ANA-HEp2ScreenELISAisasolidphaseenzymeimmunoassayforthecombinedqualitativedetectionofIgGantibodiesagainstHEp2cellsinhumanserum.EachwelliscoatedwithlysedHEp2cells.Thetestcollectivelydetects,inonewell,totalANAsagainstdoublestrandedDNA(dsDNA),histones,SS-A(Ro),SS-B(La),Sm,snRNP/Sm,Scl-70,PM-Scl,Jo-1andcentromericantigensalongwithserapositiveforHEp2immunofluorescencetest(IFT).Theassayisatoolinthedifferentialdiagnosisofsystemicrheumaticdiseaseslikesystemiclupuserythematosus(SLE),mixedconnectivetissuediseases(MCTD),scleroderma,Sjögren`ssyndrome,polymyositisanddermatomyositis.Anti-nuclearantibodies(ANA)directedagainstavarietyofnuclearandcytoplasmicantigensoccurinhighfrequencyinsystemicrheumaticdiseasesandthusareanimportanttoolforthedifferentialdiagnosis.Forinstance,SS-A(Ro)andSS-B(La)antibodiesareassociatedwithSLEandSjögren’ssyndrome(SS),anti-dsDNAandanti-SmantibodieswithSLE,anti-histoneantibodieswithSLEanddrug-inducedlupus,anti-RNPantibodieswithmixedconnectivetissuedisease(MCTD)andSLE,anti-Scl-70antibodieswithscleroderma(progressivesystemicsclerosis[PSS]),anti-Jo-1antibodieswithpolymyositisanddermatomyositisandanti-centromereantibodieswithCRESTsyndrome.Indirectimmunofluorescencetest(IFT)oneucaryoticcellslikeHeLaandHEp2hasbeentheestablishedmethodforthedetectionofANAs.AlthoughtheIFTisasensitivetest,itislaboriouswhentestinglargenumbersofpatientsamplesandissubjecttoerrorsfromhumaninterpretationandfromvariABIlityinfluorescentmicroscope.TheELISAtestsystemisanexcellentalternativetotheIFTforscreeningpatient`sserumforthepresenceofANAsofclinicalsignificance.SingleantibodyspecificitieshavetobedeterminedbymorespecifictestingusingELISAsemployingthespecifictargetantigensforasimpleandreliabledifferentiationofANAs.