Increased Serum Acetylcholine Receptor Α1 Subunit Protein in Anti-Acetylcholine Receptor Antibody-Positive Myasthenia Gravis

Complement-dependent disruption of motor endplate is detected in anti-acetylcholine receptor (AChR) antibody-positive myasthenia gravis (MG). We measured serum AChR alpha 1 subunit protein levels, which may be associated with neuromuscular damage, in 55 patients with MG (47 were seropositive and 8 were negative) and in 20 controls. Serum AChR alpha 1 subunit protein concentrations were higher in patients with anti-AChR antibody-positive MG than those in controls (P = .04), were negatively correlated with MG activities of daily living score (P = .01), and tended to be higher in ocular MG than in generalized MG. AChR alpha 1 subunit protein elevation may be related to seropositive MG pathogenesis, especially in the ocular type.