Treponema pallidum Line Immunoblot

About Treponema pallidum and syphilis (Lues)

The genus Treponema pallidum comprises several human pathogen species and subspecies. Treponema pallidum subsp. pallidum is the causative agent of syphilis (Lues), a disease occurring only in humans. Syphilis is generally transmitted sexually. Its natural course presents in three stages: primary, secondary, and tertiary syphilis, with periods of latency or inactive disease.² Additionally, T. pallidum can be transmitted to the foetus from an infected mother during pregnancy (congenital syphilis).² As T. pallidum cannot be cultured in vitro¹, diagnosis depends on serological analysis. Infection with T. pallidum provoke two groups of antibody development in the host: 

• Non-treponemal antibodies, called reagin. 
• Treponemal specific antibodies, which react with T. pallidum and related strains. 

For a good syphilis diagnosis the following step-diagnostic is recommended⁴: 

1. Screening test: TPHA-/TPPA-test or ELISA (polyvalent). 
2. Confirmatory test: FTA-ABS-test (polyvalent) or Immunoblot. 
3. Assessment of the activity of infection: 19S-IgM-FTA-ABS (IgM-ELISA) or VDRL-test. 

It is desirable to differentiate between IgG and IgM-specific Treponema-antibodies. IgM, as a rule, shows an active infection whilst IgG is an indicator for a recent infection. Additionally IgM activity in neonates indicates congenital syphilis.³ Only ELISA, Immunoblot and 19S-IgM-FTA-ABS are able to differentiate between IgG and IgM antibodies. 

The assessment of Treponema pallidum-specific IgM antibodies for the check of the treatment indication of a Treponema infection is suitable for the normal course of infection. A positive IgM antibody finding should, however, not be effected without the patient anamnesis (stage of infection, therapy), as the IgM antibodies, depending on the time interval between infection and start of the therapy, may remain detectable a few months up to several years (persistent IgM antibodies). At Neurosyphilis, Reactivation or Second Infection the IgM antibody synthesis may be nearly completely suppressed.⁴
 

Features & Benefits

• High diagnostic sensitivity
  • IgG + IgM: 100%
• High specificity
  • IgG: 99.2%
  • IgM: 98.6%
• Customer friendly test procedure with results within 2.5hrs
• Easy reading & interpretation, also with the LabImage LA^® software 

 
References

1. Lukehart, S:A:, and C.M. Marra. 2007. Isolation and Laboratory Maintenance of Treponema pallidum. Curr. Protoc. Microbiol. Chapter 12:Unit 12A.1 
2. Peeling R.W., and E.W. Hook. 2006. The pathogenesis of syphilis: the Great Mimicker, revisited. J. Pathol. 208(2):224- 32. 
3. Scotti, A.T., and L. Logan. 1968. A specific IgM antibody test in neonatal congenital syphilis. J. Pediatr. 73:242-243. 
4. H.-J. Hagedorn, Qualitätsstandards in der mikrobiologisch-infektiologischen Diagnostik, MiQ 2001 (16):1-40