REPERTOIRES OF AUTOANTIBODIES AGAINST HOMOLOGOUS EYE MUSCLE IN OCULARAND GENERALIZED MYASTHENIA-GRAVIS DIFFER

If weakness of the eye muscles remains the only symptom of myasthenia gravis (MG) for more than 2 years, the condition is operationally defi ned as ocular MG (OMG). A number of clinical, genetic, and immunologic al differences between this variant and generalized MG (GMG) have been described. We analyzed repertoires of autoantibodies against proteins of skeletal and extraocular muscle in sex- and age-matched groups of patients with either GMG or OMG (n = 10 in each group). All GMG sera d etected a group of three proteins larger than 200 kDa which were not d etected by any of the OMG sera. Two components with apparent molecular weights of 50 and 60 kDa were stained by seven of the ten OMG sera bu t by none of the GMG group. These antigens are probably soluble, cytop lasmatic proteins of the eye muscle. OMG sera, furthermore, detected a protein of about 45 kDa in the pellet fraction of eye muscle but fail ed to do so after adsorption with skeletal muscle fractions. We conclu de that OMG and GMG sera contain autoantibodies of different specifici ties. Our findings further support immunological heterogeneity in MG.