Ordering Recommendation

Aid in diagnosis of limbic encephalitis. May be used in monitoring treatment response in individuals who are antibody positive. The presence of AMPA receptor antibodies may be associated with psychosis, with or without seizures; AMPA encephalitis may be paraneoplastic but tumor type is variable (thymic, lung, and breast cancer).

New York DOH Approval Status

This test is New York state approved.

Specimen Required

Patient Preparation
Collect

CSF.

Specimen Preparation

Transfer 0.5 mL CSF 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

Methodology

Semi-Quantitative Cell-Based Indirect Fluorescent Antibody

Performed

Wed

Reported

1-8 days

Reference Interval

Less than 1:1

Interpretive Data

Alpha-amino-3-hydroxy-5-methyl-4-isoxazoleproprionic acid receptor (AMPAR) 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. A negative test result does not rule out a diagnosis of autoimmune encephalitis. Results should be interpreted in correlation with the patients clinical history and other laboratory findings.

This indirect fluorescent antibody assay utilizes AMPAR transfected cell lines for detection and semiquantification of AMPAR IgG antibody.

Compliance Category

Laboratory Developed Test (LDT)

Note

If Alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid (AMPA) Receptor Antibody, IgG by IFA with Reflex to Titer, CSF IgG is positive, then an Alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid (AMPA) Receptor Antibody Titer, IgG, CSF is reported. Additional charges apply.

Hotline History

N/A

CPT Codes

86255; if reflexed, add 86256

Components

Component Test Code* Component Chart Name LOINC
3001258 AMPA Receptor Ab IgG CBA-IFA Screen, CSF 82732-9
* 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

  • AMPA
  • AMPA Receptor Ab
  • AMPA Reflex
  • AMPA Titer
Alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid Receptor (AMPAR) Antibody, IgG by CBA-IFA With Reflex to Titer, CSF