同种异体耳移植的实验研究

目的：①观察同种异体兔耳移植后排斥反应的组织病理学、细胞免疫、体液免疫变化的情况;②为提高同种异体移植耳成活率,预防排斥反应,提供一个有效的免疫抑制治疗方案。方法：以青紫蓝兔和日本大耳白兔为实验动物。以耳大动、静脉及外侧耳缘静脉为蒂,获得单侧（右）全耳,应用显微外科微血管吻合技术进行异体移植。其中青紫蓝兔为受体,日本大耳白兔为供体。实验共选用40对（青紫蓝兔和日本大耳白兔各40只）动物,按受体免疫抑制剂治疗方案随机分为5组：O组,手术对照组（N=5对）,行自体兔耳离断回植术;C组,对照组（N=5对）,同种异体耳移植后不给予免疫抑制剂;T1组（N=10对）,同种异体耳移植后给予FK506单一免疫抑制剂;T2组（N=10对）,同种异体耳移植后给予FK506和强的松两联免疫抑制剂;T3组（N=10对）,同种异体耳移植后给予FK506、MMF和强的松三联免疫抑制剂。动脉、静脉吻合均选用端端吻合技术。术后观察移植耳存活情况、急性排异发生率及严重程度;供体组织病理分级;受体血浆IL-2、IL-4、IL-8的变化以及受体T淋巴细胞CD4^＋、CD8^＋的变化。结果：同种异体兔耳移植30天、100天后T3组在急性排斥反应发生率、供体组织病理分级和受体IL-2、IL-4、IL-8水平与CD4、CD8值的变化等方面与C组、T1组、T2组相比较均有显著差异（P〈0.05）。结论：三联免疫抑制剂方案（FK506、MMF和强的松）是预防同种异体兔耳移植排斥反应的一个有效治疗方案。     

肝肾联合移植1例报告

笔者对1例乙肝后肝硬化（失代偿期）、慢性肾衰竭（尿毒症期）的患者施行一期肝肾联合移植。采用背驮式肝移植及常规肾移植。术后免疫抑制方案采用达利珠单抗（赛尼哌）、他克莫司（FK506）、酶酚酸酯（MMF）及激素联合用药。患者顺利渡过围手术期，移植肝肾功能良好，现已存活15个月。提示完善的手术技术，围手术期合理治疗措施是肝肾联合移植成功的关键;移植肝对肾脏具有保护作用。     

我国首例异体颜面复合组织移植

同种异体颜面移植俗称"换脸术",属于同种异体复合组织移植范畴,在全世界范围内已经开展近14年。我国首例——暨世界第二例同种异体颜面移植术于2006年成功实施,成为中国异体颜面移植史上的里程碑,同时为世界同种异体颜面移植的发展奠定了一定的方法基础。笔者着重探讨中国首例换脸术的术前准备、伦理审核、手术过程、术后用药及随访检查。     

大鼠同种异体肢体移植中T淋巴细胞亚群的变化及其意义

目的 建立大鼠同种异体肢体移植模型，研究肢体移植中T细胞亚群的变化及其与急性排斥反应的关系。方法 将31只SD雄性大鼠随机分成两组，其中对照组14只为Wista→SD肢体移植术后不用药组，实验组17只为FK506(4mg／kg体重) RS-61443(30mg／kg体重)联合免疫抑制治疗组，观察各组移植术后排斥反应；用免疫荧光染色流式细胞仪检测各组手术前后T细胞亚群。结果 术后第3天，CD4／CDs比值显著增高，移植肢体开始出现肿胀、皮肤红斑等表现；CD4／CD8比值增高与排斥反应程度呈正相关，而用药组术后，CD4／CD8较术前无明显变化，未出现排斥反应。结论 T细胞亚群中CD4／CD8比值的变化与肢体移植急性排斥反应的发生、强烈程度有密切关系，可作为监测异体肢体移植急性排斥反应的免疫学指标。     

