ISSN 2997-1036
International Journal of Hematology | Vol. 14, No. 10, October 2023 | pp. 73–80
DOI: 10.46882/2023/IJH/000164
Original Article
Title: Impact of systemic hydroxyurea on plasma soluble thrombomodulin levels and microvascular velocity tracking in adult sickle cell anemia
Names of Authors: S. T. Adeyemi¹, U. V. Okoye², W. X. Salami³
Authors’ Affiliations: ¹Department of Haematology and Blood Transfusion, Obafemi Awolowo University, Ile-Ife, Nigeria; ²Department of Medicine, University of Nigeria Teaching Hospital, Enugu, Nigeria; ³Department of Paediatrics, Ahmadu Bello University, Zaria, Nigeria
Abstract: Continuous endothelial cell desquamation and low nitric oxide states fuel widespread microvascular shearing and high pulmonary pressures in sickle cell anemia. This prospective cohort study evaluated the long-term impact of optimized hydroxyurea therapy on plasma soluble thrombomodulin (sTM) levels, an index of direct endothelial injury, and tricuspid regurgitant jet velocity (TRJV) shifts in 50 adult patients presenting with steady-state sickle cell anemia (HbSS). Hydroxyurea was administered at maximum tolerated doses (15 to 25 mg/kg/day) and monitored over 12 months. Plasma markers were quantified via an enzyme-linked immunosorbent assay, and velocities were tracked using Doppler echocardiography. Baseline mean soluble thrombomodulin levels fell significantly from 14.2 ± 3.8 ng/ml to 6.2 ± 1.1 ng/ml at month 12 (P < 0.001). Concurrently, the proportion of patients presenting with high-risk velocity metrics (TRJV ≥ 2.5 m/s) fell from 36.0% to 14.0%. Thrombomodulin suppression correlated strongly with an increase in fetal hemoglobin from 5.2% to 15.6% and a drop in serum lactate dehydrogenase. These findings confirm that hydroxyurea successfully preserves endothelial integrity, limiting vascular damage and progressive cardiopulmonary remodeling in adult sickle cell variants.
Keywords: Sickle cell anemia, hydroxyurea, thrombomodulin, endothelial injury, tricuspid regurgitant jet velocity
Manuscript Timeline: Received: July 12, 2023; Revised: August 20, 2023; Accepted: September 10, 2023; Published: October 14, 2023