Surgical technique for combined liver/intestine transplantation in rats.

Simultaneous liver transplantation may reduce the risk of intestinal transplant rejection. We have recently developed two new models of combined liver/intestine transplantation (LIT) in the rat to study this phenomenon. Herein, we report our experience with LIT using a single donor (SD) or multiple donors (MD). Large volumes of fluid were required to prevent a drop in the mean arterial pressure during the anhepatic phase in the SD recipients. Many of the SD recipients died of intraoperative hypovolemic shock (57%). The MD recipients had a shorter anhepatic time (12 +/- 1 minutes vs. 17 +/- 2 minutes; P less than 0.01) and a shorter warm intestinal ischemia time (15 +/- 1 minutes vs. 32 +/- 2 minutes; P less than 0.01). Operative mortality rates were much lower in the MD recipients (10% vs. 68%; P less than 0.01). The long-term survival rate using MD was 71% at 1 month. Graft function was normal in the long-term survivors. LIT with MD provides a good model to study the immunological effects of multivisceral grafting.     

Antigen-specific immunosuppression induced by liver transplantation in the rat

We have demonstrated that DA hearts grafted into PVG rats were completely protected from rejection by simultaneous liver transplantation from the same donor. In subsequent experiments PVG animals were given DA hearts followed 5 or 6 days later by livers from the same donor strain. Instead of the expected rapid rejection, all the grafts survived for at least 18 days, despite showing definite graft-swelling, a reliable clinical sign of early rejection, immediately prior to liver transplantation. In all 13 rats the heart size returned to normal and a strong beat returned within a few days. 6 animals survived indefinitely with healthy, beating heart grafts and the remaining 7 animals died of liver transplant rejection, but in these animals also the hearts were beating normally immediately prior to death. Histological examination of the hearts revealed no active rejection, but there was extensive myocardial scarring, compatible with resolution of a rejection reaction. It seems, therefore, that the liver grafts had entirely absorbed the vigorous immune response, terminating that which had already begun in the heart. This immunosuppressive effect was donor-specific and far more powerful than that of the immunosuppressive agent cyclosporine.     

大鼠肝小肠联合移植肠壁酶活性变化的研究

目的探讨肝小肠联合移植后肠壁酶活性的变化及其与移植肠功能和免疫排斥反应之间的关系。方法用封闭群大鼠建立肝小肠联合移植模型,术后定期对移植组织进行病理学、酶组织化学检查。结果单独小肠移植组术后均发生排斥反应,肠壁酶活性消失。肝小肠联合移植组５６％可避免排斥反应,肠壁酶活性和神经成分得以保持和恢复。结论肝小肠联合移植可使供肠避免或推迟被排斥。术后检测肠壁酶活性和神经成分的变化可用于监测排斥反应     

Host immune suppression after small bowel/liver transplantation in rats

Simultaneous liver grafting in the Lewis (RT1¹)-to-DA (RT1^a) rat strain combination protects small intestinal grafts from rejection. The present study examined host immune responses after combined small bowel/liver transplantation (SBL) in this model. Orthotopic liver transplantation and heterotopic small intestinal transplantation were performed simultaneously and compared with isolated small bowel allografts (SBA) and isolated small bowel isografts (SBI). All rats were sacrificed on postoperative day (POD) 7 or 14 for immunological and histological studies. The mean time to rejection of the SBA was 6.6±0.3 days. Incontrast, there was no clinical or histological evidence of intestinal rejection in SBL recipients during the 14 days of follow-up. The SBL recipients showed clinical and histological evidence of graft-versushost disease (GVHD). Lmphocyte proliferation and IL-2 production in response to donor antigens were suppressed after SBL transplantation compared with the SBA or the SBI controls (P<0.05). Cell-mediated cytotoxicity and lymphocytotoxic antibody production against donor cells were also significantly inhibited in the SBL recipients compared with the SBA control group (P<0.05). We conclude that SBL transplantation in the Lewis-toDA rat strain combination: (1) suppresses host alloimmune responses, (2) prevents early intestinal rejection, and (3) favors the development of GVHD.     

