白细胞介素-15在心脏移植排斥反应中的表达及意义

目的 探讨白细胞介素-15（IL-15）在心脏移植排斥反应中的表达及其与排斥反应的关系。方法 采用小鼠颈部心脏移植模型，随机分为2组：同基因移植组，供、受体均为C57BL／6小鼠；异基因移植组，供、受体分别为BALB／C、C57BL／6小鼠。以pactin作内参照，分别于术后第1、3、5、7天取移植心脏，用逆转录-聚合酶链式反应（RT—PCR）法观察IL-15的表达情况。结果 随着术后天数的增加，异基因移植组IL-15表达逐渐升高，第5天达高峰（与同基因移植组相比，P〈0．01）。结论 IL-15的表达与心脏移植急性排斥反应的发生发展密切相关，可作为心脏移植急性排斥反应的监测指标，对急性排斥反应的早期诊断和移植物的预后估计具有重要的临床意义。     

Increased apoptosis is specific for acute rejection in rat small bowel transplant

Apoptosis has been associated with several events in solid organ transplantation, including ischemia/reperfusion (IR) injury and acute rejection. To determine whether apoptosis-profiles may distinguish these two conditions, we analyzed apoptosis rates in a rat orthotopic small bowel transplant (SBT) model. SBT was performed in Lewis rats with either freshly harvested or preserved (4 h, in UW at 4 degrees C) syngeneic and allogeneic (Brown-Norway) grafts. Bowel samples were collected 2 h after reperfusion and on small bowel transplant postoperative days (POD) 1, 4, and 7. Apoptosis was detected by measuring levels of histone-associated DNA fragments and caspase 3 expression, and by determining apoptotic body counts. All markers measured 2 h after reperfusion increased profoundly in association with preservation. After a significant decrease on POD 1, apoptosis rates rose again between POD 4 and 7 only in allogeneic grafts. This distinct second increase in apoptosis may be an early and specific sign of acute rejection.     

Patchy distribution of rejection changes in small intestinal transplantation.

The aim of this study is to determine the distribution of histological changes of rejection in small intestinal transplantation. Thirty-nine rats were randomized into two groups: group I (n = 15), syngeneic transplants and group II (n = 24), allogeneic transplants. Grafts were excised and examined on days 2, 4, and 8 after transplantation. All grafts of the syngeneic group showed normal mucosa by day 4. However, by this time, all grafts of the allogeneic group demonstrated rejection changes with a patchy distribution in the mucosa. Therefore, with a biopsy from the stoma site there is a risk of missing early rejection.     

Ultra‐short echo‐time magnetic resonance imaging distinguishes ischemia/reperfusion injury from acute rejection in a mouse lung transplantation model

To investigate whether lung tissue characterization by ultra‐short echo‐time (UTE) magnetic resonance imaging (MRI) allows ischemia/reperfusion injury to be distinguished from acute rejection in a mouse lung transplantation model. After orthotopic lung transplantation with 6 mice receiving syngeneic (C57Bl/6) lung transplants and 6 mice receiving allogeneic (BALB/c) transplants, they underwent postoperative imaging using three‐dimensional UTE‐MRI (echo times TE = 50–5000 μs) and conventional T2‐weighted fast spin‐echo imaging. Quantitative T2* values of lung transplant parenchyma and spin density (SD) were compared by region‐of‐interest analysis. All samples underwent histological and immunohistochemical workup. In the allogeneic group, alveolar infiltration resulting from acute organ rejection was visualized in the UTE sequences. This was reflected by the quantitative measurements of SD and T2* values with higher values in the allogeneic group compared with the syngeneic group and nontransplanted lung at the first time point (24 h postoperative: Tx allogeneic group SD: 2133.9 ± 516; Tx syngeneic group SD: 1648.61 ± 271; P = 0.004; Tx allogeneic group T2*: 1710.16 ± 644 μs, Tx syngeneic group T2*: 577.16 ± 263 μs; P = <0.001). Changes caused by acute rejection after lung transplantation can be visualized and characterized using a UTE sequence due to different relaxation properties compared with both syngeneic lung transplants and normal lung tissue.     

