What is the Difference Between Chlamydia IgG and IgM?

The main difference between Chlamydia IgG and IgM is their presence in the blood during different stages of infection. Chlamydia IgG indicates a chronic infection, while Chlamydia IgM indicates an acute infection.

• Chlamydia IgG: This type of antibody will be present in the blood after 2-3 weeks upon infection. It is not diagnosed at the initial stage of the infection. A positive IgG titer value greater than or equal to 1:64 is considered positive. Chlamydia IgG antibodies are more persistent and can be found in the blood for an extended period after the infection has been treated.
• Chlamydia IgM: This type of antibody is present in the blood after 5 days upon infection. IgM antibodies are diagnosed at the initial stage of the infection. A positive IgM titer value greater than or equal to 1:20 and titers twofold or greater than those for C. pneumoniae and C. psittaci are considered positive. Chlamydia IgM antibodies are more short-lived and decline rapidly after treatment.

Serologic testing can increase the sensitivity of detecting Chlamydia trachomatis infections, as 25 patients had positive IgG and/or IgM titers to C. trachomatis but negative antigen test results. This means that some patients with negative antigen test results may still have IgG and/or IgM antibodies in their blood, indicating a past or chronic infection.

Comparative Table: Chlamydia IgG vs IgM

The main difference between Chlamydia IgG and IgM lies in the stage of infection they indicate. Here is a table summarizing the differences:

In summary, Chlamydia IgG indicates a chronic infection, while Chlamydia IgM indicates an acute infection. The presence of these antibodies helps healthcare professionals diagnose the stage of the infection and determine the most appropriate treatment option.