《PRA的血液净化-PPT文档资料.ppt》由会员分享，可在线阅读，更多相关《PRA的血液净化-PPT文档资料.ppt（24页珍藏版）》请在三一文库上搜索。
1、目前常用的组织配型方法 Main tissue matching methods 1. ABO血型:血型基因型只有6种基因而随机人群中容易 获得配合. 2. CDC试验:检测患者体内针对供者特定位点的抗体. 3.PRA检测:检测患者体内针对同种HLA抗原的抗体. 4.HLA配型:理想的配型,尤其位点相配可使存活率 提高10%30%,对再次移植和高危患者效果更明显，具有10亿 个基因型高度多态性的成为选择配合移植的主要难题。 Main tissue matching methods include ABO blood type crossmatch, CDC (complement-depend
2、ent-cytotoxicity) test, PRA(panel reactive antibody) detection and HLA (human leukocyte antigen)typing. HLA-A,B,DR locus especially DR locus well matched will improve the survival rate for 10-30% while it is very difficult to do so in practice. 的检测原理 The principle of PRA test 利用已知抗原的淋巴细胞与未知血清及补体孵育,如
3、患 者血清中含有与淋巴细胞表面特异结合的抗体,在补体 存在的情况下,可发生细胞溶解作用,根据细胞溶解程度 判断患者的免疫状态及HLA抗体的特异性。 The principle of PRA test is that the lymphocytes whose antigens were known were incubated with complements and patients sera together, then we can judge these patients immune status and the specificity of HLA antibodies accor
4、ding to the degree of cytolysis. 检测的意义 (The sense for PRA test） 反映受者人类白细胞抗原体液致敏状态,增高，移 植后导致急性、超急性、加速排斥反应和肾功能延迟， 移植前水平的峰值比在手术时检测更能预 测移植物存活的结果。高受者的抗体为性 质,或曾经出现高峰值,近期自然或人为干预 下降,其诱导排斥反应的作用仍然存在,术后超急、加速排 斥率均比阴性高80%。 The test result of PRA can affect recipient sensitivity status of humoral immunity. It was
5、 proved that high PRA pretransplantation can lead to episodes of acute, hyperacute, accelerated rejection of renal allografts or delayed renal graft function. 的产生原因 Why did the PRAs produce? 抗体产生绝大多数由移植前输血、妊娠和再次移植所致,极少数可 能是由某些病毒或细菌的分解物所携有的类似抗原所致。初次移 植病人阳性率有明显性别差异,男女=836. 6,有两种或多重致敏 经历的病人通常峰值高居不降。 Pr
6、eformed circulating cytotoxic IgG anti-HLA alloantibodies induced by previous failed grafts, blood transfusion, pregnancy or infection are a relative contraindication to allotransplantation and apt to result in hyperacute rejection. 其他因素:(1)受者 A1或 2表型者易致敏;(2)黑人受者普遍高 ,且接受黑人移植物比接受白人或黄种人移植物的排斥率高;(3)长时间
7、 的血液透析。 (1) CDC test revealed that A1 and A2 antigens were highly immunogenic;（2 ）The black race commonly has high PRA；（3）Undergoing the hemodialysis for long time. 的分类 Classify the PRA 高所针对的免疫原可以是抗原,也可以是非 成份,抗HLA 类抗原的抗体,包括IgG14、IgM和 IgA,引起超急性排斥反应的主要是IgG1类抗体, IgG1对术 后第1年发生排斥反应的预测值为77.5%,而IgG24及 IgM的
8、预测值为0。IgA的有益作用机制可能为阻断IgG及 补体介导。 PRA mainly aim directly at HLA which comprise IgG14 、IgM and IgA. Only IgG1 antibodies account for hyperacute and accelerated rejection. IgG24 and IgM class antibodies are not associated with posttransplant rejection. furthermore, IgA does good to rejection reaction b
9、y its blockage to complements and IgG . PRA的分度 Grading of PRA 据PRA值可将患者分为非致敏性(30%)。 According to the test value, patients with elevated PRA can be divided into nonsensitized patients (30%). 超急性排斥反应的其它因素 Other factors account for hyperacute rejection 超急性排斥反应的发生除与体内预存抗HLA抗原的细 胞毒抗体有关外,尚有其他引发因素,如冷凝集素、抗内
10、 皮细胞抗体及其他非HLA抗体。大部分研究认为,抗内 皮细胞抗体可在排斥反应中起作用,并证明其与单核细 胞及角化细胞反应,不与淋巴细胞反应。这种抗体可逃 避交叉配型的检测。 Hyperacute rejection is mainly induced by preformed antibodies to HLA while other antibodies such as those antibodies to endothelial cells which are proved to interact with mononuclear cells as well as keratinocyt
11、e, not lymphocyte. Those antibodies can not be tested by common crossmatch. 高群体反应性抗体的预防 Prevention strategy for highly PRA 1.避免随机输血;使用促红素代替输血; 2.对供者的进行监测； 3.对受者水平动态监测,准确了解其致敏状态,正确判断其致 敏抗体的特异性; 4.术前注重配型; 5.选择降低时移植或等待自然消退时行移植手术 。 1. Avoid random blood transfusion and apply for erythropoietin(EPO) inst