Long-term outcome of immunosuppression withdrawal after liver transplantation

Eighteen liver transplant recipients were followed up for 10 years after a trial of immunosuppression withdrawal. Three groups were identified according to the early outcome of complete (group A, n = 5), partial (group B, n = 9), and unsuccessful (group C, n = 4) withdrawal of immunosuppression. The indications for liver transplantation (LT) (August 1983-December 1988) were as follows: primary biliary cirrhosis (n = 3), primary sclerosing cholangitis (n = 3), Budd-Chiari syndrome (n = 3), acute liver failure (n = 3), hepatitis C virus (HCV) cirrhosis (n = 1), HCV and autoimmune hepatitis (n = 1), HCV and alcohol-related cirrhosis (n = 1), HCV and hepatocellular carcinoma (HCC) (n = 1), cystic fibrosis (n = 1), and liver metastases from testicular teratoma (n = 1). Immunosuppression was based on cyclosporine. All patients experienced 1 or more complications of prolonged immunosuppression (median, 7 years; range, 5-11). Thirteen patients (72%) are alive at a median interval of 17 years (range, 16-21) after LT. Of the 5 patients in group A, 2 currently have normal graft function with no rejection episodes, and 3 have restarted immunosuppression following late low-grade acute rejection (n = 1), retransplantation for chronic rejection (n = 1), and kidney transplantation (n = 1). Of the 9 patients in group B, 5 died. The deaths were due to ruptured arterial pseudoaneurysm following retransplantation, HCC recurrence, cardiac failure, renal failure, and posttransplant lymphoma at 5, 7, 7, 14, and 17 years after LT, respectively. All 4 patients in group C are alive on a full immunosuppressive regimen. Long-term follow-up of 18 LT recipients withdrawn from immunosuppression has shown that at a median of 17 years 10% of patients remain off all immunosuppression.     

肝移植术后应用不含皮质激素的免疫抑制方案对糖代谢的影响

目的 探讨肝移植术后应用不含皮质激素的免疫抑制方案对受者糖代谢的影响.方法 回顾分析295例首次接受成人肝移植,且术后规律随访超过6个月受者的临床资料,将受者分研究组(153例)和对照组(142例),研究组受者采用他克莫司(Tac)+吗替麦考酚酯( MMF)的免疫抑制方案,对照组受者采用Tac+ MMF+皮质激素方案.分别于术前1周及术后第1、2、4、8、12、16、20和24周为观察时间点,检测两组受者的血糖水平变化,观察急性排斥反应及高血糖相关不良事件的发生情况.结果 两组间受者性别、年龄、体重等基本资料,尤其是术前空腹血糖水平和高血糖患者比例的差异均无统计学意义(P＞0.05).两组受者术后早期血糖水平均显著升高,术后1周时达到峰值,并随术后时间的延长呈逐渐下降的趋势.各时间点研究组的受者李腹血糖水平及高血糖患者比例均低于对照组,术后4周以后,与对照组比较,差异均有统计学意义(P＜0.05).研究组和对照组高血糖者的比例分别为52.9％和76.8％(P＜0.05),对照组术后发生高血糖的风险是研究组的2.94倍.随访期间,研究组和对照组的急性排斥反应发生率分别为8.50％ (13/153)和7.75％(11/142),两组比较,差异无统计学意义(P＞0.05).研究组受者出现组织愈合延迟、感染及高脂血症发生率亦低于对照组.结论 肝移植术后应用不含皮质激素的免疫抑制方案是安全的,并可降低术后发生糖尿病的风险,减少高血糖相关不良事件的发生率.     

Significant enhancement by anti-ICOS antibody of suboptimal tacrolimus immunosuppression in rat liver transplantation.

A member of the costimulatory molecule family, inducible costimulator (ICOS), is expressed on activated T cells and plays a critical role in their primary activation and cytokine production. ICOS is involved in different immune phenomena, such as Th1-mediated autoimmune disease and graft rejection. Although blockade of ICOS costimulation theoretically may protect grafts from rejection, a single dose of anti-ICOS antibody did not result in the prolongation of rat liver allograft survival. However, in this article, we report that anti-rat ICOS antibody markedly enhanced the immunosuppressive activity of a suboptimal dose of tacrolimus (FK506). After fully allogenic DA to LEW liver transplantation, recipients received a single injection of tacrolimus (1 mg/kg, intramuscularly) with or without anti-ICOS antibody (1 mg/kg, intravenously). Recipient survival was significantly prolonged in rats treated with both the antibody and suboptimal tacrolimus (median survival time 44 days vs. 28 days with tacrolimus alone, P <.01). The extent of cell infiltration into the graft was closely associated with prolongation of recipient survival. Our findings thus demonstrate that anti-ICOS antibody immunotherapy combined with suboptimal tacrolimus has a synergistic effect in preventing hepatic allograft rejection and that it may induce long-term graft acceptance intimately associated with a marked reduction of intragraft T lymphocyte infiltration.     

西罗莫司在肝移植术后免疫抑制中的效果及安全性

目的 探讨肝移植术后应用西罗莫司(SRL)的免疫抑制效果和安全性.方法 对21例以SRL作为免疫抑制维持治疗的肝移植受者进行了观察.其中术后直接应用SRL者6例(术前肾功能不全者2例、原发病为肿瘤者4例);因他克莫司(Tac)药物相关性因素替换为SRL者15例(Tac肾毒性4例、高度可疑Tae肝毒性8例、Tac用量过大仍不能达到预期血药浓度者3例).术后对21例受者平均随访25.4个月(6～42个月),评估SRL的临床免疫抑制效果及安全性.结果 随访期间,2例受者因药物副反应停药,药物耐受率为90.5%.发生急性排斥反应1例次,经治疗后痊愈,其余患者均获得良好的免疫抑制效果.Tac肾毒性患者肾功能改善3例;Tac肝毒性患者肝功能显著好转6例.结论 SRL作为受者肝移植术后的免疫抑制维持治疗是安全有效的.术后早期及时用SRL替换Tac可有效逆转后者所致的肝、肾毒性损害.     

