Control of organ transplant-associated graft-versus-host disease by activated host lymphocyte infusions

Background. Prolonged persistence of donor-derived T cells after organ transplantation has been proposed to improve long-term allograft survival. However, surviving transplant-derived T cells are also able to mediate devastating graft-versus-host disease (GvHD). Currently, GvHD after organ transplantation is usually refractory to conventional therapy and the disease outcome fatal. Methods. Graft-reactive host T cells were generated ex vivo from a patient suffering from a severe and refractory liver-transplant-associated GvHD. To control GvHD, activated alloreactive host T cells were repetitively retransferred into the patient (activated host lymphocyte infusion [aHLI]). Results. Adoptive transfer of ex vivo activated alloreactive host T cells (aHLI) led to the control and complete resolution of severe GvHD without inducing allograft rejection. Conclusions. aHLI opens a novel therapeutic window to control solid-organ transplant-associated GvHD while preserving allograft integrity.