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Test Code ENS2 Encephalopathy, Autoimmune Evaluation, Serum


Necessary Information


Provide the following information:

-Relevant clinical information

-Ordering provider name, phone number, mailing address, and e-mail address



Specimen Required


Patient Preparation:

1. For optimal antibody detection, specimen collection is recommended prior to initiation of immunosuppressant medication.

2. This test should not be requested in patients who have recently received radioisotopes, therapeutically or diagnostically, because of potential assay interference. The specific waiting period before specimen collection will depend on the isotope administered, the dose given, and the clearance rate in the individual patient. Specimens will be screened for radioactivity prior to analysis. Radioactive specimens received in the laboratory will be held 1 week and assayed if sufficiently decayed, or canceled if radioactivity remains.

3. Patient should have no general anesthetic or muscle-relaxant drugs in the previous 24 hours.

Container/Tube:

Preferred: Red top

Acceptable: Serum gel

Specimen Volume: 4 mL


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
GANG AChR Ganglionic Neuronal Ab, S No Yes
AMPCS AMPA-R Ab CBA, S No Yes
AMPHS Amphiphysin Ab, S No Yes
AGN1S Anti-Glial Nuclear Ab, Type 1 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
CS2CS CASPR2-IgG CBA, S No Yes
CRMS CRMP-5-IgG, S No Yes
DPPIS DPPX Ab IFA, S No Yes
GABCS GABA-B-R Ab CBA, S No Yes
GD65S GAD65 Ab Assay, S Yes Yes
GFAIS GFAP IFA, S No Yes
LG1CS LGI1-IgG CBA, S No Yes
GL1IS mGluR1 Ab IFA, S No Yes
NMDCS NMDA-R Ab CBA, S No Yes
CCN N-Type Calcium Channel Ab No Yes
CCPQ P/Q-Type Calcium Channel Ab 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

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
ARBI ACh Receptor (Muscle) Binding Ab Yes No
ARMO ACh Receptor (Muscle) Modulating Ab No No
AMPIS AMPA-R Ab IF Titer Assay, S No No
ABLOT Amphiphysin Western Blot, S No No
CRMWS CRMP-5-IgG Western Blot, S Yes No
DPPCS DPPX Ab CBA, S No No
DPPTS DPPX Ab IFA Titer, S No No
GABIS GABA-B-R Ab IF Titer Assay, S No No
GFACS GFAP CBA, S No No
GFATS GFAP IFA Titer, S No No
GL1CS mGluR1 Ab CBA, S No No
GL1TS mGluR1 Ab IFA Titer, S No No
NMDIS NMDA-R Ab IF Titer Assay, S No No
WBN Paraneoplastic Autoantibody WBlot,S No No

Testing Algorithm

If indirect immunofluorescence assay (IFA) (ANNA-1, ANNA-2, PCA-1, PCA-2) 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, ACh receptor (muscle) binding antibody, and ACh receptor (muscle) modulating antibody are performed at an additional charge.

 

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

 

If IFA pattern suggests AMPA-receptor antibody, and AMPA-receptor antibody cell-binding assay (CBA) is positive, then AMPA-receptor antibody IFA titer assay is performed at an additional charge.

 

If AMPA-receptor antibody CBA is positive, then CRMP-5-IgG Western blot, ACh receptor (muscle) binding antibody, and ACh receptor (muscle) modulating antibody are performed at an additional charge.

 

If CASPR2-receptor antibody CBA is positive, then CRMP-5-IgG Western blot, ACh receptor (muscle) binding antibody, and ACh receptor (muscle) modulating antibody are performed at an additional charge.

 

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

 

If IFA pattern suggests GFAP antibody, then GFAP IFA titer and GFAP CBA are performed at an additional charge.

 

If IFA pattern suggests NMDA-receptor antibody, and NMDA-receptor antibody CBA is positive, then NMDA-receptor antibody IFA titer assay is performed at an additional charge.

 

 

If IFA pattern suggests DPPX antibody, then DPPX antibody CBA and DPPX titer are performed at an additional charge.

 

If IFA pattern suggests mGluR1 antibody, then mGluR1 antibody CBA and mGluR1 titer are performed at an additional charge.

 

See Encephalopathy Autoimmune Evaluation Algorithm-Serum in Special Instructions.

Method Name

ANN1S, ANN2S, ANN3S, PCABP, PCAB2, PCATR, AMPHS, CRMS, AGN1S, DPPIS, DPPTS, GL1IS, GLITS, GFAIS, GFATS, AMPIS, GABIS, NMDIS: Indirect Immunofluorescence Assay (IFA)

AMPCS, GABCS, NMDCS, LG1CS, CS2CS, DPPCS, GL1CS, GFACS: Cell Binding Assay (CBA)

ABLOT, CRMWS, WBN; Western Blot (WB)

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

ARMO: Live Cell Assay (LCA)

Reporting Name

Encephalopathy-Autoimmune Eval, S

Specimen Type

Serum

Specimen Minimum Volume

2.5 mL

Specimen Stability Information

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

Reject Due To

Hemolysis

Mild OK; Gross reject

Lipemia

Mild OK; Gross reject

Icterus

Mild OK; Gross reject

Other

NA

Reference Values

Test ID

Reporting Name

Methodology

Reference Value

GANG

AChR Ganglionic Neuronal Ab, S

Radioimmunoassay (RIA)