Mycophenolate mofetil vs. azathioprine is associated with decreased acute rejection, late acute rejection, and risk for cardiovascular death in renal transplant recipients with pre-transplant diabetes

Outcomes specifically in mycophenolate mofetil (MMF)-treated diabetic renal transplant patients have not been previously reported. This study compared acute rejection (AR), late acute rejection (LAR), patient survival [and specifically death from cardiovascular (CV), infectious and malignant causes], incidence of post-transplant malignancies, and graft loss in MMF- or azathioprine (AZA)-treated renal transplant patients with pre-transplant diabetes. Outcomes were compared between MMF- (n = 14 144) and AZA- (n = 3001) treated diabetic patients using the Scientific Registry of Transplant Recipients data on all U.S. adult renal transplants performed between 1995 and 2002. Statistical analyses included Kaplan-Meier survival analysis, Cox multivariable regression and chi-square tests. MMF patients had less AR compared with AZA-treated patients (23.5% vs. 28.3%, p < 0.001) and less risk for LAR over 4 yr [hazard ratio (HR): 0.64, 95% CI 0.44, 0.92; p = 0.02]. While time to any-cause death did not differ between the groups, MMF treatment was associated with a 20% decreased risk of CV death (HR: 0.80, 95% CI 0.67, 0.97; p = 0.020) compared with AZA treatment. MMF patients also had a lower incidence of malignancies than AZA patients (2.2% vs. 3.7%, p < 0.001). These results suggest treatment with MMF compared with treatment with AZA in diabetic transplant patients is associated with less AR, less risk of LAR, a decreased risk of CV death, and a lower incidence of malignancies.     

Preservation injury and acute rejection of rat intestinal grafts: Protection afforded by pyruvate

Pyruvate has been shown to prevent intestinal mucosal injury after ischemia-reperfusion. The aim of the present study was to determine whether pyruvate can (1) prevent postreperfusion mucosal injury occurring after intestinal preservation and subsequent transplantation and (2) exert a protective effect on the intestinal graft mucosa during acute rejection. Preservation mucosal injury was evaluated, after 2 hours of reperfusion, by comparing grafts transplanted in a rat syngeneic combination (ACI to ACI) after 2 hours of cold preservation using pyruvate (n = 6) or placebo (n = 6). Mucosal parameters obtained during acute rejection (allogeneic combination: ACI to Lewis) were compared between placebo-treated (n =6) and pyruvate-treated (n = 6) animals. Tissue injury was evaluated by histopathologic examination, oxygen free radical production by luminol-enhanced chemiluminescence, and degree of neutrophil infiltration by myeloperoxidase staining. After reperfusion of the preserved grafts and during acute rejection, mucosal oxygen free radical levels and the number of infiltrating neutrophils were significantly (P <0.05) increased in the untreated grafts, whereas there was a statistically significant inhibition of these parameters in those treated with pyruvate. Mucosal injury, seen after reperfusion of the preserved grafts, was prevented by pyruvate. The histopathologic abnormalities observed in the untreated grafts during rejection were also significantly reduced by pyruvate. Treatment with pyruvate before cold preservation of intestinal grafts, in this rat model, reduced reperfusion mucosal injury, neutrophil infiltration, and oxygen free radical production. Oxygen free radicals were produced in the mucosa of the graft during acute rejection and their production was reduced by pyruvate, which exerted a protective effect on the rejecting allograft mucosa.     

大鼠移植心脏的细胞凋亡及其与急性排斥反应的关系

目的 观察移植心脏的细胞凋亡现象及其与急性排斥反应的关系。方法 建立大鼠异位心脏移植模型,用ＨＥ梁色和原位末端标记（ＴＵＮＥＬ）技术检测移植心脏切片,进行排斥反应的病理分级,计算凋亡指数（ＡＩ）。结果 发生凋亡的细胞主要是心肌细胞,在各级排斥反应中均可见凋亡细胞存在,且ＡＩ与急性排斥发生的分级成正相关;各级的ＡＩ与０级（无排斥反应）比较,差异均有显著性。结论 细胞凋亡与移植心脏急性排斥反应的严重程     

