Traditionally,antigen presenting cells were shown to express MHC Ⅱ antigens.However,some researchers have demonstrated that a subset of T lymphocytes could express MHCⅡ antigens in some situation.Its regulatory mechanism and biological effects remains challenging to researchers.This review provides an overview of the results of these MHC Ⅱ + T lymphocytes regarding to the generation,mechanisms,and the role in immune tolerance induction,aim to provide some insights in clinical immune tolerance induction.

ObjectiveTo evaluate the feasibility and efficacy of ex-vivo liver resection combined liver autotransplantation for patients with massive primary liver cancer who underwent complex liver resection.Methods The clinical data of 4 patients suffering from massive primary liver cancer who were admitted to the Beijing Chaoyang Hospital from January 2008 to May 2010 were retrospectively analyzed.Regular liver resection could not be carried out because the first,second and third hepatic hilum of the 4 patients were invaded by the tumors,so ex-vivo liver resection combined liver autotransplantation were performed.ResultsThe operation was successfully carried out for the 4 patients.The operation time,the duration of anhepatic phase and the volume of operative blood loss were 690-840 minutes,250-300 minutes and 400-1400 ml,respectively.Portacaval bypass operation was not performed.After ex-vivo liver resection,the inferior vena eava or hepatic vein and portal vein of the 4patients were repaired,and the allogenous blood vessels were kept to extend the superior vena cava of the remnant liver so as to facilitate the anastomosis of blood vessels and reconstruction of the first hepatic hilum. After operation,the hepatic function of 1 patient was back to normal; 1 patient who stfffered from abdominal hemorrhage received reoperation for hemostasia; 1 patient was found with hepatic dysfunction; 1 patient died of hepatorenal dysfunction at postoperative day 5.Compensatory hypertrophy was observed in the 3 patients who survived at postoperative months 1-2.Of the 3 patients,2 were found with multiple pulmonary metastases at postoperative months 8 and 9,and they died at postoperative mouths 13 and 15.Until April 2012,1 patient survived for 37 months with no tumor recurrence or metastasis. ConclusionsEx-vivo liver resection combined liver autotransplantation provides the technical feasibility for performing complex liver resection for patients. The incomplete compensation of liver function and the short-term recurrence of tumors after operation are still the main issues which hinder the development of this technique.

Objective To investigate the curative effect of percutaneous transhepatic cholangial drainage(PTCD) on patients with non-anastomotic stricture after liver transplantation when treated with endoscopic retrograde cholangio-pancreatography(ERCP) unsuccessfully.Method The clinical data of 29 patients with non-anastomotic biliary stricture after liver transplantation were retrospectively analyzed,who failed to respond to ERCP and underwent PTCD from January 2005 to December 2007.Result All patients were performed PTCD successfully including cholangiography in 141 cases,drainage tube replacement in 115 cases,and balloon dilation of bile duct stricture in 39cases.The intubation time ranged from 2 months to 65 months.The mean levels (x ± SD) of alanine aminotransferase,aspartate aminotransferase and total bilirubin were 68.0 ± 29.1 U/L,52.6 ± 34.8 U/L,63.2 ± 33.3 μmol/L after treatment in comparison to 178.3 ± 63.3 U/L,144.0 ± 59.1 U/L,154.2 ± 92.0 μmol/L before treatment.Conclusion PTCD,which could improve the symptoms and prolong the survival time of both grafts and patients in spite of inconvenience of intubation,is suggested for patients with non-anastomotic biliary stricture if they are not suitable for liver retransplantation.

Objective To investigate the use of laparoscopic ultrasound to exclude cystic duct obstruction and its related risk factors in laparoscopic cholecystectomy.Methods The data of 28 patients who underwent laparoscopic cholecystectomy in our department for cystic duct obstruction from February 2008 to April 2010 were analyzed.Subtotal resection of gallbladder and exclusion of cysticduct were carried out when the gallbladder triangle anatomy was not clear.An abdominal drain was used.Results All the patients were cured and there was no bleeding,abdominal infection,or jaundice.On univariate analysis,risk factors for cystic duct obstruction were adhesions in Calot triangle,gallbladder atrophy,acute cholecystitis,cystic duct stone incarceration,gallbladder wall thickening and white bile.Adhesion in Calot triangle,acute cholecystitis and white bile were independent risk factors on multivariate analysis.Conclusion Excluding cystic duct obstruction by laparoscopic ultrasound for patients who underwent laparoscopic cholecystectomy for cystic duct obstruction is safe and effective.

