ISSN 2997-1036
International Journal of Hematology | Vol. 17, No. 4, April 2026 | pp. 25–32
DOI: 10.46882/2026/IJH/000194
Original Article
Title: Impact of systemic hydroxyurea on plasma soluble intercellular adhesion molecule-1 levels and macrovascular velocity tracking in adult sickle cell anemia variations
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, Ahmavu Bello University, Zaria, Nigeria
Abstract: Severe endothelial activation and cell-to-wall adherence drive microvascular blockades and chronic pulmonary hypertension in sickle cell anemia. This prospective cohort study evaluated the long-term impact of optimized hydroxyurea therapy on plasma soluble intercellular adhesion molecule-1 (sICAM-1) concentrations and tricuspid regurgitant jet velocity (TRJV) modifications in 50 adult patients with steady-state sickle cell anemia variants (HbSS). Hydroxyurea was administered at maximum tolerated doses (15 to 25 mg/kg/day) over 12 months. Plasma markers were quantified using an enzyme-linked immunosorbent assay, and tricuspid velocities were tracked via Doppler echocardiography. Baseline mean sICAM-1 levels fell significantly from 344.2 ± 42.0 ng/ml to 168.4 ± 22.0 ng/ml at month 12 (P < 0.001). Concurrently, the proportion of patients presenting with elevated velocity metrics (TRJV ≥ 2.5 m/s) fell from 34.0% to 12.0%, reflecting a reduction in pulmonary vascular resistance. Adhesion molecule suppression correlated positively with an increase in fetal hemoglobin from 5.2% to 16.4%. These findings confirm that hydroxyurea successfully dampens endothelial cell activation, providing an accessible pharmacological pathway for preventing progressive macrovascular remodeling in adult sickle cell variants.
Keywords: Sickle cell anemia, hydroxyurea, ICAM-1, endothelial activation, tricuspid regurgitant jet velocity
Manuscript Timeline: Received: January 10, 2026; Revised: February 18, 2026; Accepted: March 10, 2026; Published: April 14, 2026