[Intrathecal immunoactivation in the patients with myasthenia gravis--autoantibodies in the cerebrospinal fluid].

We examined the cerebrospinal fluid (CSF) of 17 myasthenia gravis (MG) patients for certain immunological parameters in order to assess signs of intrathecal immunoactivation. We have found oligoclonal IgG bands in the CSF of 6 of 17 by the agarose gel electrophoresis and enlarged lymphoid cells in CSF of 8 of 17 patients of MG. We measured anti-nicotinic acetylcholine receptor (AChR) antibody and anti-striational muscle antibody (AMA) in serum and CSF from MG patients and compared the serum: CSF ratio with total IgG. No evidence of intrathecal anti-AChR antibody synthesis was demonstrated while AMA was partly (50%) synthesized in myasthenic CSF. This difference suggested that there is either different immunological regulation in synthesis between anti-AChR antibody and AMA in the CSF or the different behavior after transfer to CSF.