Objective To evaluate the changes and significance of lymphocyte subsets in the recipients with acute rejection after liver transplantation. Methods The recipients presenting with acute rejection after liver transplantation were assigned into the rejection group (n=17), and their counterparts with stable liver function were allocated into the control group (n=17) according to the ratio of 1∶1 by propensity score matching method. The incidence of acute rejection after liver transplantation was analyzed, and the concentration of tacrolimus in the recipients was compared between two groups. The absolute value and proportion of lymphocyte subsets in peripheral blood were compared between two groups. The diagnostic value of lymphocyte subsets for acute rejection after liver transplantation was assessed by the receiver operating characteristic (ROC) curve. The absolute value and proportion of lymphocyte subsets in the rejection group were compared before and after treatment. Results Among 17 recipients in the rejection group, 4 cases developed acute rejection within postoperative 28 d, and 13 cases had acute rejection within postoperative 29-180 d. No significant difference was noted in the tacrolimus concentration between two groups (P=0.295). Compared with the control group, the proportions of peripheral blood T cells, CD4⁺T cells, B cells and natural killer (NK) T cells were significantly increased in the rejection group (all P < 0.05). The elevated proportion of NKT cells in the early stage after liver transplantation was an independent risk factor for acute rejection following liver transplantation[odds ratio (OR) 1.774, 95% confidence interval (CI) 1.059-2.971, P=0.029]. ROC curve analysis showed that the area under curve (AUC) of CD4⁺T cells, B cells and NKT cells was 0.76, 0.73 and 0.77, respectively. The AUC of combined use of CD4⁺T cells, B cells and NKT cells was 0.89, with a cut-off value of 0.69, sensitivity of 0.706 and specificity of 0.941. After corresponding treatment, all recipients were gradually recovered, and liver functions were eventually restored to normal in the rejection group. After treatment, the proportion of T cells, CD4⁺T cells, CD8⁺T cells and NK cells was significantly decreased (all P < 0.05). Conclusions The elevated proportion of NKT cells indicates an increased risk of acute rejection after liver transplantation. Combined use of CD4⁺T cells, B cells and NKT cells may deliver early detection and diagnosis of acute rejection after liver transplantation.

To study the relationship between T helper (Th) 17 cell [CD4 +interleukin (IL)-17 +T lymphocytes]in peripheral blood and acute rejection in patients after liver transplantation.Methods A total of 76 patients receiving orthotopic liver transplantation (OLT)for benign end-stage liver diseases in Department of Hepatobiliary and Pancreas-Spleen Surgery,Affiliated Beijing Chaoyang Hospital of Capital Medical University from June 2008 to December 2012 were included in this study. According to whether the acute rejection occurred after operation,the patients were divided into rejection group (n=17)and non-rejection group (n=59). All the patients were followed up regularly by routine. The incidence of rejection and the treatment of patients were recorded. Patients in the rejection group received liver biopsy when suffered acute rejection to decide the severity. The percentage of CD4 +IL-17 +T lymphocytes to CD4 +T lymphocytes (CD4 +IL-17 +T%)in peripheral blood in all patients was measured at different time points:pre-OLT,at regular intervals (3-6 months)within 1 year after hospital discharge or before the treatment of acute rejection and after the remission (3-6 months). The CD4 +IL-17 +T% of every time point were compared between two groups.The correlations of CD4 +IL-17 +T% with the rejection activity index (RAI ), blood concentration of immunosuppressor were analyzed.Results The acute rejection occurred in 0.7-12.0 (median:2.5 ) months after OLT. The CD4 +IL-17 +T% in the rejection group increased significantly compared with that in the non-rejection group after OLT [(2.56 ±0.43)%vs. (1.79 ±0.44)%,P<0.001]. In the rejection group,the CD4 +IL-17 +T% increased significantly when acute rejection occurred compared with that when acute rejection had not occurred [(2.56 ±0.43)%vs. (1.50 ±0.25)%,P<0.001)]. The variation of CD4 +IL-17 +T%was not obvious at different time points in non-rejection group (P >0.05 ). The CD4 +IL-17 +T% was positively correlated with RAI when acute rejection occurred in the rejection group (r=0.72,P=0.001 ).The blood concentration of tacrolimus,cyclosporin in rejection and non-rejection group were not correlated with CD4 +IL-17 +T% (r=0.21,-0.13;both in P>0.05). Conclusions CD4 +IL-17 +T%in peripheral blood can be used as a monitoring index for deciding and assessing severity of acute rejection after OLT. The increase of CD4 +IL-17 +T% in peripheral blood indicates a severe acute rejection.

