IgG Herpes Test.

Positive IgG test

A positive IgG test indicates the presence of a latent herpes infection. “Latent” means currently suppressed by a healthy immune system.

Once positive, it will stay positive for life. Additionally, the IgG number fluctuates.

Once IgG-positive, always positive

Once the IgG test is positive, it will always be positive unless it was one of a low number of false positive cases.

A long-term herpes study [1] Sorting out the new HSV type specific antibody tests https://sti.bmj.com/content/77/4/232 showed that if a person has a sufficient level of IgG antibodies, they will always have a detectable level.

Suppose a once positive person turns out to be IgG-negative in consecutive tests. In that case, that is merely due to a test error rather than a significant reduction of the IgG level (to the extent of becoming undetectable).

Once a person is positive for herpes, they will stay positive for life.

Reason for fluctuations of the IgG level

The IgG antibody level increases with the amount of herpes virus in our body, but our immune system always tries to control the replication of the herpes Virus [3] Factors Associated with IgA and IgG Fluctuations at the Cervix during the Menstrual Cycle ttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC4158917/ . So, if a person has normally functioning immunity, they will also have low levels of the herpes virus and stable levels of IgG antibodies. Any immune system dysfunction permits active replication of the herpes infection, resulting in increased levels of IgG antibodies.

So, suppose a person has decreased immunity (due to stress, injury, pregnancy, HIV, chemotherapy, etc.). In that case, they will likely have increased herpes virus and IgG levels.

The clinical significance of a higher antibody level

Fluctuations of the IgG level are a common concern of patients. The assumption is that the higher the IgG level, the higher the chance of an outbreak and the higher the chance of transmission to other people (“silent shedding” of the virus).

What is the difference between the IgG and IgM herpes test?

IgM antibodies are proteins the body produces after contracting herpes. They become detectable 10 to 21 days after infection (around the same time that IgG antibodies become detectable). Unlike IgG antibodies, which persist for life, IgM antibodies might persist for a few months and then disappear. Occasionally, IgM antibodies can be detected even with recurrent infection.

Unlike the IgG test, which looks for antibodies specific to the herpes type, IgM testing does not differentiate between HSV-1 and HSV-2.

The CDC and other testing authorities discourage the use of IgM test because it does not add any value in diagnosing herpes. [2] screening for genital herpes CDC https://www.cdc.gov/herpes/testing/index.html