Effect of TGF-β1 on the Expression of IL-12, IL-15, IL-18, IL-4 and IL-10 in Heart Transplantation Rejection in Rats

To investigate the effect of TGF-β1 on the expressions of IL-12, IL-15, IL-18, IL-4 and IL-10 in heart transplantation rejection in rats, a model of rat cervical heterotopic heart transplantation was set up and the model rats were randomly divided into three groups： control group, transplant group and TGF-β1 group. The mRNA expression levels of IL-12, IL-15, IL-18, IL-4 and IL-10 were determined by RT-PCR at the 5th day after the transplantation. The mRNA expression levels of IL- 12, IL-15, IL-18 were increased obviously and those of IL-4, IL-10 were significantly decreased in the transplant group as compared with the control group （P〈0.01）. In the TGF-β1 group, the mRNA ex- pression levels of IL- 12, IL- 15, IL- 18 were significantly decreased and those of IL-4, IL- 10 were significantly increased as compared with the transplant group （P〈0.01）. The immunosuppressive effect of TGF-β1 on heart transplantation rejection was related to its inhibition of the expressions of Th1-type cytokines （IL-12, IL-15, IL-18 etc） and its promotion of the expressions of Th2-tpye cyto- kines （IL-4, IL-10）.

Magnetic resonance imaging of the transplanted pediatric heart as a potential predictor of rejection

AIM To evaluate cardiac magnetic resonance imaging(CMR) as a non-invasive tool to detect acute cellular rejection(ACR) in children after heart transplant(HT).METHODS Thirty pediatric HT recipients underwent CMR at the time of surveillance endomyocardial biopsy(EMB) and results were compared to 14 non-transplant controls. Biventricular volumes, ejection fractions(EFs), T2-weighted signal intensities, native T1 times, extracellular volumes(ECVs) and presence of late gadolinium enhancement(LGE) were compared between patients and controls and betweenpatients with International Society of Heart and Lung Transplantation(ISHLT) grade ≥ 2R rejection and those with grade 0/1R. Heart rate(HR) and brain natriuretic peptide(BNP) were assessed as potential biomarkers.RESULTS Significant ACR(ISHLT grade ≥ 2R) was an infrequent event in our population(5/30, 17%). Ventricular volumes,EFs, LGE prevalence, ECVs, native T1 times, T2 signal intensity ratios, HR and BNP were not associated with the presence of ≥ 2R ACR.CONCLUSION In this pilot study CMR did not reliably identify ACRrelated changes in pediatric HT patients.

Non-Invasive Assessment of Coronary Microcirculation in Heart Transplantation

Heart transplantation (HT) is an accepted treatment for end-stage heart failure (HF). Heart transplantation significantly increases survival, exercise capacity, quality of life and return to work in selected patients with advanced heart failure compared with conventional treatment. The survival rates have improved with the use of new immunosuppressive drugs, with a median survival after transplantation of approximately 11 years. The shortage of donor hearts represents a major limitation in this field. In addition many are the consequences of the limited effectiveness and complications of immunosuppressive therapy (i.e. antibody-mediated rejection, infection, hypertension, renal failure, malignancy and coronary artery vasculopathy). In particular, chronic rejection may occur months to years after the transplantation and is referred to as cardiac allograft vasculopathy (CAV). CAV occurs in 32% of the patients after 5 years and ensuing allograft failure from CAV eventually accounts for 30% of recipient deaths after transplantation. Cardiac allograft vasculopathy, involving coronary macro- and microcirculation, is caused by complicated interplay between immunologic and non-immunologic factors resulting in repetitive endothelial injury and localized sustained inflammatory response. Early diagnosis of microvascular dysfunction is substantial. In this review we analyze signs and symptoms of CAV presentation and the different methodologies to achieve an early and precise diagnosis. We will discuss invasive and non-invasive diagnostic tools and their specific role in evaluating graft’s function, morphology, the presence of coronary artery disease and possible microcirculation involvement.