Objective To investigate the effect of Immutol on inducing the immune tolerance of cardiac grafts in rat models. Methods A rat model of heterotopic abdominal heart transplantation was established. The recipient rats were divided into 5 groups: blank control group (n=6); dimethyl sulfoxide (DMSO) group (n=6), in which DMSO was administered until the cardiac graft arrest; Immutol group (n=6), in which Immutol was administered until the cardiac graft arrest; ciclosporin (CsA) group (n=10), in which CsA was administered for 20 d; combined group (n=13), in which Immutol was given for 60 d combined with CsA for 20 d. The survival time and pathological changes of cardiac grafts in each group were observed. The contents of serum interleukin (IL)-10 and interferon (IFN)-γ were detected. The expression levels of indoleamine 2, 3-dioxygenase (IDO) and fibrinogen-like protein 2(Fgl2) messenger RNA(mRNA) in heart tissues of rats in each group were measured. Results In the combined group, the cardiac grafts survived for >180 d and immune tolerance was induced. The pathological score of cardiac grafts in the combined group was significantly lower than that in the CsA group at postoperative 39 d (P < 0.05). The levels of serum IL-10 and IFN-γ in the combined group were significantly higher than those in the CsA group at 9 d and 39 d after operation (both P < 0.05). The content of serum IL-10 and IFN-γ in the combined group were gradually increased over time. At postoperative 39 d, the expression levels of IDO and Fgl2 mRNA in the combined group were significantly higher than those in the CsA group (both P < 0.05). The expression level of IDO mRNA in the combined group tended to gradually elevate after operation. In the combined group, the expression level of Fgl2 mRNA at postoperative 180 d was significantly higher than those at 9 d and 39 d after operation (both P < 0.05). Conclusions Combined administration of Immutol and CsA can effectively inhibit the incidence of acute rejection, and maintain the long-term survival of the cardiac grafts and induce immune tolerance after drug withdrawal.

Objective To analyse the clinical efficacy of liver transplantation and summarize the clinical experience of perioperative management in patients with hepatic coma. Methods Clinical data of 22 patients with hepatic coma undergoing liver transplantation were retrospectively analyzed. The perioperative conditions of the recipients were observed, including operation time, warm/cold ischemia time of donor liver, intraoperative anhepatic phase of the recipients, intraoperative blood loss, intraoperative blood transfusion, early postoperative blood drug concentration and incidence of postoperative complications. The survival situation of the recipients and the influencing factors of clinical prognosis were analyzed. Results The operation time of 22 recipients was 8 (6-12) h, the warm ischemia time of donor liver was 4 (2-6) min, the cold ischemia time was 7 (5-10) h, intraoperative anhepatic phase of recipients was 80 (55-120) min, intraoperative blood loss was 1 139 (400-4 000) mL and intraoperative blood transfusion was 1 440 (0-3 600) mL.The blood concentration of tacrolimus (FK506) fluctuated between 6 and 11 ng/mL at postoperative one week. Six recipients died after liver transplantation including 1 case of primary graft liver failure, 2 cases of severe infection, 1 case of severe cerebral edema caused by cerebral hemorrhage and 2 cases of multiple organ failure. The postoperative 1 month and 1 year survival rates of hepatic coma recipients were 82% and 77%. Conclusions Liver transplantation can significantly improve the survival rate of patients with hepatic coma. Preoperative decreasing blood ammonia, controlling postoperative infection, improving renal function and formulating precise individualized immunosuppression therapy according to immune status play a pivotal role in enhancing the survival rate.

