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Test ID EPIES Epilepsy, Autoimmune Evaluation, Serum

Useful For

Investigating new onset cryptogenic epilepsy with incomplete seizure control and duration of <2 years

 

Investigating new onset cryptogenic epilepsy plus 1 or more of the following accompaniments:

-Psychiatric accompaniments (psychosis, hallucinations)

-Movement disorder (myoclonus, tremor, dyskinesias)

-Headache

-Cognitive impairment/encephalopathy

-Autoimmune stigmata (personal history or family history or signs of diabetes mellitus, thyroid disorder, vitiligo, premature graying of hair, myasthenia gravis, rheumatoid arthritis, systemic lupus erythematosus, idiopathic adrenocortical insufficiency), or multiple sclerosis

-History of cancer         

-Smoking history (20+ pack years) or other cancer risk factors

-Investigating seizures occurring within the context of a subacute multifocal neurological disorder without obvious cause, especially in a patient with past or family history of cancer

-A rising autoantibody titer in a previously seropositive patient suggests cancer recurrence

Profile Information

Test ID Reporting Name Available Separately Always Performed
AEPSI Epilepsy, Interpretation, S No Yes
NMDCS NMDA-R Ab CBA, S No Yes
VGKC Neuronal (V-G) K+ Channel Ab, S No Yes
GD65S GAD65 Ab Assay, S Yes Yes
GABCS GABA-B-R Ab CBA, S No Yes
AMPCS AMPA-R Ab CBA, S No Yes
ANN1S Anti-Neuronal Nuclear Ab, Type 1 No Yes
ANN2S Anti-Neuronal Nuclear Ab, Type 2 No Yes
ANN3S Anti-Neuronal Nuclear Ab, Type 3 No Yes
AGN1S Anti-Glial Nuclear Ab, Type 1 No Yes
PCAB2 Purkinje Cell Cytoplasmic Ab Type 2 No Yes
PCATR Purkinje Cell Cytoplasmic Ab Type Tr No Yes
AMPHS Amphiphysin Ab, S No Yes
CCN N-Type Calcium Channel Ab No Yes
CCPQ P/Q-Type Calcium Channel Ab No Yes
ARBI ACh Receptor (Muscle) Binding Ab Yes Yes
GANG AChR Ganglionic Neuronal Ab, S No Yes
CRMS CRMP-5-IgG, S No Yes

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
PCABP Purkinje Cell Cytoplasmic Ab Type 1 No No
WBN Paraneoplastic Autoantibody WBlot,S No No
CRMWS CRMP-5-IgG Western Blot, S No No
ABLOT Amphiphysin Western Blot, S No No
NMOCS NMO/AQP4-IgG CBA, S Yes No
NMDIS NMDA-R Ab IF Titer Assay, S No No
AMPIS AMPA-R Ab IF Titer Assay, S No No
GABIS GABA-B-R Ab IF Titer Assay, S No No

Testing Algorithm

If indirect immunofluorescence assay (IFA) patterns suggest PCA-1, then Purkinje cell cytoplasmic antibody type 1 is performed at an additional charge.

If IFA suggests ANN1S, ANN2S, ANN3S, PCAB2, PCATR, AMPHS, CRMS, AGN1S, or is indeterminate, then paraneoplastic autoantibody Western blot is performed at an additional charge.

If client requests, or if IFA patterns suggest CRMP-5-IgG, then CRMP-5-IgG Western blot is performed at an additional charge.

If IFA patterns suggest amphiphysin antibody, then amphiphysin Western blot is performed at an additional charge.

If IFA pattern suggest NMO/AQP4-IgG, then NMO/AQP4-IgG CBA is performed at an additional charge.

If IFA pattern suggest NMDA-R antibody and NMDA-R antibody CBA is positive, then NMDA-R titer is performed at an additional charge.

If IFA pattern suggest AMPA-R antibody and AMPA-R antibody CBA is positive, then AMPA-R titer is performed at an additional charge.

If IFA pattern suggest GABA-B-R antibody and GABA-B-R antibody CBA is positive, then GABA-B-R titer is performed at an additional charge.

