Treatment of chronic inflammatory demyelinating polyneuropathy with interferon-alpha 2a.

We performed an open-label, prospective, pilot study of interferon (IFN)-alpha 2a treatment for 6 weeks in 16 patients with chronic inflammatory demyelinating polyneuropathy (CIDP). All patients had failed to improve or relapsed after treatment with at least one conventional therapy (steroids, IV gamma globulin, or plasma exchange). Assessment included MRC strength score, leg sensory score, grip dynanometry, Rankin disability score, electrodiagnostic studies, and serum concentration of tumor necrosis factor-alpha. Nine (56%) improved after IFN-alpha therapy. Mean MRC score increased by 4.2 points (p = 0.01), and mean sensory score improved by 2.3 points (p = 0.02). Five patients improved five or more points on the MRC score, nine had slight improvement or were unchanged, and two worsened. We conclude that IFN-alpha may be effective in some patients with CIDP who relapse or fail to respond to conventional immunomodulating therapy.