Enhancement of delayed cutaneous hypersensitivity in untreated cancer patients given a short-term oral treatment with C 1821.

C 1821 is a purified glycoprotein extract of Klebsiella pneumoniae serotype 2 with immunomodulating properties in animals (in vivo and in vitro) and in humans (in vitro). The compound is devoid of any apparent toxicity when given orally. The aim of the present work was to evaluate the effects of a short term oral administration of C 1821 on delayed cutaneous hypersensitivity to recall antigens in untreated cancer patients (mostly lymphomas). Consecutive patients were alternately allocated to receive C 1821 or placebo for 14 days. C 1821 restored and significantly (P less than 0.02) enhanced skin reactions, as shown using the Multitest system.