Description:
TheDiapharmaFactorXKitisaninvitrodiagnostictestkitforthequantitativedeterminationofFactorXactivityinhumancitratedplasma.FactorXactivityisusefulformonitoringpatientsonoralanticoagulanttherapy(warfarin)wherebaselineINRvaluesareprolongedandINRresultsarenotreliable,suchasinOACpatientswithlupusinhibitors.TheDiaPharmaFactorXKitisalsousefulforscreeningforfactorXdeficiencies.
TheDiapharmaFactorXchromogenicassaykitallowslabstoaccuratelypredicttherapeuticwarfarinwhenINRvaluesareunreliable,suchasinthepresenceoflupusanticoagulantsorwhendirectthrombininhibitorsarediscontinued(bridgingfromDTItowarfarin).
Advantages:
- SolutiontodealingwithunstableINRsinwarfarinpatientswithlupusinhibitors
- Eliminatestheissuesofvaryingsensitivitiesofdifferentthromboplastins
- Reliable,reADIlyavailable,andeasytouseassay
- Applicationsforautomatedcoagulationanalyzers
KitComposition:
- ChromogenicSubstratePreparation25mglyophilizedFXachromogenicsubstratewithmannitoladdedasabulkingagent.Reconstitutesubstratewith20mlsterilewater.Storage&StABIlityThereconstitutedsubstrateisstablefor6monthsat2–8°C.
- Russell’sViperVenomPreparationFXactivatingproteinfromRussell’sViperVenom.ReconstitutetheRVVwith15mlsterilewater.Storage&StabilityThereconstitutedactivatorisstablefor1monthat2–8°C.
- CaCl2Preparation20mlof0.1mol/Lcalciumchloridesolution.Beforeuse,mix1volumeofRVVwith1volumeofCaCl2.Themixtureisstablefor48hoursat2–8°C.Storage&StabilityThesolutionisstableat2–8°Cuntiltheexpirydateprintedonthelabel.
- BufferPreparation100mlbuffersolutioncontaining0.05mol/LTris,pH7.8and20mg/LPolybrene®(hexadimethrinebromide).Readyforuse.Storage&StabilityThebufferisstableat2–8°Cuntiltheexpirydateprintedonthelabel.
MeasurementPrinciple:
1
| RVV | ||
| FX | → | FXa |
| Ca+2 |
2
| Chromogenic Substrate | → | Peptide+pNA(color) |
| FXa |
Themethodisbasedonatwo-stageprinciple.Instageone,FactorXisactivatedinthepresenceofcalciumtoFactorXa(FXa)bytheactivatorRussell’sViperVenom(RVV).Instagetwo,thegeneratedFXahydrolysesthechromogenicsubstrate,thusliberatingthechromophoricgroup,pNA.Thecoloristhenreadwithaspectrophotometerat405nm.ThegeneratedFXaandthustheintensityofcolorisproportionaltoptheFXactivityinthesample.
Background:
CoagulationFactorX(StuartProwerFactor,FX)isavitaminKdependentproteinproducedbytheliver.Ithasacentralpositioninthecoagulationcascade.FactorXisactivatedbothbytheextrinsicandintrinsicsystemsbeforeexertingitseffectontheconversionofprothrombintothrombin.
Patientswhoneedanticoagulationtherapycanbetreatedwithwarfarin,whichisavitaminKantagoNIST.ThistreatmentleadstoadecreaseinallvitaminKdependentclottingfactorsandthusaprolongedclottingtimeofblood.Thetherapyrequirescarefulmonitoringsinceitisessentialtofindanoptimalbalancebetweenriskofthrombosisandriskofbleedingforeachpatient. TheDiaPharmaFactorXkitisausefultoolinthemanagementofpatientswithlupusinhibitorsreceivingwarfarintherapy.
