Antineuronal Nuclear Antibody-Type 1 (ANNA-1) Titer, Spinal Fluid

Casandra

Casandra Test Code MC74955Version 1 (DRAFT)

Performing Lab

Lab Mayo Clinic LabLab Test ID AN1TCCPT Code 86256

Antineuronal Nuclear Antibody-Type 1 (ANNA-1) Titer, Spinal Fluid

Clinical Use

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'.

Test Details

New York Approved