 

Confirmation of GAD65 antibodies when IF screening suggests GAD65 antibodies.

 

Native neuronal antigens: performed to confirm neuronal nuclear and cytoplasmic Ab specificities when IF screening is uninterpretable.

 

Recombinant human collapsin response-mediator protein 5: performed to confirm CRMP 5-IgG when IF screening is uninterpretable. Also performed for more sensitive detection of CRMP 5-IgG.

 

See Epilepsy Autoimmune Evaluation Algorithm, Serum in Special Instructions

Method Name

ANN1S, ANN2S, ANN3S, AGN1S, PCAB2, PCATR, AMPHS, CRMS, PCABP, NMDIS, AMPIS, GABIS: Indirect Immunofluorescence Assay (IFA)

VGKC, CCN, CCPQ, GANG, GD65S, ARBI: Radioimmunoassay (RIA)

WBN, CRMWS, ABLOT: Western Blot

AMPCS, GABCS, NMDCS: Cell Binding Assay (CBA)

Reporting Name

Epilepsy-Autoimmune Evaluation, S

Specimen Type

Serum

Container/Tube:

Preferred: Red top

Acceptable: Serum gel

Specimen Volume: 4 mL

Additional Information: Include relevant clinical information, name, phone number, mailing address, and e-mail address (if applicable) of ordering physician.

Forms: If not ordering electronically, complete, print, and send a Neurology Test Request Form (T732) with the specimen (http://www.mayomedicallaboratories.com/it-mmfiles/neurology-request-form.pdf)

Specimen Minimum Volume

2 mL

Specimen Stability Information

Specimen Type Temperature Time
Serum Refrigerated (preferred) 28 days
  Frozen  28 days
  Ambient  72 hours

Clinical Information

Antiepileptic drugs (AEDs) are the mainstay of treatment for epilepsy, but seizures continue in one-third of patients despite appropriate AED therapeutic trials. The etiology of epilepsy often remains unclear. Seizures are a common symptom in autoimmune neurological disorders, including limbic encephalitis and multifocal paraneoplastic disorders. Seizures may be the exclusive manifestation of an autoimmune encephalopathy without evidence of limbic encephalitis.

 

Autoimmune epilepsy is increasingly recognized in the spectrum of neurological disorders characterized by detection of neural autoantibodies in serum or spinal fluid and responsiveness to immunotherapy. The advent of more sensitive and specific serological detection methods is increasingly revealing previously underappreciated autoimmune epilepsies. Neural autoantibodies specific for intracellular and plasma membrane antigens aid the diagnosis of autoimmune epilepsy, but no single antibody is specific for this diagnosis.

 

Autoantibody specificities currently most informative for autoimmune epilepsies include voltage-gated potassium channel-complex (VGKC-complex), glutamic acid decarboxylase-65 (GAD65), N methyl-D-aspartate receptor (NMDAR), alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPAR), and gamma aminobutyric acid type B receptor (GABABR) antibodies.

 

Autoantibodies recognizing onconeural proteins shared by neurons, glia or muscle (eg, antineuronal nuclear antibody-type 1: ANNA 1, CRMP 5-IgG, N-type voltage-gated calcium channel and muscle AChR) also serve as markers of paraneoplastic or idiopathic autoimmune epilepsies. A specific neoplasm is often predictable by the individual patient's autoantibody profile.

 

Suspicion for autoimmune epilepsy on clinical grounds, justifies comprehensive evaluation of spinal fluid and serum for neural autoantibodies. Selective autoantibody testing is not advised because no single neural antibody is definitively associated with seizures, and markers of occult cancer may be missed. Failure to detect a neural antibody does not exclude the diagnosis of autoimmune epilepsy when other clinical clues exist. A trial of immunotherapy is justifiable in those cases.

