PRA的血液凈化的學(xué)習(xí)課件

PRA的血液凈化的學(xué)習(xí)課件第1頁(yè)/共25頁(yè)目前常用的組織配型方法

Maintissuematchingmethods1.ABO血型:ＡＢＯ血型基因型只有6種基因而隨機(jī)人群中容易獲得配合.2.CDC試驗(yàn):檢測(cè)患者體內(nèi)針對(duì)供者ＨＬＡ特定位點(diǎn)的抗體.3.PRA檢測(cè):檢測(cè)患者體內(nèi)針對(duì)同種HLA抗原的抗體.4.HLA配型:理想的ＨＬＡ配型,尤其ＤＲ位點(diǎn)相配可使存活率提高10%～30%,對(duì)再次移植和高危患者效果更明顯，具有10億個(gè)基因型高度多態(tài)性的ＨＬＡ成為選擇配合移植的主要難題。MaintissuematchingmethodsincludeABObloodtypecrossmatch,CDC(complement-dependent-cytotoxicity)test,PRA(panelreactiveantibody)detectionandHLA(humanleukocyteantigen)typing.HLA-A,B,DRlocusespeciallyDRlocuswellmatchedwillimprovethesurvivalratefor10-30%whileitisverydifficulttodosoinpractice.第2頁(yè)/共25頁(yè)ＰＲＡ的檢測(cè)原理

TheprincipleofPRAtest利用已知抗原的淋巴細(xì)胞與未知血清及補(bǔ)體孵育,如患者血清中含有與淋巴細(xì)胞表面特異結(jié)合的抗體,在補(bǔ)體存在的情況下,可發(fā)生細(xì)胞溶解作用,根據(jù)細(xì)胞溶解程度判斷患者的免疫狀態(tài)及HLA抗體的特異性。TheprincipleofPRAtestisthatthelymphocyteswhoseantigenswereknownwereincubatedwithcomplementsandpatients’seratogether,thenwecanjudgethesepatients'immunestatusandthespecificityofHLAantibodiesaccordingtothedegreeofcytolysis.第3頁(yè)/共25頁(yè)ＰＲＡ檢測(cè)的意義

(ThesenseforPRAtest）反映受者人類白細(xì)胞抗原體液致敏狀態(tài),ＰＲＡ增高，移植后導(dǎo)致急性、超急性、加速排斥反應(yīng)和腎功能延遲，移植前ＰＲＡ水平的峰值比在手術(shù)時(shí)檢測(cè)ＰＲＡ更能預(yù)測(cè)移植物存活的結(jié)果。高ＰＲＡ受者的抗體為ＩｇＧ性質(zhì),或曾經(jīng)出現(xiàn)高峰值ＰＲＡ,近期ＰＲＡ自然或人為干預(yù)下降,其誘導(dǎo)排斥反應(yīng)的作用仍然存在,術(shù)后超急、加速排斥率均比ＰＲＡ陰性高80%。ThetestresultofPRAcanaffectrecipient’sensitivitystatusofhumoralimmunity.ItwasprovedthathighPRApretransplantationcanleadtoepisodesofacute,hyperacute,acceleratedrejectionofrenalallograftsordelayedrenalgraftfunction.第4頁(yè)/共25頁(yè)ＰＲＡ的產(chǎn)生原因

WhydidthePRAsproduce?ＨＬＡ抗體產(chǎn)生絕大多數(shù)由移植前輸血、妊娠和再次移植所致,極少數(shù)可能是由某些病毒或細(xì)菌的分解物所攜有的類似ＨＬＡ抗原所致。初次移植病人ＰＲＡ陽(yáng)性率有明顯性別差異,男∶女=8∶36.6,有兩種或多重致敏經(jīng)歷的病人通常ＰＲＡ峰值高居不降。PreformedcirculatingcytotoxicIgGanti-HLAalloantibodiesinducedbypreviousfailedgrafts,bloodtransfusion,pregnancyorinfectionarearelativecontraindicationtoallotransplantationandapttoresultinhyperacuterejection.其他因素:(1)受者ＨＬＡA1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黃種人移植物的排斥率高;(3)長(zhǎng)時(shí)間的血液透析。(1)CDCtestrevealedthatA1andA2antigenswerehighlyimmunogenic;（2）TheblackracecommonlyhashighPRA；（3）Undergoingthehemodialysisforlongtime.

