Relationship of donor-specific mixed lymphocyte culture reactivity to graft function in recipients of cadaveric renal allografts.

The response of twelve cadaveric renal allograft recipients was serially studied in one-way MLC using the specific donor spleen lymphocytes as stimulating cells. The stimulation index (SI) progressively decreased between the second and the eighteenth post-transplantation week in the presence of normal plasma. The appearance of MLC non-reactivity (SI of less than 2.3) correlated well with the achievement of excellent graft function. In nine recipients allograft rejections have not occurred once the non-reactive state in cultures with normal plasma was established. In two of the recipients reactivity reappeared after an interval of non-reactive phase. In both instances rejection followed such reactivity and non-reactivity followed successful management of rejection. In one patient severe irreversible allograft rejection occurred in spite of the appearance of an early MLC non-reactive phase. This patient developed donor-specific lymphocytotoxic antibodies and his rejection was perhaps of antibody mediated type. Donor-specific MLC reactivity may represent cellular immune response of host to an allograft and predict cellular allograft rejection.