Prevention of Acute Lung Allograft Rejection in Rat by CTLA4Ig

CTLA4 immunoglobulin (CTLA4Ig), which binds with a high affinity to B7-1 and B7-2, interrupts T-cell activation by inhibiting costimulatory signal. CTLA4Ig has been used in hopes of achieving antigen-specific tolerance induction in several solid organ transplants. In lung allograft rejection, however, its use has been controversial in terms of its effect on prevention of rejection. In the present study, the effect of murine CTLA4Ig on rat-lung allograft rejection was investigated. Rat left-lung transplantation was performed in an RT1 incompatible donor (Brown Norway; BN)-recipient (F344) combination. All allografts (n = 12) without any treatment were rejected within 7 days after transplantation. A single injection of murine form CTLA41g at a dose of 100 microg intraperitoneally (ip) or intravenously (iv) on day 1 post-transplantation achieved long-term graft survival (>90days) in 2/5 (40%) and 3/8 (38%), respectively. Moreover, 6/7 (86%) allografts in rats that received iv injection of 500 microg CTLA4Ig survived more than 90days. Allograft survival in the CTLA4Ig 500 microg iv recipient group was significantly longer than that in the no-treatment control or control immunoglobulin group (p <0.01). Four out of seven recipients bearing functional allografts for more than 90 days with the CTLA4Ig treatment accepted donor-specific skin grafts, whereas all third-party skin grafts (n=3) were rejected. Prevention of rat-lung allograft rejection could be achieved by intravenous administration of CTLA4Ig, resulting in long-term allograft survival with acceptance of donor-specific skin grafts.     

Reduction in acute rejections decreases chronic rejection graft failure in children: a report of the North American Pediatric Renal Transplant Cooperative Study (NAPRTCS).

Chronic rejection accounted for 32% of all graft losses in 7123 pediatric transplants. In a previous study acute, multiple acute and late acute rejections were risk factors for the development of chronic rejection. We postulated that the recent decrease in acute rejections would translate into a lower risk for chronic rejection among patients with recent transplants. We reviewed our data on patients transplanted from 1995 to 2000, and using multivariate analysis and a proportional hazards model developed risk factors for patients whose grafts had failed due to chronic rejection. A late initial rejection increased the risk of chronic rejection graft failure 3.6-fold (p < 0.001), while a second rejection resulted in further increase of 4.2-fold (p < 0.001). Recipients who received less than 5 mg/kg of cyclosporine at 30 days post-transplant had a relative risk (RR) of 1.9 (p = 0.02). Patients transplanted from 1995 to 2000 had a significantly lower risk (RR = 0.54, p < 0.001) of graft failure from chronic rejection than those who received their transplants earlier (1987-94). Since we were able to demonstrate that there is a decreased risk of chronic rejection graft failure in our study cohort, we would conclude that the goal of future transplants should be to minimize acute rejections.     

他克莫司、霉酚酸酯和血浆置换联合应用治疗肾移植术后急性体液性排斥反应

目的　探讨他克莫司 (FK5 0 6 )、霉酚酸酯和血浆置换联合应用治疗急性体液性排斥反应的效果。方法　 6例肾移植后发生急性体液性排斥反应的患者 ,术后采用环孢素A、霉酚酸酯和激素行免疫抑制治疗 ,发生急性体液性排斥反应时经甲泼尼龙和抗胸腺细胞球蛋白治疗无效 ,行血浆置换 4～ 6次 ,并给予FK5 0 6 (0 .2mg·kg-1·d-1)及霉酚酸酯 (由 2 g/d加至 3g/d)治疗。 结果　经 4～ 6次血浆置换和FK5 0 6、霉酚酸酯治疗 ,排斥反应得到逆转 ,6例患者肾功能均恢复良好 ,随诊 3～ 18个月 ,患者的血肌酐水平为 (12 5 .2± 2 6 .5 ) μmol/L。 结论　FK5 0 6、霉酚酸酯和血浆置换联合应用能有效地逆转急性体液性排斥反应     