6例心脏移植围手术期的处理

目的总结6例心脏移植围手术期处理经验。方法6例晚期心肌病患者接受同种体原位心脏移植术。围术期免疫抑制剂采用赛尼哌诱导方案。维持治疗为环孢素A＋吗替麦考酚酯（或硫唑嘌呤）＋泼尼松三联方案,术后保持低水平的中心静脉压。随访23～30个月,平均（25．6＋4．2）个月。结果6例受者均存活。1例因牙髓感染并发败血症致胸部伤口延期愈合．1例出现硬膜外血肿、脑疝形成行开颅手术。所有患者围术期及随访期间受者均无急性排斥反应、移植物功能不全、肝肾功能不全等并发症。结论围术期适当强度的免疫抑制治疗,合理应用强心利尿,密切监测血流动力学和重视受者的个体化治疗是防治心脏移植术后并发症的有效方法。     

经辐照的同种异体血管在肝移植中的应用

目的研究经辐照的同种异体大隐静脉在肝移植中替代门静脉移植后其形态学和免疫学的改变。方法研究分为经辐照的同种异体大隐静脉移植组（n=11）（A组）、新鲜同种异体大隐静脉移植组（n=9）（B组）和新鲜自体大隐静脉移植组（n=14）（C组）进行大隐静脉移植。于移植后1周、2周、1个月、2个月、3个月5个时间点用彩色多普勒超声和免疫组织化学法观察移植大隐静脉的通畅情况及形态学变化,同时观察移植早期CD4^＋、CD8^＋T细胞浸润情况。结果A组大隐静脉无组织学改变,肉眼观察外形无明显变化。移植后3个月3组移植大隐静脉的通畅例数分别为9例、3例和12例。A组和C组移植后2周,移植的大隐静脉内膜出现内皮细胞,移植后2个月,血管内膜的内皮细胞覆盖完整;B组移植早期有淋巴细胞和炎性细胞浸润及明显的大隐静脉结构破坏,移植大隐静脉内膜未见内皮细胞覆盖;A组早期CD4^＋、CD8^＋T细胞比例明显低于B组,略高于C组。结论经辐照的同种异体大隐静脉符合理想的血管移植物的条件,同时具有较弱的抗原性,术后检测CD4^＋、CD8^＋T细胞的变化可作为同种异体血管移植后急性免疫排斥反应的免疫学监测指标。     

同种异体心肺联合移植1例

目的报告1例同种异体心肺联合移植术病例。方法2003年7月1例先天性心脏病、房间隔缺损合并Eisenmenger综合征女病人在全麻、中低温、全心肺转流下进行同种异体心肺联合移植术。结果手术顺利，心脏自动复跳，血流动力学平稳。无出血、感染和急性排异反应，术后1h清醒，36h拔除气管插管。第3d下床活动。术后30d病人一般情况良好，各项生命指征正常，可在隔离病房内自由活动，术后50d转普通病房。现已健康生存半年余，病人状况良好。结论选择合适的供、受体，加强心肺保存，以及重视围术期处理，同种异体心肺联合移植可以挽救终末期心肺疾患病人的生命。     

同种原位肝移植围手术期的处理

目的 总结我院自1999年8月以来，开展的3种同种异体原位肝移植（Orthotopic liver transplantation,OLT)围手术期的处理过程及经验体会。方法 2例原位肝移植，1例肝-肾联合移植术。均在术前12h口服环孢霉素A（CsA)和骁翻（MAP），术中用甲基强的松龙（MP）1000mg静脉冲击防止排斥，术后MP CsA MAP三联用药。结果 （1）中3你病人手术均获成功，其中2例原位肝移植病人存活至今，生活质量良好。肝肾联合移植病人于术后第76d死于严重混合感染。（2）移植肝的功能维护是肝移植术后处理的重点，其中包括急性排斥反应的诊断和处理，以及其它可能引起肝移植肝功能损害，衰竭等问题的处理。（3）全身非移植器官的功能恢复；包括呼吸系统，感染，出血，胸水，腹水等并发症处理过程。结论 肝移植围手术期的处理是肝移植成功与否的关键，其中包括肝移植的排斥反应及各系统的功能支持与维护。     

