Lyme Disease Antibody Index

CERNER / EPIC MNEMONIC: MICRO REF
POE DESCRIPTION: MICROBIOLOGY REFERRAL
CPT CODE: 82040 (per source); 82784 (per globulin); 86618
DAYS PERFORMED: Monday-Thursday, 0800-1430
TURNAROUND TIME: 1 week
SPECIAL INSTRUCTIONS: It is the responsibility of the ordering physician to see that both acute and convalescent specimens are obtained, if desired.
CONTAINER TYPE:

Sealed sterile container for CSF; red top Vacutainer® tube or SST tube

SPECIMEN REQUIREMENTS: Cerebrospinal fluid AND blood (serum)
REJECTION CRITERIA: Excessive hemolysis, gross contamination of specimen, chylous serum, improper storage of specimen, inappropriate specimen container, insufficient specimen volume, cerebrospinal fluid AND serum not available.
MINIMUM VOLUME: 1 ml CSF, 5 mL blood (1 mL serum)
HANDLING INSTRUCTIONS: Specimen should be transported as soon as possible. When transportation is delayed, refrigerate.
REFERENCE RANGE: No Lyme antibody detected
LIMITATIONS OF TEST: Cerebrospinal fluid specimens MUST be accompanied by a serum collected the SAME day for testing to be performed. The interpretation for cerebrospinal fluid (CSF) specimens has not been firmly established. Recent studies have shown that in cases of Lyme disease with CNS involvement, antibody may be produced intrathecally. These studies suggest that any detectable level of intrathecally produced CSF antibody may be significant. The importance of distinguishing between intrathecally produced antibody and serum antibody present in the CSF due to blood-cerebrospinal fluid barrier leakage must be emphasized. As is true with serum antibody titers, the most significant cross reaction is with specimens from patients with treponemal disease. These can be distinguished with a VDRL test.
METHODOLOGY: Enzyme-linked immunosorbent assay (ELISA)
REFERRAL LABORATORY:

Commercial laboratory

ADDITIONAL INFORMATION: The Lyme Disease Antibody Index on CSF is used as an aid for the diagnosis of neuroborreliosis. An increased Antibody Index (>1.2), accompanied by a Control Antibody Index of less than 1.0 and an Albumin Ratio of less than 0.0078 is strong evidence for intrathecal synthesis or organism-specific antibody, and thus CNS involvement by B. burgdorferi. Elevation of either the Control Antibody Index, the Albumin Ratio, or both may indicate leakage of antibody across the blood-brain barrier which may falsely elevate the B. burgdorferi Antibody Index.