pra的血液净化.ppt

目前常用的组织配型方法Main tissue matching methods
1. ABO血型:ABO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HLA特定位点的抗体.
:检测患者体内针对同种HLA抗原的抗体.
:理想的HLA配型,尤其DR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HLA成为选择配合移植的主要难题。
Main tissue matching methods include ABO blood type crossmatch, CDC (complement-dependent-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.
PRA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 plements and patients’ sera together, then we can judge these patients' immune status and the specificity of HLA antibodies according to the degree of cytolysis.
PRA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,PRA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PRA水平的峰值比在手术时检测PRA更能预测移植物存活的结果。高PRA受者的抗体为IgG性质,或曾经出现高峰值PRA,近期PRA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PRA阴性高80%。
The test result of PRA can affect recipient’ sensitivity status of humoral immunity. It was proved that high PRA pretransplantation can lead to episodes of acute, hyperacute, accelerated rejection of renal allografts or delayed renal graft function.
PRA的产生原因Why did the PRAs produce?
HLA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HLA抗原所致。初次移植病人PRA阳性率有明显性别差异,男∶女=8∶36. 6,有两种或多重致敏经历的病人通常PRA峰值高居不降。
Preformed 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HLA A1或 A2表型者易致敏;(2)黑人受者普遍高PRA,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)长时间的血液透析。
(1) CDC test revealed that A1 and A2 antigens were highly immunogenic;(2)The black monly has high PRA;(3)Undergoing the hemodialysi