Lyme Disease Antibody, Western Blot, Serum

CPT CODE:

USEFUL FOR:

Diagnosing Lyme disease
IgM assay is useful for confirming stage 1 (acute) Lyme disease
IgG assay is useful for confirming stage 2 and stage 3 Lyme disease

SPECIMEN REQUIRED:

Draw blood in a plain, red-top tube(s) or a serum gel tube(s).(Heat-inactivated serum is not acceptable.) Spin down and send 0.5 mL of serum refrigerated in a screw-capped, round-bottom, plastic vial. Forward promptly.

TRANSPORT TEMPERATURE:

Refrig\Frozen OK\Ambient NO

CLINICAL INFORMATION:

Lyme disease is caused by the spirochete Borrelia burgdorferi. The spirochete is transmitted to humans through the bite of Ixodes species ticks. Endemic areas for Lyme disease in the UnitedStates (US) correspond with the distribution of 2 tick species, Ixodes dammini (Northeastern and upper Midwestern US) and Ixodes pacificus (West Coast US). In Europe, Ixodes ricinus transmits the spirochete.
Lyme disease exhibits a variety of symptoms that may beconfused with immune and inflammatory disorders. Inflammation around the tick bite causes skin lesions. Erythema chronicum migrans (ECM), a unique expanding skin lesion with central clearing that results in a ring-like appearance, is the first stage of the disease. Any of the following clinical manifestations may be present in patients with Lyme disease: arthritis, neurological disease, cardiac disease, or skin lesions. Neurologic and cardiac symptoms may appear with stage 2 and arthritic symptoms with stage 3 of Lyme disease. In some cases, a definitive distinction between stages is not always seen. Further, secondary symptoms may occur even though the patient does not recall having a tick bite or a rash.
Early antibiotic treatment of Lyme disease can resolve clinical symptoms and prevent progression of the disease to later stages. However, the early administration of antibiotics may suppress the antibody response to levels that are undetectable by current laboratory tests.
The Second National Conference on the Serologic Diagnosis of Lyme Disease (1994) recommended that laboratories use a 2-test approach for the serologic diagnosis of Lyme disease. Accordingly, specimens are first tested by the more sensitive enzyme immunoassay (EIA). A Western blot (WB) assay is used to supplement positive or equivocal Lyme (EIA). WB identifies the specific proteins to which the patient's antibodies bind. Although there are no proteins that specifically diagnose Borrelia burgdorferi infection, the number of proteins recognized in the WB assay is correlated with diagnosis.
Culture or PCR of skin biopsies obtained near the margins of ECM are frequently positive. In late (chronic) stages of the disease, serology is often positive and the diagnostic method of choice. PCR testing also may be of use in these late stages if performed on synovial fluid or cerebrospinal fluid (CSF).

CLINICAL INTERPRETATION:

IgMIgM antibodies to Borrelia burgdorferi may be detectable within 1 to 2 weeks following the tick bite, they usually peak during the thirdto sixth week after disease onset, and then demonstrate a gradual decline over a period of months. IgM antibody may persist for monthseven though antimicrobial agents are given. The IgM assay is morelikely to be useful during early disease, and should only be testedduring the first 4 to 6 weeks after disease onset.
Negative specimens typically demonstrate antibodies to less than 2 ofthe 3 significant Borrelia burgdorferi proteins. Additional specimens should be submitted in 2 to 3 weeks if Borrelia burgdorferi exposure hasnot been ruled out.
Individuals who have recently seroconverted due to infection withBorrelia burgdorferi may display incomplete banding patterns, but maydevelop increased reactivity (both in band intensity and number) whenfollowed for a period of 4 to 6 months.
IgGSerum IgG is detected as early as 2 weeks after onset of disease.Significant concentrations of antibody and Western blot bandingpatterns for Borrelia burgdorferi can be found years after onset.
Normal specimens and false-positive EIA specimens generally have antibodies to 4 or fewer proteins. Except for early (ECM) patients, antibodies from patients with Lyme disease generally bind to 5 or more proteins.
For persons who have received recombinant OspA vaccine andwho are not infected with Borrelia burgdorferi, an intense bandrepresenting antibody to the OspA protein (band 30) should bevisible on the Western blot.

REFERENCE VALUES:

IgG:  Negative

IgM:  Negative