Evaluation of In-111 labeled lymphocytes in an acute rejection model.

Four days after surgery, canine renal allografts were studied with 290-500 microCi of In-111/10(8) lymphocytes. All transplants were visualized, implying that it may not be necessary to harvest large numbers of lymphocytes from immunosuppressed patients. On the day of renal transplant, a second set of dogs were injected with 80-150 microCi of In-111/10(8) lymphocytes. No delayed visualization could be seen 2-4 days later when rejection commenced. Cellular damage, even at this lower level of labeling, may require injection of labeled lymphocytes after the onset of the rejection process in order to visualize the rejection organ.