Erthrocyte adhesion markers [CD36] in pediatric sickle cell anemia: relation to clinical syndrome, HbF and hydroxyurea therapy

ABSTRACT

To investigate the possible role of erythrocyte adhesion marker [CD36] in modulating adhesion of sickle erythrocytes to vascular endothelium, 28 children with homozygous sickle cell anemia [SS disease] were studied using this physiologically crucial period to evaluate the relationships between a major erythrocyte adhesion marker [CD36] and HbF. CD36+ erythrocytes were assessed using the flow cytometry and expressed as% of positive cells. The mean level of CD36+ erythrocytes was 1.67% +/- 0.55% with an inverse relationship between CD36 positivity and HbF. In univariate analysis, significant correlations with various hematologic parameters and CD36 positivity were noted. Hydroxyurea therapy lowered CD36 positivity even before the peak level of HbF, it also improved all hematologic parameters. There was a strong positive correlation between CD36 positivity and the increased duration of HU therapy; this could be a from of tolerance to the drug over-time. Patients with painful crisis had lower% of CD36+ erythrocytes than stable patients but still statistically significantly higher than the controls. CD36% was strongly positively correlated to the reticulocyte count, being two faces of the same coin, implicated in the process of vasoocclusion. More therapeutic modalities are needed that tackle more effectively the primepathogenetic mechanisms of vasoocclusion; namely, adhesion molecules