Reference Values

NEURONAL NUCLEAR ANTIBODIES

Antineuronal Nuclear Ab, Type 1 (ANNA-1)

<1:240

Antineuronal Nuclear Ab, Type 2 (ANNA-2)

<1:240

Antineuronal Nuclear Ab, Type 3 (ANNA-3)

<1:240

Anti-Glial/Neuronal Nuclear Ab, Type 1 (AGNA-1)

<1:240

 

NEURONAL AND MUSCLE CYTOPLASMIC ANTIBODIES

Purkinje Cell Cytoplasmic Ab, Type1 (PCA-1)

<1:240

Purkinje Cell Cytoplasmic Ab, Type 2 (PCA-2)

<1:240

Purkinje Cell Cytoplasmic Ab, Type Tr (PCA-Tr)

<1:240

Amphiphysin Antibody

<1:240

CRMP-5-IgG

<1:240

 

WESTERN BLOT

Paraneoplastic Western Blot

Negative

CRMP-5-IgG Western Blot

Negative

Amphiphysin Western Blot

Negative

 

ISLET CELL ANTIBODIES

Glutamic Acid Decarboxylase (GAD65) Antibody

≤0.02 nmol/L

 

CATION CHANNEL ANTIBODIES

N-Type Calcium Channel Antibody

≤0.03 nmol/L

P/Q-Type Calcium Channel Antibody

≤0.02 nmol/L

AChR Ganglionic Neuronal Antibody

≤0.02 nmol/L

Neuronal VGKC Autoantibody

≤0.02 nmol/L

 

ACHR RECEPTOR ANTIBODIES

ACh Receptor (Muscle) Binding Antibody

≤0.02 nmol/L

 

N-Methyl-D-aspartate receptor (NMDA-R)

CBA: Negative

IFA: <1:120

2-amino-3-(5-methyl-3-oxo-1,2-oxazol-4-yl) propanoic acid receptor (AMPA-R)

CBA: Negative

IFA: <1:120

Gamma-Amino Butyric acid-type B receptor (GABA-B-R)

CBA: Negative

IFA: <1:120

NMO/AQP4-IgG

Negative

Cautions

Negative results do not exclude autoimmune epilepsy or cancer.

 

This test does not detect Ma2 antibody (alias: MaTa). Ma2 antibody has been described in patients with brainstem and limbic encephalitis in the context of testicular germ cell neoplasms. Scrotal ultrasound is advisable in men who present with unexplained subacute encephalitis.

Day(s) Performed

ANN1S, ANN2S, ANN3S, AGN1S, PCABP, PCAB2, PCATR, AMPHS, CRMS, AMPIS, GABIS, NMDIS: Monday through Friday; 11 a.m.

AMPCS, GABCS, NMDCS: Monday through Friday; 8 a.m.

Paraneoplastic autoantibody Western blot confirmation, CRMP-5-IgG Western blot, Amphiphysin Western blot: Monday through Friday; 8 a.m.

ARBI: Monday through Saturday; 5 p.m.

CCPQ, CCN: Monday thought Friday; 6 a.m.

GANG, VGKC, GD65S: Sunday through Thursday

Report Available

4 days if negative/7 days if positive

Performing Laboratory

Mayo Medical Laboratories in Rochester

Test Classification

See Individual Components

CPT Code Information

83519-ACh receptor (muscle) binding antibody

83519-AChR ganglionic neuronal antibody

83519-Neuronal VGKC autoantibody

83519-N-type calcium channel antibody

83519-P/Q-type calcium channel antibody

86255-AGNA-1

86255-Amphiphysin

86255-ANNA-1

86255-ANNA-2

86255-ANNA-3

86255-CRMP-5-IgG

86255-PCA-2

86255-PCA-Tr

86255-AMPAR-Ab

86255-GABAR-Ab

86255-NMDAR-Ab

86341-GAD65

 

86256-PCA-1 (if appropriate)

84182-Amphiphysin Western blot (if appropriate)

84182-CRMP-5 Western blot confirmation (if appropriate)

84182-Paraneoplastic autoantibody Western blot confirmation (if appropriate)

86255-NMO/AQP4-IgG CBA (if appropriate)

86256-AMPAR-Ab titer (if appropriate)

86256-GABAR-Ab titer (if appropriate)

86256-NMDAR-Ab titer (if appropriate)

NY State Approved

Yes