Objective To investigate the relationship between immune tolerance and the changes of helper T cell (Th), regulatory T cell (Treg) cytokines, related signaling pathway proteins during immune tolerance process in rat models of liver transplantation. Methods The orthotopic liver transplantation rat models were established by double-cuff technique. All rats were divided into 3 groups. In the operative control group (n=6), sham operation was performed without liver transplantation. In the short-term group (n=10), the rats survived for 10 d after liver transplantation. In the immune tolerance group (n=10), the rats survived for 100 d after operation and the function of the transplanted liver was restored to normal. The expression levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), Th1 cytokines [interferon (IFN)-γ, interleukin (IL)-2 and tumor necrosis factor (TNF)-α], Th2 cytokines (IL-4, IL-5, IL-6 and IL-13), Th17 cytokines [granulocyte-macrophage colony-stimulating factor (GM-CSF) and IL-17A], Treg cytokines [IL-10, transforming growth factor (TGF)-β and IL-12p] were quantitatively measured. The serum sample of rats in each group was detected by protein chip analysis. Results Compared with the operative control group, the AST level in the short-term group was significantly down-regulated, whereas the ALT level was significantly up-regulated (both P < 0.05). However, the AST and ALT levels did not significantly differ between the immune tolerance group and operative control group (both P > 0.05). In the liver tissues of rats in each group, the expression levels of Th1 cytokines IFN-γ and IL-2 in the short-term group were significantly higher than those in the operative control group (both P < 0.05). The expression level of Th2 cytokine IL-4 in the immune tolerance group was significantly lower than that in the operative control group (P < 0.05). The expression levels of Th2 cytokines IL-5, IL-6 and IL-13 in the short-term group were significantly lower than those in the operative control group (all P < 0.05). The expression level of IL-17A in the immune tolerance group was significantly higher than that in the operative control group (P < 0.05). In the immune tolerance group, the expression levels of IL-10and IL-12p were significantly higher than those in the operative control group (both P < 0.05). The expression level of TGF-β in the short-term group was significantly higher than that in the operative control group (P < 0.05). Compared with the operative control group, the expression levels of intercellular adhesion molecule (ICAM)-1, pro-platelet basic protein (Ppbp), Neuropilin-2, Notch-2 protein in the short-term group were significantly up-regulated (all P < 0.05). The expression levels of CXC chemokine ligand 17 (CXCL17), ICAM-1 and Neuroleptin-2 protein were markedly up-regulated (all P < 0.05), whereas that of B7-1 protein was significantly down-regulated (P < 0.05) in the immune tolerance group. Conclusions Treg cytokines (IL-10, TGF-β and IL-12p), IL-6, IL-17 and trans-membrane signaling pathway molecules (ICAM-1, Neuropilin-2, B7-1 proteins) play a pivotal role in the natural immune tolerance process of rat models of liver transplantation.

Objective To explore the clinical efficacy of liver transplantation for severe liver disease. Methods The clinical data of 51 patients who underwent liver transplantation for severe liver disease were retrospectively analyzed. The general intraoperative conditions were observed, including operation duration, warm ischemia time, cold ischemia time, anhepatic phase, bleeding volume, blood transfusion volume, plasma transfusion volume and so on. The changes in indexes such as total bilirubin (TB), prothrombin time activity (PTA), and prothrombin time international normalized ratio (PT-INR) were observed before operation and at 3 d, 1 week and 2 weeks after operation. The postoperative survival and occurrence of complications were analyzed. The indexes that might affect the prognosis of patients with severe liver disease were analyzed by Cox regression analysis. Results For the 51 patients, operation duration, warm ischemia time and cold ischemia time was 8 (7, 9) h, 3 (2, 3) min and 6 (5, 8) h respectively, intraoperative anhepatic phase was 80 (70, 100) min, intraoperative bleeding volume was 1 000 (550, 1 500) mL, and intraoperative blood transfusion volume was 1 200 (200, 1 600) mL. Postoperative TB, PTA, PT-INR and other indexes improved significantly compared to those preoperatively. Among the 51 patients, 10 cases died, with the death causes of multiple organ failure and severe infection(7 cases), renal insufficiency (2 cases), and cardiovascular complications (1 case). Survival rates at 1 month and 1 year post-transplantation for patients with severe liver disease were 82% and 80%, respectively. Cox regression analysis suggested that abnormal preoperative PTA and PT-INR were the risk factors for post-transplantation death in patients with severe liver disease. Conclusions Liver transplantation significantly improves the survival rate for patients with severe liver disease, perioperative infection prevention and treatment as well as multiple organ function management play key roles in improving post-transplantation survival rate in patients with severe liver disease.