第5頁(yè)/共25頁(yè)ＰＲＡ的分類

ClassifythePRA高ＰＲＡ所針對(duì)的免疫原可以是ＨＬＡ抗原,也可以是非ＨＬＡ成份,抗HLA類抗原的抗體,包括IgG1～4、IgM和IgA,引起超急性排斥反應(yīng)的主要是IgG1類抗體,IgG1對(duì)術(shù)后第1年發(fā)生排斥反應(yīng)的預(yù)測(cè)值為77.5%,而IgG2～4及IgM的預(yù)測(cè)值為0。IgA的有益作用機(jī)制可能為阻斷IgG及補(bǔ)體介導(dǎo)。PRAmainlyaimdirectlyat

HLAwhichcompriseIgG1～4、IgMandIgA.Only

IgG1antibodiesaccountforhyperacuteandacceleratedrejection.IgG2～4andIgMclassantibodiesarenotassociatedwithposttransplantrejection.furthermore,IgAdoesgoodtorejectionreactionbyitsblockagetocomplementsandIgG.第6頁(yè)/共25頁(yè)P(yáng)RA的分度

GradingofPRA據(jù)PRA值可將患者分為非致敏性(<10%)、致敏(10%～30%)及高敏(>30%)。Accordingtothetestvalue,patientswithelevatedPRAcanbedividedintononsensitizedpatients(<10%),sensitizedpatients(10%～30%)andhighlysensitizedones(>30%).第7頁(yè)/共25頁(yè)超急性排斥反應(yīng)的其它因素

Otherfactorsaccountforhyperacuterejection超急性排斥反應(yīng)的發(fā)生除與體內(nèi)預(yù)存抗HLA抗原的細(xì)胞毒抗體有關(guān)外,尚有其他引發(fā)因素,如冷凝集素、抗內(nèi)皮細(xì)胞抗體及其他非HLA抗體。大部分研究認(rèn)為,抗內(nèi)皮細(xì)胞抗體可在排斥反應(yīng)中起作用,并證明其與單核細(xì)胞及角化細(xì)胞反應(yīng),不與淋巴細(xì)胞反應(yīng)。這種抗體可逃避交叉配型的檢測(cè)。

HyperacuterejectionismainlyinducedbypreformedantibodiestoHLAwhileotherantibodiessuchasthoseantibodiestoendothelialcellswhichareprovedtointeractwithmononuclearcellsaswellaskeratinocyte,notlymphocyte.Thoseantibodiescannotbetestedbycommoncrossmatch.第8頁(yè)/共25頁(yè)高群體反應(yīng)性抗體的預(yù)防

PreventionstrategyforhighlyPRA1.避免隨機(jī)輸血;使用促紅素代替輸血;2.對(duì)供者的ＰＲＡ進(jìn)行監(jiān)測(cè)；3.對(duì)受者ＰＲＡ水平動(dòng)態(tài)監(jiān)測(cè),準(zhǔn)確了解其致敏狀態(tài),正確判斷其致敏抗體的特異性;4.術(shù)前注重ＨＬＡ配型;5.選擇ＰＲＡ降低時(shí)移植或等待自然消退時(shí)行移植手術(shù)。1.Avoidrandombloodtransfusionandapplyforerythropoietin(EPO)insteadofbloodtransfusion.2.Long-termmonitorthelevelsofdonor’PRA.3.Long-termmonitorthelevelsofrecipient’PRAsoastosuperviserecipient’sensitivitystatusofhumoralimmunity.4.OneapproachtoreducetheformationofhighPRAsistodiminishsuchcross-reactivitybyavoidingcertainmismatches.5.SelectthepropertimewhenPRAsdecreasetoalowleveltodevelopkidneytransplantation.第9頁(yè)/共25頁(yè)高群體反應(yīng)性抗體的處理

