Clinical Information

Antineuronal nuclear autoantibody type 3 (ANNA-3) is an IgG marker of an immune response to a malignancy, most often of neuroendocrine origin, in patients presenting with subacute, usually multifocal, paraneoplastic neurologic disorders.(1) Ninety percent of patients have evidence of a malignancy, most commonly neuroendocrine malignancy, particularly small-cell lung carcinoma (SCLC). Neurologic presentations may include sensorimotor or sensory neuronopathy, cerebellar ataxia, encephalopathy or multifocal involvement. Half of the patients have serologic evidence of other neuroendocrine-tumor predicting antibodies, including neuronal intermediate filament (NIF) antibody, collapsin-response-mediator-protein-5 (CRMP5) antibody, voltage-gated calcium channel (P/Q type) antibody, ANNA-1, and Purkinje-cell-autoantibody-type-2/microtubule-associated-protein-1B (PCA-2/MAP1B).