同种异体骨移植免疫学

１８８０年Ｍａｃｅｗｅｎ首先施行了人类同种异体骨移植术,本世纪四十年代末建立了骨库,使同种异体骨移植的临床应用更为安全可行,骨移植已成为仅次于输血最常用的移植术。同种异体骨移植与实质脏器移植有所不同,诱发的宿主免疫排异反应一般不引起危及生命的严重后果,但免疫排异反应往往干扰移植骨愈合,影响治疗效果。１　同种异体骨关节移植抗原骨骼中的矿物质不具有抗原性,胶原和非胶原蛋白仅是弱抗原,同种异体骨移植的抗原刺激主要来自其细胞膜表面组织相容性抗原（ＭＨＣ）。ＭＨＣ抗原分为两大类,Ⅰ类抗原在人类为ＨＬＡ－Ａ…     

不同的免疫抑制方案对肾移植受者免疫调节性T细胞及表面因子的影响

目的比较钙调磷酸酶抑制剂[环孢素A（CsA）和他克莫司（FK506）]与西罗莫司（SRL）对CD4^＋CD25^＋免疫调节性T细胞（CD4^＋CD25^＋Tregs）及其细胞表面标志性因子细胞毒T淋巴细胞相关抗原4（CTLA-4）和叉状头／翅膀状螺旋转录因子（Foxp3）的影响，为临床合理选择免疫抑制方案提供依据。方法选择2004年1月至4月行。肾移植的患者30例，男女不限，年龄20～50岁，随机分为3组，每组10例。（1）CsA组：免疫抑制方案为CsA＋霉酚酸酯（MMF）＋泼尼松（Pred）；（2）FK506组：免疫抑制方案为FK506＋MMF＋Pred；（3）SRL组：免疫抑制方案为SRL＋MMF＋Pred；3组的免疫诱导治疗方案均相同。各组分别于术前、术后半年、1年、2年取血样检测CD4^＋CD25^＋high／CD4^＋T细胞比值及CD4^＋CD25^highT细胞表面CTLA-4和Foxp3的表达率；比较3组治疗方案对各项指标的影响。结果应用3种不同的免疫抑制方案后，各组受者CD4^＋CD25^high／CD4^＋T细胞比值及CD4^＋CD25^highT细胞表面CTLA-4和Foxp3的表达率均明显低于术前，虽然半年后有所上升，但CsA和FK506组各项指标上升明显较SRL组慢，SRL组各项指标恢复水平明显优于钙调磷酸酶抑制剂组。结论SRL与钙调磷酸酶抑制剂比较，对CD4^＋CD25^＋Treg细胞影响明显较轻，可能对器官移植术后移植免疫耐受的诱导和维持有促进作用。     

Vascularized Bone Marrow‐Based Immunosuppression Inhibits Rejection of Vascularized Composite Allografts in Nonhuman Primates

Vascularized composite allograft (VCA) transplantation (also referred to as composite tissue allotransplantation) has demonstrated clinical success in cases of hand, arm and face transplantation despite prior belief that skin provides an insurmountable barrier to allograft rejection. These overall good outcomes are facilitated by substantial immunosuppressive requirements in otherwise healthy patients, yet still demonstrate frequent rejection episodes. We developed a nonhuman primate model of facial segment allotransplantation to elucidate the unique pathophysiology and immunosuppressive requirements of VCA with addition of concomitant vascularized bone marrow (VBM). Heterotopically transplanted facial segment VCA with VBM treated only with tacrolimus and mycophenolate mofetil (MMF) demonstrated prolonged rejection‐free survival, compared to VCA without VBM that demonstrated early rejection episodes and graft loss. While VCA with VBM demonstrated sporadic macrochimerism, acute and chronic rejection and graft loss occurred after discontinuation of immunosuppression. These data support an immunomodulatory role of VBM in VCA that reduces immunosuppressive requirements while providing improved outcomes.     

