
Description:
1.INTRODUCTION
Type1diabetes,alsoknownasinsulin-dependentdiabetesmellitus(IDDM),resultsfromachronicautoimmunedestructionoftheinsulin-secretingpancreaticbetacells,probablyinitiatedbyexposureofgeneticallysusceptIBLehosttoenvironmentalagents.Autoimmunedestructionofbetacellsisthoughttobecompletelyasymptomaticuntil80-90%ofthecellsarelost.Thisprocessmaytakeyearstocompleteandmayoccuratanytimeinallages.Duringthepreclinicalphase,thisautoimmuneprocessismarkedbycirculatingautoantibodiestobetacellantigens.Theseautoantibodies,suchasanti-insulin(IAA),anti-glutamicaciddecarboxylase(GAD)andanti-tyrosinephosphataseICA512(IA2),arepresentyearsbeforetheonsetoftype1diabetesandpriortoclinicalsymptoms.GAD,theenzymethatcatalyzestheconversionofglutamatetoGABA,hasbeenidentifiedintwoisoforms,molecularweight65.000(GAD65)and67.000(GAD67).AlthoughGADautoantibodiesarefoundintype1diabetesandintherareneurologicaldisorderStiff-mansyndrome(SMS),theGADautoantibodiesprofileinthetwodiseasesdiffers.AutoantibodiesofSMSpatientsrecognizeacombinationoflinearandconformationalepitopesofGADwhileGAD65autoantibodiesinpatientswithtype1diabetesarepredominantlydirectedtotheconformationalepitopes.GAD65autoantibodies(GAD65Abs)arepresentin70-80%ofnewlydiagnosedpatientswithtype1diabetes.ThecombinationoftheautoantibodiestoGAD65andIA2ishighlyrelevantforriskassessmentoftype1diabetesinchildrenandadolescence.ThesetestsincombinationaremoresensitiveandpredictivethanICAinriskgroups,e.g.relativesofpatientswithtype1diabetes.GAD65Absalsooccurinasubsetofadultswithtype2diabetes.Thesepatientscanhavepronouncedhyperglycemia,andaftertherapywithoralhypoglycemicagentsforseveralmonthstoyearstheymaybecomeinsulindependent.Therefore,thesepatientsarethoughttohaveaslowlyprogressiveformoftype1diabetes,oftencalledlatentdiabetesorlatentautoimmunediabetesinadults(LADA).ThepresenceofGAD65AbsinseraofsuchpatientsisasensitiveandspecificMarkerforfutureinsulindependency.
2.INTENDEDUSE
Anti-GADkitisforresearchonlyqualitativeELISAtestforthequantitativedeterminationofautoantibodiestoglutamicaciddecarboxylase(GAD65Abs)inhumanserumofprediabetichighriskindividualsaswellasIDDMdiabeticpatients.AntiGADkitisintendedforlaboratoryuseonly.
3.PRINCIPLEOFTHEASSAY
TheassaysystemusestheABIlityofGAD65AbsactingdivalentlyandformingabridgebetweenimmobilizedGAD65andliquid-phaseGAD65-Biotin.InthefirststepGAD65AbfromthesamplebindtoGAD65coatedonthemicrotiterplate.InasecondstepGAD65-Biotinbindstothiscomplex.TheboundGAD65-BiotincorrelateswiththeamountofGAD65Absinpatient’sserum.UnboundGAD65-Biotinisremovedbywashing.TheboundGAD65-BiotincouldbequantifiedbyadditionofStreptavidin-peroxidaseandachromogenicsubstrate(TMB)andreADIngtheopticaldensity(OD)at450nm.
AdditionalInformation:
Name | AntiGAD |
---|---|
RelatedProductNames | GlutamicAcidDecarboxylase(GAD)AntibodiesELISA,AntiGlutamicAcidDecarboxylaseELISA,AntiGADELISAKit,DiabetesAssay |
MolecularWeight | 0.5 |
Concentration | LotSpecific |
Applications | EnzymeimmunoassayforthequantitativedeterminationofGADinhumanserum |
Reactivity | Human |
IntendedUse | ResearchUseOnly |