IgG (Immunoglobulin G) er en type antistoff som reflekterer kroppens langsiktige immunrespons. Det er det mest forekommende antistoffet i blodet og spiller en nøkkelrolle i forsvaret mot infeksjoner. I sammenheng med Lyme-sykdom, forårsaket av bakterien Borrelia burgdorferi, måles IgG-antistoffer for å vurdere tidligere eksponering eller senere stadier av infeksjon. I motsetning til IgM-antistoffer, som dukker opp tidlig, utvikler IgG-antistoffene seg gradvis og kan vedvare i kroppen over lengre tid, noe som gir varig immunitet.
IgG testing is crucial for detecting later stages or past exposure to Lyme disease. IgG antibodies to Borrelia burgdorferi typically develop several weeks to months after initial infection and can persist for years, making this test useful for identifying chronic or previous infections.
Individuals with long-term symptoms that suggest Lyme disease, such as chronic joint pain, neurological symptoms, and fatigue, should consider IgG testing. It is also recommended for those who have had a previous positive Lyme disease test or who have been treated for Lyme disease in the past.
The test involves analyzing a blood sample for the presence and concentration of IgG antibodies specific to Borrelia burgdorferi. Higher levels of these antibodies suggest a later stage or a past infection.
IgG and IgM antibodies serve different roles in the immune response to Lyme disease. IgM antibodies appear first, within a few weeks of infection, indicating recent exposure. IgG antibodies develop later, remain longer, and indicate past exposure or ongoing infection. Testing for both types of antibodies at different stages can provide a more complete picture of the infection timeline.