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.

Mnemonic
GABA-B SER
Methodology

Semi-Quantitative 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 limbic encephalitis and may occur with or without associated tumor. Decreasing antibody levels may be associated with therapeutic response; therefore, clinical correlation must be strongly considered. A negative test result does not rule out a diagnosis of autoimmune encephalitis.

This indirect fluorescent antibody assay utilizes GABA-BR transfected cell lines for the detection and semi-quantification 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-B Receptor Ab IgG Screen, Serum 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 IFA with Reflex to Titer, Serum