抗肾小球基底膜(GBM)病

抗肾小球基底膜(GBM)病1抗GBM病的背景•抗GBM病：循环中出现抗GBM抗体、脏器中沉积为特征的自身免疫病•1919:Goodpasture首先报道–1例18岁男性病人，咯血、急性肾衰竭–主要累及肺和肾脏：Goodpasture病•内科危重症：危及生命•80%就诊时已进入尿毒症（ESRD）2GoodpasureEM.AmJMedSci1919;158:863-870CuiZ,ZhaoMH.NatRevNephrol.2011Dec7:697-706•少见病：1-2/百万人口•本研究所：累计诊断500余例–国际上最大的临床资源库–治疗依赖血浆置换：昂贵，但多为时已晚抗GBM病仍然是我国内科医生的重大挑战3抗GBM病的发生情况CuiZ,ZhaoMH.NatRevNephrol.2011Dec7:697-706抗GBM病是典型的自身免疫病•靶抗原–3(IV)NC1（肺、肾）•Epitope–Ea和Eb---构象性SausJ,etal.JBiolChem1988;15;263:13374-80SalantDJ.NEnglJMed2010;363;4:381-39156抗GBM病的科学问题•病因•表型差异病因遗传易感背景自身免疫T细胞B细胞3(IV)NC1表型？6免疫耐受？诱发因素？7抗GBM病的科学问题•病因•表型差异•肾受累轻重•1/3合并ANCA•少数合并MN7病因遗传易感背景自身免疫T细胞B细胞3(IV)NC1表型？免疫耐受？诱发因素？823/M间断咯血4个月，加重1个月HGB:71g/L;PO258mmHg;Scr94.0μmol/l尿常规:protein(+),RBC5-8/HPF血清抗GBM抗体(+),ANCA(-)肾活检:IgG沿GBM线样沉积,肾小球轻微病变治疗：Pred1mg/kg/dx8w,无PE和CTX随访7年肾功能正常CuiZ,etal.KidneyInt2007;72:1403-88肾受累轻患者介于正常人与重症患者之间？转换机制？既往：健康人血清无抗GBM抗体发现天然抗GBM抗体：中国和瑞典：各10名献血员IgG成分---亲和层析“阴性选择”？如何发展成致病性抗体？CuiZ,etal.KidneyInt2006:69:894-9CuiZ,etal.KidneyInt2010;78:590-7Naturalanti-GBMab9抗GBM抗体如何转变成致病性？天然抗GBM抗体Anti-GBM(+)严重肾受累Anti-GBM(+)正常肾功能正常人病人A病人CIntra-moleculeEpitopespreading3,41、2、3、4和5SubclassswitchingIgG2、IgG4IgG1、IgG2、IgG3和IgG4治疗个体化T细胞调控3Ea、Eb3内其他位点10Anti-GBM(+)轻度肾受累病人BCuiZ,etal.KidneyInt2006;69:894-9.YangR,etal.JAmSocNephrol2007;18(4):1338-43.CuiZ,etal.KidneyInt2007;72(11):1403-8.ZhaoJ&CuiZ,etal.KidneyInt.2009;76:1108-15.CuiZ,etal.KidneyInt2010;78(6):590-7.ChenJL&HuSY,etal.ClinJAmSocNephrol.2013;8(1):51-8.Inter-moleculeEpitopespreadingNATUREREVIEWS|NEPHROLOGYCuiZ,ZhaoMH.NatRevNephrol.2011Dec;7:697-706.抗GBM病的科学问题•病因•表型差异•肾受累轻重•1/3合并ANCA•少数合并MN12病因遗传易感背景自身免疫T细胞B细胞3(IV)NC1表型？免疫耐受？诱发因素？13抗GBM病合并MN•个例报道•MN→GBMdamage：释放α3→抗GBM病•抗GBM病→足细胞损伤：表达M-PLA2R→MN13•8patientswithMNandanti-GBMdisease–Sequentialorsimultaneous–Betterprognosis–Anti-α3(+):narrowantigenspectrum–Anti-PLA2R(-)JiaXY,etal.KidneyInt2014Apr;85(4):945-52抗GBM病的科学问题•病因–易感性：HLA？–诱发因素–病因•表型差异15病因遗传易感背景自身免疫T细胞B细胞3(IV)NC1表型？免疫耐受？诱发因素？16抗GBM病的免疫学发病机制?LineartoConformational•涉及感染、抗原递呈、抗原决定簇扩展、分子模拟17Background(HLA)HLAgeneLocation:CHR6p21.3ClassicalHLAgeneMHCclassIImolecular:Distribution:DCs、Bcells、MøStructure:hetero-dimerrecognizedbyCD4+TcellAgprocessed、presentationMHC&disease:MS、RA、IDDM、SLEetal.18(Rees,KidInt,1999)DominantlyprotectiveallelesDR1andDR7NogenedosageeffectMHCIIdominantprotection–HLA-DRB1*01:01generates3136-146specificregulatoryTcells.–HLA-DRB1*15:01generates3136-146specificeffectorTcellprecursors.