细胞因子在心脏移植急性排斥反应中的表达及其作用机理

目的观察同种大鼠心脏移植急性排斥反应中,局部细胞因子网络的变化及其机理.方法健康雄性Wistar大鼠(受体)和SD大鼠各48只,将接受移植心脏的Wistar大鼠分4组,每组12只.A组对照组;B组抗白介素2单克隆抗体(IL-2Mab)组;C组环孢菌素A(CsA)组;D组IL-2Mab加CsA组.4组大鼠分别静脉给予生理盐水、抗白介素2单克隆抗体及口服CsA、静脉给予抗白介素2单克隆抗体加口服CsA,采用改良的移植术式建立移植模型.常规监测排斥反应发生情况.应用RT-PCR的方法于术后第1、3、5、7、9、11、14天动态检测移植物局部细胞因子IL-1β、IL-2、CD25、IL-4、IL-5、IL-6、IL-10、TNFα、IFNγ的表达水平.结果移植心脏存活时间,A组为(8.3±1.7)d;B组为(29.2±7.1)d;C组为(26.4±5.7)d;D组为(55.0±11.6)d.B、C、D组移植心脏存活时间显著延长,与A组相比,差异有极显著性意义(P＜0.01).存活时间较长的移植心脏的淋巴细胞浸润和心肌坏死的程度比存活时间较短的心脏明显减轻.IL-1β的表达在各组均较高;IL-4、IL-5、IL-6、IL-10的表达水平在移植心脏存活时间较长的组较高;而IL-2、CD25、IFN-γ、TNFα的表达则相对较低;4组相比差异有显著性意义(P＜0.05).结论细胞因子网络在心脏移植排斥反应中发生了相应的变化,并与干预的因素及移植物存活时间有密切的关系.IL-2Mab、CsA联合用药促使TH1类细胞因子向TH2类细胞因子整体偏离,这种免疫偏离使移植心脏存活时间显著延长.     

Glomerular transplant rejection: a distinctive pattern of early graft damage

Five hundred seventy-six consecutive biopsy or nephrectomy specimens obtained during the first 6 months of transplantation from 300 grafts in 431 recipients were examined by light microscopy for focal or diffuse endocapillary hypercellularity. Forty-seven (8.2%) of the 576 specimens obtained from 37 (12.3%) of the 300 grafts exhibited segmental or global occlusion of capillaries by swollen cells in 40-100% of glomeruli per biopsy. The lesions occurred at any time after transplantation, but 34 (72.3%) were present by day 60 and 7 (14.9%) before day 10. Immunofluorescence in 39 affected biopsies revealed focal or segmental glomerular staining in 18 (46.2%), among which IgM was found most frequently, and was considered to be non-specific. Electron micrographs of 17 biopsies from 14 grafts revealed that glomerular capillaries were narrowed or occluded by mononuclear cells of uncertain type, possibly monocytes, as well as lymphocytes and a few neutrophils. Complement-fixing antibody titers to cytomegalovirus rose at least fourfold in 10 (45.5%) of the 22 patients studied, but glomerular lesions were no more severe in the seroconverters than in the non-converters, and there was no consistent temporal relationship between the occurrence of glomerular changes and seroconversion. Cellular or vascular rejection was present in most biopsies. One year graft survival was 34% among 35 accessed grafts with glomerular lesions, compared to 55% among 243 biopsied grafts with no glomerular changes. We consider that these lesions do not have a consistent association with cytomegalovirus infection and that they represent a distinctive form of glomerular rejection. Whether they indicate a poor graft survival, as the present results suggest but do not prove, requires further studies of other series of cases.     

Expression of membrane-bound mucins (MUC1 and MUC4) and secreted mucins (MUC2, MUC5AC, MUC5B, MUC6 and MUC7) in mucoepidermoid carcinomas of salivary glands

