Effects of hydroxyurea in a population of Brazilian patients with sickle cell anemia.
Fetal hemoglobin (HbF) inhibits the polymerization of sickle hemoglobin, modulating the clinical features of sickle cell anemia (SCA). Hydroxyurea (HU) therapy can increase the HbF level, although its production can be influenced by genetic determinants. Twenty-two Brazilian SCA patients were evaluated over 5 years before and after HU use. We analyzed (1) betaS haplotype; (2) patient characteristics; and (3) toxicity. No differences between age, sex, and HU response were observed. We found 40.9% of homozygous for Bantu haplotype, and, in contrasting to other trials, we observed HbF level increase in this group (3.84-9.08 g/dL, P=0.003). Adverse effects were rare. Labyrinthitis was observed in 2 (9.10%) patients after HU use, although this complication had not been described before.
Vicari
Perla
P
Disciplina de Hematologia e Hemoterapia, Universidade Federal de São Paulo-EPM, São Paulo, Brazil. perlavicari@hotmail.com
Barretto de Mello
Adriana
A
Figueiredo
Maria Stella
MS
D000293:Adolescent; D000328:Adult; D000755:Anemia, Sickle Cell / Q000188:drug therapy* / Q000235:genetics; D000986:Antisickling Agents / Q000627:therapeutic use*; D001938:Brazil; D005260:Female; D005319:Fetal Hemoglobin / Q000235:genetics*; D005500:Follow-Up Studies; D006239:Haplotypes; D006720:Homozygote; D006801:Humans; D006918:Hydroxyurea / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D016896:Treatment Outcome
D000986:Antisickling Agents; D005319:Fetal Hemoglobin; D006918:Hydroxyurea