Laboratory Test Guide

Lyme CNS Infection IgG with reflex to Antibody Index (Sendout)

General Information

Lab Name

Lab Code

892

External Test Id

LNBAB

Description

Useful For: 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).

Test Algorithm: This test begins with IgG screening of the spinal fluid 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: Anti-Borrelia species IgG levels in CSF and serum, total IgG in CSF and serum, and 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. Testing is performed at an additional charge.

Ordering Requirements: This test requires both CSF and blood, collected within 24 hours of each other.

References

Mayo Clinical & Interpretive Information: Lyme Central Nervous System Infection IgG with Antibody Index Reflex, Serum and Spinal Fluid

Synonyms

Borrelia species, LNBAB, Lyme CNS Disease, Neuroborreliosis, Neuroinvasive Lyme Disease

Interpretation

Method

Enzyme-Linked Immunosorbent Assay (ELISA)

Ref. Range Notes

Reference Values:

Negative

Interpretation:

Negative: No antibodies to Lyme disease causing Borrelia species detected in spinal fluid. A negative result in a patient with appropriate exposure history and symptoms consistent with neuroinvasive Lyme disease should not be used to exclude infection. Testing for antibodies to Lyme disease-causing Borrelia species in serum should be performed.
Reactive: Supplemental testing to determine a Lyme central nervous system antibody index has been ordered. Diagnosis of neuroinvasive Lyme disease should not be established solely based on a reactive screening result.

Interferences and Limitations

Cautions: A single negative result should not be used to exclude the diagnosis of neuroinvasive Lyme disease in a patient with appropriate exposure history and symptoms suggestive of infection. Testing of serum samples using the Centers for Disease Control and Prevention recommended standard 2-tiered testing algorithm should be performed (see Lyme Disease Serology w/ Conf (Sendout) [RLYMES]).

False-negative results may be acquired in patients tested soon after infection, prior to the development of a detectable level of antibodies in the spinal fluid.

False-reactive results may occur in patients with syphilis or Leptospira infections. Patient management decisions should not be made on a single reactive result.

Guidelines

Washington DOH Notifiable Conditions

Ordering & Collection

Specimen Type

CSF and Blood

Collection

CSF: 1.5 mL Spinal Fluid
Blood: 5 mL blood in RED TOP tube or GOLD SST

Note: Blood and CSF samples must be collected within 24 hours of each other.

Handling Instructions

Outside Laboratories:

CSF: Refrigerate CSF.
Blood: Centrifuge sample and transfer serum to a separate plastic vial. Refrigerate serum while awaiting shipment.
Transport CSF and serum samples with a cold pack. Send samples together to avoid delays.

Stability: Refrigerated (Preferred): 11 days; Frozen: 35 days; Ambient: Unacceptable.

Quantity

requested: 1.5 mL CSF and 1.5 mL Serum
minimum: 1.2 mL CSF and 1.2 mL Serum

Processing

CSF: Refrigerate sample.
Blood: Centrifuge sample and transfer serum to a separate plastic vial. Refrigerate serum.

Login: SEND1-;REFRIG

RSNDTO: MAYOSD
RSPTYP: CSF-SRM
RTSTRQ: ;Lyme CNS Infection IgG with Reflex (Mayo Test LNBAB)

Sendouts:

Order Mayo Test: LNBAB
Write the sample type (CSF or Serum) on the aliquot tubes and band them together. Samples should be sent together to prevent delays at Mayo.