Operational tolerance in nonvascularized transplant models induced by AR-C117977, a monocarboxylate transporter inhibitor

AR-C117977, a monocarboxylate transporter inhibitor, reduces immune responses both in vitro and in vivo, maintains long-term graft survival, and induces operational tolerance. To evaluate the immunosuppressive limitations of AR-C117977, this study was performed in nonvascularized transplant models noted for their refractive response to standard immunosuppressive agents. Rat skin was transplanted from DA(RT1avl) into PVG(RT1c) and the reverse. Mouse islet allotransplantation was performed with BALB/c H2d donors and C57Bl/6J H2b recipients. In the skin graft model, AR-C117977 monotherapy was associated with long-term skin graft survival in one rat strain combination. AR-C117977 and cyclosporine A (CsA) in combination resulted in significant prolongation of graft survival in both rat strains. CsA monotherapy did not prevent acute rejection in either strain. Islet allograft survival was moderately prolonged with CsA or AR-C117977. AR-C117977 is an efficient immunosuppressive drug in stringent rodent transplant models and further studies are warranted.     

Clinicopathologic monitoring of the skin and oral mucosa of the first human face allograft: Report on the first eight months

BACKGROUND: The first human face allograft was performed in France on November 27, 2005. We report herein the clinicopathologic findings from the skin and oral mucosa of this allograft during the first eight months. METHODS: Sequential biopsies were taken from the facial skin (n = 3), oral mucosa (n = 20), and sentinel skin graft (n = 11) from day 3 to day 220 postgraft and examined (immuno)histologically, using a pathological score previously proposed for evaluation of rejection in composite tissue (hand) transplantation. RESULTS: The patient developed clinically rejection episodes at day 20 and during the eighth month postgraft, manifesting with redness and edema of the facial skin, oral mucosa, and sentinel graft skin. Pathologically, changes suggestive of rejection grades 0, I, II, and III were seen in 1, 1, 1, and 0 biopsies of facial skin, 7, 2, 1, and 1 biopsies of sentinel skin graft and 3, 5, 8, and 4 biopsies of oral mucosa, respectively. Pathological changes were generally more severe in the oral mucosa than in facial and sentinel graft skin (mean scores 1.85, 0.64, and 1, respectively). CONCLUSIONS: As it happens with other composite tissue allografts, close clinicopathologic monitoring of the skin (and oral mucosa) seems to be the most reliable way to detect rejection in the setting of human facial tissue allotransplantation. Apart from these rejection episodes, the skin and mucosa maintained a normal microscopic structure, paralleling functional recovery.     

Immunosuppressive effect of combination schedules of brequinar with leflunomide or tacrolimus on rat cardiac allotransplantation

Drug toxicity is one of the major problems in clinical immunosuppression. Combining two immunosuppressants in low or ineffective doses is an attractive strategy if it helps to reduce drug-related toxicity. We examined the immunosuppressive efficacy of brequinar (BQR) in combination with leflunomide (Lef) or tacrolimus (FK) in a heterotopic rat cardiac allotransplantation model. Abdominal heterotopic heart grafts (DA x LEW) were immunosuppressed from the time of transplantation and continued until the ninth posttransplant day (POD) in experiments examining prophylaxis of rejection treatment (PRT). In a separate series of experiments designed to test rescue treatment (RT), immunosuppression was begun on POD 4 and continued for 10 days; transplanted rats were sacrificed the following day intentionally. Cardiac rejection was monitored by palpation and documented by light microscopy. Immunosuppressive drugs (BQR 3 mg/kg and 12 mg/kg; BQR 3 mg/kg + Lef 5 mg/kg; BQR 3 mg/kg + FK 0.5 mg/kg) were given orally by gavage; thrice weekly according to the monotherapy or dual-therapy dosing protocol. Median survival time of the cardiac graft for controls (no treatment) was 5 days. BQR monotherapy 3 mg/kg (low dose) improved graft survival (P = 0.003); graft histology showed moderate acute rejection. BQR monotherapy 12 mg/kg (therapeutic dose) application in the PRT or RT treatment arms of the study design resulted in aortic-graft ruptures and clinical toxicity in each treatment arm due to overimmunosuppression; normal graft morphology was maintained. Successful rescue of rejecting grafts was histologically documented. Combining BQR with Lef or FK in the PRT protocol showed prolonged graft survival in both drug combination groups (median survival time, 14 days; P = 0.009 and 0.014, respectively). Using an identical combination protocol for RT, all grafts achieved a 14-day graft survival; cardiac histology showed reversible moderate acute rejection. BQR given in the presence of Lef or FK not only prevented acute rejection but intercepted it so long as it was administered; grafts were rejected within 4 days of stopping immunosuppression in the PRT study. These combinations using low or subtherapeutic doses may be important for controlling transplant rejection and rescuing ongoing graft rejection. The need for continuing treatment in this strongly allogeneic model is highlighted.     