Long-term immunosuppression after liver transplantation: are steroids necessary?

Steroid therapy was withdrawn in 85% of 152 orthotopic liver transplant recipients with grafts surviving for more than 3 months, and 87% of these remained steroid-free. Steroid therapy was restarted in 8% for reasons other than rejection. The most common was conversion of immunosuppression because of cyclosporine nephrotoxicity. The incidence of rejection after steroid withdrawal was low: 3.8% for chronic rejection (CR) and 4.5% for acute rejection. Only 3 grafts (1.9%) were lost because of CR. No risk factors have been identified for the development of CR after steroid withdrawal, but a protective role for azathioprine has been suggested.     

Outcomes of immunosuppression minimization and withdrawal early after liver transplantation

The Immune Tolerance Network ITN030ST A‐WISH assessed immunosuppression withdrawal in liver transplant recipients with hepatitis C or nonimmune nonviral liver disease. Of 275 recipients enrolled before transplantation, 95 were randomly assigned 4:1 to withdrawal (n = 77) or maintenance (n = 18) 1‐ to 2‐years posttransplant. Randomization eligibility criteria included stable immunosuppression monotherapy; adequate liver and kidney function; ≤Stage 2 Ishak fibrosis; and absence of rejection on biopsy. Immunosuppression withdrawal followed an 8‐step reduction algorithm with ≥8 weeks per level. Fifty‐two of 77 subjects (67.5%) reduced to ≤50% of baseline dose, and 10 of 77 (13.0%) discontinued all immunosuppression for ≥1 year. Acute rejection and/or abnormal liver tests were treated with increased immunosuppression; 5 of 32 rejection episodes required a methylprednisolone bolus. The composite end point (death or graft loss; grade 4 secondary malignancy or opportunistic infection; Ishak stage ≥3; or >25% decrease in glomerular filtration rate within 24 months of randomization) occurred in 12 of 66 (18%) and 4 of 13 (31%) subjects in the withdrawal and maintenance groups. Early immunosuppression minimization is feasible in selected liver recipients, while complete withdrawal is successful in only a small proportion. The composite end point comparison was inconclusive for noninferiority of the withdrawal to the maintenance group.     

肝或肾移植术后受者再次行一期肝肾联合移植三例报告

目的 探讨肝或肾移植术后受者再次行一期肝肾联合移植的手术适应证、术后并发症及存活情况.方法 对2003年10月至2008年12月施行的3例肝或肾移植术后再次行一期肝肾联合移植的受者进行随访,并进行文献复习.对其围手术期死亡率、术后并发症及存活情况进行总结.结果 围手术期死亡率为33.3%(1/3).术后并发症:1例因腹腔出血术后第29天死于肺部感染、急性移植肾功能衰竭和多器官功能衰竭;3例患者均发生了肺部感染;无急性排斥反应发生.2例存活患者,从首次移植计算,已经分别存活56个月和228个月;从一期肝肾联合移植计算,已经分别存活40个月和48个月.结论 肝肾联合移植是治疗终末期肝肾疾病的有效方法.肝或肾移植术后受者再次行一期肝肾联合移植是可行的.     

Nitric oxide-related neural components in the rat small intestine after transplantation

Abstract The changes in nitric oxide (NO)-related neural components in the transplanted small intestine are unknown. In this study, the NO neural component was examined using electrophysiological and NADPH-diaphorase his-tochemical techniques in a rat small bowel transplantation model. Syngeneic total small bowel transplantation was performed in 26 male Lewis rats using microsurgical techniques. The rats were divided into four groups: an untreated control group and animals at 1 (G1), 2 (G2), and 4 (G4) weeks after transplantation. Jejunal strips were mounted in a superfusion apparatus for examination. In the presence of atropine and guanethidine, the effect of the NO synthesis inhibitor L-N^G-nitro-arginine (L-NNA, 100 µM) relaxation mediated by the nonadrenergic, noncholinergic (NANC) neural system was assessed following electrical stimulation at 2 Hz. The inhibitory effect of L-NNA on relaxation was taken as an indicator of NO production. The percentage of inhibition in the control group, and in G1, G2, and G4 was 43.30 %+ 6.08 % (mean ± SE), 42.10 %± 6.69 %, 43.62 ± 10.00 %, and 52.46 %+ 6.00 %, respectively. Inhibition in G4 was significantly higher than in the other groups ( P< 0.01). The percentage of NADPH-diaphorase-positive fibers in the control group, G1, G2, and G4 was 25.06%+4.70% (mean ± SE), 26.27 %± 2.17 %, 24.73%±2.87%, and 30.76 %± 3.19 %, respectively. Again, G4 showed a significantly higher level than the other groups ( P < 0.01). We conclude that increased NO production may play a significant role in maintaining the intrinsic nervous system of the small intestine after transplantation.