Description:
REAADSAnti-ProthrombinIgM isan anti-ProthrombinantibodyELISAtestkitforthe semi-quantitative,indirectdetectionofantibodiesagainsthumanprothrombin.AsinglepointcalibratorisusedtodetermineIgManti-prothrombinantibodyconcentrationsinhumanserumofcitratedplasma.
Features:
- ConvenientELISAprocedure
- ForthespecificdeterminationofIgMisotype
- Objective,accurateandreproducIBLe
- Reagentcompletekits
- Totalincubationtime:40minutesatroomtemperature
PrincipleandProcedure:
Principle
TheREAADSIgManti-Prothrombinantibodytestkitsaresemiquantitative,indirectELISAsforthedetectionofantibodiesagainsthumanprothrombin.AsinglepointcalibratorisusedtodetermineIgManti-prothrombinantibodyconcentrationsinhumanserumofcitratedplasma.
Procedure
Dilutedpatientserumorplasmaisincubatedinmicrowellscoatedwithhumanprothrombin.Anti-Prothrombin(aPT)antibodiesinpatientsampleswillbindtotheimmobilizedantigeninthewells.Afterwashingtoremoveunboundserumorplasmaproteins,antibodiesspecificforhumanIgM,labeledwithhorserADIshperoxidase(HRP),areboundantibodies.Thewellsarewashed,andachromogenicsubstrateisadded,resultinginacolorchangethatisproportionaltotheamountofantibodypresent.Theassayiscompletedbytheadditionofastoppingsolution.ResultsareobtainedbyreadingtheO.D.(opticaldensityorabsorbance)at450nmofeachwellinaspectrophotometer.TheO.D.valuesofcontrolandpatientsamplesaremultipliedbythecalibratorconversionfactortoobtainIgMaPTantibodyconcentrationstimeis40minutesatroomtemperature.
ClinicalPerformance*:
ClinicalSpecificity:serumsamplesfrom100healthyblooddonorsweretestedforaPTantibodies.Againstanestablishedcutoffvalueof20Gand20Munits,thespecificityoftheIgMassaywas97%.Aspresentedinthetablebelow,similarresultswereseenwhenplasmasamplesfrom100healthyblooddonorsweretested.Assayspecificitywith42infectiousdisease(syphilis)patientsand42RheumatoidArthritis(RA)patientsisalsopresentedinthetable.
ClinicalSensitivity:serumsamplesfrom41unselectedSLEpatientsweretestedforIgMaPTantibodies.14.6%ofthesampleswerepositiveforIgMaPTantibodies(meanvaluesof11.8Munits).Serumsamplesfrom11selectedfemalepatientswithprimaryanti-phospholipidsyndrome(APS)werealsoevaluatedforantibodiestoprothrombin.27.3%werepositiveforIgMantibodies(meanvaluesof15.7Munits).
| IgMaPT (%positive) | |
| Healthyserum (n=100) | 3% |
| Healthyplasma (n=100) | 3% |
| Syphilis (n=42) | 11.9% |
| RA (n=42) | 4.8% |
| SLE (n=41) | 12.2% |
| APS (n=11) | 27.3% |
*Dataavailableuponrequest.
Background:
Severalplasmaproteinsassociatedwiththecoagulationsystemandwithstrongphospholipidbindingpropertieshavebeenidentifiedasantiphospholipidcofactors.Antibodiestoprothrombin,oneoftheseplasmaproteins,havebeenreportedinpatientswithantiphospholipidsyndrome.TestingfortheseantibodiesisproposedtobeincludedintheSEROlogicevaluationofantiphospholipidantibodies.Clinically,elevatedserumlevelsofanti-prothrombin(aPT)antibodiesareassociatedwithanincreasedriskforAPS,characterizedbyrecurrentarterialorvenousthrombosis,thrombocytopeniaand/orfetalloss.HighserumorplasmalevelsofaPTantibodiesmayaddvaluableinformationinthelaboratoryassessmentofantiphospholipidantibodies.
