Beta 2-adrenergic receptor antibodies in myasthenia gravis.

Although autoantibodies against the nicotinic acetylcholine receptor are the characteristic feature of the autoimmune disease myasthenia gravis (MG), no strong correlation is found between the autoantibody titer and the degree of clinical severity. Numerous studies have attempted to detect the presence of other autoantibody populations that might have a role in the pathology of the disease. We report, for the first time, that 18% of the MG patients we screened have antibodies in their serum to a peptide corresponding to the second extracellular loop of the human beta 2-adrenergic receptor (residues 172-197).