From the Research
Opsoclonus-myoclonus syndrome is associated with several antibodies, including anti-Ri (ANNA-2), anti-Yo (PCA-1), anti-Hu (ANNA-1), anti-Ma2, anti-NMDA receptor, anti-GAD65, and Contactin-Associated Protein-Like 2 (Caspr2) antibodies, as well as acetylcholine receptor autoantibodies, which are often linked to underlying cancers or autoimmune conditions 1.
Key Antibodies Associated with Opsoclonus-Myoclonus Syndrome
- Anti-Ri (ANNA-2) antibodies, commonly found in breast and gynecological cancers
- Anti-Hu (ANNA-1) antibodies, associated with small cell lung cancer
- Anti-Yo (PCA-1) antibodies
- Anti-Ma2 antibodies
- Anti-NMDA receptor antibodies
- Anti-GAD65 antibodies, which can cause opsoclonus in non-paraneoplastic autoimmune conditions
- Contactin-Associated Protein-Like 2 (Caspr2) antibodies, recently identified in association with paraneoplastic opsoclonus-myoclonus syndrome in a patient with non-small cell lung carcinoma 1
- Acetylcholine receptor autoantibodies, also implicated in the pathogenesis of opsoclonus-myoclonus syndrome 1
Clinical Implications
Testing for these antibodies is crucial for diagnosis and determining underlying causes, as identifying the specific antibody can guide treatment approaches and prompt cancer screening when appropriate 2, 3, 4, 5. However, some cases of opsoclonus remain seronegative despite having an autoimmune etiology, suggesting that other antibodies not yet identified may be involved. Prompt immunotherapy and neoplasm treatment may result in improvement, highlighting the importance of early diagnosis and treatment 1.