Thallium kinetics in rat cardiac transplant rejection

Cardiac transplant rejection is a very complex process involving both cellular and vascular injury. Recently, thallium imaging has been used to assess acute transplant rejection. It has been suggested that changes in thallium kinetics might be a sensitive indicator of transplant rejection. Accordingly, thallium kinetics were assessed in vivo in acute untreated rat heterotopic (cervical) transplant rejection. Male Lewis rats weighing 225-250 g received heterotopic heart transplants from syngeneic Lewis rats (group A; n = 13), or allogeneic Brown Norway rats (group B; n = 11). Rats were imaged serially on the 2nd and the 7th postoperative days. Serial cardiac thallium content was determined utilizing data collected every 150 sec for 2 hr. The data were fit to a monoexponential curve and the decay rate constant (/sec) derived. By day 7 all group B hearts had histological evidence of severe acute rejection, and demonstrated decreased global contraction. Group A hearts showed normal histology and contractility. However, thallium uptakes and washout of the two groups were the same. Peak thallium uptake of group B was +/- 3758 1166 counts compared with 3553 +/- 950 counts in the control group A (P = 0.6395); The 2-hr percentage of washout was 12.1 +/- 1.04 compared with 12.1 +/- 9.3 (P = 1.0000); and the decay constant was -0.00002065 +/- 0.00001799 compared with -0.00002202 +/- 0.00001508 (P = 0.8409). These data indicate that in vivo global thallium kinetics are preserved during mild-to-severe acute transplant rejection. These findings suggest that the complex cellular and extracellular processes of acute rejection limit the usefulness of thallium kinetics in the detection of acute transplant rejection.     

心肌内心电图监测和诊断大鼠心脏移植术后的排斥反应

目的寻找监测和诊断心脏移植术后排斥反应的敏感心电指标。方法建立40只改良Ono法大鼠腹部异位心脏移植模型，其中对照组（同基因大鼠心脏移植）10只，实验组（异基因大鼠心脏移植）30只。在心脏移植术中，于供心右室流出道的心肌处缝置一单极的心表起搏导线，描记心肌内心电图，测量QRS波波幅和心率。对照组大鼠在术后第7天处死，实验组分别在术后3、5、7d处死，取移植心组织进行病理检查。结果对照组大鼠的ORS波波幅在手术2d后趋于稳定，术后3、5、7d各时点间的ORS波波幅差异不显著；实验组大鼠术后ORS波波幅呈进行性下降，术后3、5、7d各时点间比较，其波幅的降低幅度差异有统计学意义。对照组和实验组大鼠术后心率变化无明显规律，两组间比较，差异无统计学意义。心肌组织病理检查显示排斥反应的分级与ORS波波幅下降有明显的相关性。结论心肌内心电图描记是监测和诊断心脏移植术后排斥反应的有效方法，ORS波波幅是诊断和监测排斥反应发生的敏感指标，严重排斥反应发生时ORS波波幅明显下降。心率的变化不是监测心脏排斥反应的可靠指标。     

血氧水平依赖的磁共振成像对早期移植肾排异的诊断和预测作用

目的 探讨血氧水平依赖的功能磁共振成像（BOLD-MRI）在早期移植肾排异中的诊断和预测作用。 方法 纳入2005年12月至2007年3月在浙江大学医学院附属第一医院肾脏病中心首次接受同种异体尸体肾移植患者共103例，分为肾功能正常组82例，急性排异组（病理证实）21例，记录两组的基线资料并测量移植肾皮、髓质磁共振参数R2*。 结果 急性排异组髓质R2*（MR2*）值显著低于肾功能正常组[（14.02±2.68）/s比（16.66±2.82）/s，P < 0.01]；ROC曲线分析显示MR2*值可作为急性排异的辅助诊断指标；肾功能正常组中低水平MR2*值（MR2*<14.9/s，23例）者日后发生急性排异的比例高于高水平MR2*值（MR2*≥14.9/s，59例）者，但差异无统计学意义（17.39％ 比 8.47％，P ＝ 0.259）。 结论 移植肾MR2*值可以作为肾移植术后早期急性排异的辅助诊断指标，并且可能有一定的预测价值。     

