Interferon-alpha is effective in HTLV-I-associated myelopathy: A multicenter, randomized, double-blind, controlled trial

A double-blind, multi-center study was performed on patients with HTLV-I-associated myelopathy (HAM) to evaluate the therapeutic effect of treatment with natural interferon-alpha (HLBI). Forty-eight HAM patients were enrolled and treated with either 0.3 MU (n = 15), 1.0 MU (n = 17), or 3.0 MU (n = 16) of HLBI for 28 days. Clinical evaluation included motor dysfunction, urinary disturbances, and changes of neurologic signs. The frequency of therapeutic response judged as excellent to good 4 weeks after starting therapy and 4 weeks after completion of therapy were 7.1% (1 of 14) and 8.3% (1 of 12) in the 0.3-MU group, 23.5% (4 of 17) and 26.7% (4 of 15) for the 1.0-MU group, and 66.7% (10 of 15) and 61.5% (8 of 13) for the 3.0-MU group. The therapeutic benefit in the 3.0-MU group was significantly higher than in the 0.3-MU group. There was no significant difference in the incidence of symptomatic side effects between groups. Abnormal laboratory data were obtained for some patients in the 1.0-MU and 3.0-MU groups; however, the treatment schedule could be continued in most patients. These results suggest that HAM patients may be safely treated with HLBI 3.0 MU every day for 4 weeks with favorable clinical effects.