Oligoclonal immunoglobulin G in cerebrospinal fluid of myasthenia gravis patients.

Immunoglobulin G (IgG) band patterns were investigated in cerebrospinal fluid (CSF) from 19 patients with myasthenia gravis (MG) in a search for abnormalities indicating central nervous system (CNS) involvement in this disorder. Using the isoelectric focusing (IEF) technique and antiserum immunoblotting against IgG, we found no evidence of the presence of oligoclonal IgG in CSF from most of MG patients. In 2 cases, the positive findings of oligoclonal IgG in CSF may have reflected a manifestation of an associated disease, which has already been associated with immune abnormalities within the CNS. Further investigations with more sophisticated techniques are required to give additional insight into humoral immune events within the CNS in MG patients.