CD44在大鼠肾移植急性排斥反应中的表达

目的:探讨移植肾组织CD44的表达及血清中可溶性CD44的含量与急性排斥反应的关系。方法:雄性Wistar大鼠和SD大鼠分别作为供体和受体,共分为四组,采用改进的Blom法大鼠原位肾移植模型。免疫组织化学染色法检测移植肾组织CD44分子的表达;酶联免疫吸附试验测定术后血清中可溶性CD44水平的变化。结果:移植肾组织CD44分子的表达在同种异体移植组显著高于同品系移植组、手术对照组及药物治疗组(均P<0.05);移植肾组织CD44分子的表达与急性排斥反应呈正相关(皮质:r=0.734,髓质:r=0.670,均P<0.01);发生急性排斥反应的移植肾组织CD44分子的表达与Banff急性排斥反应指数无相关性(P>0.05);血清中可溶性CD44分子各组间差异无统计学意义,与急性排斥反应及Banff指数均无相关性(均P>0.05)。结论:CD44分子在肾移植急性排斥反应的发病机制中起着重要作用,为进一步提高移植排斥反应防治水平提供理论依据。     

Urine cytologic profile in renal allograft recipients determined by monoclonal antibodies. Diagnosis of allograft rejection

Controversy exists as to the type of cells present in the urine during renal allograft rejection. In order to resolve this controversy as well as to evaluate the value of urine sediment examination as a means of detecting AR, we quantitated the different cells present in urine during AR using an immunoperoxidase technique and monoclonal antibodies reactive with lymphocytes, monocytes, granulocytes, glomerular epithelial, tubular, and urothelial cells. Urine sediment (n = 176) was examined serially over 3 months in 15 transplant recipients. There were 12 episodes of early posttransplant acute tubular necrosis and 21 episodes of AR. It was possible to detect AR as well as to distinguish AR from ATN. Lymphocyte and tubular cell excretions were increased significantly during AR. Excretion of urothelial cells was also significantly increased during most episodes of AR suggesting that rejection of ureters occurs concomitantly with rejection of the kidneys.     

Increased impact of acute rejection on chronic allograft failure in recent era

BACKGROUND: Acute rejection (AR) remains a major risk factor for the development of chronic renal allograft failure (CAF), which is a major cause of late graft loss. With the introduction of several newer immunosuppressive agents (e.g., mycophenolate mofetil, tacrolimus and neoral) acute rejection rates have been steadily decreasing. However, the incidence of CAF has not decreased as dramatically as the incidence of acute rejection. One possible explanation is that the impact of AR on CAF is changing. The goal of this study was to analyze the relative impact of AR era on the development of CAF. METHODS: We evaluated 63,045 primary renal transplant recipients reported to the USRDS from 1988 to 1997. CAF was defined as graft loss after 6 months posttransplantation, censored for death, acute rejection, thrombosis, infection, surgical complications, or recurrent disease. A Cox proportional hazard model correcting for 15 possible confounding factors evaluated the relative impact of AR on CAF. The era effect (years 1988-1989, 1990-1991, 1992-1993, 1994-1995 and 1996-1997) was evaluated by an era versus AR interaction term. RESULTS: An AR episode within the first 6 months after transplantation was the most important risk factor for subsequent CAF (RR=2.4, CI 2.3-2.5). Compared with the reference group (1988-89 with no rejection), having an AR episode in 1988-89, 1990-1991, 1992-1993, 1994-1995, and 1996-1997, conferred a 1.67, 2.35, 3.4, 4.98 and 5.2-fold relative risk for the subsequent development of CAF (P<0.001). CONCLUSIONS: Independently of known confounding variables, the impact of AR on CAF has significantly increased from 1988 to 1997. This effect may in part explain the relative lack of improvements in long term renal allograft survival, despite a decline in AR rates.     

