Aiding in the diagnosis of neuroinvasive Lyme disease or neuroborreliosis due to Borrelia species associated with Lyme disease (eg, B burgdorferi, B garinii, B afzelli)
This test should be ordered in patients with suspected neuroinvasive Lyme disease.
Although a small percentage of patients with neuroinvasive Lyme disease may be seronegative, it is recommended that all patients test by the Lyme Antibody Index assay also have standard 2-tiered testing for Lyme disease performed on serum.
This test compares the level of IgG antibodies to Lyme disease-causing Borrelia species in spinal fluid (CSF) and serum. The level of anti-Borrelia species IgG is normalized to total IgG and albumin in CSF and serum.
This test can help identify whether the presence of IgG to Borrelia species in the CSF is due to true intrathecal antibody synthesis, suggesting neuroinvasive Lyme disease, versus antibody presence due to passive diffusion through the blood-brain barrier or possibly, due to blood contamination of the CSF as a result of a traumatic lumbar puncture.
This test begins with IgG screening of the spinal fluid (CSF) specimen. If the screen is negative, no additional testing will be performed.
If the screen is positive, the paired CSF and serum specimens will be used to establish the antibody index. In order to establish the antibody index, the paired serum and CSF samples (collected within 24 hours of each other) are tested on the same run using quantitative assays to determine levels for the following analytes:
1. Anti-Borrelia species IgG levels in CSF and serum
2. Total IgG in CSF and serum
3. Albumin in CSF and serum
These additional tests are necessary in order to normalize the level of anti-Borrelia antibodies to total IgG and albumin in the CSF and establish the antibody index ratio of anti-Borrelia antibodies in CSF-to-serum. This testing is performed at an additional charge.
The following algorithms are available in Special Instructions:
-Lyme Neuroborreliosis Diagnostic Algorithm
-Acute Tick-Bourne Disease Testing Algorithm
-Meningitis/Encephalitis Panel Algorithm
