High plasma levels of the endothelial marker E-selectin were found to be associated with retinopathy in sickle cell disease (SCD), according to a study in the European Journal of Haematology.

The endothelium plays a significant role in vascular homeostasis; in SCD, the vascular endothelium is severely disrupted and is associated with a converging cascade of pathophysiological processes of valvular complications.

“Circulating endothelial cells (CEC) detached from injured vessels and extracellular vesicles (EVs) released from activated or apoptotic endothelial cells constitute a hallmark of these deleterious responses affecting the vessel wall,” the authors wrote. 

They investigated plasma levels of CECs, E-selectin, progenitor endothelial cells (EPC), and circulating extracellular vesicles (EVs) in 50 patients with SCD and 16 individuals who had vasculopathy. The aim of this study was to identify any relationship between these markers and microvascular complications such as retinopathy, nephropathy, and chronic affective ulcers. 

Read more about SCD etiology 

The study recruitment took over 12 months and researchers only recruited patients with SCD who were at least 18 years of age and were in a steady state. Participants were considered to be in a steady state if they did not undergo red blood cell transfusion or red cell therapy in the last 12 months. They must also be free from any vaso-occlusive crises, acute chest syndrome, or other SCD-related complications 4 weeks prior to the study. 

The researchers collected blood samples twice from the participants at 2-week intervals. Aside from measuring normal biological results of the blood test, researchers specifically investigated endothelial injury and repair biomarkers: CEC, EVs, and EPC. They found that higher levels of E-selectin were reported in diabetic patients with proliferative retinopathy. 

“Our study provides evidence that circulating E-Selectin is associated with sickle cell retinopathy,” the authors concluded. “These interesting results need further studies in large cohorts of SCD patients.”


Agouti I, Masson E, Loundou A, et al. Plasma levels of E-selectin are associated with retinopathy in sickle cell diseaseEur J Haematol. 2022;10.1111/ejh.13902. doi:10.1111/ejh.13902