Comparison of a Treponema pallidum IgM immunoblot with a 19S fluorescent treponemal antibody absorption test for the diagnosis of congenital syphilis.

Abstract

We compared an in-house Treponema pallidum IgM immunoblot (IB) with a 19S fluorescent treponemal antibody absorption (IgM) test during routine use for the diagnosis of congenital syphilis (CS) in a national reference laboratory in a nonendemic setting. The overall agreement between the assays was high (97%), and 19S positive samples had at least 2 reactive bands in the IB. The high agreement is mainly caused by the large number of negative results (95%). If the 19S is taken as the gold standard, the estimate sensitivity of the IB was at least 88% with a specificity of 97.2%. Analysis of the discrepancies revealed that the IB was positive with 1 or 2 specific bands in 2.8% of the cases, whereas 19S was negative, possibly indicating higher sensitivity of the IB. We conclude that the IB is a sensitive method to detect contact with T. pallidum in neonates and can replace the 19S in routine laboratory screening for CS cases.

• Authors: Martina Herremans, Daan W Notermans, Mart Mommers, Laetitia M Kortbeek
• Journal: Diagnostic microbiology and infectious disease (Diagn Microbiol Infect Dis) Vol. 59 Issue 1 Pg. 61-6 (Sep 2007) ISSN: 0732-8893 [Print] United States
• PMID: 17662551 (Publication Type: Comparative Study, Evaluation Study, Journal Article)

Chemical References

• Immunoglobulin M

Topics

• Female
• Fluorescent Treponemal Antibody-Absorption Test
• Humans
• Immunoblotting (methods)
• Immunoglobulin M (analysis)
• Infant
• Infant, Newborn
• Infectious Disease Transmission, Vertical
• Pregnancy
• Sensitivity and Specificity
• Syphilis, Congenital (diagnosis, immunology)
• Treponema pallidum (immunology)