Mucins are glycoproteins normally synthesized by a variety of secretory epithelial cells. The aim of this study was to investigate the expression of mucins (MUC1, MUC2, MUC4, MUC5AC, MUCB, MUC6, MUC7) in mucoepidermoid carcinomas, the most frequent malignant tumor of salivary glands. Forty mucoepidermoid carcinomas and twenty-two normal salivary glands were studied for these mucins by immunohistochemistry from formalin-fixed and paraffin-embedded material. Normal salivary glands frequently expressed MUC1 and MUC4, mainly in ductal cells; MUC5B and MUC7 stained mucous and serous acini respectively of submandibular and minor salivary glands; and MUC5AC and MUC2 were poorly detected in excretory ducts. All mucoepidermoid carcinomas expressed MUC1, and 38/40 tumors expressed MUC4. Both membrane-bound mucins stained membranes and cytoplasm of all cell types (epidermoid, intermediate, mucous, clear and columnar). MUC5AC and MUC5B stained glandular differentiated cells in most tumors (29/40 and 33/40 cases, respectively). MUC6 was positive in 13/40 tumors, and both MUC2 and MUC7 in only 2/40 tumors. The high expression of MUC1 was related to high histologic grades, high recurrence and metastasis rates and a shorter disease-free interval (P < 0.05). Conversely, MUC4 high expression was mainly related to low-grade tumors, lower recurrence rates and a longer disease-free interval (P < 0.05). In conclusion, mucoepidermoid carcinomas of salivary glands usually express MUC1, MUC4, MUC5AC and MUC5B; less frequently MUC6; and rarely MUC2 and MUC7. This mucin expression pattern can be useful for diagnostic purposes. Therefore, MUC1 expression is related to tumor progression and worse prognosis, whereas MUC4 expression is related to a better prognosis.     

51Cr-EDTA: a marker of early intestinal rejection in the rat

Intestinal permeability was studied after accessory intestinal transplantation in Lewis rats. Five groups were evaluated: Group 1--isografts (N = 6); Group 2--Lewis X Brown Norway F1 (LBN-F1) allografts (N = 6); Group 3--isografts treated with CsA 2 mg/kg/day X 10 days (N = 6); Group 4--LBN-F1 allografts treated with CsA 2 mg/kg/day X 10 days (N = 6); Group 5--LBN-F1 allografts treated with CsA 4 mg/kg/day X 28 days (N = 6). Chromium-labeled ethylenedimianetetraacetate (51Cr-EDTA) was given through the proximal stoma of the graft. Renal clearance of 51Cr-EDTA and mucosal biopsies were followed post-transplant. The biopsies of the intestinal graft showed no rejection in Groups 1, 3, and 5; fulminant rejection in Group 2; and mild atypical rejection in Group 4. 51Cr-EDTA clearance was elevated in all groups during the first 7 days post-transplant. Thereafter, 51Cr-EDTA excretion fell to lower levels in the animals with histologically normal grafts (Groups 1, 3, and 5). 51Cr-EDTA excretion in Group 4 was increased with the first histological evidence of rejection on Day 14 and remained elevated until sacrifice (P less than 0.02 compared to Groups 3 and 5). A transient permeability defect occurs after intestinal grafting. Once the graft has recovered from this injury, 51Cr-EDTA is a sensitive marker for intestinal rejection.     

Cytokine gene polymorphism and early graft rejection in liver transplant recipients

Cytokines, which play important roles in allograft rejection, show variable production among individuals. These variations may be related to genetic polymorphisms within the regulatory regions of the cytokine genes. We investigated the association between the role tumor necrosis factor alpha (TNF-alpha), transforming growth factor-beta (TGF-beta), interferon gamma (IFN-gamma), interleukin (IL)-10 and IL-6 gene polymorphisms and early graft rejection among liver transplant recipients. Forty-three liver transplant recipients enrolled in this study were divided into 2 groups based on events in the first 2 months posttransplantations, namely, those experiencing at least 1 rejection episode (n = 26) or those without any episode (n = 17). The allele or genotype frequencies of cytokine gene polymorphisms showed no difference between liver recipients with or without nonrejection. In conclusion, there was no significant correlation between early graft rejection and cytokine gene polymorphism of TNF-alpha, TGF-beta, IL-10, IL-6, and IFN-gamma in liver transplant recipients.     

