Human endothelial cell antigens: molecular independence from HLA and expression in blood monocytes

Human alloantisera identified antigens in endothelial cells from umbilical cord veins that were not detectable in peripheral blood lymphocytes. Results of antigen redistribution experiments by the resistance to lysis induction method suggested that E-antigens were present in separate molecules of the endothelial cell surface. Monocytes from peripheral blood reacted like endothelial cells in cytotoxicity tests and were able to absorb the endothelial cytotoxic antibodies. Comparison of concordant and discordant monocyte reactions in first-degree relatives indicated that the antigens involved were inherited in linkage with HLA.