TreatmentofpatientswithhighPRA1.藥物抑制：包括環(huán)磷酰胺、6-巰基嘌呤、驍悉(cellcept)等;2.免疫誘導(dǎo)；3.靜脈注射免疫球蛋白(IVIG);4.血漿置換;5.免疫吸附;1.DepresstheproductionofPRAbyapplyingforsomedrugssuchascyclophosphamide(ＣＴＸ),mercaptopurine(6-ＭＰ),mycophenolatemofetil(MMF)andsoon.2.Inducetoimmunetoleration.3.Applyingforintravenousimmunoglobulin(IVIg).4.Therapeuticplasmaexchange.5.Therapeuticimmunoadsorption.第10頁(yè)/共25頁(yè)免疫誘導(dǎo)

Inducetoimmunetoleration小劑量ATG、OKT3誘導(dǎo)治療，ATG可以降低PRA值,在治療加速性及急性排斥方面很有成效。但是它也有使白細(xì)胞、血小板下降,增加細(xì)菌、病毒感染,γ-球蛋白增高及腫瘤發(fā)生率升高等問題，也有報(bào)道認(rèn)為,術(shù)前應(yīng)用ATG、OKT3等誘導(dǎo)療法并未減少術(shù)后6個(gè)月內(nèi)的排斥反應(yīng)發(fā)生次數(shù)。LittledoseofATG(antithymocyteglobulin)orOKT3canreducePRAlevelssotheycantreatacceleratedandacuterejectionsuccessfully.Unfortunatelytheymayleadtothesideeffectsofreducingleukocyteandplateletandleadtoinfections.FurthermoresomeresearchshowedtheusingofATGorOKT3didnotlowerthefrequencyofrejectionwithinthefirst6monthsposttransplantation.第11頁(yè)/共25頁(yè)免疫球蛋白降高PRA

DepressPRAbyusingimmunoglobulin免疫球蛋白主要通過拮抗自身的抗獨(dú)特型抗體及阻斷抗原結(jié)合部位而發(fā)揮降ＰＲＡ作用,濃度越高,拮抗作用越強(qiáng)。在ＰＲＡ值下降的同時(shí),ＨＬＡ的敏感位點(diǎn)也發(fā)生變化。IVIgprobablyworksbyanti-idiotypicantibodiesandblockingofantigenicsites.AtthesametimeofthedecreaseofPRA,thesensitivelociofHLAwillchange.第12頁(yè)/共25頁(yè)血漿置換治療高ＰＲＡ

PEactsasamethodofreducingPRA血漿置換是是將患者的血液抽出,分離血漿和細(xì)胞成分,棄去血漿,而把細(xì)胞成分以及所需補(bǔ)充的置換液回輸體內(nèi),以達(dá)到清除致病介質(zhì)的治療目的。對(duì)于高PRA患者,術(shù)前行血漿置換可有效地清除或減少體內(nèi)預(yù)存的抗HLA抗體,降低PRA值。該法在處理高PRA時(shí)被廣泛采用,常與其他方法配合使用。血漿置換一般3～5次,術(shù)前1日1次或隔日1次.Therapeuticplasmaexchangeisawell-establishedextracorporealtechniqueforthetreatmentofcertainimmunologicandmetabolicdiseases.Thesetreatmentsincludenonselectiveplasmaexchangeormoreselectiveadsorptionprocedures,likeproteinAimmunoadsorption.Plasmaexchangewassuccessfullyusedtopreparesensitizedpatientsforrenaltransplantation,totreathumoralrenalallograftrejection.第13頁(yè)/共25頁(yè)血漿置換液

