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Test Code ENC2 Encephalopathy, Autoimmune Evaluation, Spinal Fluid


Necessary Information


Provide the following information:

-Relevant clinical information

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



Specimen Required


Container/Tube: Sterile vial

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 spinal fluid 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 cerebrospinal 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
AEECI Encephalopathy, Interpretation, CSF No Yes
AMPCC AMPA-R Ab CBA, CSF No Yes
AMPHC Amphiphysin Ab, CSF No Yes
AGN1C Anti-Glial Nuclear Ab, Type 1 No Yes
ANN1C Anti-Neuronal Nuclear Ab, Type 1 No Yes
ANN2C Anti-Neuronal Nuclear Ab, Type 2 No Yes
ANN3C Anti-Neuronal Nuclear Ab, Type 3 No Yes
CS2CC CASPR2-IgG CBA, CSF No Yes
CRMC CRMP-5-IgG, CSF No Yes
DPPIC DPPX Ab IFA, CSF No Yes
GABCC GABA-B-R Ab CBA, CSF No Yes
GD65C GAD65 Ab Assay, CSF Yes Yes
GFAIC GFAP IFA, CSF No Yes
LG1CC LGI1-IgG CBA, CSF No Yes
GL1IC mGluR1 Ab IFA, CSF No Yes
NMDCC NMDA-R Ab CBA, CSF No Yes
PCTRC Purkinje Cell Cytoplasmc Ab Type Tr No Yes
PCA1C Purkinje Cell Cytoplasmic Ab Type 1 No Yes
PCA2C Purkinje Cell Cytoplasmic Ab Type 2 No Yes

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
AMPIC AMPA-R Ab IF Titer Assay, CSF No No
ABLTC Amphiphysin Western Blot, CSF No No
CRMWC CRMP-5-IgG Western Blot, CSF Yes No
DPPCC DPPX Ab CBA, CSF No No
DPPTC DPPX Ab IFA Titer, CSF No No
GABIC GABA-B-R Ab IF Titer Assay, CSF No No
GFACC GFAP CBA, CSF No No
GFATC GFAP IFA Titer, CSF No No
GL1CC mGluR1 Ab CBA, CSF No No
GL1TC mGluR1 Ab IFA Titer, CSF No No
NMDIC NMDA-R Ab IF Titer Assay, CSF No No
WBNC Paraneoplas Autoantibody WBlot,CSF No No

Testing Algorithm

If indirect immunofluorescence assay (IFA) (ANNA-1, ANNA-2, ANNA-3, PCA-1, PCA-2, PCA-Tr, amphiphysin, CRMP-5-IgG, AGNA-1) 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 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 IFA pattern suggests GABA-B-Receptor antibody, and GABA-B-R Receptor antibody CBA 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-Spinal Fluid in Special Instructions.

Method Name

ANN1C, ANN2C, ANN3C, PCA1C, PCA2C, PCTRC, AMPHC, CRMC, AGN1C, DPPIC, DPPTC, GL1IC, GL1TC, GFAIC, GFATC, AMPIC, GABIC, NMDIC: Indirect Immunofluorescence Assay (IFA)

AMPCC, GABCC, NMDCC, LG1CC, CS2CC, DPPCC, GL1CC, GFACC: Cell Binding Assay (CBA)

ABLTC, CRMWC, WBNC: Western Blot

GD65C: Immunoprecipitation Assay (IPA)

Reporting Name

Encephalopathy-Autoimmune Eval, CSF

Specimen Type

CSF

Specimen Minimum Volume

2 mL

Specimen Stability Information

Specimen Type Temperature Time
CSF 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

AMPCC

AMPA-R Ab CBA, CSF

Cell-binding assay (CBA)

Negative

AMPHC

Amphiphysin Ab, CSF

Immunofluorescence (IFA)

<1:2

AGN1C

Anti-Glial Nuclear Ab, Type 1

IFA

<1:2

ANN1C

Anti-Neuronal Nuclear Ab, Type 1

IFA

<1:2

ANN2C

Anti-Neuronal Nuclear Ab, Type 2

IFA

<1:2

ANN3C

Anti-Neuronal Nuclear Ab, Type 3

IFA

<1:2

CS2CC

CASPR2-IgG CBA, CSF

CBA

Negative

CRMC

CRMP-5-IgG, CSF

IFA

<1:2

DPPIC

DPPX Ab IFA, CSF

IFA

Negative

GABCC

GABA-B-R Ab CBA, CSF

CBA

Negative

GD65C

GAD65 Ab Assay, CSF

Immunoprecipitation assay (IPA)