Phenotyping of ex vivo propagated graft-infiltrating cells-a tool to monitor rejection in the early post-operative period

Objective and fast methods to diagnose rejection after organ transplantation are needed. In the present study, the ex vivo propagation technique was evaluated for its ability to detect rejection at two different time-points after experimental heart transplantation. Syngeneic and allogeneic heterotopic heart transplantations were performed using inbred rat strains. After 6 or 15 days, cardiac graft biopsies were put in culture and infiltrating cells isolated by the ex vivo propagation technique. The isolated cells were counted and phenotyped by flow cytometry. In parallel, graft sections were analysed with regard to morphology and the presence of infiltrating cells as determined by immunohistochemical stainings. On day 15 after transplantation, the number of cells possible to isolate through ex vivo propagation reflected the morphological changes of the graft, i.e. considerably more cells were obtained from allogeneic transplants undergoing rejection (1052 +/- 205) than from allogeneic grafts under cyclosporine protection (513 +/- 135; p < 0.05) or from syngeneic grafts (378 +/- 87; p < 0.01). Six days after transplantation the allogeneic grafts were strongly rejected with massive cellular infiltration, still there was no difference between allogeneic and syngeneic grafts as to the number of ex vivo propagated cells. However, the proportion of IL-2-receptor expressing T lymphocytes was increased (15.4 +/- 1.8% vs. 9.5 +/- 1.4%; p < 0.05) and the CD4/CD8 ratio reduced (1.0 +/- 0.1 vs. 2.8 +/- 0.2; p < 0.001) in the allogeneic group as compared with the syngeneic. We conclude that the ex vivo propagation technique can be used to distinguish rejection from non-rejection both early and later after transplantation, provided that not just cell counting but also phenotyping of the graft-infiltrating cells is performed.     

热休克蛋白70在大鼠胰腺移植后急性排斥反应诊断中的意义

目的　探讨热休克蛋白 (HSP) 70在大鼠胰腺移植急性排斥反应诊断中的意义。方法　建立大鼠全胰、十二指肠移植模型 ,用免疫组织化学及WesternBlotting法定量检测移植胰腺组织中HSP70的表达 ,并观察其与病理学检查的相关性。结果　同基因移植组移植胰腺HSP70的表达水平在术后无明显变化 (P >0 .0 5) ;异基因移植组移植胰腺HSP70的表达水平在术后第 3、5和 7d逐渐升高 (P <0 .0 1 ) ,而且与病理学评分之间存在着明显的正相关 (P <0 .0 1 ,r =0 .934)。结论　检测HSP70在移植胰中的表达对急性排斥反应的早期诊断有一定价值     

Leakage of intraluminal low molecular weight polyethylene glycol as a marker of small bowel transplant rejection

To facilitate early detection of small bowel allograft rejection, we correlated transluminal leakage of low molecular weight polyethylene glycol (PEG) with the development of allograft rejection. Vascularized allogeneic and syngeneic jejunal transplants were performed in rats, without immunosuppression. A control group underwent creation of jejunal Thiry-Vella fistulas of similar length. Jejunal segments were perfused with a physiologic solution containing [3H]-PEG-900. At the end of an equilibrium period, an urinary bladder aspirate was collected and [3H]-PEG-900 measured by scintillation counting. Results are expressed as disintegrations per minute per 100 microL urine. Histologic examinations were performed at all experimental time points. Two days following transplantation, urinary PEG levels were elevated in both allogeneic and syngeneic groups (3943 +/- 935 and 4007 +/- 1164, respectively). Four days after the transplant, syngeneic urine PEG levels decreased to 581 +/- 159, and were not significantly different (P greater than .05) from Thiry-Vella controls (635 +/- 145). Syngeneic levels remained at this low level for the rest of the experiment. The allogeneic group continued to show significantly higher levels (P less than .05) compared with syngeneic and Thiry-Vella groups from day 4 until the end of the experiment. These elevated levels most likely represented the development of rejection, preceding the first significant histologic signs of rejection, which were found at six days post-transplant. Detection of transluminal leakage of low molecular weight PEG may be a useful adjunct in monitoring for small bowel transplant rejection.     