Immunological advantage on small bowel graft induced by simultaneously transplanted liver in porcine auxiliary liver/small bowel transplantation

BACKGROUND: We developed a new porcine model for auxiliary liver/small bowel transplantation (LSBT). The possible immunological advantage on small bowel graft induced by simultaneously transplanted liver in the large animal was assessed. METHODS: Thirty outbreed long-white pigs were randomized into two groups. Group A animals received LSBT without immunosuppressive treatment (n = 10). Group B animals had segmental small bowel allotransplantation without immunosuppressive treatment (n = 10). The postoperative survival time, initial acute rejection time, and pathological rejection scores were analyzed. RESULTS: There was no remarkable difference in survival time between groups A and B (10.33 days vs 12.89 days, P > .05), but the initial time of acute rejection in intestinal grafts in group A was obviously delayed when compared to group B (8.22 days vs 4.33 days, P < .05), and the rejection scores in group A were remarkably lower than those of group B (0 vs 0.44 on postoperative day (POD) 3, P < .05; 0.22 vs 1.78 on POD 5, P < .05; 1.11 vs 2.56 on POD 7, P < .05). CONCLUSIONS: An immunological advantage on intestinal graft can be induced by simultaneously transplanted liver in auxiliary LSBT. Compared to isolated segmental small bowel allotransplantation, the intestinal graft in LSBT has a delayed initial time of acute rejection and lower acute rejection scores. The liver graft may reduce the risk of intestinal rejection and thus protect the bowel graft.     

Malononitrilamides synergistically prevent acute and treat ongoing skin allograft rejection with cyclosporine

Abstract The low molecular weight malononitrilamides (MNAs), a new class of immunosuppressive agents, belong to the derivatives of leflunomide's active metabolite, A771726. They have been shown to bind specifically to dehydroorotate dehydrogenase and inhibit de novo pyrimidine biosynthesis, thereby blocking T- and B-cell proliferation and strongly suppressing IgM and IgG antibody production. Here we evaluated their efficacy together with cyclosporine (CyA) in rat skin allotransplantation models, using different strain combinations. Monotherapy of transplanted animals in these models with the MNAs HMR 1279 and HMR 1715 resulted in a significant and dose-dependent prolongation of the graft survival time. Even a short-term application showed efficacy in the prevention of acute rejection. The MNAs were also effective when treatment was started at the time of expected rejection crisis, demonstrating strong therapeutic activity to reverse ongoing acute rejection, whereas CyA was ineffective for the treatment of ongoing allograft rejection episodes. Combination therapy of MNAs with CyA proved to be very effective for the prevention of acute skin graft rejection. Interestingly, whereas CyA alone was unable to treat ongoing acute rejection episodes, comedication of MNAs and CyA, even after a short-term application, was synergistically effective and significantly suppressed ongoing allogeneic skin graft rejection. These results demonstrate that MNAs are potent and well tolerated immunosuppressants with a potential comparable to that of CyA, but they are superior to CyA in their ability to reverse acute rejection episodes. They represent powerful rescue drugs and demonstrate synergistic activity with CyA to prevent acute and treat ongoing skin allograft rejection.     

