Levamisole and Cell-Mediated Immunity

Abstract
Current widespread interest in the contribution of host immunity to resistance to tumor growth is based on evidence from a variety of animal and human studies.1 Host resistance is mediated by sensitized lymphocytes, and in some cases, in vitro studies have indicated that serum factors may abrogate this protective function.2 In addition to the effect of cells sensitized to tumor antigens, protection may also result from nonspecific stimulation of the immune system such as that caused by BCG.Previous studies have shown that patients with cancer who have absent delayed-type hypersensitivity have a poorer prognosis than those with positive skin . . .