Autoantibody to dihydropyridine receptor in myasthenia gravis.

To investigate autoantibodies related to excitation-contraction (E-C) coupling in patients with myasthenia gravis (MG), we developed a novel method to detect autoantibodies against dihydropyridine receptor (DHPR). Using this method, we detected DHPR antibody in 37% (11 out of 30) of MG patients with thymoma. Antibodies were not detected in normal nor disease controls. The titer of DHPR antibodies showed no significant correlation with autoantibodies to acetylcholine nor ryanodine receptors. The DHPR antibody is another marker for thymoma in MG, and it might have some role in clinical symptoms related to E-C coupling.