≤0.02

AMPCS

AMPA-R Ab CBA, S

Cell-binding assay (CBA)

Negative

AMPHS

Amphiphysin Ab, S

Immunofluorescence (IFA)

<1:240

AGN1S

Anti-Glial Nuclear Ab, Type 1

IFA

<1:240

ANN1S

Anti-Neuronal Nuclear Ab, Type 1

IFA

<1:240

ANN2S

Anti-Neuronal Nuclear Ab, Type 2

IFA

<1:240

ANN3S

Anti-Neuronal Nuclear Ab, Type 3

IFA

<1:240

CS2CS

CASPR2-IgG CBA, S

CBA

Negative

CRMS

CRMP-5-IgG, S

IFA

<1:240

DPPIS

DPPX Ab IFA, S

IFA

Negative

GABCS

GABA-B-R Ab CBA, S

CBA

Negative

GD65S

GAD65 Ab Assay, S

RIA

≤0.02

Reference values apply to all ages

GFAIS

GFAP IFA, S

IFA

Negative

LG1CS

LGI1-IgG CBA, S

CBA

Negative

GL1IS

mGluR1 Ab IFA, S

IFA

Negative

NMDCS

NMDA-R Ab CBA, S

CBA

Negative

CCN

N-Type Calcium Channel Ab

RIA

≤0.03

CCPQ

P/Q-Type Calcium Channel Ab

RIA

≤0.02

PCABP

Purkinje Cell Cytoplasmic Ab Type 1

IFA

<1:240

PCAB2

Purkinje Cell Cytoplasmic Ab Type 2

IFA

<1:240

PCATR

Purkinje Cell Cytoplasmic Ab Type Tr

IFA

<1:240

 

Reflex Information:

Test ID

Reporting Name

Methodology

Reference Value

ARBI

ACh Receptor (Muscle) Binding Ab

RIA

≤0.02

ARMO

ACh Receptor (Muscle) Modulating Ab

Live-cell assay (LCA)

0-20%

AMPIS

AMPA-R Ab IF Titer Assay, S

IFA

<1:120

ABLOT

Amphiphysin Western Blot, S

Western blot (WB)

Negative

CRMWS

CRMP-5-IgG Western Blot, S

WB

Negative

DPPCS

DPPX Ab CBA, S

CBA

Negative

DPPTS

DPPX Ab IFA Titer, S

IFA

<1:240

GABIS

GABA-B-R Ab IF Titer Assay, S

IFA

<1:120

GFACS

GFAP CBA, S

CBA

Negative

GFATS

GFAP IFA Titer, S

IFA

<1:240

GL1CS

mGluR1 Ab CBA, S

CBA

Negative

GL1TS

mGluR1 Ab IFA Titer, S

IFA

<1:240

NMDIS

NMDA-R Ab IF Titer Assay, S

IFA

<1:120

WBN

Paraneoplastic Autoantibody WBlot, S

WB

Negative

 

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."

 

Note: 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.

Day(s) and Time(s) Performed

AMPHS, AGN1S, ANN1S, ANN2S, ANN3S, CRMS, GFAIS, PCAB2, PCATR, AMPIS, GABIS, GFATS, NMDIS, PCABP, DPPIS, GL1IS, DPPTS, GL1TS:

Monday through Friday; 5 a.m., 7 a.m., 5 p.m.

Saturday, Sunday; 6 a.m.

 

DPPCS, GL1CS:

Wednesday; 6 p.m.

 

AMPCS, GABCS, NMDCS, CS2CS, LG1CS:

Monday through Thursday; 10 p.m.

Sunday; 3 p.m.

 

GFACS:

Monday, Wednesday; 6 p.m.

 

ABLOT, CRMWS, WBN:

Monday through Thursday; 8 a.m.

 

ARMO:

Monday through Thursday; 1 p.m.

Saturday; 8 a.m.

 

GD65S:

Monday through Friday; 5 a.m., 2 p.m.

Saturday, Sunday; 7 a.m.

 

ARBI, GANG, CCN, CCPQ:

Monday through Friday; 6 a.m., 8 a.m., 6 p.m.

Saturday, Sunday; 7 a.m.

Analytic Time

7 days

Specimen Retention Time

28 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information

83519 x 3

86255 x 17

86341 x 1

86255 x 3 (if appropriate)

86256 x 6 (if appropriate)

84182 x 3 (if appropriate)

83519 x 2 (if appropriate)

LOINC Code Information

Test ID Test Order Name Order LOINC Value
ENS2 Encephalopathy-Autoimmune Eval, S In Process

 

Result ID Test Result Name Result LOINC Value
61516 NMDA-R Ab CBA, S In Process
61518 AMPA-R Ab CBA, S In Process
61519 GABA-B-R Ab CBA, S 93428-1
34257 Encephalopathy, Interpretation, S 69048-7
64279 LGI1-IgG CBA, S In Process
64281 CASPR2-IgG CBA, S In Process
64930 DPPX Ab IFA, S 82976-2
64928 mGluR1 Ab IFA, S In Process
605155 GFAP IFA, S In Process
80776 ANNA-2, S 43188-2
83137 ANNA-3, S 33924-2
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 56550-7
89080 AGNA-1, S 53709-2
81722 Amphiphysin Ab, S 33927-5
80150 ANNA-1, S 13997-2
36349 Reflex Added 77202-0