IMMUNE STATUS OF RECIPIENTS FOLLOWING BONE MARROW-AUGMENTED SOLID-ORGAN TRANSPLANTATION

It has been postulated that the resident ''passenger'' leukocytes of h ematolymphoid origin that migrate from whole organ grafts and subseque ntly establish systemic chimerism are essential for graft acceptance a nd the induction of donor-specific nonreactivity. This phenomenon was augmented by infusing 3x10(8) unmodified donor bone-marrow cells into 40 patients at the time of organ transplantation. Fifteen of the first 18 analyzable patients had sequential immunological evaluation over p ostoperative intervals of 5 to 17 months, (which included 7 kidney (tw o with islets), 7 liver (one with islets), and one heart recipient). T he evolution of changes was compared with that in 16 kidney and liver nonmarrow controls followed for 4 to 5 months. The generic immune reac tivity of peripheral blood mononuclear cells (PBMC) was determined by their proliferative responses to mitogens (PHA, ConA). Alloreactivity was measured by the recipient mixed lymphocyte reaction (MLR) to donor and HLA-mismatched third-party panel cells, Based on all 3 tests, the recipients were classified as donor-specific hyporeactive, intermedia te, and responsive; patients who were globally suppressed made up a fo urth category. Eight (53%) of the 15 marrow-treated recipients exhibit ed progressive modulation of donor-specific reactivity (3 hyporeactive and 5 intermediate) while 7 remained antidonor-responsive. In the non marrow controls, 2 (12.5%) of the 16 patients showed donor-specific hy poreactivity, 10 (62.5%) were reactive, and 4 (25%) studied during a C MV infection had global suppression of responsiveness to all stimuli.