The Status of Procoagulant Tissue Factor-bearing Microvesicles Among Saudi Children with Sickle Cell Disease During Steady State

Abstract

Abstract: Introduction: Sickle cell disease (SCD) is a common genetic disorders characterized by episodic occlusion of the microcirculation leading to life-threating complications, including thrombosis. Coagulation activation is a prominent feature of SCD, as shown, among others, by an increased expression of tissue factor (TF). Objectives: To measure and compare the levels of plasma circulating tissue factor bearing microvesicles (TF-MVs) in Saudi children with SCD in steady state and in matched healthy control (MHCs). Method: This was a prospective observational hospital-based study in which citrated whole blood was collected from 102 SCD children homozygous for sickle hemoglobin (HbSS) (aged from 2 to 18 years-old) and 51 HMCs. TF-MVs were measured using an indirect ELISA method. Results: TF-MVs level in Saudi children with SCD is significantly elevated than in MHCs (0.82 vs 0.50 pg/ml) (P = < 0.0001).The level of TF-MVs in children below age 7 years was comparable to that in normal children.(0.76 vs 0.63 pg/ml,P 0.4). Male children with SCD showed higher levels of TF-MVs in their plasma than female children but that was not statistically significant (0.93 vs 0.77 pg/ml) (P= 0.1).There was no statistically significant correlation between the TF-MVs level and total MVs (r=0.24) (P value 0.06). Conclusion: This study demonstrated an elevated level of TF-MVs activity in Saudi children with SCD compared to the control. Children below the age of seven years in the study group had a level of TF-MVs comparable to that in the control group. Male children in the study group were observed to have higher level of TF-MVs than females