Analysis of post-transplant immune status in recipients of liver/bone marrow allografts

The aims of this study were to assess the effect, of donor bone marrow infu sion on the reactivity of recipient peripheral blood lymphocytes (PBL) to m itogen and to donor and third-party cells after primary liver allotransplan tation and co identify any correlation between altered immunoreactivity and HLA mismatches, occurrence of rejection, and immunosuppression. The immuno reactivity of recipient PBL toward frozen donor splenocytes was evaluated i n mixed lymphocyte culture (MLC) (n = 29) and cell-mediated lympholysis (CM L) (n = 27) assays in rime intervals ranging from 0.7 to 27 months after tr ansplant. Overall, the mean anti-donor MLC stimulation index (SI) fell from 25.6 +/- 5.2 preoperatively to 4.8 +/- 1.7 after transplantation (p < 0.00 2), with 14 out of 29 (48.3%) patients developing donor-specific MLC hypore activity. HLA class II mismatches were significantly associated with recipi ent post-transplant immune profile (p < 0.05): MLC donor specific hyporespo nsiveness was observed in 70%, versus 37% of patients who shared a class II antigen, versus those that did not. Of the control group, 61.1% developed donor-specific nonreactivity versus 27.2% in the donor bone marrow cells (D BMC) group (p = 0.02). Donor-specific CML hyporeactivity was observed after transplantation, independent of DBMC infusion, with mean percentage values of pre- and post-transplant donor-specific lysis of 22.4% +/- 4.1% versus 3.1% +/- 1.6%, p = 0.0004, respectively. Our results suggest that DBMC infu sion favors development of nonspecific MLC hyporesponsiveness to donor and third-parry alloantigen, with maintenance of reactivity to mitogen and no a dditional effect on T-cell cytotoxicity. (C) American Society for Histocomp atibility and Immunogenetics, 1999. Published by Elsevier Science Inc.