[Interferon therapy of multiple sclerosis].

The use of beta-interferon in the relapsing-remitting phase of multiple sclerosis is a new though fairly established therapy. The beneficial effect of this treatment is thought to be due to immune modulation, with inhibitory action on proliferation of leukocytes and antigen presentation, an increased amount of interleukins, but no change in the proinflammatory cytokine interferon-gamma. In Norway, one interferon-beta 1b and two interferon-beta 1a products have recently been introduced for administration by either subcutaneous or intramuscular injection. Approximately 30% reduction in the relapse rate is reported for both products,but differences appear in the effect on the disability progression, and also with regard to adverse reactions. Patients less strongly affected by the illness seem to have the best outcome. Neutralizing antibodies are often produced during this treatment, but the significance of this is still unclear. Results from international studies on interferon therapy of multiple sclerosis are discussed. Initial results from studies on interferon treatment of secondary progressive multiple sclerosis are now available. A further expansion, also in Norway, of the indications for beta-interferon therapy of multiple sclerosis is expected in the near future.