Phenotypic variations with time of some HL-A antigens.

In order to study the HL-A antigen turnover in vivo, the HL-A reactivities of the lymphocytes of eight blood donors were tested every week for six weeks with antisera HL-A1, 2, 3, 5, 7, 8 and 11. The analysis of variance showed that the "time" effect and the "time times donors" interaction were statistically significant for the HL-2, 3, 5 and 11 specificities. This supports the hypothesis that phenotypic expression of such antigens on the lymphocyte membrane of some of the blood donors examined varied with time. From a practical point of view, the HL-A antigenic fluctuation with time should be taken into consideration when lymphocyte typing is required for tissue transplantation.