12、ead of blood transfusion. 2. Long-term monitor the levels of donor PRA. 3. Long-term monitor the levels of recipient PRA so as to supervise recipient sensitivity status of humoral immunity. 4. One approach to reduce the formation of high PRAs is to diminish such cross-reactivity by avoiding certain
13、mismatches. 5. Select the proper time when PRAs decrease to a low level to develop kidney transplantation. 高群体反应性抗体的处理 Treatment of patients with high PRA 1.药物抑制：包括环磷酰胺、6-巯基嘌呤、骁悉(cellcept)等; 2.免疫诱导； 3.静脉注射免疫球蛋白(IVIG); 4.血浆置换; 5.免疫吸附; 1. Depress the production of PRA by applying for some drugs such a
14、s cyclophosphamide(), mercaptopurine(6 -), mycophenolate mofetil (MMF) and so on. 2. Induce to immune toleration. 3. Applying for intravenous immunoglobulin (IVIg). 4. Therapeutic plasma exchange. 5. Therapeutic immunoadsorption. 免疫诱导 Induce to immune toleration 小剂量ATG、OKT3诱导治疗，ATG可以降低PRA值, 在治疗加速性及急
15、性排斥方面很有成效。但是它也有 使白细胞、血小板下降,增加细菌、病毒感染,-球蛋白 增高及肿瘤发生率升高等问题，也有报道认为,术前应 用ATG、OKT3等诱导疗法并未减少术后6个月内的排 斥反应发生次数。 Little dose of ATG( antithymocyte globulin)or OKT3 can reduce PRA levels so they can treat accelerated and acute rejection successfully. Unfortunately they may lead to the side effects of reducing
16、leukocyte and platelet and lead to infections. Furthermore some research showed the using of ATG or OKT3 did not lower the frequency of rejection within the first 6 months posttransplantation. 免疫球蛋白降高PRA Depress PRA by using immunoglobulin 免疫球蛋白主要通过拮抗自身的抗独特型抗 体及阻断抗原结合部位而发挥降作用, 浓度越高,拮抗作用越强。在值下降的 同时,的
17、敏感位点也发生变化。 IVIg probably works by anti-idiotypic antibodies and blocking of antigenic sites. At the same time of the decrease of PRA, the sensitive loci of HLA will change. 血浆置换治疗高 PE acts as a method of reducing PRA 血浆置换是是将患者的血液抽出,分离血浆和细胞成分,弃去血 浆,而把细胞成分以及所需补充的置换液回输体内,以达到清除 致病介质的治疗目的。对于高PRA患者,术前行血浆置
18、换可有 效地清除或减少体内预存的抗HLA抗体,降低PRA值。该法在 处理高PRA时被广泛采用,常与其他方法配合使用。血浆置换 一般35次,术前1日1次或隔日1次. Therapeutic plasma exchange is a well-established extracorporeal technique for the treatment of certain immunologic and metabolic diseases. These treatments include nonselective plasma exchange or more selective adsorp
19、tion procedures, like protein A immunoadsorption. Plasma exchange was successfully used to prepare sensitized patients for renal transplantation, to treat humoral renal allograft rejection. 血浆置换液 Plasma substitutes 1.新鲜冰冻血浆。 2.血浆替代物:(1)晶体液;(2)胶体液:包括白蛋白 及多糖类中的中、低分子右旋糖苷及羟乙基淀 粉等。 Plasma substitutes inc
20、lude fresh frozen plasma and plasma substitutes such as crystalloid fluid and colloid fluid including albumin, low and medium molecular dextran, hydroxyethylamylum. 血浆置换疗效预测 Evaluation the effect of PE 血浆容量（PV）=（1-HCT）（b+cw）其中b为常数（男1530，女 864），c为常数（男41，女47.2), HCT(hematocrit)为红细 胞压积 ,w为体重. 每次血浆置换通常仅
21、需置换1至1.5个血浆容量,最多不超过两个, 置换第一个血浆容量可清除PRA总量的55%,继续 置换第二个血 浆容量,却只能使其浓度再下降15%. In the formula PV=（1-HCT）（b+cw), both b and c are constants and w represents for the weight of the patient undergoing plasma exchange. to 1.5 patient plasma volumes were processed per session. substitution of one patient plasm
22、a volume by 5% human albumin can decrease PRA levels to 45%. Large volumes of plasma (usually 50 ml/kg) is recommended to PE. 血浆置换注意事项 Side effects of PE 补充新鲜冰冻血浆进行血浆置换,可能的副作用有:过 敏反应,低钙血症,传播感染性疾病以及产生PRA抗体 等.一般每1000ml血浆需给10%葡萄糖酸钙5-10ml.以 白蛋白为置换液的优点是过敏反应少,传播疾病的概 率低,但不含凝血因子,免疫球蛋白,补体成分. Common side effe
23、cts are related to the procedure itself, to the problems of vascular access, and to the replacement solutions. It is also an additional immunosuppressive factor in the already depressed milieu of renal transplant recipient. Neuromuscular signs of hypocalcemia, transmission of bloodborne viruses and