≤0.02 nmol/L

GFAIC

GFAP IFA, CSF

IFA

Negative

LG1CC

LGI1-IgG CBA, CSF

CBA

Negative

GL1IC

mGluR1 Ab IFA, CSF

IFA

Negative

NMDCC

NMDA-R Ab CBA, CSF

CBA

Negative

PCTRC

Purkinje Cell Cytoplasmc Ab Type Tr

IFA

<1:2

PCA1C

Purkinje Cell Cytoplasmic Ab Type 1

IFA

<1:2

PCA2C

Purkinje Cell Cytoplasmic Ab Type 2

IFA

<1:2

 

Reflex Information:

Test ID

Reporting Name

Methodology

Reference Value

AMPIC

AMPA-R Ab IF Titer Assay, CSF

IFA

<1:2

ABLTC

Amphiphysin Western Blot, CSF

Western blot (WB)

Negative

CRMWC

CRMP-5-IgG Western Blot, CSF

WB

Negative

DPPCC

DPPX Ab CBA, CSF

CBA

Negative

DPPTC

DPPX Ab IFA Titer, CSF

IFA

<1:2

GABIC

GABA-B-R Ab IF Titer Assay, CSF

IFA

<1:2

GFACC

GFAP CBA, CSF

CBA

Negative

GFATC

GFAP IFA Titer, CSF

IFA

<1:2

GL1CC

mGluR1 Ab CBA, CSF

CBA

Negative

GL1TC

mGluR1 Ab IFA Titer, CSF

IFA

<1:2

NMDIC

NMDA-R Ab IF Titer Assay, CSF

IFA

<1:2

WBNC

Paraneoplas Autoantibody WBlot, CSF

WB

Negative

 

Neuron-restricted patterns of IgG staining that do not fulfill criteria for ANNA-1, ANNA-2, ANNA-3, 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 1:2 are detectable by recombinant CRMP-5 Western blot analysis. CRMP-5 Western blot analysis will be done on request on stored spinal fluid (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

ANN1C, ANN2C, ANN3C, PCA1C, PCA2C, PCTRC, AMPHC, CRMC, AGN1C, DPPIC, DPPTC, GL1IC, GLITC, GFAIC, AMPIC, GABIC, NMDIC:

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

Saturday, Sunday; 6 a.m.

 

AMPCC, GABCC, NMDCC, LG1CC, CS2CC:

Monday through Thursday; 10 p.m.

Sunday; 3 p.m.

 

DPPCC, GL1CC

Wednesday; 6 p.m.

 

GFACC:

Tuesday, Thursday; 6 p.m.

 

ABLTC, CRMWC, WBNC:

Monday, Wednesday, Friday; 8 a.m.

 

GD65C:

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

Saturday, Sunday; 7 a.m.

Analytic Time

5 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

86255 x17

86341 x1

86255 x3 (if appropriate)

86256 x6 (if appropriate)

84182 x3 (if appropriate)

LOINC Code Information

Test ID Test Order Name Order LOINC Value
ENC2 Encephalopathy-Autoimmune Eval, CSF In Process

 

Result ID Test Result Name Result LOINC Value
61513 NMDA-R Ab CBA, CSF In Process
61514 AMPA-R Ab CBA, CSF In Process
61515 GABA-B-R Ab CBA, CSF In Process
34256 Encephalopathy, Interpretation, CSF 69048-7
64280 LGI1-IgG CBA, CSF In Process
64282 CASPR2-IgG CBA, CSF In Process
64929 DPPX Ab IFA, CSF 82989-5
64927 mGluR1 Ab IFA, CSF In Process
605156 GFAP IFA, CSF In Process
89079 AGNA-1, CSF 53714-2
5906 Amphiphysin Ab, CSF 56531-7
3852 ANNA-1, CSF 24400-4
7472 ANNA-2, CSF 24401-2
21633 ANNA-3, CSF 90837-6
21650 CRMP-5-IgG, CSF 35385-4
3988 PCA-1, CSF 53713-4
21632 PCA-2, CSF 35143-7
21631 PCA-Tr, CSF 56551-5
21702 GAD65 Ab Assay, CSF 53708-4
36429 Reflex Added 77202-0