Abstract
The efficacy of intermittent high-dose vitamin C therapy was evaluated in seven patients with HTLV-I-associated myelopathy (HAM). All HAM patients responded well to this therapy without serious side effects. Grade of disability score improved at 9.7 (SD 5.8) months after the therapy from 7.1 (3.3) to 3.6 (2.0) (p < 0.01). Serum immunosuppressive acidic protein was elevated before and decreased after the therapy from 747 (316) to 398 (86) micrograms/ml (p < 0.05), suggesting favourable immunomodulatory action of vitamin C therapy in HAM patients.