
Description:
ThepresenceofantibodiesagainsttheSSB(alsoknownasLa)antigenhasbeenadvocatedasadiagnosticMarkerforSjogren"ssyndrome(SS),anautoimmunediseasecharacterizedbyinflammationoftheglandsleADIngtodiminishedorabsentglandularsecretion.SSmaypresentasaprimarydiseaseorassociatewithothersystemicautoimmunediseasesassecondarySS.TheSSBantigenisa47kDribonucleicproteinassociatedwithaspectrumofsmallRNAsandprimarilyresidesinthenucleus.AntibodiestotheSSBantigenappearinmorethan80%ofpatientswithprimaryorsecondarySS.Anti-SSBantibodiesusuallyco-presentwithanti-SSAantibodies,howeverduetomorecommonofanti-SSAantibodiesinotherrheumatologicalconditionssuchassystemiclupuserythematosis(SLE)andmixedconnectivetissuedisease(MCTD).Itsuggeststhatanti-SSBismorespecificforprimaryandsecondarySSthananti-SSA.Principle:
AutoimmuneELISAkitsmeasureautoimmuneantibodiesintheserum.Itisbasedontheprincipleofasolidphaseenzyme-linkedimmunosorbentassay.Theassayutilizesaspecificantigenforimmobilizationonthemicrotiterwellsandanti-humanIgGantibodyconjugatedtohorseradishperoxidase(HRP)fordetection.Thetestsampleisallowedtoreactsimultaneouslywiththetwocomponents,resultingin autoimmuneantibodiesbeingsandwichedbetweenthesolidphaseandenzyme-linkedantibodies.Afterincubation,thewellsarewashedtoremoveunbound-labeledantibodies.AHRPsubstrate,TMB,isaddedtoresultinthedevelopmentofabluecolor.ThecolordevelopmentisthenstoppedwiththeadditionofStopSolutionchangingthecolortoyellow.Theconcentrationofautoimmuneantibodies isdirectlyproportionaltothecolorintensityofthetestsample.Absorbanceismeasuredspectrophotometricallyat450nm.