We tested the effect of human leukocyte interferon on early localized herpes zoster infections in three placebo-controlled, randomized double-blind trials involving 90 patients with cancer. There were no significant differences in pretreatment severity of infection or nature of underlying disease in the groups. Higher dosages of more purified interferon in the second and third trials produced a significant (P less than or equal to 0.01) decrease in cutaneous dissemination. No dissemination occurred in those receiving the highest dosage (5.1 x 10(5) U per kilogram per day) (P less than or equal to 0.025). The number of days of new-vesicle formation in the primary dermatome decreased (mean, 2.3 days, P less than or equal to 0.05) in this group. Treated patients had a trend toward less acute pain, and significantly (P less than or equal to 0.05) diminished severity of post-herpetic neuralgia, at the two highest dosage levels. Visceral complications were six times less frequent in interferon recipients. High-dosage interferon appeared effective in limiting cutaneous dissemination, visceral complications and progression within the primary dermatome.

Recently, we found interferon in the sera of patients with systemic lupus erythematosus, rheumatoid arthritis, scleroderma, and Sjögren's syndrome. In this study, we surveyed a variety of other immunologically mediated diseases. We did not find interferon in the sera of patients with Wegener's granulomatosis, sarcoidosis, infectious mononucleosis, minimal change nephritis, kidney transplants, myasthenia gravis, or uveitis, but we did find this protein in the sera of patients with active systemic and cutaneous vasculitis. Attempts to characterize the interferon in the sera of patients with systemic lupus erythematosus and vasculitis revealed that antibody to alpha (leukocyte) interferon, but not to beta (fibroblast) interferon, partially or completely neutralized the antiviral activity. The failure of antibody to alpha interferon to completely neutralize the antiviral activity in certain specimens and the lability of the antiviral activity in some specimens to pH 2.0 treatment both suggest that more than one type of interferon was present.