Review of heart transplantation from hepatitis C-positive donors

Significant scarcity of a donor pool exists for heart transplantation(HT)as the prevalence of patients with end-stage refractory heart failure is increasing exceptionally.With the discovery of effective direct-acting antiviral and favorable short-term outcomes following HT,the hearts from hepatitis C virus(HCV)patient are being utilized to increase the donor pool.Short-term outcomes with regards to graft function,coronary artery vasculopathy,and kidney and liver disease is comparable in HCV-negative recipients undergoing HT from HCVpositive donors compared to HCV-negative donors.A significant high incidence of donor-derived HCV transmission was observed with great success of achieving sustained viral response with the use of direct-acting antivirals.By accepting HCV-positive organs,the donor pool has expanded with younger donors,a shorter waitlist time,and a reduction in waitlist mortality.However,the longterm outcomes and impact of specific HCV genotypes remains to be seen.We reviewed the current literature on HT from HCV-positive donors.

Monitoring of Acute Rejection after Orthotopic Heart Tranplantation

Objectives To study the monitoting of rejection after orthotopic heart thansplantation. Methods From 1998 to 2005, 10 othotopic heart thansplans were performed, and acute rejection was monitored by endomyocardial biopsy as well as by clinical features, ECG, ultrasonocardiography and blood serum determination of Tropin Ⅰ, and by the combination of these methods, we analysed the monitoring of acute rejection after the heart transplantation. Results With the combination of clinical features, ECG, ultrasonocardiography and blood serum test, 5 occurences of acute rejection were judged in the postoperative course, which were comfirmed by endomyocardial biopsy to be 2 acute rejections in Ⅰ b degree, 3 acute rejections in Ⅲa degree. Endomyocardial biopsy were routinely performed 21 times postoperatively in which there were 1 acute rejection in Ⅰa degree and 5 acute rejections in Ⅰ b degree. Conclusions Acute rejection is an important factor influencing the postoperative course of heart transplantation, so it is imperative to have an intime, effective and planned monitoring procedure for acute rejection. Endomyocardial biopsy is a sensitive and reliable method in diagnosis of acute rejection, but it is invasive and probable for some complications. The noninvasive method such as clinical features, ECG, ultrasonocardiography and blood serum test can be used as additive means in the diagnosis of acute rejection. Endomyocardial biopsy should be combined with some noninvasive methods in monitoring acute rejection after the heart transplantation.

Persistent Epstein-Barr viral load in Epstein-Barr viral na?ve pediatric heart transplant recipients:Risk of late-onset post-transplant lymphoproliferative disease

AIM To examine the risk of late-onset post-transplant lymphoproliferative disorder(PTLD) in the presence of persisting high Epstein-Barr virus(EBV) in EBV na?ve pediatric heart transplant(HT) recipients. METHODS A retrospective review of the medical records of the 145 pediatric HT recipients who had serial EBV viral load monitoring at our center was performed. We defined EBV naive patients whose EBV serology either IgM or IgG in the blood were negative at the time of HT and excluded passive transmission from mother to child in subjects less than 6 mo of age. RESULTS PTLD was diagnosed in 8 out of 145 patients(5.5%); 6/91(6.5%) in those who were EBV seropositive and 2/54(3.7%) in the EBV na?ve group at the time of HT(P = 0.71). We found 32/145(22%) patients with persistently high EBV load during continuing follow-up; 20/91(22%) in EBV seropositive group vs 12/54(22%) in EBV na?ve group(P = 0.97). There was no significant association between pre-HT serostatus and EBV load after transplant(P > 0.05). In the EBV seropositive group, PTLD was diagnosed in 15%(3/20) of patients with high EBV vs 4.2%(3/71) of patients with low or undetectable EBV load(P = 0.14) whereas in EBV na?ve patients 8.3%(1/12) of those withhigh EBV load and 2.3%(1/42) with low or undetectable EBV load(P = 0.41). There was a highly significant association between occurrence of PTLD in those with high EBV load and duration of follow up(4.3 ± 3.9 years) after HT by Cochran-Armitage test for the entire cohort(P = 0.005). At least one episode of acute rejection occurred in 72%(23/32) of patients with high EBV vs 36%(41/113) patients with low or undetectable EBV after HT(P < 0.05). CONCLUSION There is an association between persistently high EBV load during post-HT follow up and the occurrence of late-onset PTLD in pediatric HT recipients irrespective of serostatus at the time of transplant. The occurrence of allograft rejection increased in patients with high EBV load presumably due to reduction in immunosuppression.

