Clinical Information

Antiglial/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 N-type Ca(++) channel antibody, greater than collapsin response-mediator protein-5 (CRMP-5)-IgG greater than striational antibody equal to ANNA-1 greater than other antibodies.