–InHLA-DRB1*15:01x01:01mice,3136-146specificeffectorTcellprecursorsaredominantlysuppressedby3136-146specificregulatoryTcellsReesetal,KidneyInt1999Ooietal,JAmSocNephrol2013AssociationofHLAalleles(4digits,P3.55E-4)AlleleCase_freControl_freORP_valDRB1*15010.43840.14694.5495.658E-28DQB1*06020.38400.15443.3362.032E-17DQA1*05020.0255470.000834730.696.987E-7DQB1*03030.04710.14440.28858.575E-6DRB1*09010.065220.14940.39111.611E-420DeterminethesignificantvariationmarkerofgenotypeCase:138vs.Control:599rs41541412:theonlysignificantSNP,belongstoDQA1*0502nonsensemutation,changethe82thAAofDQαpolypeptide.CHRSNPCaseControlCHISQP-valOR632609249.C0.02550.00083524.626.99E-730.69632609249.G0.02550.00083524.626.99E-730.69AssociationofanovelHLASNP(P1.9E-4)Unpublisheddata2121Extendedhaplotypecase_freControl_freHaplo.scoreP-valDRB1*1501-DQB1*06020.290.0958.8389.7×10-19DRB1*1501-DRB1*06010.0270.00784.1183.8×10-5DRB1*0901-DQB1*03030.0220.1-4.3121.6×10-5DRB1*1501-DQA1*0102-DQB1*06020.190.094.621.0×10-6DRB1*0901-DQA1*0302-DQB1*03030.0110.092-4.487.3×10-6DRB1*1501-DQA1*0102-DQB1*0602-DPB1*02010.0840.0343.50.00042DRB1*0901-DQA1*0302-DQB1*0303-DPB1*05010.00410.056-3.50.00042ExtendedhaplotypesamongHLA-DRB1,DQA1,DQB1,DPB1inanti-GBMdiseaseUnpublisheddataAllele-1Allele-2D'r2LODscoreDRB1*1501DQB1*06020.5620.30551.22DRB1*1501DRB1*090110.03910.41DRB1*1501DQB1*03030.8170.0244.44DRB1*1501DQA1*05020.2430.0011.03DQB1*0602DRB1*09010.6850.0182.81DQB1*0602DQB1*030310.0358.55DQB1*0602DQA1*05020.460.0050.82DQB1*0303DRB1*09010.6410.38556.05DQB1*0303DQA1*050210.0010.47DQA1*0502DRB1*09010.1480022LOD3:Confirmedlinkage.LOD-2:Nolinkage.LOD=0:thepossibilityisequalLinkageanalysisamongthesignificantallelesUnpublisheddata抗GBM病的科学问题•病因–易感性–诱发因素：环境？–病因•表型差异23病因遗传易感背景自身免疫T细胞B细胞3(IV)NC1表型？免疫耐受？诱发因素？24抗GBM病的科学问题•病因–易感性–诱发因素–病因：感染？•表型差异24病因遗传易感背景自身免疫T细胞B细胞3(IV)NC1表型？免疫耐受？诱发因素？25假说：微生物可能是抗GBM病的病因之一•1919:Goodpasture首先报道–1例18岁男性病人，咯血、急性肾衰竭–流感？•60%的患者发病前有前驱感染症状–病原微生物----分子模拟?GoodpasureEM.AmJMedSci1919;158:863-87025分子模拟B细胞表位T细胞表位26B细胞的线性抗原决定簇合成24条重叠肽段：–覆盖3(IV)NC1的234aa–起始的线性抗原决定簇：P14（aa129-150）2422212019181716151413121110987654321Linearpeptidesalongα3(IV)NC1100%80%60%40%20%0%FrequencyofrecognitionInitiationepitope?Riskepitope?JiaXY,etal.ClinJAmSocNephrol2012Jun;7(6):926-33P14(22mer)诱发WKY大鼠抗GBM肾炎•P14（aa129-150）–分子内抗原决定簇扩展–诱发自身免疫性T细胞增殖–T/B细胞共同抗原决定簇27UnpublisheddataB细胞的关键抗原决定簇与核心氨基酸基序•P14氨基酸序列:–P14:TDIPPCPHGWISLWKGFSFIMF–P14a:TDIPPCPHGWISL–P14b:CPHGWISLWKGFS–P14c:ISLWKGFSFIMFT28•P14c逐个氨基酸突变•B细胞识别的关键氨基酸基序–GFxFp14cISLWKGFSFIMFT-0.20.00.20.40.60.81.01.21.4ResiduesofsubstitutionNetODvalueat405nmUnpublisheddat