In serology, lack of specificity can generally be attributed to cross-reactions between different pathogens with antigens bearing similar epitopes. During seroepidemiologic surveys of contagious agalactia of sheep caused by Mycoplasma agalactiae infection, numerous sera were analyzed by enzyme-linked immunosorbent assay (ELISA). A few sera reacted with various antigens coated on plates, including the well with no antigen. This reactivity was not due to cross-reactions as initially suspected, and these multipositive sera were designated false-positive sera. Elimination of this false positivity was not possible by using covalent ELISA plates or different rabbit anti-sheep IgG conjugates. Only conjugates using monoclonal antibodies or protein G were efficient in elimination of false positivities without reducing the true specific positive titers. No false-positive sera have been observed since the implementation of protein G conjugates in the serologic diagnosis of contagious agalactia by ELISA for the past 2 years.
References
1.
AckerstromBBjorckL: 1986, A physicochemical study of protein G, a molecule with unique immunoglobulin G binding propertiesJ Biol Chem261:10240–10247
2.
BanksM: 1989, Aujeszky's disease ELISA: Cross-reactions with other herpesvirus antiseraVet Microbiol20:1–8
3.
CalamelMLambertM: 1988, E.L.I.S.A. standardized technique.CNEVA, Sophia Antipolis, France
4.
CookRFGannSJMumfordJA: 1989, The effects of vaccination with tissue culture-derived viral vaccines on detection of antibodies to equine arteritis virus by enzyme-linked immunosorbent assay (ELISA)Vet Microbiol20:181–189
5.
DaMassaAJWakenellPSBrooksDL: 1992, Mycoplasmas of goats and sheepJ Vet Diagn Invest4:101–113
6.
DeLeeuwWACornelissenJB: 1993, Comparison of three enzyme immunoassays for diagnosis of Dictyocaulus viviparus infectionVet Parasitol49:229–241
7.
Diaz-AparicioEMarinCAlonsourmetaB.: 1994, Evaluation of serological tests for diagnosis of Brucella melitensis infection of goatsJ Clin Microbiol5:1159–1165
8.
FicapalAAlonsourmenetaBVelascoJ.: 1995, Diagnosis of Brucella ovis infection of rams with an ELISA using protein-G as conjugateVet Rec137:145–147
9.
GerbierGGarin-BastujiBPouillotR.: 1997, False positive serological reactions in bovine brucellosis: Evidence of the role of Yersinia enterocolitica serotype O:9 in a field trialVet Res28:375–383
10.
HasselaarPTriplettDALaRueA.: 1990, Heat treatment of serum and plasma induces false positive results in the anti-phospholipid antibody ELISAJ Rheumatol17:186–191
11.
KariwaHArikawaJTakashimaIHashimotoN: 1992, Development and application of protein G antibody assay for the detection of antibody to hantavirusJ Virol Methods37:345–354
12.
KellyPJTagwiraMMatthewmanL.: 1993, Reactions of sera from laboratory, domestic and wild animals in Africa with protein A and a recombinant chimeric protein AGComp Immunol Microbiol Infect Dis16:299–305
13.
KittelbergerRLaybournBJReichelMP.: 1996, Attempted definition by immunoblotting of the causes of reactivity in suspected false-positive sera in the Brucella ovis complement fixation testNZ Vet J44:170–174
14.
LambertM: 1987, Agalaxie contagieuse des brebis et des chèvresRev Sci Tech Off Int Epizoot6:681–697
15.
LambertMCabasseE: 1989, Sérologie de l'agalaxie contagieuse des brebis: Comparaison ELISA—Fixation du complémentRev Méd Vét140:107–112
16.
LindenmayerJWeberMBryantJ.: 1990, Comparison of indirect immunofluorescent-antibody assay, enzyme-linked immunosorbent assay, and western immunoblot for the diagnosis of Lyme disease in dogsJ Clin Microbiol28:92–96
17.
LopezNAJacobsonRHScarlettJM.: 1989, Sensitivity and specificity of blood test kits for feline leukemia virus antigenJ Am Vet Med Assoc195:747–751
18.
LuntRABlacksellSDNewberryKM: 1994, The use of an indirect ELISA with protein G-peroxidase conjugate and a blocking ELISA to demonstrate recent bluetongue infection in sheepJ Virol Methods48:53–63
19.
McFarlaneIGSmithHMJohnsonPJ.: 1990, Hepatitis C virus antibodies in chronic active hepatitis: Pathogenetic factor or false-positive result?Lancet335:754–757
20.
McKenzieWRDavisJPPetersonDE.: 1992, Multiple false-positive serologic tests for HIV, HTLV-1, and hepatitis C following influenza vaccinationJ Am Med Assoc268:1015–1017
21.
MolinaCaballero JMAnguianoAFerrerO.: 1993, Use of an enzyme-linked immunosorbent assay for serodiagnosis of clinical paratuberculosis in goats. Study by western blotting of false-positive reactionsRev Sci Tech Off Int Epizoot12:629–638
22.
PapoianR: 1992, Non-specific immunoglobulin interactions may lead to false-positive results in assays for human anti-mouse monoclonal antibodies (HAMA)J Immunoassay13:289–296
23.
PoumaratFPerrinMBelliP.: 1989, Studies of the origin of false positive reactions in the serodiagnosis of contagious bovine pleuropneumoniaRev Elev Med Vet Pays Trop42:371–378
24.
RiveraEJackertjernbergerMMejerlandTKarlssonKA: 1994, Evaluation of protein A and protein G as indicator system in an ELISA for detecting antibodies in mink to Pseudomonas aeruginosaVet Microbiol42:265–271
25.
SeppalaIJKroneldRSchaumanK.: 1994, Diagnosis of Lyme borreliosis: Non-specific serological reactions with Borrelia burgdorferi sonicate antigen caused by IgG2 antibodiesJ Med Microbiol40:293–302
26.
ThoenCOQuinnWJMillerLD.: 1997, Mycobacterium bovis infection in North American elk (Cervus elaphus)J Vet Diagn Invest4:423–427
27.
TylerJWCullorJS: 1989, Titers, tests, and truisms: Rational interpretation of diagnostic serologic testingJ Am Vet Med Assoc194:1550–1558
28.
YoshidaHIshikawaHHondaS.: 1992, False positive reaction of heat-inactivated sera in enzyme-linked immunosor-bent assay for antibody to hepatitis C virusFukushima J Med Sci38:35–41
29.
ZanoniRKriegAPeterhansE: 1989, Detection of antibodies to caprine arthritis encephalitis virus by protein G ELISA and immunoblottingJ Clin Microbiol27:580–582