Plasmasubstitutes

1.新鮮冰凍血漿。2.血漿替代物:(1)晶體液;(2)膠體液:包括白蛋白及多糖類中的中、低分子右旋糖苷及羥乙基淀粉等。Plasmasubstitutesincludefreshfrozenplasmaandplasmasubstitutessuchascrystalloidfluidandcolloidfluidincludingalbumin,lowandmediummoleculardextran,hydroxyethylamylum.第14頁(yè)/共25頁(yè)血漿置換療效預(yù)測(cè)

EvaluationtheeffectofPE血漿容量（PV）=（1-HCT）（b+cw）其中b為常數(shù)（男1530，女864），c為常數(shù)（男41，女47.2),HCT(hematocrit)為紅細(xì)胞壓積,w為體重.每次血漿置換通常僅需置換1至1.5個(gè)血漿容量,最多不超過兩個(gè),置換第一個(gè)血漿容量可清除PRA總量的55%,繼續(xù)置換第二個(gè)血漿容量,卻只能使其濃度再下降15%.

IntheformulaPV=（1-HCT）（b+cw),bothbandcareconstantsandwrepresentsfortheweightofthepatientundergoingplasmaexchange.１to1.5

patientplasmavolumeswereprocessedpersession.substitutionofonepatientplasmavolumeby5%humanalbumincandecreasePRAlevelsto45%.Largevolumesofplasma(usually50ml/kg)isrecommendedtoPE.第15頁(yè)/共25頁(yè)血漿置換注意事項(xiàng)

SideeffectsofPE補(bǔ)充新鮮冰凍血漿進(jìn)行血漿置換,可能的副作用有:過敏反應(yīng),低鈣血癥,傳播感染性疾病以及產(chǎn)生PRA抗體等.一般每1000ml血漿需給10%葡萄糖酸鈣5-10ml.以白蛋白為置換液的優(yōu)點(diǎn)是過敏反應(yīng)少,傳播疾病的概率低,但不含凝血因子,免疫球蛋白,補(bǔ)體成分.Commonsideeffectsarerelatedtotheprocedureitself,totheproblemsofvascularaccess,andtothereplacementsolutions.Itisalsoanadditionalimmunosuppressivefactorinthealreadydepressedmilieuofrenaltransplantrecipient.Neuromuscularsignsofhypocalcemia,transmissionofbloodbornevirusesandtheallergicreaction,eventhepossibilityoflife-threateninganaphylacticreactionsarelikelytooccur.第16頁(yè)/共25頁(yè)ＰＥ治療加速性排斥反應(yīng)

TherapeuticPEinacceleratedrejection

血漿置換是治療加速性排斥反應(yīng)的一種有效的輔助治療方法?？汕宄h(huán)中的淋巴毒抗體、免疫復(fù)合物及淋巴因子等有關(guān)介質(zhì),其應(yīng)用指征是:(1)腎移植術(shù)后5ｄ內(nèi)發(fā)生的少尿型嚴(yán)重排斥(加速性),3ｄ激素沖擊及2～3ｄＡＬＧ或ＯＫＴ3治療無效者;(2)腎活檢為血管性急性排斥者;同時(shí)應(yīng)在排斥反應(yīng)發(fā)生早期,免疫抗體尚未與受體結(jié)合沉積于血管產(chǎn)生損害時(shí)使用為好,如組織學(xué)顯示腎小動(dòng)脈內(nèi)或腎小球毛細(xì)血管內(nèi)血栓形成大多不能逆轉(zhuǎn)。BecausetheapplicationofPEcanremovelymphotoxicantibodies,circularimmunecomplexandlymphakineoffpatients’blood,satisfactoryresultwouldbeusuallyachievedwiththeadoptionofplasmaexchangeintheearlyperiodofacceleratedrejectionwhenimmuneantibodiesdonotcombinewithreceptorssoasnottoadheretovascularwallanddamageit.第17頁(yè)/共25頁(yè)ＰＥ治療控制急性排斥反應(yīng)

