CPT® Code 86617

The CPT® Code 86617 refers to a laboratory test specifically designed to confirm the presence of antibodies against Borrelia burgdorferi, the bacterium responsible for Lyme disease. This confirmatory test is typically performed when a patient exhibits symptoms indicative of Lyme disease and has previously undergone an ELISA (Enzyme-Linked Immunosorbent Assay) test that returned positive or equivocal results for B. burgdorferi antibodies. The test is crucial for accurate diagnosis, as it helps differentiate between active infection and past exposure to the bacterium. The presence of IgM antibodies, which typically begin to rise 2-3 weeks post-exposure, indicates a recent infection, reaching peak levels around 6 weeks before gradually declining. Conversely, IgG antibodies, which may take several weeks to become detectable, can remain elevated for an extended period, sometimes lasting for years after the initial infection. The testing process involves obtaining a blood sample through venipuncture or cerebrospinal fluid (CSF) via lumbar puncture, both of which are separately reportable procedures. The analysis of serum and CSF samples is conducted using quantitative methods such as the western blot or immunoblot techniques, which provide a detailed assessment of antibody levels and confirm the diagnosis of Lyme disease.