Variation of Microchimerism in Long-Term Renal Allograft Transplantation and Progression of Immune Tolerance

Chimerism, resulting from the trafficking of donor's passenger cells from the transplanted organ into the recipient's body, was postulated to be responsible for the induction of donor-immune tolerance. These cells were able to inhibit donor-specific immune reactivity in patients who had reached transplant tolerance. However, in some series of longitudinal follow-up of recently transplanted patients, the amount of microchimerism could have great variation in individuals. Even in the same patient, the level of microchimerism could wax and wane in different post- transplantation periods. The relationship between microhimerism and rejection in these recently transplanted patients was also obscured. This study therfore followed up the existence of microchimerism in patients with different elapse of time after renal transplantation. Mixed lymphocyte culture (MLC) was also performed to evaluate their donor- specific immune reactivity