Renal subcapsular islet cell transplantation

This study was directed towards improving islet cell allotransplantation (ICTx) by testing the renal subcapsular region (RSC) as an alternative site for graft placement. In addition, a simplified, non-collagenase method was assessed for preparation of the allograft from the donor pancreas. Five groups of pancreatectomized mongrel dogs were followed. Group I (n = 10) were not transplanted and survived 5.0 +/- 2.92 days (M +/- SD). Five of six animals in Group II (n = 6) which received an ICTx prepared without collagenase in the RSC survived until allograft removal by nephrectomy at greater than 90 days (P less than .0005). No immunosuppression was given to this group. Recipients in Group III (n = 11) were transplanted as in Group II, but were given minimal immunosuppression with azathioprine. They also demonstrated excellent graft function until removal of the graft by nephrectomy at between 3 weeks and greater than 90 days. Animals in Group IV (n = 6) received an intrasplenic (IS) ICTx prepared without collagenase and survived only 4.16 +/- 1.16 days. In Group V (n = 6) poor survival was also noted (7.66 +/- 4.58 days) after IS-ICTx of a collagenase prepared allograft. All animals in Group IV and V received minimal immunosuppression as in Group III. These results indicate the potential for utilization of the RSC as an alternative site for ICTx. In addition, the collagenase-free method was satisfactory for ICTx preparation.