title: Hydroxyurea lowers transcranial Doppler flow velocities in children with sickle cell anaemia in a Nigerian cohort.
abstract: BACKGROUND
  Sickle cell anaemia (SCA) is the leading genetic disorder in Nigeria. Elevated velocities ≥170 cm/sec occur in about a third of Nigerian children with SCA. Chronic blood transfusion for stroke prevention is faced with a myriad of challenges in our practice.
  
  
  OBJECTIVE
  To evaluate the effectiveness of hydroxyurea (HU) in reducing flow velocities in a cohort of Nigerian children with SCA and elevated velocities treated with HU.
  
  
  METHODS
  An observational study was carried out on a cohort of Nigerian children with SCA and elevated velocities identified on routine transcranial Doppler (TCD) screening. HU was recommended in those with TCD velocities ≥ 170cm/sec as stipulated in our hospital protocol. Outcomes were compared after ≥12 months of observation.
  
  
  RESULTS
  Fifty children with elevated TCD velocities were studied; 31 consented to HU therapy and 19 declined. Children on HU showed a statistically significant decline in mean velocities from 199.7 [17.1] cm/sec to 165.8 [20.7] cm/sec (P < 0.001) with a significant increase in mean packed cell volume from 21.1 [3.4] to 25.0 [2.8]%. Children without treatment had a significant rise in mean velocities from 190.2 [10.8] cm/sec to 199.7 [14.9] cm/sec (P = 0.003). Children with conditional risk velocities on HU were less likely to convert to abnormal risk (P < 0.001). Two stroke events occurred, one in each group. No adverse effects of HU were recorded in the cohort.
  
  
  CONCLUSIONS
  HU appears to significantly reduce TCD velocities in Nigerian children with SCA and elevated velocities ≥170 cm/sec with beneficial effect on the haematological profile. HU may provide an effective approach to primary stroke prevention, particularly in Africa.
authors.affiliation: Department of Paediatrics, College of Medicine, University of Ibadan, Ibadan, Nigeria.|Department of Paediatrics, University College Hospital, Ibadan, Nigeria.
authors.forename: IkeOluwa
authors.initials: I
authors.lastname: Lagunju
authors.affiliation: Department of Paediatrics, College of Medicine, University of Ibadan, Ibadan, Nigeria.|Department of Paediatrics, University College Hospital, Ibadan, Nigeria.
authors.forename: Biobele J
authors.initials: BJ
authors.lastname: Brown
authors.affiliation: Department of Paediatrics, College of Medicine, University of Ibadan, Ibadan, Nigeria.|Department of Paediatrics, University College Hospital, Ibadan, Nigeria.
authors.forename: Olugbemiro
authors.initials: O
authors.lastname: Sodeinde
mesh_terms: D000293:Adolescent; D000755:Anemia, Sickle Cell / Q000150:complications / Q000188:drug therapy / Q000503:physiopathology* / Q000628:therapy; D001772:Blood Cell Count; D001783:Blood Flow Velocity / Q000187:drug effects*; D001803:Blood Transfusion; D002536:Cerebral Arteries / Q000000981:diagnostic imaging; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006400:Hematocrit; D006801:Humans; D006918:Hydroxyurea / Q000494:pharmacology* / Q000627:therapeutic use; D008297:Male; D009549:Nigeria; D018570:Risk Assessment; D020521:Stroke / Q000209:etiology / Q000517:prevention & control; D016312:Treatment Refusal; D017585:Ultrasonography, Doppler, Transcranial
chemical_list: D006918:Hydroxyurea
keywords: TCD velocities; anaemia; hydroxyurea; sickle cell