SeroELISA Chlamydia True IgM Assay

Additional Information

Assay Background

Chlamydia is a gram-negative obligate intracellular bacteria that causes acute and chronic diseases in mammalian and avian species. The genus Chlamydia is comprised of four species: C.trachomatis, C.pneumoniae, C.psittaci and C. pecorum. C.trachomatis is divided into 15 serovars. Serovars A, B, Ba and C are agents of trachoma, the leading cause of preventable blindness endemic in third world countries. Serovars L1-L3 are the agents of lymphogranuloma venereum. Serovars D-K are the common cause of sexually transmitted genital infection worldwide: cervicitis, endometritis/ salpingitis in females and urethritis in both males and females. Endometritis/salpingitis can lead to tubal occlusion with a higher risk of extra uterine pregnancy and infertility. Genital infection may cause an acute and persistent infection occasionally without any clinical symptoms. Generally, these infections are treatable once they are diagnosed. However without any treatment the infection may progress to a severe chronic inflammation leading to infertility, ectopic pregnancy, induced abortion or premature delivery. Moreover, infants to infected mothers may be infected during birth, leading to conjunctivitis or pneumonia. C.pneumoniae is an important respiratory pathogen in humans and causes up to 10% of community-acquired pneumonia cases. It has been associated with acute respiratory diseases, pneumonia, asthma, bronchitis, pharyngitis, acute chest syndrome of sickle cell disease, coronary heart disease, and Guillain-Barre syndrome. C.psittaci infects a diverse range of host species from molluscs to birds to mammals and also causes severe pneumonia.

Serodiagnostic tests, which rely on specific immunologic markers, serve as a non-invasive diagnostic tool in identification of both distal and deep infections. It has been found that ANTI-Chlamydia IgM antibody is of diagnostic value in pneumonia caused by C. pneumoniae (TWAR) and C.psittaci. The serological pattern of Chlamydia IgM in chlamydial pneumonititis is as follows: antibodies are produced in the early stages of an infection, peak after 1-2 weeks and generally decline gradually to undetectable levels within 2-3 months. This pattern has been observed in 20-50% of infants born to mothers who were culture positive for Chlamydia trachomatis and/or demonstrated elevated levels of specific IgG and IgA antibodies to Chlamydia. These infants developed chlamydial pneumonitis during the first 6 months of life. Since IgM is present only in acute and/or recent disease, the Chlamydia IgM test requires only a single serum specimen and results can be reported in terms of presence or absence of immune IgM. High titers of immune IgG, which compete with immune IgM for the same antigenic sites, may produce false negative IgM results. Rheumatoid factor (Rf, autoimmune activity) causes false positive IgM results. Therefore, removal of IgG and Rf is an essential part of the IgM assay. SeroELISATM Chlamydia test employs the L2 serovar broadly reacting antigen of C. trachomatis. It will detect C. trachomatis, C. psittaci and C. pneumoniae (TWAR) antibodies.