Autoimmune Encephalitis Panel, Serum (Sendout)
General Information
- Lab Name
- Autoimmune Encephalitis Panel, Serum (Sendout)
- Lab Code
- RSAENP
- Epic Name
- Autoimmune Encephalitis Panel, Serum (Sendout)
- External Test Id
- ENS2
- Description
Test Information:
The Mayo Autoimmune Encephalitis Panel (serum) includes tests for 27 autoantibodies (as of 10/13/26), listed in the Mayo Autoimmune Neurology Antibody Matrix. This panel includes all 9 antibodies previously included in the serum paraneoplastic autoantibody panel (RPNPV, PAVAL). Oncologic associations for the autoantibodies in this panel are displayed in a table in the Antibody Matrix document.
Encephalitis is a debilitating neurologic condition caused by infectious and autoimmune conditions that result in inflammation of the brain parenchyma. The identification of autoantibodies may augment a diagnosis of autoimmune encephalitis, but is not required for the diagnosis or initiation of therapy. The most frequently identified antibodies target NMDA-R. NMDA Receptor IgG Antibody with Reflex, Serum (Sendout) [RNMDA] is recommended as first-line testing for autoimmune encephalitis prior to ordering this full panel, as outlined in the Autoimmune Encephalitis Testing Recommendations.
Monitoring titers over time for these antibodies is not recommended; however, this recommendation is based on limited currently available literature.
Test Algorithm: Refer to Mayo's algorithm (linked below) for additional detail on tests and potential reflex tests included in this panel. Reflex testing may be performed at additional charge.
Ordering Guidance: Refer to Autoimmune Encephalitis Testing Recommendations or consult the Laboratory Medicine Resident on-call.
- The Mayo Antibody Prevalence in Epilepsy and Encephalopathy (APE²) Scorecard may be used to determine the likelihood of neural antibody positivity in patients with encephalopathy and/or seizures.
- For a list of antibodies performed in each phenotype-specific autoimmune neurology panel, refer to the Mayo Autoimmune Neurology Antibody Matrix.
Ordering Requirements: Orders from UW Medicine Neurology Clinics are pre-approved. For all other orders, Laboratory Medicine Resident (LMR) approval is required.
***Note: Effective 10/13/26, the Encephalopathy, Autoimmune/Paraneoplastic Evaluation, Serum profile will undergo the following component changes at Mayo Clinic Laboratories:
- Tests Added to Profile: AK5 IFA, GABA-A-R CBA, KLHL11 CBA, mGlur5 IFA, and Ma2
- Tests Removed from Profile: GFAP IFA, NIF IFA
Additional antibodies will be reported under the Encephalopathy Interpretation, Serum [RAEESI] component until a battery revision is completed on December 1st, 2026.***
- References
- Mayo Clinical & Interpretive Information: Encephalopathy, Autoimmune/Paraneoplastic Evaluation, Serum
- Synonyms
- AGNA-1, AK5 IFA, AMPA-R Ab CBA, Amphiphysin Ab, ANNA-1, ANNA-2, ANNA-3, Anti-Glial Nuclear Antibody, Anti-Neuronal Nuclear Antibody Type 1, Anti-Neuronal Nuclear Antibody Type 2, Anti-Neuronal Nuclear Antibody Type 3, CASPR2 IgG, Contactin-Associated Protein-Like-2 (CASPR2) IgG, CRMP-5 IgG, Dipeptidyl-Peptidase-Like Protein-6 (DPPX) Antibody, DPPX, Encephalitis, Encephalopathy, Encephalopathy Autoimmune Paraneoplastic Evaluation, Encephalopathy Autoimmune/Paraneoplastic Evaluation Serum, ENS2, GABA-A-R Antibody CBA, GABA-B-R Antibody CBA, GAD65, Glutamic Acid Decarboxylase, IgLON Family Member 5 Antibody, IGLON5, KLHL11 CBA, Leucine-Rich Glioma Inactivated Protein-1 IgG, LGI1 IgG, Limbic encephalitis, Ma2, mGluR1 IFA, mGluR5 IFA, Neurochondrin, NMDA-R Ab CBA, Paraneoplastic, PCA-1, PCA-2, PCA-Tr, PDE10A, Phosphodiesterase 10A (PDE10A) IgG, Purkinje Cell Cytoplasmc Antibody Type Tr, Purkinje Cell Cytoplasmic Antibody Type 1, Purkinje Cell Cytoplasmic Antibody Type 2, Septin-7, TRIM46, Tripartite Motif-Containing Protein 46 (TRIM46) IgG
- Components
-
Code Name RAEESI Encephalopathy Interpretation, Serum RAESIF IFA Notes RAMPCS AMPA-R Antibody CBA RAMPHS Amphiphysin Antibody RAGNA1 Anti Glial Nuclear Antibody 1 RANN1 Anti Neuronal Nuclear Antibody 1 RANN2 Anti Neuronal Nuclear Antibody 2 RANN3 Anti Neuronal Nuclear Antibody 3 RCS2CS CASPR2 IgG CBA RCRMP CRMP 5 IgG RDPPCS DPPX Antibody CBA RGABCS GABA B R Antibody CBA RGAD65 GAD65 Antibody Assay RGFAIS GFAP IFA RIG5CS IgLON5 CBA RLG1CS LGI1 IgG CBA RMGL1S mGluR1 Antibody IFA RNCDIS Neurochondrin IFA RNIFIS NIF IFA RNMDCS NMDA R Antibody CBA RPCA1 Purkinje Cell Cytoplasmic Antibody 1 RPCA2 Purkinje Cell Cytoplasmic Antibody 2 RPCATR Purkinje Cell Cytoplasmic Antibody Tr RPDEIS PDE10A Antibody IFA RSP7IS Septin 7 IFA RTRM46 TRIM46 Antibody IFA
