title: Analysis of western blotting (immunoblotting) technique in diagnosis of congenital syphilis.
abstract: The diagnosis of congenital syphilis in apparently healthy infants continues to be problematic. Immunoglobulin M antibodies specific for a subset of Treponema pallidum antigens have been detected by Western blotting (immunoblotting). In the present study we investigated the sensitivity and specificity of this method. We tested 26 infants aged 0 to 4 months who fulfilled the accepted criteria for the diagnosis of congenital syphilis. There were 14 symptomatic infants. Sera from 13 of these infants were positive for the 47-kDa treponemal antigen (92% sensitivity). The remaining 12 infants were clinically asymptomatic when tested at birth but subsequently displayed features consistent with the disease. Reactive blots (antibodies to the 47- and/or the 15-kDa antigens) were noted in 10 of the 12 infants (83% sensitivity). Thirty infants whose mothers had syphilis were monitored and shown to be uninfected. Nonreactive blots were seen in sera from 27 infants, while sera from 3 older infants had false-positive tests (90% specificity). The Western blotting technique is sensitive (even in the diagnosis of clinically inapparent cases) and, in the absence of immunoglobulin M rheumatoid factor, is a useful confirmatory test for congenital syphilis.
authors.affiliation: Department of Paediatrics and Child Health, University of Cape Town, South Africa.
authors.forename: M P
authors.initials: MP
authors.lastname: Meyer
authors.forename: T
authors.initials: T
authors.lastname: Eddy
authors.forename: R E
authors.initials: RE
authors.lastname: Baughn
mesh_terms: D000907:Antibodies, Bacterial / Q000097:blood; D015153:Blotting, Western / Q000379:methods* / Q000706:statistics & numerical data; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D007075:Immunoglobulin M / Q000097:blood; D007223:Infant; D007231:Infant, Newborn; D011247:Pregnancy; D012680:Sensitivity and Specificity; D013588:Syphilis Serodiagnosis / Q000379:methods* / Q000706:statistics & numerical data; D013590:Syphilis, Congenital / Q000175:diagnosis* / Q000276:immunology; D014210:Treponema pallidum / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D007075:Immunoglobulin M