Evaluation of Serum Angiopoietin-2 in Children and Adolescents with Sickle Cell Disease: Relation to Sickle Vasculopathy and Carotid Intima Media Thickness

Abstract

SUMMARY S ickle cell disease (SCD) is one of the most common severe monogenic disorders in the world. Hemoglobin polymerisation, leading to erythrocyte rigidity and vaso-occlusion, is central to the pathophysiology of this disease, although the importance of chronic anemia, hemolysis, and vasculopathy has been established. SCD patients may experience a variety of clinical complications attributed to anemia, hemolysis, and iron overload. Angiopoietin-2 (Ang-2) is expressed primarily in the vascular endothelium at sites of vascular remodeling. It acts by binding to the endothelium-specific receptor tyrosine kinase 2 (Tie-2). The Ang/Tie system tightly controls the endothelial phenotype during angiogenesis and vascular inflammation. Hypoxia-induced angiogenesis may play an important role in the pathophysiology of SCD patients. Therefore, we determined the levels of ang-2 in young SCD patients and assessed its relation to markers of hemolysis, iron overload and vascular complications including retinopathy as well as carotid intima media thickness (CIMT). This study included 40 SCD patients (16 males and 24 females) recruited from the regular attendants of the Pediatric Hematology Clinic, Pediatric Hospital, Ain Shams University.