Quantitative analysis of cardiac 3-L-nitrotyrosine during acute allograft rejection in an experimental heart transplantation

BACKGROUND: Recent studies have shown that nitric oxide interacts with superoxide to form peroxynitrite, a potent oxidant that modifies cellular proteins producing 3-L-nitrotyrosine (N-Tyr). This study was designed to evaluate N-Tyr quantitatively with high-performance liquid chromatography (HPLC) during cardiac allograft rejection. METHODS: Rat transplanted hearts (allogeneic or syngeneic grafts) were examined with HPLC analysis, immunohistochemistry for N-Tyr, and histological studies on 0, 1, 3, and 7 days after transplantation. RESULTS: No histological rejection was found in syngeneic grafts, or day 0 or 1 allografts. HPLC demonstrated that N-Tyr in allografts increased on day 1 and continued to increase through day 7, while N-Tyr was not detected in any syngeneic grafts. Immunostaining of the allografts did not show N-Tyr on day 1. CONCLUSION: These results demonstrate that N-Tyr shows a time-dependent accumulation in cardiac allografts during acute rejection. N-Tyr detection using HPLC may be an useful maker for early diagnosis of acute rejection before pathological rejection occurs.     

Cytokine gene polymorphisms and risks of acute rejection and delayed graft function after kidney transplantation

BACKGROUND: Pretransplantation identification of patients at an increased risk for adverse events would allow more individualized treatment strategies possibly improving long-term outcome. We studied cytokine gene polymorphisms of kidney allograft recipients and their donors to identify factors predisposing for acute rejection (AR) and delayed graft function (DGF). METHODS: A total of 291 adult cadaver kidney recipients transplanted at a single transplantation centre between 1999 and 2002 were investigated. Recipients and donors were typed for TNF-alpha(-308G/A), TGF-beta1(codon 10T/C, codon 25C/G), IL-10(-1082G/A, -819C/T, -592C/A), IL-6(-174C/G), and IFN-gamma(+874T/A) polymorphisms using a SSP-PCR kit. An AR episode was defined based on clinical and histological findings (Banff criteria). RESULTS.: The incidence of AR was 17%. In univariate statistical analyses recipients with TNF-alpha -308AA-genotype were found to be at a significantly increased risk for rejection (odds ratio [OR] 5.0, 95% CI 3.0-8.3, P = 0.003). The association was independent from the patient-donor HLA-mismatch status. In addition, patients with IL-10 ACCACC, ATAATA, GCCATA (-1082A/G, -819C/T, -592C/A, respectively) haplotypes were predisposed to rejection (OR 1.9, 95% CI 1.1-3.1, P = 0.016). Further, the combination of recipient TGF-beta1 25GG-genotype and donor IL-10 -819T-allele was associated with rejection (OR 1.8, 95% CI 1.1-3.0, P = 0.027). These variables remained significant risk factors also in a multivariate logistic regression analysis. The incidence of DGF was 22%. The risk was increased by a donor TNF-alpha -308GA-genotype (OR 1.6, 95% CI 1.1-2.6, P = 0.040). CONCLUSIONS: Our results confirm that cytokine gene polymorphisms influence the outcome of kidney transplantation. Our data especially identify the TNF-alpha -308AA-genotype as a factor predisposing for AR episodes.     

肾移植后急性排斥反应发生相关术前因素分析

目的探讨影响肾移植术后发生急性排斥反应的相关术前因素,为预防移植肾急性排斥反应的发生提供临床依据。方法回顾性分析2002年1月～2008年12月在浙江大学医学院附属第一医院肾脏病中心首次接受同种异体尸体肾移植受者1316例资料,记录基线资料及术后急性排斥反应发生情况;按群体反应性抗体(PRA)水平10%和≥10%将受者分为PRA阴性组和致敏组;以2005年10月1日为界分为回顾性HLA配型组和前瞻性HLA配型组。统计分析各基线资料对术后急性排斥反应发生的影响以及不同组间急性排斥反应发生率的差异。结果手术时受者年龄、术前PRA水平、热缺血时间、HLA错配数对术后急性排斥反应的发生有显著影响。致敏组术后6个月内急性排斥反应发生率(58.8%比17.9%,P0.001)以及6个月内组织病理学检查证实急性排斥反应发生率(29.4%比11.9%,P=0.028)均显著高于PRA阴性组。采用前瞻性HLA配型后受者HLA错配数减少,且术后6个月内急性排斥反应发生率也降低(20.9%比15.5%,P=0.012)。结论术前检测受者的PRA水平从而准确评估其致敏状态,尽可能选择良好的HLA配型谱可减少移植肾术后急性排斥反应的发生。