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.

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.

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 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 guiding role of quantitative evaluation system of immune status in the individualized management of immunosuppressants for the recipients after liver transplantation. Methods Clinical data of 239 liver transplant recipients were retrospectively analyzed. MingDao Immune Cell Analysis (MICA) was established. All recipients were divided into two groups according to the adjustment regimens of immunosuppressants. The immunosuppressant regimen was adjusted according to MingDao Immune System Score (MISS) in the MISS group (n=84), and the medication plan was empirically adjusted during the same period in the control group (n=155). According to the time of postoperative detection (t), the recipients in the MISS group were divided into subgroup A (t ≤ 28 d, n=78), subgroup B (28 d < t ≤ 6 months, n=68), subgroup C (6 months < t ≤ 12 months, n=18), subgroup D (12 months < t ≤ 24 months, n=18) and subgroup E (t > 24 months, n=19). In the MISS group, postoperative MISS scores of recipients in subgroups A-E were analyzed. The incidence of acute rejection and opportunistic infection and the overall survival rate were statistically compared between the MISS and control groups. Results The MISS scores in subgroups A-E were -7.0 (-13.2, -2.0), -2.0 (-5.8, 1.8), -0.5 (-7.3, 2.8), -2.0 (-4.5, 3.3) and -3.0 (-6.0, 1.0), respectively. The immune status of the recipients was gradually improved over postoperative time, and the difference between two groups was statistically significant (P < 0.05). In the MISS group, 15% (13/84) of the recipients developed acute rejection, and 27% (42/155) in the control group, and the difference was statistically significant (P < 0.05). In the MISS group, the MISS score of the recipients with acute rejection was 0 (-2.5, 3.5), and -5.0 (-12.0, -1.0) for their counterparts without acute rejection, and the difference was statistically significant (P < 0.05). In the MISS group, 2% (2/84) of the recipients presented with postoperative opportunistic infection, and 9% (14/155) in the control group, and the difference was statistically significant (P < 0.05). In the MISS group, the 1- and 3-year overall survival rates were 86.9% and 79.8%, and 83.2% and 76.8% in the control group, and no significant difference was observed between two groups (P > 0.05). Conclusions MICA and MISS score may reflect the immune status of liver transplant recipients, and guide the individualized management of administration of immunosuppressants after liver transplantation.

Objective:To explore the risk factors of Pneumocystis carinii pneumonia (PCP) after orthotopic liver transplantation (OLT), and optimize the treatment strategy. Methods:From May 2015 to March 2019, patients undergoing OLT and suffering from postoperative PCP were selected into PCP group ( n=8). Using the propensity score matching method, controls without postoperative PCP were selected from concurrent OLT patients at a ratio of 1: 4 ( n=32). Clinical data were collected and counted for analyzing the risk factors of PCP post-OLT. Results:During this period, 385 cases of OLT were performed. The incidence of PCP was 2.1% (8/385). PCP group were all males with an average age of (52.63±12.99)(27-69) years. PCP has an average onset time of (19.88±13.22)(9-50) weeks post-OLT. There were benign liver disease ( n=2) and malignant liver tumor ( n=6). All operative approaches were modified camel OLT. Univariate analysis revealed significant differences in rejection, peripheral blood lymphocyte count and percentage of peripheral blood lymphocyte after OLT ( P<0.05) and no significant differences existed in other factors ( P>0.05). Logistic regression analysis indicated that a lower count of peripheral blood lymphocyte post-OLT was an independent risk factor for postoperative PCP. Conclusions:A lower count of peripheral blood lymphocyte post-OLT elevates the risk of PCP. For high-risk patients, prophylaxis with TMP-SMX (trimethoprim-sulfamethoxazole) may effectively lower the incidence of PCP post-OLT.

Objective:To investigate the clinical efficacy of superior mesenteric artery priority approach in infracolic compartment in the surgical treatment of resectable pancreatic head cancer.Methods:The clinical data of 79 patients with resectable pancreatic head cancer who underwent radical pancreaticoduodenectomy (PD) in the Department of Hepatobiliary Surgery of Beijing Chaoyang Hospital Affiliated to Capital Medical University from January 2016 to December 2019 were analyzed retrospectively. According to the surgical approach, they were divided into arterial priority approach group (arterial priority group, 48 cases) and conventional approach group (conventional approach group, 31 cases). The arterial priority group was to first explore the superior mesenteric artery in the subcolone, then cut off the tumor blood supply after ascertaining that the tumor can be removed, and finally remove the tumor and anastomose it routinely. The conventional approach group underwent traditional radical PD. The operation time, intraoperative bleeding, intraoperative blood transfusion, lymph node metastasis, number of lymph node dissections, resection criteria, tumor length diameter, degree of tumor differentiation, occurrence of postoperative complications (pancreatic fistula, impaired gastric emptying, abdominal bleeding, biliary fistula and diarrhea), postoperative hospital stay and postoperative chemotherapy were observed. The patients were followed up by the way of outpatient and/or telephone. The follow-up time was up to March 2021. The survival rate was calculated by Kaplan Meier method.Results:Compared with the conventional approach group, the amount of intraoperative bleeding in the arterial priority group was significantly reduced (400 ml vs 600 ml, P=0.005), the intraoperative blood transfusion rate was significantly reduced (39.6% vs 64.5%, P=0.030), the number of lymph node dissections was significantly increased (19 vs 13, P=0.024), the R 0 resection rate was significantly increased (83.3% vs 58.1%, P=0.013), but the incidence of diarrhea was significantly increased (39.6% vs 16.1%, P=0.027). The differences were statistically significant. The median survival time of arterial priority group and conventional approach group was both 19 months. The overall survival rates of 1, 2 and 3 years were 72.0%, 39.5%, 28.5% and 64.1%, 33.7% and 15.4% respectively. The median tumor free survival time was 15 months and 12 months. There was no significant difference. However, the 1, 2 and 3-year tumor free survival rate of patients in arterial priority group was significantly improved (61.2%, 39.5% and 25.9% vs 46.0%, 21.3% and 7.1%, P=0.042) , and the difference was statistically significant. Conclusions:Superior mesenteric artery priority approach in infracolic compartment can improve R 0 resection rate, prolong postoperative survival time, reduce recurrence and improve prognosis.

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.