尿流式细胞学在诊断移植肾急性排斥反应中的应用价值

目的：探讨尿流式细胞学在诊断移植肾急性排斥反应中的临床应用价值。方法：对43例肾移植受者的116份尿样本进行尿流式细胞学分析，并将急性排斥组和肾功能稳定组的分析结果进行比较。结果：急性排斥反应组尿淋巴细胞总数以及HLA－DR^ 淋巴细胞数显著增多，与肾功能稳定组比较，P＜0．01，CD8^ 细胞亦增多（P＜0．05），而CD3^ ,CD4^ ,CD19^ 细胞数变化两组差异不显著（P＞0．05），在诊断移植肾急性排斥反应上，HLA－DR阳性样本和淋巴细胞数阳性样本的诊断敏感性和特异性分别达95．2％，90．5％，和92．6％，87．4％，结论：尿流式细胞学分析可反映移植肾内的免疫状态，尿淋巴细胞数的显著增多和尿HLA－DR^ 淋巴细胞增多可以作为诊断急性排斥反应的有意义指标。     

Endothelial nitric oxide synthase expression in ischemia-reperfusion injury after living related-donor renal transplantation

Ischemia-reperfusion injury during renal transplantation has been linked to early graft dysfunction and late graft failure. Nitric oxide (NO), produced by NO synthase (NOS), participates in the recovery from ischemia. We correlated the intensity of graft immunoreactivity for the endothelial NOS isoform (eNOS) during early reperfusion with graft function in 25 children receiving grafts from related donors. Renal allograft biopsy specimens were obtained before transplantation, 1 h after renal artery reperfusion, and 1 year after transplantation. Immunohistochemical staining for eNOS occurred mainly within the endothelium of glomerular capillaries and peritubular capillaries as well as in tubule cells. The mean intensity score for eNOS staining (0-9) was 3.0+/-1.4 before transplantation, 4.5+/-1.9 at 1 h, and 3.3+/-1.9 at 1 year (baseline vs 1 h, P<0.05). Creatinine clearance (ml/min) in patients with a 1-h eNOS score of below 5 and of at least 5, respectively, was 77.1+/-28.4 vs 104.3+/-25.3 at 1 month, 78.7+/-33.4 vs 105.2+/-24.4 at 3 months, 64.7+/-30.1 vs 100.1+/-25.3 at 1 year, 58.2+/-31.3 vs 84.7+/-18.8 at 3 years, and 71.2+/-19.7 vs 78.3+/-23.1 at 5 years ( P<0.05 for 1 month, 1 year, and 3 years). We concluded that elevated eNOS expression after reperfusion in living related-donor renal transplantation enhances the recovery from renal ischemia and, consequently, reduces late graft deterioration.     

Acute rejection in the elderly recipient: Influence of age in the outcome of kidney transplantation

Since the immune response in older recipientsis weaker they should be less likely to rejecta transplanted organ and should need lessaggressive immunosuppressive treatment. Our aimwas to record the incidence and severity ofepisodes of acute rejection (AR), estimate theinfluence of these events on graft survival ofelderly recipients (60) and to comparethese with that in younger ones.We performed 363 kidney transplants between1/94 and 12/98, and recorded clinical andimmunological data, incidence-severity of ARand cause of graft loss. Patients were dividedinto two groups, according to the age attransplantation: A (<60, n = 281/77.4%) and B( 60, n = 82/22.6%). The percentage ofaging recipients and mean age of donors andrecipients increased throughout the period.Although the incidence of ATN was higher in theolder group (29% vs.19%, p < 0.0001) thenumber of graft biopsies was equal in bothgroups. The incidence of AR was similar, 33.4%vs. 26.8%, pNS. The number of AR episodes perpatient was 0.44 and 0.41 respectively. Theseverity of AR was: Banff grade I: A (40.3%)/B (45.7%) pNS; grade II: A (44.1%)/B(48.57) pNS; grade III: A (15.5%)/B (5.7%)pNS. Younger recipients presented a higherlevel of panel-reactive antibodies (PRA) (4.3%vs. 2.07%, p = 0.01). One-year patient survivalwas 96%/91% (p<0.05) and graft survivalwas 81%/78% (pNS) respectively.The age of recipient does not seem to haveinfluenced the incidence-severity of AR or thegraft survival. Thus immunosuppression shouldbe individualised for each patient and shouldnot depend on the age at transplantation.     

