Cell-mediated lympholysis in vitro. Independence of mixed lymphocyte reactions and T-cell mitogen responses from the in vitro generation of cytotoxic effectors in primary immunodeficiency diseases.

Cell-mediated lympholysis (CML) in eighteen patients suffering from primary immune deficiencies was studied. Fourteen of these patients had the variable type. Mixed lymphocyte response (MLR) and CML were clearly found to be independent: as well as two groups of patients in whom the two functions were either both normal or both deficient, two other groups were found in whom they were definitely separate. In one group MLR and T-cell mitogen responses were normal but no CML occurred against allogenic lymphocytes, and in the other cytotoxic effectors were generated normally but MLR and T-cell mitogen responses were very much lower than normal. These results show that the functions are independent, and are compatible with the theory that more than one subpopulation of T cells is involved. Neither the MLR or T-cell mitogen responses of these patients can predict their ability to generate cytotoxic effectors.