Extra- and intrathecal production of antinerve and antibrain antibodies in Guillain-Barré syndrome: evaluation by an antibody index.

In serum and CSF samples from 19 patients with the Guillain-Barré syndrome (GBS), we assayed complement-fixing autoantibodies that react with peripheral and central nervous tissue. About two thirds of the serum and CSF samples reacted with preparations of one or both tissues. The distribution of antibodies, evaluated by the antibody index (CSF/serum titer divided by CSF/serum albumin), suggested predominantly extrathecal production in most patients, but an intrathecal contribution was also seen. Thus, the possible pathogenic effects of antineural antibodies in GBS may be exerted on both sides of the blood-brain barrier.