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AMPA Receptor 1 (GluA1) Antibody, Serum — Qualitative, Immunofluorescence Assay

Published: August 9, 2026Updated: August 16, 2026

This blood test detects antibodies against the AMPA receptor 1 protein, which may support evaluation for autoimmune encephalitis.

Quick summary

["Detected AMPA receptor 1 antibodies may indicate an autoimmune neurologic condition when other findings support the diagnosis."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
93869-6
Short code
AMPAR1 Ab Ser Ql CBA IFA
Synonyms
AMPAR1 Ab Ser Ql CBA IFA
Category
liver
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
cba-ifa
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What is this test?

This test checks serum for antibodies directed against AMPA receptor 1, also called GluA1. These antibodies can be associated with autoimmune encephalitis, an uncommon condition in which the immune system attacks the brain.

Why might I need this test?

Your clinician may order this test when you have rapidly developing confusion, seizures, memory problems, movement changes, psychiatric symptoms, or other neurologic changes that could suggest autoimmune encephalitis. It is usually considered alongside other laboratory tests, brain imaging, and cerebrospinal fluid analysis.

How is the test performed?

A blood sample is collected, and the serum is tested using an immunofluorescence-based laboratory method. The result is generally reported as detected or not detected, and it is interpreted together with your symptoms and other clinical findings.

How do I prepare for the test?

Fasting is usually not required, but follow any instructions provided by your clinician or laboratory. Tell the healthcare team if you recently received immunoglobulin products, underwent plasma exchange, or take medicines that affect the immune system, because these factors may influence interpretation.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

AMPA receptor 1 antibody

Frequently asked questions

Does a positive result mean I definitely have autoimmune encephalitis?
No. A positive result indicates that AMPA receptor 1 antibodies are present, but it must be interpreted with your symptoms, examination, and other test results. Antibodies can sometimes be present in people without active disease.
Can this test rule out autoimmune encephalitis if it is negative?
No. A negative serum result does not completely exclude the condition. If suspicion remains high, your clinician may recommend additional antibody testing or cerebrospinal fluid analysis.
Do I need to stop any medicines before this test?
Do not stop medicines on your own. Tell your clinician about immunosuppressive treatment, immunoglobulin therapy, or recent plasma exchange because these may need to be considered when interpreting the result.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy