Electrophysiologic and histological monitoring of MHC-matched and mismatched canine intestinal allografts.

Intestinal transplantation (ITx) has potential applications for the treatment of short-bowel syndrome (SBS). A major obstacle to its clinical use is rejection, which may partly be overcome by major histocompatibility complex (MHC) matching. At present, it is impossible to predict accurately the early onset of rejection. The aim of this study was to assess the value of in vivo measurements of transepithelial potential difference (PD) for the determination of rejection in MHC-matched and -mismatched canine ITx. A heterotopic ITx was performed in MHC tissue-typed Beagle dogs. Two ileostomies were created for PD monitoring and histology. Via one ileostomy, a well-defined segment of the IT, was isolated by a double balloon catheter and the intraluminal PD was measured in reference to a subcutaneous electrode. The PD responses during perfusion of a theophylline solution (crypt cell stimulation, PD theophylline) and during perfusion of a glucose solution (villus cell stimulation, PD glucose) were assessed. The results of in vivo PD measurements were compared with simultaneously obtained histology specimens. Four groups of dogs were studied: group 1 (controls, n = 10) ileal autotransplants; group 2 (n = 6) ileal allotransplants, fully mismatched; group 3 (n = 3) ileal allotransplants, 1 haplotype identical; and group 4 (n = 5), ileal allotransplants, fully matched. No immunosuppression was given. All dogs of group 1 survived indefinitely and both PD and histology showed no abnormalities. In group 2, 3, and 4 the onset of histological changes related to rejection corresponded well with decreased PD responses.(ABSTRACT TRUNCATED AT 250 WORDS)