G GM试验-真菌检测

G试验和GM试验

----真菌检测马桂伶2011-3-161真菌感染会带来怎样的后果呢？Mortality,lengthofhospitalization,andcostsassociatedwithinvasivefungalinfectionsinhigh-riskpatients.MenzinJ,MeyersJL,FriedmanM,PerfectJR,LangstonAA,DannaRP,PapadopoulosG.AmJHealthSystPharm.2009Oct1;66(19):1711-7.3456789G试验和GM试验

----真菌检测马桂伶2011-3-1610深部真菌白色念珠菌新型隐球菌曲霉菌毛霉菌11传统的检测方法主要为血培养和组织活检，但血培养历时太长，且阳性率较低。近年来，用于检则真菌的抗原、抗体及代谢产物的血清学检查已用于深部真菌感染的实验室检测。

目前的血清学检查主要针对真菌胞壁或胞内成分——beta-葡聚糖、甘露糖、烯醇化酶和Cand-Tec抗原等。12G试验-（1，3）-β-D葡聚糖试验G试验检测的是真菌细胞壁成分(1，3)-β-D葡聚糖，由于(1，3)-β-D-葡聚糖仅广泛存在于真菌的细胞壁中，当真菌进入人体血液或深部组织后，经吞噬细胞的吞噬、消化等处理后，(1，3)-β-D-葡聚糖可从胞壁中释放出来，从而使血液及其它体液中(1，3)-β-D-葡聚糖含量增高。

当真菌在体内含量减少时，机体免疫可迅速清除(1，3)-β-D-葡聚糖。

在浅部真菌感染中，(1，3)-β-D-葡聚糖未被释放出来，故其在体液中的量不增高。13

20世纪90年代初发现,(1-3)-beta-D-葡聚糖可特异性激活自鲎变形细胞溶解产物提取的G因子,从而旁路激活鲎试验,此过程称为G试验。临床上,由于深部真菌感染的严重程度常常与血浆多糖的升高水平一致,故G试验可协助深部真菌感染的诊断(包括念珠菌感染和曲霉菌感染等)。14GM实验-半乳甘露聚糖试验甘露糖是目前研究最为广泛的一种抗原,广泛存在于真菌胞壁中,是真菌胞壁的重要组成成分.15Plasma(1-3)-beta-Dglucanmeasurementindiagnosisofinvasivedeepmycosisandfungalfebileepisodes目的：探讨(1-3)-beta-Dglucan在筛查侵袭性真菌感染及

真菌性发热中的价值。方法：检测了202例病员标本，以(1-3)-beta-D-葡聚糖

的血浆浓度20pg/ml为界值,41例

确诊病员(以活

检和培养阳性为标准)，37例为阳性,阳性率为90%;59例其他原因所致发热者全部阴性,阴性率为100%结论：(1-3)-beta-D-葡聚糖可用于早期诊断深部真菌感

染,其缺点是不能定性,且此法不能检测出隐球菌

感染,可能是因为隐球菌具有厚壁胞膜。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试验在非血液病患者真菌检测中的应用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试验在COP