Cautions

Anaplasma phagocytophilum:

Serology for IgG may be negative during the acute phase of infection (<7 days post-symptom onset), during which time detection using targeted nucleic acid amplification testing (eg, polymerase chain reaction: PCR) is recommended.

Detectable IgG-class antibodies typically appear within 7 to 10 days post-symptom onset.

IgG-class antibodies may remain detectable to months to years following prior infection. Therefore, a single time point-positive titer needs to be interpreted alongside other findings to differentiate recent versus past infection.

Other members of the Ehrlichia genus (eg, Ehrlichia ewingii) may not be detected by this assay.

Ehrlichia chaffeensis:

Serology for IgG may be negative during the acute phase of infection (<7 days post symptom onset), during which time detection using targeted nucleic acid amplification testing (eg, PCR) is recommended.

Detectable IgG-class antibodies typically appear within 7 to 10 days post symptom onset.

IgG-class antibodies may remain detectable for months to years following prior infection. Therefore, a single time point-positive titer needs to be interpreted alongside other findings to differentiate recent versus past infection.

Other members of the Ehrlichia genus (eg, E ewingii) may not be detected by this assay.

Babesia microti:

Previous episodes of babesiosis may produce a positive serologic result.

In selected cases, documentation of infection may be attempted by animal inoculation or PCR methods (LBAB / Babesia species, Molecular Detection, PCR, Blood)

Performance characteristics have not been established for the following specimen characteristics:

-Lipemic

-Hemolyzed

Lyme disease:

A negative result does not exclude the possibility of infection with Lyme disease causing Borrelia species. Patients in the early stages of Lyme disease and those who have been treated with antibiotics may not exhibit detectable antibody titers. Patients with clinical history, signs, or symptoms suggestive of Lyme disease should be retested in 2 to 4 weeks in the event that the initial test result is negative.

A positive result is not definitive evidence of infection with Borrelia burgdorferi. It is possible that other disease conditions may produce artifactual reactivity in the assay (eg, infectious mononucleosis, syphilis). All equivocal or positive results should be supplemented immunoblot testing for IgM- and IgG-class antibodies in accordance with Centers for Disease Control and Prevention and the Association of State and Territorial Public Health Laboratory. Directors (CDC/ASTPHLD) recommendations.

Patients infected with other members of the B burgdorferi sensu lato complex, including B garinii, B afzelii, and B mayonii will be detected by this assay; however, they cannot be differentiated.

This test should not be performed as a screening procedure for the general population. The predictive value of a positive or negative result depends on the prevalence of analyte (antibodies present to VlsE1 and pepC10 antigens) in a given population. Testing should only be performed when clinical evidence suggests the diagnosis of Borrelia infection or related etiological conditions observed by the physician. 

Lyme serology should not be used for treatment monitoring as IgG can remain for years post-resolution of infection. Instead, monitoring resolution of symptoms in response to treatment is recommended.