Accelerated acute rejection of the intestinal graft in CD28-deficient mice

OBJECTIVE: Multiple in vivo studies have shown that the pace and severity of graft rejection is little or not at all changed by deleting CD28 molecules in the recipient. These findings contrast with the effects of monoclonal antibody therapy aimed the same costimulatory target. The objective of the present study was to evaluate how the acute rejection process is affected in CD28-deficient mice using a fully allogeneic, highly immunologically reactive transplant model. METHODS: Heterotopic vascularized small bowel transplants were performed in 24 recipient mice divided into 4 groups: 2 wild-type and 2 knockout groups. Each group consisted of 5 to 7 animals in which BalbC mice were used as intestinal donors to either wild-type C57BL6 or C57BL6 background CD28-deficient recipient mice. Selected endpoints were 3 and 6 postoperative days (POD). Intestinal rejection was evaluated by mucosal laser Doppler flowmetry (expressed in perfusion units) and histology (expressed in rejection grades). RESULTS: Acute rejection occurred in both wild-type and CD28-deficient groups. At POD 3, no significant difference was noted between groups in terms of mucosal perfusion and histology. At POD 6, significant differences in graft mucosal perfusion and histology revealed a more aggressive rejection in the CD28-deficient group compared to the wild-type group. CONCLUSIONS: The present study showed that the severity of intestinal graft rejection responses was amplified by deleting CD28 molecules. Together with data from other studies, these results suggest a different pattern of distribution and/or activation of CD28/B7 receptors in various organs.     

MUC1, MUC2, MUC4, and MUC5AC expression in salivary gland mucoepidermoid carcinoma: diagnostic and prognostic implications

We determined whether immunostaining for mucins could provide a better characterization of salivary gland mucoepidermoid carcinoma (MEC). We investigated 63 MECs by immunohistochemistry for MUC1, MUC2, MUC4, and MUC5AC. Mucin expressing cell types and labeling patterns were recorded. The results were compared with microscopic grade, tumor-associated lymphoid infiltrate, mucin expression in surrounding salivary glands, clinical features, and outcome. MUC1 and MUC4 labeled the apical membrane of glandular tumor cells and the entire membrane of intermediate, clear, and epidermoid tumor cells. MUC2 and MUC5AC were expressed in the cytoplasm of glandular, mucous, and intermediate tumor cells. In contrast to MUC1, MUC4 expression decreased with tumor grade (P < 0.01). Unlike MUC2, MUC5AC was expressed in more than 50% of high-grade tumors, including 2 cases that were not stained with Alcian blue. MUC1 and MUC5AC were associated with tumor-associated lymphoid infiltrates (P < 0.05), but not with tumor-associated lymphoid follicles. The proportions of tumors expressing mucins were 71% for MUC1, 21% for MUC2, 79% for MUC4, and 68% for MUC5AC. MUC1 and MUC5AC were more frequently expressed in tumors than in surrounding glands (P < 0.0001). MUC1 expression correlated with shorter progression-free survival (P < 0.05). In conclusion, mucin expression in MEC differs from that in salivary glands. Intermediate cells express MUC1 and MUC4 all along their cell surface and MUC2 and MUC5AC in their cytoplasm. Staining for MUC5AC in high-grade tumors can be helpful for distinguishing high-grade MEC from squamous cell carcinoma. While MUC4 is related to tumor differentiation, MUC1 expression indicates a worse prognosis.     

Creatinine clearance and proteinuria as early markers of kidney graft survival

Introduction

In patients who receive a kidney transplant from expanded criteria donors (ECDs), few studies are available concerning the relation between the clinical characteristics, pretransplant biopsies, and graft outcomes.

Aim

To identify early clinical markers predicting worse graft survival in recipients of kidneys from ECDs.

Materials and methods

Between 1999 and 2006, we performed a prospective, observational study in 180 recipients of kidney grafts from ECDs that had undergone a preoperative biopsy to evaluate viability. The patients received immunosuppression with basiliximab, late introduction of tacrolimus, mycophenolate mofetil, and steroids. Data were gathered on demographic and posttransplantation clinical characteristics at 1, 3, 6, and 9 months, including estimates of proteinuria and of the glomerular filtration rate using the Modification of Diet in Renal Disease (MDRD) formula.

Results

The mean age of the donors was 63.54 years and of the recipients, 58.38 years. A creatinine clearance below the median (40 mL/min, interquartile range 32-50 mL/min) in the first posttransplant year was significantly associated with worse death-censored graft survival (log-rank 14.22, P < .0001). A proteinuria value above the median (100 mg/24 h, interquartile range 40-275 mg/24 h) at 1 year posttransplant significantly reduced the death-censored graft survival (log-rank 14.3, P < .0001). Multivariate Cox analysis showed that a creatinine clearance < 40 mL/min in the first year (hazardsratio [HR] 5.7, 95% Confidence Interval [CI] 1.62-20.37; P = .007) and proteinuria at 1 year greater tan 100 mg/24 h (HR 8.3, 95% CI 2.15-32.06; P = .002) were independent risk factors for death-censored graft loss after adjusting for donor age and acute rejection episodes.

