G GM試驗(yàn)-真菌檢測

G試驗(yàn)和GM試驗(yàn)

----真菌檢測馬桂伶2011-3-161真菌感染會帶來怎樣的后果呢？Mortality,lengthofhospitalization,andcostsassociatedwithinvasivefungalinfectionsinhigh-riskpatients.MenzinJ,MeyersJL,FriedmanM,PerfectJR,LangstonAA,DannaRP,PapadopoulosG.AmJHealthSystPharm.2009Oct1;66(19):1711-7.3456789G試驗(yàn)和GM試驗(yàn)

----真菌檢測馬桂伶2011-3-1610深部真菌白色念珠菌新型隱球菌曲霉菌毛霉菌11傳統(tǒng)的檢測方法主要為血培養(yǎng)和組織活檢，但血培養(yǎng)歷時太長，且陽性率較低。近年來，用于檢則真菌的抗原、抗體及代謝產(chǎn)物的血清學(xué)檢查已用于深部真菌感染的實(shí)驗(yàn)室檢測。

目前的血清學(xué)檢查主要針對真菌胞壁或胞內(nèi)成分——beta-葡聚糖、甘露糖、烯醇化酶和Cand-Tec抗原等。12G試驗(yàn)-（1，3）-β-D葡聚糖試驗(yàn)G試驗(yàn)檢測的是真菌細(xì)胞壁成分(1，3)-β-D葡聚糖，由于(1，3)-β-D-葡聚糖僅廣泛存在于真菌的細(xì)胞壁中，當(dāng)真菌進(jìn)入人體血液或深部組織后，經(jīng)吞噬細(xì)胞的吞噬、消化等處理后，(1，3)-β-D-葡聚糖可從胞壁中釋放出來，從而使血液及其它體液中(1，3)-β-D-葡聚糖含量增高。

當(dāng)真菌在體內(nèi)含量減少時，機(jī)體免疫可迅速清除(1，3)-β-D-葡聚糖。

在淺部真菌感染中，(1，3)-β-D-葡聚糖未被釋放出來，故其在體液中的量不增高。13

20世紀(jì)90年代初發(fā)現(xiàn),(1-3)-beta-D-葡聚糖可特異性激活自鱟變形細(xì)胞溶解產(chǎn)物提取的G因子,從而旁路激活鱟試驗(yàn),此過程稱為G試驗(yàn)。臨床上,由于深部真菌感染的嚴(yán)重程度常常與血漿多糖的升高水平一致,故G試驗(yàn)可協(xié)助深部真菌感染的診斷(包括念珠菌感染和曲霉菌感染等)。14GM實(shí)驗(yàn)-半乳甘露聚糖試驗(yàn)甘露糖是目前研究最為廣泛的一種抗原,廣泛存在于真菌胞壁中,是真菌胞壁的重要組成成分.15Plasma(1-3)-beta-Dglucanmeasurementindiagnosisofinvasivedeepmycosisandfungalfebileepisodes目的：探討(1-3)-beta-Dglucan在篩查侵襲性真菌感染及

真菌性發(fā)熱中的價(jià)值。方法：檢測了202例病員標(biāo)本，以(1-3)-beta-D-葡聚糖

的血漿濃度20pg/ml為界值,41例

確診病員(以活

檢和培養(yǎng)陽性為標(biāo)準(zhǔn))，37例為陽性,陽性率為90%;59例其他原因所致發(fā)熱者全部陰性,陰性率為100%結(jié)論：(1-3)-beta-D-葡聚糖可用于早期診斷深部真菌感

染,其缺點(diǎn)是不能定性,且此法不能檢測出隱球菌

感染,可能是因?yàn)殡[球菌具有厚壁胞膜。ObayashiT,YoshidaM,MoriT,etal.Plasma(1，3)-beta-Dglucanmeasurementindiagnosisofinvasivedeepmycosisandfungalfebileepisodes[J].Lancet,1995,345(1):17-20.1617Karageorgopoulos

DM,b-D-GlucanAssayfortheDiagnosisofInvasiveFungalInfections:AMeta-analysis,ClinicalInfectiousDiseases.2011;52(6):750–771876.8%85.3%19conclusionBDGhasgooddiagnosticaccuracyfordistinguishingprovenorprobableIFIsfromnoIFIs.Itcanbeusefulinclinicalpractice,ifimplementedinthepropersetting.20Toupdatethe

case-fatalityrate(CFR)

associatedwithinvasiveaspergillosisaccordingtounderlyingconditions,siteofinfection,andantifungaltherapy,dataweresystematicallyreviewedandpooledfromclinicaltrials,cohortorcase-controlstudies,andcaseseriesof≥10patientswithdefiniteorprobableaspergillosis.Subjectswere1941patientsdescribedinstudiespublishedafter1995thatprovidedsufficientoutcomedata;casesincludedwereidentifiedbyMEDLINEandEMBASEsearches.ThemainoutcomemeasurewastheCFR.Fiftyof222studiesmettheinclusioncriteria.TheoverallCFRwas58%,andtheCFRwashighestforbonemarrowtransplantrecipients(86.7%).

AmphotericinBdeoxycholateandlipidformulationsofamphotericinBfailedtopreventdeathinone-halftotwo-thirdsofpatients.MortalityishighdespiteimprovementsindiagnosisanddespitetheadventofnewerformulationsofamphotericinB.Underlyingpatientconditionsandthesiteofinfectionremainimportantprognosticfactors.LinSJ,SchranzJ,TeutschSM.Aspergillosiscase-fatalityrate:systematicreviewoftheliterature.ClinInfectDis.2001;32:358–366.21ChristopherD,DiagnosisofInvasiveAspergillosisUsingaGalactomannanAssay:AMeta-Analysis,ClinicalInfectiousDiseases2006;42:1417–27222300.930.0.710.6100.8924ConclusionsGMtesthasmoderateaccuracyfordiagnosisofinvasiveaspergillosisinimmunocompromisedpatients.Thetestismoreusefulinpatientswhohavehematologicalmalignancyorwhohaveundergonehematopoieticcelltransplantation25GM試驗(yàn)在非血液病患者真菌檢測中的應(yīng)用26272829conclusion1TheprevalenceofinvasiveaspergillosisinthegroupofpatientswithCOPDwas16.13%。2The1ng/mlcut-offshowedahigherpositivepredictivevalue(100%)andcomparablenegativepredictivevaluetothe0.5ng/mlcut-off.ThevalueofthetestinCOPDpatientsyieldedsimilarresults.30COPDpatientsmayhaveincreasedsusceptibilityto

fungalinvasiveinfectionforseveralreasons(1)structuralchangesinlungarchitecturerelatedtothepulmonarydisease;(2)thecommonuseoflong-termorrepeatedshort-termsteroidtreatmentsasanadditionalimmunosuppressivefactor;(3)frequenthospitalisationandantibiotictreatment,leadingtoexposuretoselectedfungalpathogens;(4)co-morbidityfactorssuchasalcoholism,diabetesmellitusormalnutrition.F.Ader.Invasivepulmonaryaspergillosisinchronicobstructivepulmonarydisease:anemergingfungalpathogen.ClinMicrobiolInfect,2005;11:427–42931GM試驗(yàn)在COP