Lyme ImmunoBlot IgM (325)

Overview:

The Lyme ImmunoBlot is a qualitative immunoassay in which antibodies specific to the B. burgdorferi antigens on a membrane strip are visualized. It is a qualitative test and is more sensitive and specific than the ELISA, IFA, and traditional Western Blot tests. In early or late stage Lyme, when antibody levels are very low, the ImmunoBlot can be positive, whereas ELISA and IFA tests can be negative.

The Lyme ImmunoBlot IgM is a very sensitive indicator of exposure to B. burgdorferi. It may be positive as early as 1 week after a tick bite and will usually remain positive for six to eight weeks after initial exposure; in some patients it can remain positive for even longer. Re-exposure will also cause this test to be positive for a brief period of time.

This test is recommended to be performed at least one week after possible exposure. The Lyme ImmunoBlot IgM must be performed on any sample with positive or equivocal result for Lyme IgG/IgM antibody serology or Lyme IgG/IgA/IgM IFA, and should ideally be run alongside the IgG ImmunoBlot.

Principle: The Lyme ImmunoBlot assay is based upon an antigen-antibody complex formation in the following steps:

1. Binding of anti-Borrelia specific antibodies in human serum to the ImmunoBlot strip. The ImmunoBlot strip is a membrane strip with fixed B. burgdorferi recombinant antigens on it.
2. Binding of enzyme labeled anti-human IgG or IgM antibodies to the human anti Borrelia antibodies bound to fixed B. burgdorferi antigens on the membrane.
3. Reaction with BCIP/NBT, a chromogenic substrate with bound antibodies on the strip. A dark purple colored precipitate (band) develops on the antigen-antibody complexes.

Stage of Disease: Early Disease

Test Methodology: ImmunoBlot