Eight groups of human endothelial cell alloantigens.

Human endothelial cells were shown to express a new system of alloantigens. Using 63 selected sera eight specificities could be defined. Each group was characterized using two to seven sera which had high correlation coefficients among them. The distribution of the phenotypes among 30 cells gave the appearance of an allelic system. Only one cell with a triplet was observed. Approximately half of the possible genes were detected with sera defining these eight groups.