DNA released from ischemic and rejecting organs as an indicator of graft cellular damage

Donor cellular debris contains fragments of nuclei with genetic material. The question arises whether the amount of donor graft released DNA accumulating in the recipient lymphoid tissues after transplantation could be a measure of donor organ damage caused by ischemia and preservation as well as rejection. We found that donor heart passenger cells do not contribute to the DNA disseminated in the recipient. All donor DNA was, then, derived from the damaged graft cells. Immediately and 1 day after transplantation, it was present in blood (plasma and cells) to accumulate later in the spleen. Higher values of donor DNA in the syngeneic than allogeneic combination, most evident on day 7, were presumably due to better perfusion of graft not undergoing rejection. Immunosuppression attenuated donor DNA release and accumulation in recipient tissues, nevertheless, relatively high concentrations could still be detected. Further studies are in progress on the usefulness of measuring DNA concentration for evaluation of the graft damage.