Plasma VWF levels in children with SCD treated with hydroxycarbamide compared to blood transfusion. Comparisons between children with SCD treated with HC or BT are shown for plasma levels of (A) VWF:Ag, (B) VWF:CB, and (C) VWFpp. (D) VWF:Ag levels are shown comparing group O and non-O blood groups. Dotted red lines denote the upper and lower limit of the local reference range, with green shaded area falling within normal limits. Data are presented as median and the IQR. Comparisons between groups were assessed by the Mann-Whitney U test. Correlations between plasma VWF:Ag levels and (E) Hb and (F) LDH are shown. Correlations were evaluated using the Spearman rank correlation test; ∗∗P < .01, ∗∗∗P < .001, and ∗∗∗∗P < .0001.