Effect of FTY720 and ICAM-1 mAb mono and combination therapy in cardiac allo-transplantation in rats

Objective To observe the effect of FTY720 and ICAM-1 mAb mono and combination therapy in cardiac silo-transplantation in rats.Methods Rats were randomly assigned to 9 groups,heart allo-transplantation were performed in abdominal site with micro-surgical technique.Recipients with allografts were treated with different doses of FTY720 and(or)ICAM-1 mAb.Graft survival,histopathology andlevel of serum IL-2,IFN-γ,IL-4,IL-10were investigated.Results Low doses of FTY720(lmg/kg)combined with ICAM-1 mAb achieved synergistic effect in the prolongation of cardiac graft survival,combination index CD=0.67.Conclusion Concomitant therapy of FTY720 and ICAM-1 mAb achieved a synergistic effect in the prolongation of heart allograft survival in rats.

异种器官移植排斥反应及其预防治疗策略

异种器官移植是解决人类器官短缺问题的潜在方案。在过去的上百年里,异种器官移植经历了早期尝试和不断进步,目前已进入新的高速发展阶段,取得了一系列的成果,但异种器官移植排斥反应的管理较同种异体器官移植排斥反应更为棘手。为此,研究者们开发出了一系列免疫抑制策略,如使用基因修饰猪供体、使用传统和新型免疫抑制药、将供体猪的胸腺与供器官一同移植等,以实现调整受体免疫系统反应,降低排斥反应强度并延长移植物存活时间。本文就异种器官移植排斥反应发生机制、预防和治疗策略的相关研究进行评述,以期为促进异种器官移植的进一步发展提供参考。

异种器官移植配型现状及解决思路

器官移植术前配型是器官移植成功与否的关键,当前的异种器官移植术前配型方法源于人类同种异体器官移植,但方法简单,不能准确预判移植术后是否会发生排斥反应。异种器官移植的一个显著特点是供体来源稳定、基因型明确,因此取材方便,可重复性强。充分利用异种器官移植中供体可控的优势,在完善传统细胞学配型基础上,拓展组织水平配型手段,重视内皮细胞在配型中的作用,开发器官水平配型方法,通过多环节、多维度的术前配型有利于精确筛选出合适的供体,有利于减少异种器官移植术后排斥反应的发生。为此,本文从同种异体器官移植配型方法,当前异种器官移植配型方法、存在问题及可能的突破点进行综述,以期为异种器官移植配型的进一步研究提供参考。

Using intramyocardial electrograms combined with other noninvasive methods for monitoring acute rejection following human heart transplantation

Background Acute allograft rejection in heart transplantation remains as one of the major complications. Obligatory graft surveillance is still achieved with the invasive and expensive endomyocardial biopsy （EMB）. Our study aimed to study the use of intramyocardial electrograms combined with other noninvasive methods for the monitoring of acute rejection after human heart transplantation. Methods Permanent pacemakers were implanted in 58 patients undergoing heart transplantations. Intramyocardial electrograms （IMEG） were recorded periodically and the results were compared with those from EMBs. The R wave amplitude of the IMEG was used as the index value, the average R wave amplitude at the third week following transplantation was considered as the baseline, and a reduction of 〉20% compared with the baseline was regarded as a positive result. EMB was performed in cases of positive IMEG results and also at other times. Other noninvasive methods were used to help the diagnosis. Acute rejection （AR） was defined as International Society of Heart-Lung Transplantation grade IliA or higher. Results We obtained 1231 IMEG records and 127 EMBs. Of the total 127 EMBs, 53 were positive, in which there were 42 IMEG positive results and 11 negative, while in the rest 74 negative EMBs, there were 9 IMEG positive results and 65 negative. The sensitivity of IMEG for the diagnosis of AR was 79.2%, and the specificity was 87.8%. The positive predictive value was 82.4% and the negative predictive value was 85.5%. Of the total of 1231 IMEG records, 51 were positive and 1180 were negative. Excluding 11 proved by EMB to be false negative, if the other 1169 were considered as no evidence of rejection, through the other noninvasive methods, AR diagnosed by this noninvasive monitoring strategy, the sensitivity was 79.2%, and the specificity was 99.2%. The positive predictive value was 82.4% and the negative predictive value was 99.1%. Conclusions IMEG can be used as a noninvasive method for monitoring AR following heart transplantation. It is a continuous, safe and inexpensive method, and could reduce the need for EMB combined with other noninvasive methods without reducing the detection of rejection. Chin Med J 2009; 122（2）： 136-139

