Cross-matching assays of cell-mediated immunity for transplant patients

Assays of cell-mediated immunity before transplantation were performed on 34 patients who were defined as being at high risk by the presence of preformed lymphocytotoxic antibodies and/or HL-A incompatibilities at FOUR locus. Assays for cell-mediated lympholysis type I (cml I) were performed in donor serum, and for CML II in recipient serum, to assess the possible effect of blocking factors in the patients' sera. A positive (greater than 5% specific Cr release) and in particular a greater than 10% Cr release correlated strongly with graft rejection. The correlation between CML II and graft survival was unimpressive. No clinically beneficial blocking factor was demonstrable in the patients's sera in that 5 of 6 patients with a positive CML I but a negative CML II rejected their grafts. Conversely, 6 of 8 patients with a positive CML II and a negative CML I had excellent long-term courses. The use of CML I assay in the selection of grafts for patients at high risk is recommended.