Cerebral artery conditional blood velocity in sickle cell disease: a multicentre study and evidence for active treatment.

OBJECTIVE: To obtain multicentre data on the prevalence of normal, high or conditional (intermediate) blood velocity in the cerebral arteries among children with sickle cell disease (SCD) in Nigeria. DESIGN: A prospective observational study in five tertiary healthcare institutions. By transcranial Doppler (TCD) ultrasonography, cerebral artery peak systolic blood velocity (PSV) was determined in 193 children with SCD and time averaged mean of the maximum blood velocity (TAMMV) in a different cohort of 115 children. This design was to make the findings relevant to hospitals with TCD equipment that measure either PSV or TAMMV. SETTING: Nigeria. PARTICIPANTS: 308 children (126 girls, 182 boys; age 2-16 years). MAIN OUTCOME MEASURES: Percentage of children with SCD who have normal, high or intermediate (often termed conditional) PSV or TAMMV. RESULTS: In the cohort of 193 children, PSV was normal in 150 (77.7%), high in 7 (3.6%) and conditional in 36 (18.7%). In the cohort of 115 children, TAMMV was normal in 96 (84%), high in 7 (6%) and conditional in 12 (10%). There were no significant differences in gender or age distribution between the PSV and TAMMV cohorts. Altogether, cerebral artery blood velocity was normal in 246/308 children (80%), high in 14 (4.5%) and conditional in 48 (15.5%). CONCLUSION: Since conditional blood velocity in cerebral arteries can progress to high values and predispose to stroke, the proportion of children with SCD who are affected (15.5%) raises the question of whether regular monitoring and proactive intervention ought to be the standard of care.

Plasma concentration of fucosyltransferase 7 is not associated with the number of clinically overt vaso-occlusive events in sickle cell disease.

Objective: To determine if the number of vaso-occlusive events in SCD relates to plasma concentration of fucosyltransferase 7 (FUT7), which catalyses the synthesis of selectin ligands. Design: A prospective, analytical study. Setting: Haematology and Chemical Pathology Departments of tertiary healthcare centres. Participants: Steady state HbSS individuals aged 13-45 years, 20 had 3 or more vaso-occlusive crises that required hospital admission in the previous year (with or without complications of SCD); 17 other HbSS persons had 0-1 vaso-occlusive crisis that required hospital admission in the previous year and no disease complications. Intervention: Steady-state plasma concentrations of FUT7 measured by ELISA were compared between SCD patients who had one vaso-occlusive crisis requiring hospital treatment in the previous year but no disease complications and those who had >3 crises with or without complications. Main Outcome Measures: Plasma level of FUT7and the number of vaso-occlusive events in each HbSS patient. Results: Mean + standard deviation plasma concentration of FUT7 was 8.6 + 2.7 ng/ml in patients with >3 vasoocclusive crises in the previous year and 7.3 + 1.7 ng/ml in those with 0-1 crisis and no complications; independent sample t-test, p > 0.05, not significantly different. Conclusion: Plasma concentration of fucosyltransferase7 is not associated with the number of vaso-occlusive events in sickle cell disease. Funding: None declared.