Acceptance of allogeneic fibroblasts in skin equivalent transplants

Living skin equivalents (SE) were prepared by combining cultured fibroblasts with a collagen matrix and overlaying this lattice with keratinocytes. SEs prepared using allogeneic female rat fibroblasts or xenogeneic rabbit or human fibroblasts and keratinocytes isogeneic to the graft recipient were transplanted to recipient male rats. Biopsies of some of these SE grafts were examined histologically at intervals ranging from 5 days to 2 months. Biopsies of other grafts were done, and fibroblasts grown from them were karyotyped to determine the percentage of donor fibroblasts remaining in the graft. SEs containing xenogeneic fibroblasts were rejected. Allografted fibroblasts in SEs were accepted by recipient rats after a transient mononuclear cell response. A second SE allograft from the same donor strain did not provoke rejection either in the original allograft or in the challenge allograft. A secondary graft of allogeneic skin did not provoke rejection in the original SE graft, although the skin graft was rejected. Grafting the recipient first with allogeneic skin and then with the SE allograft led to rejection of the skin but not of the SE graft, ruling out the possibility that suppressor T cells were responsible for SE allograft acceptance. Allografted fibroblasts in SEs do not provoke a rejection response, even in presensitized animals, do not render the recipient tolerant to allogeneic skin, and do not act as targets when active rejection is taking place. We propose that cells bearing class I antigens may be acceptable graft constitutents if incorporated in a tissue equivalent excluding cells with class II antigens.     

Rejection and survival of auxiliary partial liver grafts in non-tissue-typed pigs

A technique for auxiliary heterotopic transplantation of 60% of the liver has been developed in the pig to study acute and chronic rejection. Transplantations were performed in 13 non-tissue-typed donor-recipient combinations without immunosuppressive medication. Three pigs died in the 1st postoperative week from technical problems. In the remaining 10 animals acute rejection of the graft was not found, but signs of chronic rejection developed in 6 animals. It is concluded that auxiliary partial liver transplantation is technically feasible in the pig. Although the auxiliary liver graft is subject to immune attack, long-term graft survival without immunosuppressive medication can be achieved.     

Cytomegalovirus and Clostridium difficile ischemic colitis in a renal transplant recipient: a lethal complication of anti-rejection therapy?

Intestinal ischemia is reported to be the most common gastrointestinal complication of renal transplantation and a potential cause of morbidity and mortality. The recent use of more potent immunosuppressive drug regimens has reduced the incidence of acute rejection, increasing the incidence of potentially fatal infectious complications, such as clinically important cytomegalovirus (CMV) infection. A 42-year-old kidney transplant recipient experienced on postoperative day 10 a dehiscence of the ureterovesical anastomosis, associated with a 7-cm longitudinal tear graft on the lower pole of the kidney and an ureteral ischemia. A graft biopsy demonstrated a mild acute rejection for which the patient received an unsuccessful administration of steroids, with progression of the rejection, so that 1 mg/kg/day antithymocyte globulin was administered. Two days later the patient presented with fever (39.5 degrees C), diffuse abdominal pain with tenderness and bloody diarrhea, and diagnosis of CMV colitis was achieved; rectal samples were taken for histologic examination, and Clostridium difficile toxin was isolated. A subtotal colectomy with Hartmann's procedure was performed, but the patient died 13 days later of a multiple organ failure. The risk of lethal CMV colitis is increased in patients being treated with anti-rejection therapy for severe acute rejection; the occurrence of simultaneous infection, such as pseudomembranous colitis, usually characterized by a favorable prognosis, increases the mortality rate in these patients.     

雷帕霉素对大鼠心脏移植的免疫抑制效果

为了探讨雷帕霉素对ＳＤ、Ｗｉｓｔａｒ大鼠心脏移植的免疫抑制效果，将大鼠分为３组，实验组给ＲＰＭ，对照且包括未治疗组及环孢素组。结果显示ＲＰＭ为一强效免疫抑制剂，治疗优于ＣｓＡ。ＲＰＭ具有强大的免疫抑制效果，可显著延长心脏移植物的存活时间。