Lyme Serology IgM (195)

IgM antibodies appear early in response to infection, therefore this test may be positive between 2 to 6 weeks after exposure. Though the level of IgM declines over time, the IgM response may persist in patients with prolonged illness and a new IgM response may appear later in persistent or recurrent disease, or from re-infection. This test is recommended approximately 2 weeks after suspected exposure.

The Lyme IgM antibody assay is another serologic test in ELISA format, and it detects the presence of IgM antibodies to B. burgdorferi after exposure to an infected tick. Because IgM antibodies appear early in response to infection, this test may be positive two to six weeks after exposure. But since the level of IgM rapidly declines over time, testing for IgM antibodies too late can cause a missed infection.

A positive or equivocal IgM antibody test must be confirmed by an IgM Western Blot or Lyme ImmunoBlot IgM. The sensitivity concerns mentioned for the IgG/IgM assay also affect this assay.

Stage of Disease: Early Disease

Test Methodology: Serology