Statistics from Altmetric.com
Some people with sickle cell disease experience many problems and yet others with the same genetic defect have relatively mild disease. Why should this be so? The answer may lie in the activity of the vascular endothelium.
American investigators (Anna Solovey and colleagues; New England Journal of Medicine1997;337:1584-90) have studied circulating endothelial cells (ECs) using a mouse monoclonal antibody to human ECs. They identified ECs in 14 normal subjects, 18 patients with sickle cell disease (including some children), three with sickle cell trait, and four with non-sickle cell haemolytic anaemias. Sickle cell disease patients, when well, had about five times the normal number of circulating ECs (13 v 2.6 cells/ml) but on the first day of a painful crisis the number almost doubled to 23 cells/ml. Subjects with sickle cell trait or other haemolytic anaemias had normal numbers of ECs in their blood. About two thirds of circulating ECs were thought to be viable. In sickle cell disease the ECs were mostly of microvascular origin and had surface markers of activation.
There is no certainty that the circulating ECs reflect the state of activity of those remaining in the vascular endothelium, but the strong suggestion is that endothelial activation may play an important part in the pathogenesis of sickle cell vascular crises. We can hope that such research will lead to new methods of treatment.