MuSK antibody
Pronunciation: MUSK antibody
Autoantibodies against muscle-specific kinase protein, found in seronegative myasthenia gravis with distinct clinical features.
Full Definition
Muscle-specific kinase (MuSK) antibodies are autoantibodies directed against the muscle-specific kinase protein, essential for neuromuscular junction formation and maintenance. Found in approximately 5-10% of myasthenia gravis patients who are acetylcholine receptor antibody negative, MuSK antibody-positive myasthenia has distinct clinical characteristics. Patients typically present with prominent bulbar symptoms, facial and neck weakness, and respiratory involvement, with less common ocular symptoms compared to AChR antibody-positive disease. The condition shows female predominance and different treatment responses, often requiring more aggressive immunosuppression and showing poor response to anticholinesterases. Thymectomy is generally not beneficial, and plasma exchange is often more effective than IVIg for acute exacerbations.
Usage
Usage note: MuSK is an acronym but often written as word; distinguish from other myasthenia antibodies.
In Context
- "MuSK antibody testing was positive in this AChR-seronegative patient with bulbar predominant myasthenia." — Laboratory results interpretation
- "The patient's MuSK antibody-positive myasthenia required plasmapheresis for symptom control." — Treatment plan documentation