HBV的變異及其耐藥的診治上海瑞金醫(yī)院陸志檬教授變異是病毒重要生物學(xué)特征之一慢性HBV感染者體內(nèi)每天可產(chǎn)生1011~13個病毒體復(fù)制過程中DNA多聚酶可發(fā)生錯誤導(dǎo)致病毒DNA中出現(xiàn)核苷錯誤配對HBVDNA每個復(fù)制循環(huán)中每10,000個堿基對可發(fā)生1個核苷錯誤，因而形成HBV突變株：可能改變了宿主對病毒的免疫反應(yīng)可能增強了病毒的復(fù)制能力1CarmanWF,London:ChurchillLivingstone,1998;141-172變異株≠突變株

（variant）（mutant）HBV變異株

是指在自然環(huán)境中發(fā)生變化的病毒株HBV基因型、HBsAg血清型和亞型HBV突變株

是指在宿主體內(nèi)自發(fā)產(chǎn)生或者在治療壓力或其它壓力下發(fā)生改變的病毒株HBV自發(fā)性前核心區(qū)/核心區(qū)和核心啟動子(BCP)突變與HBV基因型密切相關(guān)1LokAS,Gastroenterology,2001;120:1828-1853病毒感染的持久性及耐藥性病毒肝細胞病毒多聚酶缺乏矯正功能CCCDNA半衰期長受染細胞半衰期長宿主選擇性壓力免疫應(yīng)答病毒感染的持久性對耐藥突變株的選擇1ZoulimF,SeminLiverdis,2002;22S1:23-322ZoulimF,AntivirChemChemother,2001,12:131-142病毒高復(fù)制高變異率耐藥分析耐藥基序 （Drugresistancemotifs）HBV表型耐藥 （Phenotypicresistance）臨床耐藥 （Clinicalresistance）三者相關(guān)，但不完全等同

HBVpolymerase(wild-type)Lamivudineandwild-typeHBV(一)

Nucleotides

ss(-)DNAhighaffinity

Y

M

D

D

Lamivudineandwild-typeHBV(二)HBVpolymerase

(wild-type)

NucleotideshighaffinityLamivudineinhibitionss(-)DNA

Y

M

D

D

LamivudineandYMDDvariantHBV

YV/I

D

DNucleotidesreducedaffinityLamivudineweakinhibitionss(-)DNAHBVpolymerase(variant)病毒耐藥性的診斷表型耐藥－在治療期間血清病毒DNA水平上升基因型耐藥－病毒多聚酶基因出現(xiàn)突變1NafaS,Hepatology,2000;32:1078-1088

2StuyverL,JclinMicrobiol,2000;38;702-707耐藥變異的檢測方法SequencesanalysisLineprobeassayPCR-RFLPanalysis (Restrictionfragmentlengthpolymorphism)Real-timePCRMolecularbeaconsDNAchipLightCyclerDetectionFormats

MutationAnalysisTemperaturelow medium highMismatchPerfect

MatchYMDD變異檢測結(jié)果YMDD基序變異發(fā)生后的臨床影響IncidenceofYMDDvariantHBVIncidenceofdetectableserumYMDDvariantHBVinHBeAg+vepatientsafterlamivudinetherapyfor:1yr=24%(Laietal,2001)2yr=38%(Liawetal,2000)3yr=49%(Leungetal,1999)4yr=67%(Changetal,2000)EmergenceofYMDDvariantsdoesnotnecessarilyequatetoclinicalresistanceYMDD變異檢測結(jié)果00020153017510002000002146511068.720213100181013.603192100231010.511171變異株百分比(%)YVDDYIDDYMDD變異株百分比(%)YVDDYIDDYMDD治療48周治療前編號張欣欣等瑞金醫(yī)院YMDD變異對臨床的影響張欣欣等瑞金醫(yī)院YMDD變異對臨床的影響張欣欣等瑞金醫(yī)院CountryMethodNumberofPatientsPercentsofDetectionofYMDDmutantinuntreatedpatientsChinaCloneAnalysis580%(4/5)Japan1PCR–ELISA&mini-sequencemethod1828%(5/18)Japan2Peptidenucleicacid(PNA)mediatedpolymerasechainreactionclamping1822%(4/18)GermanyLine-probe-assay86

Ofthepatientswhodevelopedresistance,32%hadYMDDmutantspretreatment.Ofthosewhodidnotdevelopresistance,59%hadYMDDmutantspretreatment.Therefore,YMDDpre-treateddoesn’tpredicttreatmentfailure.Japan1:SatsukiKobayashi,TatsuyaIde,MichioSataJapan2:ToshihikoKirishima,TakeshiOkanoue,YukikoDaimon,etal.對拉米夫定耐藥株的治療不明部分活性不明LFd4C不明不明不明LdC不明不明不明LdT不明無不明Clevudine不明無不明Emtricitabine有部分活性無報道恩替卡韋有有無報道阿地福韋無無有:25%/1y;50%/2y拉米夫定有尚未研究有:75%的患者干擾素

對拉米夫定耐藥株的活性體外體內(nèi)耐藥性抗病毒藥物1NafaS,Hepatology,2000;32:1078-1088

2DelaneyWet,AntimicrobAgentsChemother,2001;45:1705-17132002年歐洲肝病會議信息（二）2002.4.西班牙

Adefovir治療CHB及對LAM耐藥變異的體內(nèi)外試驗

Inhibitionoflamivudine-ResistantHBVbyAdefovirinCellCultureAssay

FoldIncreaseinIC50MutationLamivudineAdefovirWidetype11

V521L1.41.9

L528M3.51.9M552I3803.2L528M+M552V20802.5V521L+L528M+M552V16660.7L528M

&

V521L:

compensatorymutationsenhancingreplicationfitnessViralLoadSuppressioninPatientsTreatedwithADVforUpto72Weeks

MedianDecreaseinDurationofADVNo.ofHBVDNATherapypatients*(Log10c/ml)24weeks106-3.648weeks46-4.472weeks14-4.7Genotypedpatientswithbothbaselineandpost-treatmentHBVDNAdataavailable

對拉米夫定耐藥的預(yù)防針對病毒拉米夫定+泛昔洛韋拉米夫定+阿地福韋(或+恩替卡韋,LdT)拉米夫定+干擾素

(或IFN

續(xù)貫治療)針對宿主恢復(fù)特異性抗HBVCD4/CD8免疫應(yīng)答誘導(dǎo)持續(xù)病毒抑制HBVDNA疫苗細胞因子1GishRG,AntimicrobAgentsChemother,2002;46:1734-1740

2SantantonioT,JHepatol,2002;36:799-804患者用拉米夫定前后的病情演變拉米夫定100mg

干擾素HBeAg+HBeAb-HBeAg-HBeAb+HBsAg-102日達仙1.6mgTIW104103105106107108DNAALT男性，36歲展望治療拉