Treponema pallidum, previously called Spirochaeta pallida, is the spirochete causing syphilis. It is usually transmitted sexually, but can also be transmitted vertically during pregnancy, leading to congenital syphilis; WHO estimates that by 2020, 7.1 million adults aged 15-49 years will be diagnosed with syphilis.
Currently, possible cases of syphilis are usually investigated by the treponemal serological tests T. pallidum antibodies (IgG and/or IgM).
T. pallidum Lipoproteins
Treponemal antigens consist of 15 kDa lipoprotein (Tp15), 17 kDa lipoprotein (Tp17), 44.5 kDa lipoprotein (Tp44.5, TmpA), and 47 kDa lipoprotein (Tp47). To detect T. pallidum specific antibodies, a combination of T. pallidum recombinant antigens (obtained in Escherichia coli), or the whole T. pallidum lysate is widely used.
Enzyme Immunoassay (EIA)
Being an anti-treponemal assay, the enzyme immunoassay (EIA) is commonly used as an automated screening test. Many commercial assays detect IgM, IgG, or both with recombinant treponemal antigens (Tp15, Tp17, and Tp47).
Chemiluminescence Immunoassay (CLIA)
The chemiluminescence immunoassay (CLIA) is a type of EIA: it is a rapid, high-throughput automated method that uses paramagnetic particles with recombinant antigen-coated to catch IgM and/or IgG, and then a chemiluminescent substrate is added to produce a signal proportional to the amount of antigen-antibody complex. The automated availability of EIA and CLIA makes them the basis of rapid diagnostic tests for syphilis screening.
Immunoblot Assay
Immunoblot analysis is primarily used as an additional confirmatory test to clarify results when other syphilis tests fail to produce a definitive result. It is a highly specific Western blotting assay that detects IgM and IgG respectively. An original immunoblotting assay that uses whole-cell organisms as the antigen and detects antibodies directed against the major surface antigens of T. pallidum (TpN15, TpN17, TpN44.5, and TpN47).
Whole-cell organisms are labor-intensive and difficult to interpret because of nonspecific reactions. Commercial recombinant immunoblot assays, such as the INNO-LIA Syphilis (Innogenetics NV, Ghent, Belgium), ViraBlot (Viramed Biotech, Planegg, Germany), and MarDx test (Trinity Biotech, Bary, Ireland), can supersede the whole-cell organism.
Yaohai Bio-Pharma Offers One-Stop CDMO Solution for Treponema Antigen
EN
AR
HR
CS
DA
NL
FI
FR
DE
EL
IT
JA
KO
NO
PL
PT
RO
RU
ES
SV
IW
ID
LV
LT
SR
SK
SL
UK
VI
ET
HU
TH
TR
FA
AF
MS
BE
MK
UR
BN