单细胞测序揭示心脏移植物中树突状细胞和B细胞的抗原提呈特性

目的探讨心脏移植物中树突状细胞(DC)和B细胞的抗原提呈特性。方法将BALB/c小鼠的心脏移植到C57BL/6J小鼠腹腔内,术后5 d(急性排斥反应早期)提取并流式分选心脏移植物中的CD45+细胞,进行单细胞RNA测序。以心脏移植物中的DC和B细胞的亚群为主要对象,通过生物信息学分析和流式细胞术,研究其在心脏移植后变化趋势、抗原提呈能力及其与T细胞之间的胞间通讯情况。采用基因本体(GO)功能富集差异分析佐证细胞亚群特异性功能和细胞亚群注释可信度。结果生发中心样B细胞(GC-L B)是急性排斥反应期心脏移植物中增幅最大、比例高达87%的B细胞亚群,经典DC(cDC)2是心脏移植急性排斥期间唯一大量增多的DC亚群,占44%,是心脏移植后与T细胞的胞间通讯中占据最高通讯强度的DC亚群;单核样DC(moDC)与记忆性B细胞(MBC)是未心脏移植中T细胞输入信号的主要发出者,而在心脏移植后急性排斥反应期中,转变为cDC2与GC-L B;其中MBC与GC-L B分别是心脏移植前后的主要T细胞输入信号来源。结论在未移植心脏和移植心脏指向T细胞的胞间通讯中,与DC相比,B细胞均占据更高的通讯数量和权重,推测在心脏移植急性排斥反应早期,B细胞的抗原提呈活动比DC更加活跃,强度更大。

异种肝移植的探索之路:从科学研究走向临床应用

随着手术技术进步及围手术期管理水平提升,器官移植受者及移植物存活率显著提高,供器官短缺已成为限制器官移植进一步发展的主要障碍。近期,以基因修饰猪为供体的异种肾移植和异种心脏移植已进入临床试验并取得了不错的效果,异种移植再一次成为生物医学研究的热点。与心脏和肾脏相比,基因修饰猪的肝脏在非人灵长类动物体内的存活时间还比较短,且实验结果差异性较大,尚不具备进入临床试验的条件。因此,本文从术式选择、凝血功能障碍和急性血管性排斥反应3个方面,总结目前异种肝移植的研究进展,讨论阻碍异种肝移植进入临床试验的主要问题及可能的解决策略,以期为异种肝移植从科学研究走向临床提供参考。

异种实体器官移植亚临床研究中的突破与问题

异种实体器官移植是指将非人类来源的心脏、肾脏、肝脏等实体器官移植到人类受体中的一类探索性治疗技术。目前,来源于异种基因编辑猪肾脏、心脏的非人灵长类异种实体器官移植动物模型中已获得2~3年生存记录,因此,进一步改进基因编辑方式和效果,推进异种移植进入临床已成为器官移植的热点。2021—2023年,国外研究团队已经开展了十余例基因编辑猪脑死亡遗体的肾脏和心脏移植亚临床研究,均未出现超急性排斥反应。本文综述近年报道的7例异种移植亚临床研究结果及2例猪心移植病例,讨论异种心脏、肾脏移植目前亟待解决的问题,为我国异种移植进入临床阶段研究提供一定的参考。

CD47在肾移植中的最新研究与展望

CD47是一种广泛表达于细胞表面的跨膜蛋白,被认为是细胞发生免疫逃逸的关键分子。随着相关研究日益增多,CD47及其配体参与的免疫调节作用逐渐被人们所知晓。近年来,多项研究探讨了CD47在同种异体肾移植缺血-再灌注损伤、排斥反应以及异种肾移植中的作用,但具体作用还有待明确,关键机制仍不清楚。因此,本文从CD47的结构和功能、CD47的常见配体、CD47与肾移植的关系以及CD47在肾移植中的应用进行综述,总结CD47在肾移植中的最新研究进展,分析现有研究的不足和未来研究的方向,以期为后续CD47在同种和异种肾移植中的应用提供参考。

