Antineuronal Nuclear Antibody-Type 1 (ANNA-1) Titer, Spinal Fluid
Use
This test is used for the diagnosis of paraneoplastic autoimmune neuropathies, encephalomyeloradiculopathies, related neurologic disorders, and intestinal pseudo-obstruction/dysmotility associated with small-cell lung carcinoma. ANNA-1 antibodies are valuable markers of paraneoplastic intestinal dysmotilities associated with SCLC, ranging from gastroparesis to pseudo-obstruction. They are significant in paraneoplastic neurological disorders such as neuropathies, limbic encephalitis, subacute cerebellar degeneration, myelopathy, and radiculopathy. ANNA-1 is rare in patients without neuropathy, including those with Lambert-Eaton myasthenic syndrome or pure cerebellar ataxia.
Special Instructions
This test is not suitable as a general screening test for lung carcinoma. Ordering guidance suggests serum is preferred; spinal fluid testing is useful if serum contains interfering antibodies. The test is only orderable as a reflex. Provide the ordering physician's name, phone number, mailing address, and email address.
Limitations
ANNA-1 antibodies are less common in patients without underlying neuropathies, such as those with Lambert-Eaton syndrome or pure cerebellar ataxia. Small-cell lung carcinoma may be difficult to detect, sometimes requiring advanced imaging techniques. The presence of other cancers may occur with SCLC. Interfering antibodies in serum can affect test results, necessitating spinal fluid testing. Results that do not meet the criteria may be reported as 'unclassified antineuronal IgG'.
New York Approved
Methodology
Immunoassay (IFA)
Biomarkers
LOINC Codes
- 94356-3
- 94356-3
Result Turnaround Time
6-8 days
Related Documents
For more information, please review the documents below
Specimen
Cerebrospinal Fluid
Volume
2 mL
Minimum Volume
1 mL
Container
Sterile vial
Collection Instructions
Specimen should be collected in a sterile vial. Ideal for situations where serum contains interfering antibodies.
Causes for Rejection
Gross hemolysis, lipemia, or icterus.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 72 hours |
| Refrigerated | 28 days |
| Frozen | 28 days |