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Test Code PAC1 Paraneoplastic, Autoantibody Evaluation, Spinal Fluid

Useful For

Aiding in the diagnosis of paraneoplastic neurological autoimmune disorders related to carcinoma of lung, breast, ovary, thymoma, or Hodgkin lymphoma using spinal fluid specimens

Profile Information

Test ID Reporting Name Available Separately Always Performed
PNEOI Paraneoplastic Interpretation, 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
CRMC CRMP-5-IgG, 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

Testing Algorithm

If the indirect immunofluorescence assay (IFA) pattern suggests AGNA-1 antibody, then AGNA-1 immunoblot (IB) and AGNA-1 IFA titer will be performed at an additional charge.

 

If the IFA pattern suggests antineuronal nuclear antibody type 1 (ANNA-1), then ANNA-1 IB, ANNA-1 IFA titer, and ANNA-2 IB will be performed at an additional charge.

 

If the IFA pattern suggests ANNA-2 antibody, then ANNA-2 IB, ANNA-2 IFA titer, and ANNA-1 IB will be performed at an additional charge.

 

If the IFA pattern suggests ANNA-3 antibody, then ANNA-3 titer will be performed at an additional charge.

 

If the IFA pattern suggests Purkinje cytoplasmic antibody type 1 (PCA-1), then PCA-1 IB, and PCA-1 IFA titer will be performed at an additional charge.

 

If the IFA pattern suggests PCA-2 antibody, then PCA-2 IFA titer will be performed at an additional charge.

 

If the IFA pattern suggests PCA-Tr antibody, then PCA-Tr immunoblot, and PCA-Tr IFA titer will be performed at an additional charge.

 

If client requests or the IFA patterns suggest CRMP-5-IgG, then CRMP-5-IgG IFA titer and CRMP-5-IgG western blot will be performed at an additional charge.

 

If the IFA patterns suggest amphiphysin antibody, then amphiphysin IB and amphiphysin IFA titer will be performed at an additional charge.

 

The following algorithm is available: Paraneoplastic Evaluation Algorithm-Spinal Fluid.

Method Name

AGN1C, AMPHC, ANN1C, ANN2C, ANN3C, CRMC, PCA1C, PCA2C7, PCTRC, AGNTC, APHTC, AN1TC, AN2TC, AN3TC, CRMTC, PC1TC, PC2TC, PCTTC: Indirect Immunofluorescence Assay (IFA)

CRMWC: Western Blot

AGNBC, AMIBC, AN1BC, AN2BC, PC1BC, PCTBC: Immunoblot (IB)

Reporting Name

Paraneoplas Autoantibody Eval,CSF

Specimen Type

CSF


Ordering Guidance


This test no longer contains all known, clinically relevant antibodies for patients suspected of autoimmune neurological disorders. Instead, consider a comprehensive neurological phenotype-specific autoimmune/paraneoplastic evaluation (eg, encephalopathy, movement disorders, myelopathy, axonal neuropathy). For more information as well as phenotype-specific testing options, refer to Autoimmune Neurology Test Ordering Guide or the Neurology specialty website.



Additional Testing Requirements


In patients with a history of tobacco use or other lung cancer risk, or if thymoma is suspected, PAVAL / Paraneoplastic Autoantibody Evaluation, Serum is also recommended.



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

Preferred: Vial number 2

Acceptable: Any vial

Specimen Volume: 4 mL


Specimen Minimum Volume

2 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
CSF Refrigerated (preferred) 28 days
  Frozen  28 days
  Ambient  72 hours

Reject Due To

Gross hemolysis Reject
Gross lipemia Reject
Gross icterus Reject

Clinical Information

Several antineuronal and glial autoantibodies are recognized clinically as markers of a patient's immune response to specific cancers (paraneoplastic autoantibodies). Seropositive patients present with neurologic signs and symptoms in more than 90% of cases. The cancers are most commonly small-cell lung carcinoma, ovarian (or related mullerian) carcinoma, breast carcinoma, thymoma, or Hodgkin lymphoma. The cancers may be new or recurrent, are usually limited in metastatic volume, and are often occult by standard imaging procedures. Detection of the informative marker autoantibodies allows early diagnosis and treatment of the cancer, which may lessen neurological morbidity and improve survival.

 

Serum is the preferred specimen for paraneoplastic autoantibodies. However, cerebrospinal fluid (CSF) results are sometimes positive when serum results are negative (especially for collapsin response-mediator protein-5-IgG [CRMP-5] and other inflammatory central nervous system autoimmunity). Additionally, CSF is more readily interpretable because it generally lacks the interfering nonorgan-specific antibodies that are common in the serum of patients with cancer. Because neurologists typically perform spinal taps in these patients, the recommendation is to submit CSF specimens with serum specimens, either for simultaneous testing or to be held for testing only if serum is negative.

