Segmental small intestinal allografts. II. Inadequate function with cyclosporine immunosuppression: evidence of a protein-losing enteropathy.

Terminal ileum was autografted (24 dogs) or allografted (18 dogs) as a 100-cm Thiry-Vella segment, and absorption, motility, and histology were studied. Dogs with allografts were given cyclosporine (CsA) 20 mg/kg/day. At a second operation 5 to 6 weeks after transplantation continuity of the nontransplanted intestine with the Thiry-Vella segment was restored. At a third operation 3 months after autografting, all the non-transplanted small intestine was excised. All technically successful autografts survived indefinitely, and the dogs weights were maintained at 88 +/- 0.6% (mean +/- SE) of preoperative weights by absorption from the autografted intestine. Administration of cyclosporine to dogs with intestinal autografts produced a reversible impairment of intestinal absorption. Dogs with allografts survived 63.3 +/- 15.5 days (mean +/- SE). Death within 9 weeks of transplantation was from peritonitis secondary to graft rejection. Death in long survivors was a consequence of inadequate intestinal absorption. In the first 4 weeks after transplantation absorption and motility of allografted Thiry-Vella segments was comparable to the intestinal autografts but allografts showed evidence of a protein losing enteropathy. Large volumes of high protein-content fluid were lost from the allografted Thiry-Vella segments, and dogs with allografts became hypoalbuminemic.