Interpretation
- Guidelines
- Method
Panel and reflex tests include the following methods: Immunofluorescence assay (IFA), Cell-binding assay (CBA), Western blot (WB), Radioimmunoassay (RIA), Immunoblot (IB)
- Reference Range
- See individual components
- Ref. Range Notes
Reference Values:
AK5 Ab IFA: Negative AMPA-R Ab CBA: Negative Amphiphysin Ab: Negative Anti-Glial Nuclear Ab, Type 1: Negative Anti-Neuronal Nuclear Ab, Type 1: Negative Anti-Neuronal Nuclear Ab, Type 2: Negative Anti-Neuronal Nuclear Ab, Type 3: Negative CASPR2-IgG CBA: Negative CRMP-5-IgG: Negative DPPX Ab CBA: Negative GABA-A-R Ab CBA: Negative GABA-B-R Ab CBA: Negative GAD65 Ab Assay: < or =0.02 nmol/L IgLON5 CBA: Negative KLHL11-IgG CBA: Negative LGI1-IgG CBA: Negative Ma2 Ab ELISA: Negative mGluR1 Ab IFA: Negative mGluR5 Ab IFA: Negative Neurochondrin IFA: Negative NMDA-R Ab CBA: Negative Purkinje Cell Cytoplasmic Ab Type 1: Negative Purkinje Cell Cytoplasmic Ab Type 2: Negative Purkinje Cell Cytoplasmic Ab Type Tr: Negative PDE10A Ab IFA: Negative Septin-7 IFA: Negative TRIM46 IFA: Negative Note: Includes reference values for panel tests only.
Neuron-restricted patterns of IgG staining that do not fulfill criteria for ANNA-1, ANNA-2, CRMP-5-IgG, PCA-1, PCA-2, or PCA-Tr may be reported as "unclassified anti-neuronal IgG." Complex patterns that include nonneuronal elements may be reported as "uninterpretable."
CRMP-5 titers lower than 1:240 are detectable by recombinant CRMP-5 Western blot analysis. CRMP-5 Western blot analysis will be done on request on stored serum (held 4 weeks). This supplemental testing is recommended in cases of chorea, vision loss, cranial neuropathy, and myelopathy. Call the Neuroimmunology Laboratory at 800-533-1710 to request CRMP-5 Western blot.
Interpretation: Neuronal, glial, and muscle autoantibodies are valuable serological markers of autoimmune encephalopathy and of a patient's immune response to cancer. These autoantibodies are usually accompanied by subacute neurological symptoms and signs are not found in healthy subjects. It is not uncommon for more than 1 of the following autoantibody specificities to be detected in patients with an autoimmune encephalopathy:
-
Plasma membrane autoantibodies: N-methyl-D-aspartate (NMDA) receptor; 2-amino-3-(5-methyl-3-oxo-1,2- oxazol-4-yl) propanoic acid (AMPA) receptor; gamma-amino butyric acid (GABA-B) receptor; neuronal ACh receptor. These are all potential effectors of neurological dysfunction.
-
Neuronal nuclear autoantibodies, type 1 (ANNA-1), type 2 (ANNA-2), or type 3 (ANNA-3)
-
Neuronal or muscle cytoplasmic antibodies: amphiphysin, Purkinje cell antibodies (PCA-1) and PCA-2, CRMP-5, GAD65, or striational
-
- Interferences and Limitations
Cautions:
Negative results do not exclude autoimmune encephalopathy or cancer.
Intravenous immunoglobulin (IVIg) treatment prior to the serum collection may cause a false-positive result.
- References
- Mayo Clinical & Interpretive Information: Encephalopathy, Autoimmune/Paraneoplastic Evaluation, Serum
Ordering & Collection
- Specimen Type
- Blood
- Collection
-
12 mL blood in RED TOP or GOLD SST tubes
- Approval Required
- Orders from UW Medicine Neurology Clinics are pre-approved. For all other orders, Laboratory Medicine Resident (LMR) approval is required.
- Handling Instructions
Outside Laboratories: Centrifuge samples and transfer serum to a separate plastic vial. Refrigerate serum while awaiting shipment. Transport with a cold pack.
Stability: Refrigerated (preferred): 28 days; Frozen: 28 days; Ambient: 72 hours.
Reject Due To: Gross hemolysis, gross lipemia, gross icterus, insufficient sample volume.
- Quantity
-
Requested: 4 mL serum
Minimum: 2.5 mL serum
Processing
- Receiving Instructions
Centrifuge samples and transfer 4 mL serum (2.5 mL minimum) to a separate plastic aliquot. Refrigerate serum.
Sendouts:
- Order Mayo Test: ENS2
- Interfaced: Yes [Interface: 601; Worksheet: MARF]
Stability: Refrigerated (preferred): 28 days; Frozen: 28 days; Ambient: 72 hours.
Reject Due To: Gross hemolysis, gross lipemia, gross icterus, insufficient sample volume.
- Misc Sendout
Performance
- Lab Department
- Sendouts Mayo Lab (RF)(MARF)
- Frequency
- Performed: Varies. Report available: 10-13 days from sample receipt at Mayo Clinic Laboratories.
- Available STAT?
- No
- Performing Location(s)
-
Sendout Mayo Clinic Laboratories
800-533-1710200 First Street Southwest
Rochester, MN 55901
Billing & Coding
- CPT Codes
- 86255x23, 86341
- LOINC
- 94697-0
- Interfaced Order Code
- UOW4912
- Billing Comments
Reflex testing may be performed at additional charge.