 

CRMP-5-IgG western blot is also performed by specific request for more sensitive detection of CRMP-5-IgG. Testing should be requested in cases of subacute basal ganglionic disorders (chorea, parkinsonism), cranial neuropathies (especially loss of vision, taste, or smell), and myelopathies.

Reference Values

Test ID

Reporting name

Methodology

Reference value

AMPHC

Amphiphysin Ab, CSF

IFA

Negative

AGN1C

Anti-Glial Nuclear Ab, Type 1

IFA

Negative

ANN1C

Anti-Neuronal Nuclear Ab, Type 1

IFA

Negative

ANN2C

Anti-Neuronal Nuclear Ab, Type 2

IFA

Negative

ANN3C

Anti-Neuronal Nuclear Ab, Type 3

IFA

Negative

CRMC

CRMP-5-IgG, CSF

IFA

Negative

PCTRC

Purkinje Cell Cytoplasmc Ab Type Tr

IFA

Negative

PCA1C

Purkinje Cell Cytoplasmic Ab Type 1

IFA

Negative

PCA2C

Purkinje Cell Cytoplasmic Ab Type 2

IFA

Negative

 

Reflex Information:

Test ID

Reporting name

Methodology

Reference value

AGNBC

AGNA-1 Immunoblot, CSF

IB

Negative

AGNTC

AGNA-1 Titer, CSF

IFA

<1:2

AMIBC

Amphiphysin Immunoblot, CSF

IB

Negative

AN1BC

ANNA-1 Immunoblot, CSF

IB

Negative

AN1TC

ANNA-1 Titer, CSF

IFA

<1:2

AN2BC

ANNA-2 Immunoblot, CSF

IB

Negative

AN2TC

ANNA-2 Titer, CSF

IFA

<1:2

AN3TC

ANNA-3 Titer, CSF

IFA

<1:2

APHTC

Amphiphysin Ab Titer, CSF

IFA

<1:2

CRMTC

CRMP-5-IgG Titer, CSF

IFA

<1:2

CRMWC

CRMP-5-IgG Western Blot, CSF

WB

Negative

PC1BC

PCA-1 Immunoblot, CSF

IB

Negative

PC1TC

PCA-1 Titer, CSF

IFA

<1:2

PC2TC

PCA-2 Titer, CSF

IFA

<1:2

PCTBC

PCA-Tr Immunoblot, CSF

IB

Negative

PCTTC

PCA-Tr Titer, CSF

IFA

<1:2

 

*Methodology abbreviations:

Immunofluorescence assay (IFA)

Western blot (WB)

Immunoblot (IB)

 

Neuron-restricted patterns of IgG staining that do not fulfill criteria for amphiphysin, ANNA-1, ANNA-2, ANNA-3, AGNA-1, PCA-1, PCA-2, PCA-Tr, or CRMP-5-IgG may be reported as "unclassified antineuronal IgG." Complex patterns that include non-neuronal elements may be reported as "uninterpretable."

 

Note: 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 800-533-1710 to request CRMP-5 Western blot.

Interpretation

Antibodies directed at onconeural proteins shared by neurons, glia, muscle, and certain cancers are valuable serological markers of a patient's immune response to cancer. They are not found in healthy subjects and are usually accompanied by subacute neurological signs and symptoms. Several autoantibodies have a syndromic association, but no autoantibody predicts a specific neurological syndrome. Conversely, a positive autoantibody profile has 80% to 90% predictive value for a specific cancer. It is not uncommon for more than one paraneoplastic autoantibody to be detected, each predictive of the same cancer.

Cautions

No significant cautionary statements

Method Description

Indirect Immunofluorescence Assay (IFA):

The patient's sample is tested by a standardized immunofluorescence assay (IFA) that uses a composite frozen section of mouse cerebellum, kidney, and gut tissues. After incubation with sample and washing, fluorescein-conjugated goat-antihuman IgG is applied. Neuron-specific autoantibodies are identified by their characteristic fluorescence staining patterns. Samples that are scored positive for any neuronal nuclear or cytoplasmic autoantibody are titrated to an endpoint. Interference by coexisting non-neuron-specific autoantibodies can usually be eliminated by serologic absorption.(Honorat JA, Komorowski L, Josephs KA, et al: IgLON5 antibody: neurological accompaniments and outcomes in 20 patients. Neurol Neuroimmunol Neuroinflamm. 2017 Jul 18;4(5):e385. doi: 10.1212/NXI.0000000000000385689)

