Ordering Recommendation

Aid in diagnosis of limbic encephalitis. May be used in monitoring treatment response in individuals who are antibody positive. The presence of GABA-BR antibodies may be associated with seizures; GABA-BR encephalitis may be paraneoplastic as about 50% of cases are associated with small cell lung cancer.

Methodology

Semi-Quantitative Cell-Based Indirect Fluorescent Antibody

Performed

Wed

Reported

1-8 days

New York DOH Approval Status

This test is New York DOH approved.

Specimen Required

Patient Preparation
Collect

Serum separator tube (SST) or plain red.

Specimen Preparation

Transfer 1 mL serum to an ARUP standard transport tube. (Min: 0.15 mL)

Storage/Transport Temperature

Refrigerated.

Unacceptable Conditions

Hemolyzed, contaminated, or severely lipemic specimens.

Remarks
Stability

Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 month

Reference Interval

Less than 1:10

Interpretive Data

Gamma-amino butyric acid receptor, type B (GABA-BR) antibody is found in a subset of patients with autoimmune epilepsy and other autoimmune neurologic phenotypes; it may occur with or without associated tumor. Decreasing antibody levels may be associated with therapeutic response. A negative test result does not rule out a diagnosis of autoimmune neurologic disease. Results should be interpreted in correlation with the patients clinical history and other laboratory findings.
This indirect fluorescent antibody assay utilizes GABA-BR transfected cell lines for the detection and semiquantification of GABA-BR IgG antibody.

Compliance Category

Laboratory Developed Test (LDT)

Note

If Gamma Aminobutyric Acid Receptor, Type B (GABA-BR) Antibody, IgG by IFA with Reflex to Titer, Serum is positive, then a Gamma Aminobutyric Acid Receptor, Type B (GABA-BR) Antibody Titer, IgG, Serum is performed. Additional charges apply.

Hotline History

N/A

CPT Codes

86255; if reflexed, add 86256

Components

Component Test Code* Component Chart Name LOINC
3001271 GABA-BR Ab IgG CBA-IFA Scrn, Ser 93428-1
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.

Aliases

  • GABA
  • GABA Receptor
  • GABA Reflex
  • GABA Titer
  • GABA-B
Gamma Aminobutyric Acid Receptor, Type B (GABA-BR) Antibody, IgG by CBA-IFA With Reflex to Titer, Serum