Clinical Information

Antineuronal nuclear autoantibodies (ANNA) are recognized clinically as markers of a patient's immune response to specific cancers (paraneoplastic autoantibodies).

In 1985, an antineuronal nuclear autoantibody (now known as ANNA-1 or anti-Hu)(1) was described as a serological accompaniment of subacute sensory neuropathy related to small-cell lung carcinoma (SCLC). ANNA-1 was subsequently recognized as an IgG marker for a spectrum of encephalomyeloradiculoneuropathy (including gastrointestinal dysmotilities) related to SCLC,(2) childhood neuroblastoma, and thymoma. The second antineuronal nuclear antibody to be recognized (known as ANNA-2 or anti-Ri) is an IgG marker of neurological autoimmunity related to SCLC and breast carcinoma.(3)

ANNA-3 is an IgG marker of an immune response to SCLC in patients presenting with a subacute, usually multifocal, paraneoplastic neurologic disorder.(4) Paraneoplastic sensorimotor neuropathy, cerebellar ataxia, and limbic encephalopathy are the most common presentations. However, an ANNA-3-positive patient may present with any element of an encephalomyeloradiculoneuropathy.

Other autoantibody markers of immune responses to SCLC include amphiphysin, collapsin response-mediated protein-5 (CRMP-5) IgG, Purkinje cell antibody type 2 (PCA-2), antiglial neuronal nuclear antibody (AGNA-1), voltage-gated calcium channel (P/Q-type) and potassium channel (VGKC) antibodies and muscle acetylcholine receptor antibodies.