Immunological treatment of multiple sclerosis.

Immunosuppressive treatment of multiple sclerosis (MS) is based on the autoimmune hypothesis for which the main evidence is the close histological similarity between the human disease and chronic relapsing EAE. Although controlled trials indicate that ACTH is effective in accelerating recovery from relapses, long term ACTH or oral steroids are ineffective. Two controlled trials have suggested a beneficial effect of azathioprine, but neither was conducted "blind" and neither was sufficiently convincing to cause the widespread adoption of azathioprine by neurologists. One controlled trial, also not blind, reported a beneficial effect of an intensive course of cyclophosphamide, but this hazardous treatment will not be widely adopted unless other trials confirm this result. The converse hypothesis that MS is due to a deficient immune response to a virus has led to trials of immunostimulation. Interferon and levamisole have proven ineffective so far, but transfer factor slowed disease progression in one well conducted trial.