Limitations of CDC recommended testing for Lyme disease.
Most labs follow federally recommended two-tier ELISA/Western Blot testing by the CDC, using criteria which was developed in 1995 when Lyme disease was less known. The CDC has not updated their guidelines for over 20 years, which now have a much lower sensitivity to identifying Lyme disease. Although these tests can provide useful information by detecting antibodies for Lyme, they do not provide the whole picture like IGeneX can.
The Western Blot test is used to determine if a person with characteristic signs and symptoms has been infected by the bacteria, Borrelia burgdorferi, that cause Lyme disease. The tests detect antibodies produced by the immune system in response to the infection. The Western Blot test looks for the presence of both IgG and IgM antibodies to confirm exposure.
- IgM Antibodies: This is the earliest of antibodies to appear in response to recent exposure. Typically it takes 14 days for these antibodies to be produced. IgM antibodies represent a new active infection or an infection that has become reactivated. Testing patients during the first weeks of infection is more likely to give false negative results.
- IgG Antibodies: These antibodies are produced after 4-6 weeks of exposure, and it can persist for years. Tests for IgG antibodies could be an indicator for chronic or long-term exposure to Lyme.
Testing positive for all antibodies does not mean a person has Lyme disease, only that they have been exposed to it. The doctor will evaluate a patient’s IgG and IgM test results together with symptoms in order to diagnose Lyme disease and provide the best course of treatment.