The assessment of histocompatibility by mixed lymphocyte reaction as measured by the macrophage electrophoretic mobility (MEM) test.

The mixed lymphocyte reaction (MLR) between donor and recipient lymphocytes has been measured by the macrophage electrophoretic mobility (MEM) test and the modified (MOD-MEM) test. Its value as a measure of compatibility has been assessed by comparison with conventional HL-A serotyping and with the outcome of renal transplantation. Thirty-six living donor/recipient pairs and 59 cadaver donor/recipient pairs for transplantation have been studied. Whilst uniovular twins gave lymphocyte interactions, measured as macrophage slowings of about 1%, the slowing produced by paired allogeneic lymphocytes ranged from 2% to 26% depending on the number of HL-A matches. The test measurement of lymphocytic interaction was significantly correlated with histocompatibility measured by HL-A serotyping, in both living and cadaver donors. One way MEM-MLR showed the dominant role of the second HL-A sublocus in mixed lymphocyte reactivity. The long term success of the renal graft correlated with the pre-transplant initial reaction between donor and recipient lymphocytes. The test has advantages in the field of human histocompatibility assessment since no particular reference to individual antigens is made and it may be performed in a matter of hours.