Levamisole: a double blind immunological study.
The immunological effects of a 4-week course of levamisole have been assessed by a randomised double blind study of a group of cancer patients judged to have a poor prognosis. No change in immunological status was recorded during a 6 months follow up, using a battery of tests including DNCB response. Mantoux response, lymphocyte count, PHA stimulation and serum immunoglobulin levels. 38% of patients complained of side-effects from the levamisole and 17% stopped the treatment. It is concluded that any beneficial effects of levamisole in patients with advanced cancer may be mediated by a non-immunological mechanism, or by some immunological process other than those studied here, or may require a longer period of administration than 4 weeks. Variation in skin test results in the placebo group throw some doubt on previous reports of immunopotentiation of cancer patients by levamisole.