Ordering Recommendation

Aids in the diagnosis of limbic encephalitis and autoimmune epilepsy. May be used to monitor treatment response in individuals who are antibody positive. The presence of GABA-AR antibodies may be associated with refractory seizures, memory loss, behavior changes, abnormal movements, and decreased level of consciousness. GABA-AR encephalitis may be paraneoplastic, but tumor type is variable (eg, thymoma, small cell lung cancer, rectal cancers, and hematologic malignancy). GABA-AR encephalitis may also be associated with post-viral and autoimmune diseases.

New York DOH Approval Status

This test is New York state approved.

Specimen Required

Patient Preparation

Serum separator tube.

Specimen Preparation

Separate serum from cells within 2 hours of collection. Transfer 1 mL serum to an ARUP standard transport tube. (Min: 0.2 mL)

Storage/Transport Temperature


Unacceptable Conditions

CSF or plasma. Contaminated, grossly hemolyzed, icteric, or lipemic specimens.


Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 month (Three freeze/thaw cycles are acceptable)


Semiquantitative Cell-Based Indirect Fluorescent Antibody




1-8 days

Reference Interval

Less than 1:10

Interpretive Data

Gamma-aminobutyric acid receptor, type A (GABA-AR) antibody is found in a subset of patients with autoimmune encephalitis or autoimmune epilepsy and may occur with or without associated tumor. A negative test result does not rule out a diagnosis of autoimmune limbic encephalitis or autoimmune epilepsy. Interpretation of any antineural antibody test requires clinical correlation. 
This indirect fluorescent antibody assay utilizes GABA-AR transfected cell lines for detection and semiquantification of GABA-AR IgG antibody.

Compliance Category

Laboratory Developed Test (LDT)


If GABA-AR antibody IgG is positive, then GABA-AR antibody IgG titer will be added. Additional charges apply.

Hotline History


CPT Codes

86255; if reflexed, add 86256


Component Test Code* Component Chart Name LOINC
3006009 GABA-AR Ab IgG CBA-IFA Screen, Serum
* 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.


  • autoimmune encephalitis
  • autoimmune epilepsy
  • encephalopathy
  • GABA-A
  • Limbic encephalitis
Gamma-Aminobutyric Acid Receptor, Type A (GABA-AR) Antibody, IgG by CBA-IFA with Reflex to Titer, Serum