Erythrocyte Indices / Q000187:drug effects; D005260:Female; D005319:Fetal Hemoglobin / Q000187:drug effects; D006451:Hemoglobin, Sickle / Q000187:drug effects; D006801:Humans; D006918:Hydroxyurea / Q000494:pharmacology / Q000627:therapeutic use*; D008297:Male; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000986:Antisickling Agents; D006451:Hemoglobin, Sickle; D005319:Fetal Hemoglobin; D006918:Hydroxyurea