Conclusions

Limited renal function and/or low proteinuria at 1 year posttransplant were associated with worse kidney graft survival among recipients of kidneys from ECDS.     

Serum albumin level during intestinal exfoliative rejection: a potential predictor of graft recovery and patient outcome

Exfoliative rejection is a severe complication after intestinal transplant. The assessment of mucosa histology is restricted to the area reached by endoscopy. We aim to evaluate the serum albumin (SA) value as a parameter of graft damage and clinical prognosis in intestinal exfoliative rejection (ExR). The present study is a retrospective analysis of 11 episodes of ExR occurred in a cohort of 26 patients. SA levels were measured 24 h after diagnosis and twice a week thereafter and then correlated with parameters of clinical and graft histological recovery (HR). During ExR, all patients had very low SA levels, reaching a minimum average of 1.9 ± 0.3 g/dL. According to the value of albumin levels at ExR diagnosis, the patients were grouped finding a correlation with their clinical evolution. Six ExR episodes presented with severe hipoalbuminemia (<2.2 g/dL; p < 0.05) that correlated with worse patient and graft outcome, ranging from graft loss and need for re‐transplantation to delayed clinical and HR. SA at ExR diagnosis may be an indicator of the severity of the ExR process, and it could also be used as an early predictor of patient and graft outcome.     

In vivo bioluminescence imaging of transplanted islets and early detection of graft rejection

BACKGROUND: Bioluminescence imaging (BLI) modalities are being developed to monitor islet transplant mass and function in vivo. The aim of this study was to use the BLI system to determine how the change in functional islet mass correlated to metabolic abnormalities during the course of alloimmune rejection in a murine transplant model. METHODS: Islets obtained from a transgenic mouse strain (FVB/NJ-luc) that constitutively expressed firefly luciferase were transplanted to various implantation sites of syngeneic wild-type FVB/NJ or allogeneic Balb/C streptozotocin-induced diabetic recipients. In vivo graft luminescent signals were repeatedly measured after transplantation using the BLI system and related to blood glucose levels and graft site histologic findings. RESULTS: The BLI signals were detected in as few as 10 islets implanted in the renal subcapsular space, intrahepatic, intraabdominal, and subcutaneous locations. There was a linear relationship between the number of islets transplanted and luminescence intensity. In isografts, stable luminescence intensity signals occurred within 2 weeks of transplantation and remained consistent on a long-term basis (18 months) after transplantation. In allografts, after normoglycemia was achieved and stable luminescence intensity occurred, graft bioluminescent intensity progressively decreased several days before permanent recurrence of hyperglycemia as a result of histologically proven rejection ensued. CONCLUSIONS: Bioluminescence imaging is a sensitive method for tracking the fate of islets after transplantation and is a useful method to detect early loss of functional islet mass caused by host immune responses even before overt metabolic dysfunction is evident. Bioluminescence imaging holds promise for use in designing and testing interventions to prolong islet graft survival.     

辅助性同种异体肝肠联合移植术后急性排斥反应的监测

目的评价猪同种异体辅助性肝肠联合移植术后排斥反应的监测方法。方法将50头杂交长白猪分为3组．A、B组各20头各完成10次猪辅助性带胰头及十二指肠的同种异体肝肠联合移植术．其中B组术后予以免疫抑制治疗：C组10头完成交互的同种异体节段性小肠移植术10例。术后1、3、5、7、14、21及30d经移植肠远端造口取小肠黏膜经常规处理后。分别在光镜和电镜下观察并进行排斥反应评分。结果术后A组出现排斥反应的中位时间为8（7～12）d．迟于c组的5（3～5）d（P〈0．05）。术后1周,A组的排斥反应评分为1．11±0．20。低于C组（2．56±0．18,P〈0．05）;但比B组高（O．20±0．13,P〈O．05）。A组移植术后中位存活时问为9（7～25）d,C组为12（7～20）d．而B组术后全部成活超过30d．与以上两组比较,P〈0.05．差异有统计学意义。结论移植术后排斥反应通过肠造口取材进行监测方便有效。