Inconsistencies between LD phenotypes and the predicted mixed lymphocyte reaction (MLR).

Abstract

This chapter discusses the inconsistencies between LD phenotypes and the predicted mixed lymphocyte reaction (MLR). It describes a study that was conducted to answer whether unrelated individuals who had been typed phenotypically identical at the major LD locus give no reactivity in the mixed lymphocyte culture (MLC) test when tested directly against each other. In the study, a sample of 120 individuals was typed for 10 LD determinants by using 22 typing cells from consanguineous marriages as stimulators in the MLC test. 24 individuals constituting eight different phenotypically-LD-identical (PLDI) groups were selected and tested directly against each other in the MLC test. For each group, appropriate LD non-identical controls were included. The common finding for all the combinations was that the reactions between PLDI individuals were always lower than those between LD non-identical individuals. The LD typing of the unrelated MLC negative individuals seemed to be identical within each group.