No abstract

Using a simple fingerstick-whole blood technique, we demonstrated that patients with disseminated neuroblastoma have diminished lymphocyte responses to phytohemagglutinin (PHA) and that their sensitivity to antilymphocyte serum inhibition of PHA responses was increased over that of tumor-free controls. These altered immunologic reactivities led us to question the chronologic sequence between the occurrence of the tumor and the lymphocyte defect. Tumor-bearing patients had serum substances that exerted an inhibitory effect on the transformation responses of lymphocytes from unrelated normal individuals; these substances may be present in sera for long periods after the tumor is eliminated.

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The technical details of a new procedure for the simultaneous transplantation of the spleen and the heart in rats are described. One hundred sixty-four such twin grafts from LEW to ACI rats and vice versa were performed. Seventeen animals were followed postoperatively without additional immunologic manipulations. There is a definite change in rejection pattern in terms of timing as well as intensity when heart and spleen twin grafts are compared with single cardiac grafts. A delay and mild form of rejection of twin grafts were observed especially in the strain combination of LEW to ACI. No graft-versus-host reaction occurred. There was no perfect correlation of the cardiac and splenic allografts in regard to their survival time. When the cardiac allograft arrested, however, the spleen was found to be rejected as well in all cases. In three cases a selective survival of the heart over the spleen was observed. Thus, the cardiac allograft can be used as a simple but not completely reliable indicator of the functional state of both grafts.

Heart and spleen twin grafts from LEW to ACI rats may survive permanently, whereas those grafted from ACI to LEW rats do not. This strain difference in graft acceptance was analyzed quantitatively by transplanting one to three ACI spleens into LEW rats in order to compensate for the relatively small size of ACI spleens (Fig. 1). Under these conditions permanent graft survival was not observed in LEW recipients. However, during host splenectomy 3 days after transplantation, a nonimmunological factor was observed. The transplanted ACI spleens showed congestion and infarctions, while in the LEW to ACI transplant model the LEW spleens did not. This observation could be explained by the size of the vascular pedicle in ACI spleens. Although no problem was encountered immediately after completing the anastomoses, allogeneic spleens react by increasing in size, to such an extent that their size exceeds the capacity of the smaller vascular pedicle in ACI rats and results in congestion. Hence, the concept is formulated that early compromise of hemodynamics on a nonimmunological base may determine the fate of ACI spleen graft before immunological factors have a chance to become effective.