国际首例6-基因编辑猪-猴肝肾联合移植围术期治疗研究

目的探讨国际首例6基因编辑猪猴肝肾联合移植模型的构建,探究异种肝脏移植对异种肾脏移植的影响。方法将人源化6基因编辑猪的肝脏、肾脏移植给恒河猴受体,肝脏移植采用腹腔异位移植,肾脏移植采用原位移植,保留对侧肾脏,观察血流灌注恢复后,移植肝、肾的情况及受体存活情况;定期进行移植物超声及功能检查;监测受体猴生化指标及生理指标变化;受体猴生命终点取移植肾、移植肝进行病理检查。结果手术历时14 h结束,术后受体猴各项生理指标基本正常,移植物开放血流后可见移植肝灌注良好,即刻可见胆汁流出;移植肾灌注良好,即刻可见尿液流出,未见明显超急性排斥反应发生;术后移植肾功能良好,术后5 d移植肾尿量减少,考虑排斥反应发生,术后受体猴最终存活14 d。结论多基因编辑猪猴异种肝肾联合移植模型构建成功,术后移植肾未见明显超急性排斥反应发生,异种肝移植可减轻异种肾脏移植急性排斥反应发生。

六基因编辑猪-食蟹猴异种肾移植围手术期监测初步报道

目的探讨六基因编辑猪-非人灵长类动物异种肾移植模型的构建。方法将人源化基因编辑猪(GTKO/β4GalNT2KO/CMAHKO/hCD55/hCD46/hTBM)的肾脏移植给食蟹猴,观察受体存活情况及恢复血流灌注后肾脏情况。定期监测肾脏实质回声、血流变化及大小;进行血常规、肾功能检测及电解质检测;监测尿液、粪便及体质量动态变化。食蟹猴生命终点取移植肾、心脏、肝脏、脾脏、肺脏、盲肠行病理学检查。结果受体术后7 d死亡。恢复血流后,肾脏灌注良好,器官质地柔软,色泽正常。受体生命终点时见肾脏腹侧有少量脓性分泌物附着,明显充血肿大,呈“大红肾”外观。术后随时间延长,肾实质回声增高,血流减少,皮质逐渐增厚,肾周及腹腔有少量积液。受体术后外周血红细胞、血红蛋白、白蛋白及血小板进行性下降,血清肌酐在术后7 d升高至308μmol/L,K^(+)变化不大。术后即有淡黄色尿液排出,术后3 h内即恢复饮食及饮水并排淡黄色成形大便1次。术后1 d内尿液颜色逐渐变淡红至恢复正常,尿常规检测结果相符。术后2 d晨起排褐色血便2次,量较多,予以奥美拉唑进行抑酸治疗,至术后4 d大便恢复正常。β2-微球蛋白在术后7 d增至0.75 mg/L。体质量增加1.7 kg。尸检病理学检查发现移植肾间质水肿出血,大量淋巴细胞和巨噬细胞浸润,小动脉壁及动脉腔内淋巴细胞浸润,有动脉炎改变;盲肠间质有淋巴细胞浸润;脾脏组织有淤血表现;其余器官未见明显异常改变。结论人源化基因编辑猪-非人灵长类动物异种肾移植模型构建获得初步成功,术后受体存活时间达1周。

“转基因猪心”可期?异种心脏移植研究进展

心脏移植是终末期心力衰竭的有效治疗手段,但供体严重不足制约了心脏移植的广泛开展。异种移植由于供体器官来源不受数量和时间的限制,可以更好地满足临床需要,最有可能成为解决供需矛盾的可靠方法。近年来,由于基因编辑猪的应用及新的免疫抑制方案实施,心脏异种移植实验研究方面取得了巨大的进展,相继克服了超急性排斥反应、早期移植物失功、人畜共患病及异种移植器官过度生长等难题。在此基础上,研究者开展了一系列准临床级别的人体试验,取得了巨大的突破。但是,异种移植仍面临如何维持移植心脏长期存活及开展临床试验所涉及的伦理和行政监管等诸多问题的挑战。本文通过对异种移植研究现状及面临的问题进行综述,为心脏异种移植的进一步实验研究和临床试验提供更多的思考。

基因编辑“猪-恒河猴”异位心脏异种移植的围术期治疗及管理经验

目的总结异种异位心脏移植动物实验的经验,旨在为成功转化基因编辑猪心脏异种移植临床应用积累研究基础。方法2022年10月在1只恒河猴的腹腔内完成了异位猪心脏移植。“猪-恒河猴”异位心脏异种移植实验从多个方面对受体进行精细化管理,围术期针对免疫排斥和凝血功能障碍,维持供体心脏功能,延长受体生存时间,尽可能保证其生存和生活质量。结果受者存活20天,死于凝血功能障碍。结论为了克服免疫排斥、跨物种感染、凝血功能障碍等致命障碍,仍需要大量的临床前动物实验。

心脏移植和人工心脏治疗终末期心力衰竭面临的问题与挑战

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