Limitation of donor source for allograft makes the research on xenograft progress. Pig is regarded as one of the ideal donor animals. The major obstacle in xenograft is hyperacute rejection, which is caused by complements after they are activated by xenogeneic antigens combined with natural antibodies. It has been confirmed that alpha-Gal is the major target antigen, whose expression is incharged by alpha-1,3 galactosyltransferase (alpha-GT). The approaches to overcome hyperacute rejection against alpha-Gal included: immunoadsorption of xenogeneic natural antibodies, lysis of antigen by enzyme and genetic manupilation to obtain animal lack of alpha-GT. Besides alpha-Gal, there were other antigens binding to human serum antibody, such as gp65 and gp100, which was expressed on PAEC after induced by TNF, the A-like antigen. But their function was still unknown. It was debatable on the role of MHC in xenograft. Both direct and indirect pathway were involved in cellular response in xenograft.
Insufficient supply of organ for allotransplantation made the study on finding new organ resources from animal progress. Pig is regarded as one of the optimal donor animals for human. The major obstacle in this field is hyperacute reaction (HAR), which is triggered after the xenogenic natural antibodies preexisting in recipient blood combine to the antigens on the surface of the endothelium and activate the complement system. alpha-Galactose residues (alpha-Gal) on the endothelial cell have been identified as the major xenoantigens. NJZ Pig has been closely breed since 1938, whose family history is clear. Tissue samples from heart, liver, kidney, pancreas, lung, small intestine, skin, spleen, thymus and lymph node were obtained and embedded in paraffin. The sections were performed the immunohistochemical staining with the sera from health volunteers (including all the blood types) as the primary antibodies as well as the biotin labeled bandeirae simplicifolia I isolectin B4 (BS I-B4), which has specific affinity to alpha-galactose. All the staining sections were compared with the tissues digested with alpha-galactosidase. There was no difference between the antigens recognized by sera of different blood types. alpha-Gal was still the major xenoantigen on the endothelial cells. There might exist non-alpha-Gal antigens on the distal convoluted tubules and collecting tubules of the kidney. There was no alpha-Gal distributing on the secreting part of pancreas, either the islet cells or the matrix cells, but surely on pancreatic duct and vessels. All the antigenity was destroyed after the enzyme digestion except that the small intestine gland still positive with the BS I-B4. alpha-Gal is the major xenogenic antigen in NJZ Pigs. There exist some unknown antigens on the distal convoluted tubules and collecting ducts of the kidney. The blood type of recipient is not the first affair to be considered in pig-to-human xenotransplantation. The specificity of BS I-B4 for the alpha-galactose needs more detail research.
Objective Ｔo summarize the advancement of ABO-incompatible liver transplantation. Methods Relevant literatures about ABO-incompatible liver transplantation, which were published recently domestic and abroad were reviewed and analyzed. Results Owing to various treatments recent years, outcomes of ABO-incompatible liver transplantation have been improved dramatically. Conclusion With effective immnosuppressive protocols and effective perioperative management, ABO-incompatible liver transplantation is feasible.
Objective To summarize the clinical experience of liver retransplantation. Methods Six liver retransplantations were performed. The indications consisted of primary non-function (PNF, 2 cases), acute or chronic rejection (2 cases), stomas stenosis of biliary tract (1 case) and primary sclerosing cholangitis (1 case). The immunosuppressive protocols included tacrolimus, methylprednisolone (MP) and mycophenolate mofetil (MMF). Results Five patients were cured. One patient died on day 4 after liver retransplantation because of multiple organ failure. Postoperative complications included deep fungal infection and wound infection. Conclusions Liver retransplantation is an effective method for graft failure after liver transplantation. Proper indication and optimum operative time, intensive perioperative supervision and proper treatment are very important to improv effect of liver retransplantation.
ObjectiveTo investigate the aim antigen coursing the hyperacute rejection of xenotransplantation. MethodsDocuments about hyperacute rejection in xenotransplantation were reviewed and summarized in detail. ResultsPig is thought to be one of the ideal donors of xenotransplantation, but the major obstacle is hyperacute rejection mediated by complement that is activated though human serum. αGal is recognized as the major antigen and its expression is controlled by α1,3 galactosyltransferase. Immunoabsorption of preexsisted antibody, enzymatic digestion of αGal, knockout αGT gene and transgenic technology have been used to solve this problem. Even so, there remain other antigens which can combine with natural antibodies in human serum, such as, 40×103 molecule in erythrocyte, 210×103, 105×103 and 50×103 antigen in pig embryo brain cell, etc. Conclusion αGal is the major antigen which course the hyperacute rejection. Besides αGal, many nonalphagal need further investigation.