肾移植受者抗HLA抗体监测的临床意义

目的探讨动态监测肾移植受者抗HLA抗体的临床意义。方法采用酶联免疫吸附试验(ELISA)对1517例肾移植受者进行手术前、后血清群体反应性抗体(panel reactive antibody,PRA)强度动态监测,对PRA阳性受体进一步行抗HLA抗体分型并进行随访,观察PRA水平对移植物长期存活和移植肾功能的影响。结果1517例中,术前PRA阴性者1336例,阳性者181例。术前PRA阳性受者和阴性受者的移植物功能延迟恢复(DGF)发生率分别为34.8%、11.9%,两组比较差异有统计学意义(P0.01)。术前PRA阳性受者的移植肾1、3、5、8年存活率分别为94%、85%、73%和63%,术前PRA阴性受者相应为96%、87%、72%和65%,两组比较差异均无统计学意义(P0.05)。移植前及移植6个月后PRA均为阴性的265例受者中,血清肌酐水平异常者仅占19.6%,而术后PRA转为阳性的57例受者中,血清肌酐异常者高达61%,两者比较差异有统计学意义(P0.01);移植前PRA阳性的53例受者中,有24例移植后PRA转为阴性,术后血清肌酐全部正常。结论术前筛查PRA可科学评估肾移植患者的体液致敏状态,为致敏患者选配合适供者;术后监测PRA可及时了解移植肾的免疫状态,有利于防治排斥反应。     

急性细胞性排斥伴补体裂解片断C4d沉积对移植肾预后的影响

探讨急性细胞性排斥伴肾小管周围毛细血管补体裂解片断(C4d)沉积对移植肾预后的影响.方法 经病理证实的急性细胞性排斥肾移植患者 145 例,根据病理表现有否肾小管周围毛细血管C4d沉积,将其分为细胞性排斥+C4d阳性组(C4d阳性组)64例,单纯细胞性排斥组(C4d阴性组)81例.比较两组术前一般情况、排斥反应发病情况、抗排斥治疗、移植肾失功率及移植肾存活率.结果两组的术前一般情况比较差异无统计学意义(P>0.05).C4d阳性组的急性细胞性排斥反应发生时间明显早于C4d阴性组,比较差异有统计学意义(P<0.05).两组Banff 分型Ⅰ型与Ⅱ型比例差异有统计学意义(P<0.01).随访期间C4d阳性组有22例(34%)移植肾失功,明显高于C4d阴性组的11例(14%),比较差异有统计学意义(P<0.01).Kaplan-Meier法分析发现C4d阳性组的移植肾存活率明显低于C4d阴性组(P<0.01),移植肾的5年生存率分别为51%、79%.结论 急性细胞性排斥反应伴肾小管周围毛细血管C4d沉积的肾移植患者,术后较早发生排斥反应,抗排斥治疗效果较差,移植肾存活率低.     

全角膜移植术后移植排斥反应及继发性青光眼的防治研究

目的探讨全角膜移植术后移植排斥反应和继发性青光眼的预防和治疗的有效方法,提高全角膜移植术的成功率。方法回顾性分析全角膜移植患者50例(50只眼)。手术方式包括带周边巩膜环的创缘叠加式缝合全角膜移植或移植片和植床边对边缝合的全角膜移植。术后眼表面分别应用他克莫司(tacrolimus,FK506)和环孢素(cyclosporin,CsA)预防和治疗移植排斥反应。应用房水引流植入物或睫状体冷凝术治疗角膜移植术后青光眼,比较其疗效。结果术后随访6～27个月。总的眼球保存率是96%,角膜移植片透明率是42%,手术后获得了超过0.05以上的视力16例,最好视力为1.2。FK506组的最终视力和术后12个月移植片透明率均高于CsA组(P0.01和P0.05)。FK506组和CsA组术后12个月的移植片透明率分别是61%和24%。与边对边缝合全角膜移植相比,叠加式缝合全角膜移植能明显降低手术后青光眼发生率(P0.01)。房水引流植入物和睫状体冷凝术均可有效控制全角膜移植术后青光眼,但睫状体冷凝术的并发症较严重。结论通过改良手术技术,应用强效免疫抑制剂FK506和房水引流植入物,全角膜移植术不仅可以挽救角膜严重损毁的眼球,而且可以使患者的视力得到较好的恢复。