Immunological protection of small bowel by simultaneously transplanted liver graft in pigs.
BACKGROUND
A simultaneously transplanted liver shields a bowel graft from immunologic attack in small animals, while the possible immuno-tolerance induced by the liver in liver and small bowel transplantation (LSBT) is uncertain in large animal models. To investigate the clinically suspected beneficial effect of the liver on small bowel allograft, we developed a new model of composite LSBT in the pig.


METHODS
Seventy outbred long-white pigs were randomized into four groups. LSBT without immunosuppressive treatment (n=10, group A); LSBT with routine immunosuppressive treatment (n=10, group B); LSBT with a lower dose of immunosuppressive treatment (n=10, group C); and small bowel segment allotransplantation without immunosuppressive treatment (n=10, group D).


RESULTS
There was no remarkable difference in survival time between groups A and D (10.33 vs. 12.89 days, P>0.05), but the initial time of acute rejection of the intestinal graft in group A was clearly delayed when compared to group D (8.22 vs. 4.33 days, P<0.05), and the rejection scores in group A were remarkably lower than those in group D at each postoperative time point (0 vs. 0.44 on day 3, P<0.05; 0.22 vs. 1.78 on day 5, P<0.05; 1.11 vs. 2.56 on day 7, P<0.05). There were evident differences in postoperative survival time, initial time of acute rejection and postoperative rejection scores between groups A, B and C. Postoperative survival time (30.00 vs. 28.13 days, P>0.05), initial acute rejection time (25.40 vs. 22.13 days, P>0.05) or rejection score did not differ between groups B and C within one postoperative month.


CONCLUSIONS
Compared to isolated segment small bowel allotransplantation, the intestinal graft in LSBT (group A) had a delayed initial time of acute rejection and a lower postoperative acute rejection score, and a lower dose of immunosuppressive treatment led to persistent graft immuno-tolerance in LSBT. Thus the simultaneously transplanted liver graft may reduce the risk of intestinal rejection and protect the bowel graft from severe acute rejection.
Yin
Zhen-Yu
ZY
Institute of General Surgery, Jinling Hospital, Nanjing University School of Medicine, Nanjing 210002, China.
Li
Ning
N
Wang
Xiao-Ming
XM
Ni
Xiao-Dong
XD
Jiang
Feng
F
Li
You-Sheng
YS
Li
Jie-Shou
JS
D000208:Acute Disease; D000818:Animals; D006084:Graft Rejection / Q000276:immunology / Q000473:pathology / Q000517:prevention & control*; D006085:Graft Survival; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D007421:Intestine, Small / Q000276:immunology / Q000637:transplantation* / Q000648:ultrastructure; D016031:Liver Transplantation; D023421:Models, Animal; D012720:Severity of Illness Index; D013552:Swine; D013997:Time Factors; D023001:Transplantation Tolerance
D007166:Immunosuppressive Agents