24、the allergic reaction, even the possibility of life-threatening anaphylactic reactions are likely to occur. 治疗加速性排斥反应 Therapeutic PE in accelerated rejection 血浆置换是治疗加速性排斥反应的一种有效的辅助治疗方法 。可清除循环中的淋巴毒抗体、免疫复合物及淋巴因子等有 关介质,其应用指征是:(1)肾移植术后5内发生的少尿型严重 排斥(加速性),3激素冲击及23或3治疗无 效者;(2)肾活检为血管性急性排斥者;同时应在排斥反应发生 早期,免疫抗
25、体尚未与受体结合沉积于血管产生损害时使用为 好,如组织学显示肾小动脉内或肾小球毛细血管内血栓形成大 多不能逆转。 Because the application of PE can remove lymphotoxic antibodies, circular immune complex and lymphakine off patients blood, satisfactory result would be usually achieved with the adoption of plasma exchange in the early period of accelerated r
26、ejection when immune antibodies do not combine with receptors so as not to adhere to vascular wall and damage it. 治疗控制急性排斥反应 The therapy of acute rejection by PE 血浆置换不仅能通过清除体内多种抗体及免疫复合 物来调整体液免疫反应,同时也能清除异常增高的 免疫细胞因子、 2以调节细胞免疫 反应,达到控制急性排异反应的目的。 Plasma exchange eliminates not only a variety of antibodi
27、es and circular immune complex, but also elevated immunocyte factors such as TNF (tumor necrosis factor) and sIL2R (soluble interleukin receptor) so it can control acute rejection by modulating cell mediated immunity reaction. 免疫吸附治疗高 Immunoadsorption in high PRA 免疫吸附是指用高度特异性的抗原或抗体或有特定物理化学 亲和力的物质与吸附
28、材料结合,制成吸附剂,当全血或血浆通过 这种吸附剂时,即可选择性或特异地吸附清除体内相应的致病 因子。目前常用的是葡萄球菌A蛋白固定吸附柱。通常每次 治疗时间为2-3小时,移植前治疗3-8次。能迅速清除患者 体内抗 及类抗体,降低水平。 Intensive, high-volume immunoadsorption(IA) procedures very effectively remove immunoglobulins, especially IgG. IA can be carried out until the desired reduction of immunoglobulins
29、is achieved with tolerable reduction of other proteins. Plasma separation for the IAs was also done with a continuously working cell separator and protein A immunoadsorption column was widely used for clearing the PRAs. 免疫吸附治疗的优点 The merit of IA 免疫吸附治疗是一种新型的方法，与PE相比其优点 为：1.迅速特异地祛除PRA抗体. 2.不丢失血浆. 3.不
30、 传播输血相关传染病. 4.避免非选择性清除血浆中 有益成分. 5.不使用置换液,减少过敏. 6.再生吸附柱 可供重复使用. IA is theoretically superior to PE, as it removes antibodies more efficiently and faster. Reuse of columns without the need of albumin or plasma substitution leads to reduction of treatment costs and avoiding bloodborne virus infection a
31、s well as anaphylactic reactions. 血液净化治疗不足之处 The deficiency of purification 经血浆置换或免疫吸附治疗受者的水平暂时降 低,但一段时间后其抗体水平又恢复到置换前水平，原 因:虽可清除或降低受者外周血中预存的致敏抗体,受者 体内合成和分泌抗体的免疫致敏细胞和免疫记忆细胞 并未清除,如再次受相同抗原刺激,必将再次发生免疫应 答,迅速合成和分泌大量的抗体,从而导致超急排斥和加 速排斥反应的发生。 Purification methods include both PE and IA can only decrease PRAs
32、 levels transitorily because of not eliminating immune sensitized cells and immune memory cells, which can produce lots of antibodies when meeting with the same antigens. These antibodies will lead to the occurrence of hyperacute or accelerated rejection. 最佳处理方案 The optimal management 首先选择良好配型的肾脏,其次
33、再努力清除或降低患者 体内的抗HLA抗体,如行血浆置换的同时用IVIG;或用 ATG、OKT3诱导治疗,并配以新型的免疫抑制剂等。 今后是否可以在基因水平上进行阻断，有待论证。 The benefits of combination of plasma exchange and IVIG for treating immunologically sensitized patient have been reported by an increasing number of transplant centers. Other strategy such as the preventive app
34、lication of ATG and OKT3 and other new immunosuppressives may achieve success. 最新尝试 The newest try 隔日一次血浆置换，每次置换一个血浆容量，之后给 以100 mg/kg 的巨细胞病毒超免疫球蛋白，然后予四联 抗免疫药物（他克莫司，类固醇激素，骁悉，达珠单 抗），可使抗体特异而持久降低 Treatment consisted of alternate-day, single-volume plasma exchange followed by 100 mg/kg CMV-Ig. In addition, patients received tacrolimus, steroids, mycophenolate mofetil, and daclizumab. Plasma exchange and low-dose CMV-Ig combined with traditional immunosuppression is effective in producing a specific and durable elimination of antibody to donor HLA. THANKS!