Interaction between endothelial cells and thalassemic red cells in vitro.

Erythrocytes from 45 patients with thalassemia and/or hemoglobinopathies were studied for their cytoadherence property to the vascular endothelial cells in vitro. In plasma free medium, erythrocytes from patients with beta-thal/Hb E both splenectomized and nonsplenectomized, HbH diseases (alpha-thal 1/alpha-thal 2 and alpha-thal 1/Hb Constant Spring genotypes) and homozygous Hb E subjects bind to endothelial cells at a greater number as compared to the binding cell number of normal erythrocytes (p-value < 0.05 in all types). Addition of autologous platelet-rich plasma or whole blood to the culture system causes further increase in the number of adhering beta-thalassemia red cells. Platelet-rich plasma had more enhancement effect than the whole blood. However, no such enhancement of both platelet-rich plasma and whole blood was demonstrated in the culture of normal or alpha-thalassemia erythrocytes. Increased binding between red cells and endothelial cells may contribute to the greater risk of vascular occlusion in thalassemic patients.