Explanation about antibody tests
When the inflammation is not visible, diagnosis is a bit more troublesome. In most cases, diagnosis is prolonged until the patience experiences the first symptoms, like flulike symptoms, after a tick bite. When a patient has these symptoms, an antibody test is often performed; the so-called ELISA test. Such a test shows whether or not antibodies against specific proteins of the Borrelia bacteria in the blood are present.
Two types of antibodies are tested for; IgM and IgG. In general, the body first produces IgM antibodies, and then, IgG. It takes several weeks before enough antibodies are made to show up in the test. However, every person reacts differently to an infection. In some cases, the antibodies are already present after 3 weeks, while for some people, it takes 10 weeks before the antibodies can be measured.
The ELISA test can separately measure the created IgM and IgG antibodies. Also, the so-called C6-ELISA is executed on a regular basis. This test doesn’t distinguish between the two types of antibodies, and therefore, shows the total amount of both. However, the result of the C6 test doesn’t always correspond with the other ELISA tests. Therefore, three ELISA test should be executed together in the early phase of a possible infection. This is also the basic package that Innatoss uses for the screening of people who are bitten by a tick on a regular basis.
When you have been bitten by a tick more than once, it possible that you already have antibodies. This makes the diagnosis of a new infection more difficult. However, when the results of previous ELISA tests are known, a new infection can easily be recognized. The new test results of the ELISA tests are simply compared to the known profile.
A positive ELISA doesn’t necessarily indicate Lyme disease. It might show an older, already treated infection. This is what makes making the right diagnosis difficult. Therefore, a positive ELISA test is always confirmed with a more sensitive test, the immunoblot, in order to prevent cross-reactivity for example. Cross-reactivity means that the test has detected a different disease than Lyme disease. In some case, a positive IgM result is, for example, caused by gum inflammation.
A doctor will also look at the test result in combination with the clinical observations (symptoms, medical history). The complete picture of the antibodies that are present, such as the 5-in-1 test of Innatoss provides, is an important factor in the diagnosis. However, it is not a diagnosis on its own.