Background: Sickle cell disease (SCD) is frequently referred to as a hypercoagulable state. Hydroxyurea (HU) is known to decrease the frequency of vaso-occlusive complications and need for blood transfusions in severely affected individuals.

Aims: Our aim wasto assess the effect of HU on markers of fibrinolysis (D-dimer) and endothelial activation (soluble vascular cell adhesion molecule-1 [soluble VCAM-1]) in patients with SCD in their non-crisis, “steady state.”

Methods: Patient’s ≤15 years of age, with documented HbSS or HbSβ-thalassemia, eligible for treatment with HU were studied in this prospective, observational study.

Results: Seventy-five patients with SCD were enrolled (females: 45 [60%]), with a median age of 13 years (IQR: 3). Following 6 months of HU, median values for WBC count (9.02 x 109/L vs. 7.4 x 109/L, p< 0.001), APTT (33 sec vs. 24 sec p< 0.000), D-dimer (1243.2 ng/mL vs. 802.9 ng/mL,
p< 0.000), lactate dehydrogenase (744 U/L vs. 562 U/L, p< 0.002), soluble VCAM-1 (544.9 ng/mL vs. 492 ng/mL, p< 0.003), platelet count (250 109/L vs. 196 109/L, p< 0.002), and retic count (11.7% vs. 5.4%, p< 0.000) were significantly lower than baseline values, while the mean corpuscular volume (74 fL vs. 76 fL, p< 0.000) were higher than the baseline value. No significant differences from baseline was observed in the median values for hemoglobin
(9.1 g/dL vs. 10.5 g/dL, p< 0.72) following 6 months of HU therapy.

Conclusions: In this study of children from Pakistan, we find that treatment with HU for up to 6 months resulted in decreased levels of D-dimer and VCAM-1. With the increasing evidence that coagulation activation contributes to SCD pathophysiology, the clinical benefit of HU may be due, in part, to decreased coagulation activation.

« Back to ISTH 2020 Congress

ISTH Congress Abstracts - https://abstracts.isth.org/abstract/to-evaluate-the-effect-of-hydroxyurea-on-blood-coagulation-and-endothelial-activation-in-sickle-cell-disease/