Objective To establish the rat orthotopic liver transplantation model by characterizing the blood supply of hepatic artery with the Cuff skill and the modified arterial sleeve anastomosis, to explore the possible mechanisms of acute rejection and the express of Fractalkine (Fkn) in the early stage after hepatic allograft operation. Methods SD rats were selected as donors and Wistar rats as receptor for the rejection model of orthotopic liver transplantation. Recipient rats were divided into 2 groups randomly after operationand the drugs were given intraperitoneally once a day in each group. In the experimental group, cyclosporine A (CsA) was delivered with 3 mg/kg. In the control group, only normal saline was given with 3 ml/kg. Condition of survivals were observed. The rejection actvity index (RAI) and the expression of Fkn of liver tissue were observed after 3rd, 5th and 7th days in 5 rats. The rest of rats in each group were fed and given drug or normal saline until they were died and the mean survival time were recorded. Results There were 18 survivals in control group, and 19 in experimental group after liver transplantation. Condition of survivals in experimental group was better than that of control group. The mean survival times of experimental group(19.50±4.51 days) was significantly longer than that of control group(7.60±1.60 days), showing statistically significant difference (P＜0.05). After 3rd, 5th and 7th days of transplantation, RAI of control group were 3.80±0.35,5.90±0.87 and 7.50±1.30,respectively;RAI of experimental group were 3.10±0.21,3.90±0.41 and 4.50±0.52.Therewasstatistically significant difference in RAI between 2 groups on the 7th day after transplantation (Plt;0.01). On the 3rd,5th and 7th days after transplantation, the Fkn of control group was 8.20±0.57,21.30±3.30 and 25.70±4.91, and that of experimental group was 8.30±0.56,10.30±0.67 and 11.70±1.23. There were statistically significant differences in Fkn between 2 groups on the 5th, 7th days after transplantation (Plt;0.01). Conclusion Fkn is a participant inacute rejection after the rat orthotopic liver transplantation and can be chosen as a useful target in the diagnosis of acute rejection. CsA has immunosuppressive property in the condition of acute rejection in the rat orthotopic liver transplantation, which may be result from the decreased the level of Fkn.
Objective To discuss the differentiation between transient intrahepatic cholestasis (TIHC) and acute rejection (AR) after liver transplantation． Methods Characteristics and the changes (before and within 21 d after transplantation) of alanine aminotransferase (ALT) and direct bilirubin (DBIL) in 30 patients undergone liver transplantation were observed. These patients were divided into TIHC group and AR group following the diagnosis criteria, and the serum levels of ALT and DBIL were compared respectively on day 1 before liver transplantation, day 3, 7 and 21 after liver transplantation． Results Compared with day 3 after transplantation in the TIHC group， DBIL significantly ascended while ALT was changeless on day 7 after transplantation. But in the AR group， DBIL ascended significantly and ALT showed an increasing tendency on day 7 after transplantation． After appropriate therapy, DBIL and ALT of two groups both descended significantly on day 21 after transplantation． Conclusion The changes of DBIL and ALT are available for the differentiation between TIHC and AR after transplantation.
Objective To investigate the expression of RNA editase ADAR1 in the lymphocytes in rats’ spleen with liver transplantation rejection. Methods Thirty SD rats and 75 Wistar rats were included. Fifteen livers from Wistar rats were transplanted to 15 Wistar rats (isograft group), 30 livers from SD rats were transplanted to 30 Wistar rats (allograft group and allograft+FK506 group), and 15 of them were then intramuscularly injected with FK506, 2 mg/(kg·d), the other 15 Wistar rats were only operated similarly to the other rats without any liver transplantation (control group). Five rats were killed and their splenetic tissues were collected on day 3, day 5, and day 7, respectively. The expression of ADAR1 mRNA in lymphocytes of the spleen in acute rejection was detected by RT-PCR. Results Different performance of pathology was observed in all the liver and spleen tissues from the transplanted rats over time, especially in allograft group. The expression of ADAR1 mRNA in the allograft group was significant higher than that of isograft and allograft+FK506 groups （P＜0.001）, especially on the 5th day. Conclusion There was a significant positive correlation between expression of ADAR1 and the severity of acute rejection, but the mechanism by which ADAR1 affected the acute rejection is unknown and needs to be further studied. FK506 may inhibit the expression of ADAR1 and remarkably reduce the severity of acute rejection.
ObjectiveTo investigate the early diagnostic value of transforming growth factor-β1(TGF-β1) on acute rejection after liver transplantation in rhesus by detecting the expression of TGF-β1 in the liver tissue. MethodsLiver transplantation models in rhesus were constructed by the improved vascular dual cuff, supporting tube of biliary tract, and artery anastomosis method.The successful models were randomly divided into experimental group (no immunosuppressant treatment in perioperative period) and control group (treated by immunosuppressant in perioperative period).Then the blood samples and liver tissues were collected at 6, 12, 24, and 72 hours after surgery.Allograft rejections of liver tissue after liver transplantation were monitored by liver function test, hematoxylin-eosin staining and Banff score.Finally, the expression level of TGF-β1 was detected by Western blot analysis or immunohistochemistry technique. Results①The acute rejection happened in all the rhesus at 12 h, 24 h and 72 h after liver transplantation, especially at 72 h after liver transplantation in the experimental group, the Banff grade levels of acute rejection in the liver tissue was more severe than that in the control group (P < 0.05).②The levels of ALT, AST, and TBIL after liver transplantation was gradually increased, which were similar at 6 h and 12 h after transplantation between the two groups, but which at 24 h and 72 h after transplantation in the experimental group were significantly higher than those in the control group (P < 0.05).③The results of TGF-β1 protein expression using immunohistochemical detection:The percentage of positive area of TGF-β1 of liver tissue at 12 h in the experimental group was significantly higher than that in the control group (P < 0.05).With the extension of time, it was gradually increased and significantly higher than that in the control group at 24 h or 72 h (P < 0.05).④The semi-quantitative results of TGF-β1 protein expression using Western blot detection:The TGF-β1 protein expressions began to increase at 6 h after liver transplantation in the experimental group and the control group, and the magnitude of increase was more obvious in the experimental group.The TGF-β1 protein expressions at different time (6 h, 12 h, 24 h, and 72 h) in the experimental group were significantly higher than those in the control group (P value was 0.003, 0.001, 0.001, and 0.001, respectively). ConclusionsThe elevated level of TGF-β1 of liver tissue after liver transplantation might suggest the enhanced cellular immune function, it might have certain significance for early diagnosis of acute rejection after liver transplantation.