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Test Code ENS1 Encephalopathy, Autoimmune Evaluation, Serum

Useful For

Evaluating new onset encephalopathy (noninfectious or metabolic) comprising confusional states, psychosis, delirium, memory loss, hallucinations, movement disorders, sensory or motor complaints, seizures, dyssomnias, ataxias, nausea, vomiting, inappropriate antidiuresis, coma, dysautonomias, or hypoventilation in serum specimens

 

The following accompaniments should increase of suspicion for autoimmune encephalopathy:

-Headache

-Autoimmune stigmata (personal or family history or signs of diabetes mellitus, thyroid disorder, vitiligo, poliosis [premature graying], myasthenia gravis, rheumatoid arthritis, systemic lupus erythematosus)

-History of cancer

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

-Inflammatory cerebral spinal fluid (or isolated protein elevation)

-Neuroimaging signs suggesting inflammation

 

Evaluating limbic encephalitis (noninfectious)

 

Directing a focused search for cancer

 

Investigating encephalopathy appearing in the course or wake of cancer therapy and not explainable by metastasis or drug effect

Profile Information

Test ID Reporting Name Available Separately Always Performed
AEESI Encephalopathy, Interpretation, S No Yes
NMDCS NMDA-R Ab CBA, S No Yes
VGKC Neuronal (V-G) K+ Channel Ab, S No Yes
LG1CS LGI1-IgG CBA, S No Yes
CS2CS CASPR2-IgG CBA, 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
PCABP Purkinje Cell Cytoplasmic 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 No 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
WBN Paraneoplastic Autoantibody WBlot,S No No
CRMWS CRMP-5-IgG Western Blot, S Yes No
ABLOT Amphiphysin Western Blot, S No No
NMOFS NMO/AQP4 FACS, S Yes No
NMOTS NMO/AQP4 FACS Titer, S No No
AMPIS AMPA-R Ab IF Titer Assay, S No No
GABIS GABA-B-R Ab IF Titer Assay, S No No
NMDIS NMDA-R Ab IF Titer Assay, S No No

Testing Algorithm

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

 

If client requests, or if IFA patterns suggests 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 FACS is performed at an additional charge.

 

If NMO/AQP4-IgG FACS screen assay requires further investigation, then NMO/AQP4-IgG FACS titration assay 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.

 

Western Blot: Native neuronal antigens: performed to confirm neuronal nuclear and cytoplasmic antibody 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.

 

RIA: Confirmation of GAD65 antibodies when IF screening suggests GAD65 antibodies.

 

See Encephalopathy 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, ABLOT: Western Blot

AMPCS, GABCS, NMDCS, LG1CS, CS2CS: Cell Binding Assay (CBA)

Reporting Name

Encephalopathy-Autoimmune Eval, S

Specimen Type

Serum

Specimen Required

Container/Tube:

Preferred: Red top

Acceptable: Serum gel

Specimen Volume: 4 mL

Specimen Minimum Volume

2 mL

Specimen Stability Information

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

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

LGI1-IgG CBA, S: Negative

CASPR2-IgG CBA, S: Negative          

 

Neuromyelitis Optica (NMO)/Aquaporin-4-IgG FACS Assay, S

Negative

Day(s) and Time(s) Performed

ANN1S, ANN2S, ANN3S, AGN1S, PCABP, PCAB2, PCATR, AMPHS, CRMS, AMPIS, GABIS, NMDIS:

Monday through Friday; 11:30 a.m. and 8:00 p.m.; Saturday and Sunday 8:00 a.m.

AMPCS, GABCS, NMDCS, LG1CS, CS2CS: Monday through Friday; 6 a.m.

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

ARBI: Monday through Saturday; 5 p.m.

CCPQ, CCN, GANG, VGKC: Monday through Friday 11:00 a.m. and 6:00 p.m.; Saturday 6:00 a.m.; Sunday 6:00 a.m.

GD65S: Monday to Friday; 6:00 a.m. and 4:00 p.m.

Performing Laboratory

Mayo Medical Laboratories in Rochester

Test Classification

See Individual Test IDs

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-1

86255-PCA-2

86255-PCA-Tr

86255-AMPAR-Ab

86255-GABAR-Ab

86255-NMDAR-Ab

86341-GAD65

86255-LG1CS

86255- CS2CS

 

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 FACS (if appropriate)

86256-AMPAR-Ab titer (if appropriate)

86256-GABAR-Ab titer (if appropriate)

86256-NMDAR-Ab titer (if appropriate)

86256- NMO/AQP4-IgG FACS titer (if appropriate)

LOINC Code Information

Test ID Test Order Name Order LOINC Value
ENS1 Encephalopathy-Autoimmune Eval, S In Process

 

Result ID Test Result Name Result LOINC Value
61516 NMDA-R Ab CBA, S No LOINC Needed
61518 AMPA-R Ab CBA, S No LOINC Needed
61519 GABA-B-R Ab CBA, S No LOINC Needed
34257 Encephalopathy, Interpretation, S 69048-7
64279 LGI1-IgG CBA, S In Process
64281 CASPR2-IgG CBA, S In Process
89080 AGNA-1, S 53709-2
81722 Amphiphysin Ab, S 33927-5
80150 ANNA-1, S 13997-2
80776 ANNA-2, S 43188-2
83137 ANNA-3, S 33924-2
8338 ACh Receptor (Muscle) Binding Ab 11034-6
81184 N-Type Calcium Channel Ab 33979-6
81185 P/Q-Type Calcium Channel Ab 33980-4
83077 CRMP-5-IgG, S 35386-2
84321 AChR Ganglionic Neuronal Ab, S 42233-7
81596 GAD65 Ab Assay, S 30347-9
83138 PCA-2, S 33925-9
9477 PCA-1, S 53717-5
83076 PCA-Tr, S 33926-7
89165 Neuronal (V-G) K+ Channel Ab, S 41871-5
36349 Reflex Added No LOINC Needed

Forms

If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:

General Request Form (Supply T239) with the specimen.

Neurology Test Request Form (T732) (http://www.mayomedicallaboratories.com/media/customer-service/forms/neurology-request-form.pdf)

Necessary Information

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