Sign in →

Test Code AGNTC Anti-Glial/Neuronal Nuclear Antibody-Type 1 (AGNA-1) Titer, Spinal Fluid


Ordering Guidance


Serum is preferred; see AGN1S / Anti-Glial/Neuronal Nuclear Antibody-Type 1, Serum.

 

Spinal fluid is particularly useful if interfering antibodies are present.



Specimen Required


Only orderable as a reflex. For more information see:

-DMC2 / Dementia, Autoimmune/Paraneoplastic Evaluation, Spinal Fluid

-ENC2 / Encephalopathy, Autoimmune/Paraneoplastic Evaluation, Spinal Fluid

-EPC2 / Epilepsy, Autoimmune/Paraneoplastic Evaluation, Spinal Fluid

-MDC2 / Movement Disorder, Autoimmune/Paraneoplastic Evaluation, Spinal Fluid

-MAC1 / Myelopathy, Autoimmune/Paraneoplastic Evaluation, Spinal Fluid

 

Container/Tube: Sterile vial

Specimen Volume: 2 mL


Secondary ID

43443

Useful For

Reporting an end titer result from cerebrospinal fluid (CSF) specimens

 

Serological evaluation using CSF specimens from patients who present with a subacute neurological disorder of undetermined etiology, especially those with risk factors for primary lung carcinoma

 

Directing a focused search for cancer

 

Investigating neurological symptoms that appear during, or after, cancer therapy and are not explainable by metastasis

 

Differentiating autoimmune neuropathies from neurotoxic effects of chemotherapy

 

Monitoring the immune response of seropositive patients during cancer therapy

 

Detecting early evidence of cancer recurrence in previously seropositive patients

Testing Algorithm

If the indirect immunofluorescence pattern suggests anti-glial/neuronal nuclear antibody-type 1 (AGNA-1), then this test will be performed at an additional charge.

Method Name

Only orderable as a reflex. For more information see:

-DMC2 / Dementia, Autoimmune/Paraneoplastic Evaluation, Spinal Fluid

-ENC2 / Encephalopathy, Autoimmune/Paraneoplastic Evaluation, Spinal Fluid

-EPC2 / Epilepsy, Autoimmune/Paraneoplastic Evaluation, Spinal Fluid

-MDC2 / Movement Disorder, Autoimmune/Paraneoplastic Evaluation, Spinal Fluid

-MAC1 / Myelopathy, Autoimmune/Paraneoplastic Evaluation, Spinal Fluid

 

Indirect Immunofluorescence Assay (IFA)

Reporting Name

AGNA-1 Titer, CSF

Specimen Type

CSF

Specimen Minimum Volume

1 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

Anti-glial/neuronal nuclear autoantibody-type 1 (AGNA-1) is recognized clinically as a marker of a patient's immune response to a lung cancer that is usually limited in metastasis but manifests as an autoimmune neurological disorder.

 

AGNA-1 is an IgG marker of an immune response to cancer (usually a small-cell lung carcinoma: SCLC) in patients presenting with a subacute, generally multifocal, paraneoplastic neurological disorder.(1-3) It binds to the nucleus, but not cytoplasm, of SCLC cell lines and, in the adult central nervous system, to nuclei in subsets of astrocytes and neurons, as well as ependyma. Its previous name was antineuronal nuclear antibody (ANNA)-4.(2) The most common neurological presentations of patients who are positive for AGNA-1 are Lambert-Eaton myasthenic syndrome, sensorimotor or autonomic neuropathy, limbic encephalopathy, and ataxias.

 

To date, all 45 seropositive patients identified in the Mayo Clinic Neuroimmunology Laboratory have been smokers. SCLC was confirmed in more than 80% of cases. In 59% of patients, one or more identifiable coexisting paraneoplastic autoantibodies support the prediction of SCLC: P/Q-type Ca(++) channel antibody (41%) greater than collapsin response-mediator protein-5 (CRMP-5)-IgG equal to ANNA-1 greater than other antibodies.

Reference Values

Only orderable as a reflex. For more information see:

-DMC2 / Dementia, Autoimmune/Paraneoplastic Evaluation, Spinal Fluid

-ENC2 / Encephalopathy, Autoimmune/Paraneoplastic Evaluation, Spinal Fluid

-EPC2 / Epilepsy, Autoimmune/Paraneoplastic Evaluation, Spinal Fluid

-MDC2 / Movement Disorder, Autoimmune/Paraneoplastic Evaluation, Spinal Fluid

-MAC1 / Myelopathy, Autoimmune/Paraneoplastic Evaluation, Spinal Fluid

 

<1:2

Neuron-restricted patterns of IgG staining that do not fulfill criteria for anti-glial/neuronal nuclear antibody-type 1 may be reported as "unclassified anti-neuronal IgG." Complex patterns that include nonneuronal elements may be reported as "uninterpretable."

Interpretation

A positive result confirms that the patient's subacute neurological disorder has an autoimmune basis and predicts with greater than 80% certainty that the patient has a lung carcinoma (usually small-cell lung carcinoma: SCLC), either new or recurrent, and confined to the chest. Fifteen percent of seropositive patients who are eventually proven to have SCLC additionally have an unrelated, often more obvious, cancer, either coexisting or by past history.

 

Anti-glial/neuronal nuclear autoantibody-type 1 (AGNA-1) has not been encountered in healthy subjects (n=170). Its onconeural antigen is the nuclear transcription factor Sox1.(2) IgG of this specifically has been reported detectable in 30% to 40% of patients with SCLC who lack neurological complications.(4)

Day(s) Performed

Monday through Sunday

Report Available

6 to 8 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. It has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information

86256

LOINC Code Information

Test ID Test Order Name Order LOINC Value
AGNTC AGNA-1 Titer, CSF 93455-5

 

Result ID Test Result Name Result LOINC Value
43443 AGNA-1 Titer, CSF 94355-5