ThetherapyofacuterejectionbyPE血漿置換不僅能通過清除體內(nèi)多種抗體及免疫復(fù)合物來調(diào)整體液免疫反應(yīng),同時(shí)也能清除異常增高的免疫細(xì)胞因子ＴＮＦ、ｓＩＬ2Ｒ以調(diào)節(jié)細(xì)胞免疫反應(yīng),達(dá)到控制急性排異反應(yīng)的目的。Plasmaexchangeeliminatesnotonlyavarietyofantibodiesandcircularimmunecomplex,butalsoelevatedimmunocytefactorssuchasTNF

(tumor

necrosisfactor)andsIL2R(solubleinterleukinreceptor)

soitcancontrolacuterejectionbymodulatingcellmediatedimmunityreaction.第18頁(yè)/共25頁(yè)免疫吸附治療高ＰＲＡImmunoadsorptioninhighPRA免疫吸附是指用高度特異性的抗原或抗體或有特定物理化學(xué)親和力的物質(zhì)與吸附材料結(jié)合,制成吸附劑,當(dāng)全血或血漿通過這種吸附劑時(shí),即可選擇性或特異地吸附清除體內(nèi)相應(yīng)的致病因子。目前常用的是葡萄球菌A蛋白固定吸附柱。通常每次治療時(shí)間為2-3小時(shí),移植前治療3-8次。ＩＡ能迅速清除患者體內(nèi)抗ＨＬＡⅠ及Ⅱ類抗體,降低ＰＲＡ水平。Intensive,high-volumeimmunoadsorption(IA)proceduresveryeffectivelyremoveimmunoglobulins,especiallyIgG.IAcanbecarriedoutuntilthedesiredreductionofimmunoglobulinsisachievedwithtolerablereductionofotherproteins.PlasmaseparationfortheIAswasalsodonewithacontinuouslyworkingcellseparatorandproteinAimmunoadsorptioncolumnwaswidelyusedforclearingthePRAs.第19頁(yè)/共25頁(yè)第20頁(yè)/共25頁(yè)免疫吸附治療的優(yōu)點(diǎn)

ThemeritofIA免疫吸附治療是一種新型的方法，與PE相比其優(yōu)點(diǎn)為：1.迅速特異地祛除PRA抗體.2.不丟失血漿.3.不傳播輸血相關(guān)傳染病.4.避免非選擇性清除血漿中有益成分.5.不使用置換液,減少過敏.6.再生吸附柱可供重復(fù)使用.IAistheoreticallysuperior

toPE,asitremovesantibodiesmoreefficientlyandfaster.Reuseofcolumnswithouttheneedofalbuminorplasmasubstitutionleadstoreductionoftreatmentcostsandavoidingbloodbornevirusinfectionaswellasanaphylacticreactions.第21頁(yè)/共25頁(yè)血液凈化治療不足之處

Thedeficiencyofpurification經(jīng)血漿置換或免疫吸附治療受者的ＰＲＡ水平暫時(shí)降低,但一段時(shí)間后其抗體水平又恢復(fù)到置換前水平，原因:雖可清除或降低受者外周血中預(yù)存的致敏抗體,受者體內(nèi)合成和分泌抗體的免疫致敏細(xì)胞和免疫記憶細(xì)胞并未清除,如再次受相同抗原刺激,必將再次發(fā)生免疫應(yīng)答,迅速合成和分泌大量的抗體,從而導(dǎo)致超急排斥和加速排斥反應(yīng)的發(fā)生。PurificationmethodsincludebothPEandIAcanonlydecreasePRAslevelstransitorilybecauseofnoteliminatingimmunesensitizedcellsandimmun