 

Western Blot:

Neuronal antigens extracted aqueously from adult rat cerebellum, full-length recombinant human collapsin response-mediator protein-5 (CRMP-5), or full-length recombinant human amphiphysin protein is denatured, reduced, and separated by electrophoresis on 10% polyacrylamide gel. IgG is detected autoradiographically by enhanced chemiluminescence.(Yu Z, Kryzer TJ, Griesmann GE, et al: CRMP-5 neuronal autoantibody: marker of lung cancer and thymoma-related autoimmunity. Ann Neurol. 2001 Feb;49[2]:146-154; Dubey D, Jitprapaikulsan J, Bi H, et al: Amphiphysin-IgG autoimmune neuropathy: A recognizable clinicopathologic syndrome. Neurology. 2019 Nov 12;93(20):e1873-e1880

 

Immunoblot (IB):

All steps are performed at ambient temperature (18-28° C) utilizing the EUROBlot One instrument. Diluted patient serum (1:12.5) is added to test strips (strips containing recombinant antigen manufactured and purified using biochemical methods) in individual channels and incubated for 30 minutes. Positive specimens will bind to the purified recombinant antigen and negative specimens will not bind. Strips are washed to remove unbound antibodies and then incubated with anti-human IgG antibodies (alkaline phosphatase-labelled) for 30 minutes. The strips are again washed to remove unbound anti-human IgG antibodies and nitroblue tetrazolium chloride/5-bromo-4-chloro-3-indolylphosphate (NBT/BCIP) substrate is added. Alkaline phosphatase enzyme converts the soluble substrate into a colored insoluble product on the membrane to produces a black band. Strips are digitized via picture capture on the EUROBlot One instrument and evaluated with the EUROLineScan software.(O'Connor K, Waters P, Komorowski L, et al: GABAA receptor autoimmunity: A multicenter experience. Neurol Neuroimmunol Neuroinflamm. 2019 Apr 4;6[3]:e552. doi: 10.1212/NXI.0000000000000552)

Day(s) Performed

Profile tests: Monday through Sunday; Reflex tests: Varies

Report Available

10 to 17 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. It has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information

86255 x 9

84182-AGNBC (if appropriate)

86256-AGNTC (if appropriate)

84182-AMIBC (if appropriate)

84182-AN1BC (if appropriate)

86256-AN1TC (if appropriate)

84182-AN2BC (if appropriate)

86256-AN2TC (if appropriate)

86256-AN3TC (if appropriate)

86256-APHTC (if appropriate)

86256-CRMTC (if appropriate)

84182-CRMWC (if appropriate)

84182-PC1BC (if appropriate)

86256-PC1TC (if appropriate)

86256-PC2TC (if appropriate)

84182-PCTBC (if appropriate)

86256-PCTTC (if appropriate)

LOINC Code Information

Test ID Test Order Name Order LOINC Value
PAC1 Paraneoplas Autoantibody Eval,CSF 94818-2

 

Result ID Test Result Name Result LOINC Value
89079 AGNA-1, CSF 90827-7
5906 Amphiphysin Ab, CSF 90815-2
3852 ANNA-1, CSF 44768-0
7472 ANNA-2, CSF 56959-0
21633 ANNA-3, CSF 90836-8
21650 CRMP-5-IgG, CSF 63216-6
3988 PCA-1, CSF 90841-8
21632 PCA-2, CSF 90843-4
21631 PCA-Tr, CSF 90845-9
34271 Paraneoplastic Interpretation, CSF 57771-8
619519 IFA Notes 48767-8

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
AGNBC AGNA-1 Immunoblot, CSF No No
AMIBC Amphiphysin Immunoblot, CSF No No
AN1BC ANNA-1 Immunoblot, CSF No No
AN2BC ANNA-2 Immunoblot, CSF No No
CRMWC CRMP-5-IgG Western Blot, CSF Yes No
PC1BC PCA-1 Immunoblot, CSF No No
PCTBC PCA-Tr Immunoblot, CSF No No
AGNTC AGNA-1 Titer, CSF No No
AN1TC ANNA-1 Titer, CSF No No
AN2TC ANNA-2 Titer, CSF No No
AN3TC ANNA-3 Titer, CSF No No
APHTC Amphiphysin Ab Titer, CSF No No
CRMTC CRMP-5-IgG Titer, CSF No No
PC1TC PCA-1 Titer, CSF No No
PC2TC PCA-2 Titer, CSF No No
PCTTC PCA-Tr Titer, CSF No No