In vitro and in vivo effects produced by the immunomodulating agent RU 41740 on human polymorphonuclear leukocytes in the elderly.

The activity of RU 41740, a glycoprotein extract from Klebsiella pneumoniae has been investigated on some polymorphonuclear (PMN) functions. Chemotaxis, random migration and oxidative metabolism (assessed by chemiluminescence, O2 consumption and O2- generation) were studied in parallel. PMN were collected from adult and aged human volunteers. Experiments were performed either in vitro or in vivo in a double blind placebo assay. In both PMN populations RU 41740 enhanced oxidative metabolism either in in vivo or in vitro experiments. However, a higher and dose-related activity was observed on PMN collected from the younger subjects whereas maximal effective concentration was reached earlier with PMN collected from aged subjects. RU 41740 did not modify random migration but inhibited chemotaxis of PMN collected from the younger population in a dose-related manner. These data corroborated previous results observed on PMN collected from various animal species and suggested an interaction of RU 41740 on PMN membrane. Moreover drug-induced macrophage and lymphocyte stimulation might also explain, at least in part, the in vivo effects described in this study. Thus RU 41740 could partly account for the protective effects exerted against bacterial and fungal infections through its activity on PMN functions.

Enhancement of delayed cutaneous hypersensitivity by oral administration of RU 41740 (Biostim) in lymphoma patients--a randomized double blind multicentric trial.

RU 41740 (Biostim) is a glycoprotein extract from Klebsiella pneumoniae with immunostimulating properties in animal studies and in in vitro assays of human leukocyte functions. The present randomized double blind phase II trial showed that RU 41740 significantly (P less than 0.05, Mann & Whitney test) enhanced delayed cutaneous hypersensitivity to seven recall antigens (Multitest system) in lymphoma patients in unmaintained complete remission when given orally for 14 days at a daily dose of 8 mg, and compared to placebo. Daily doses of 2 and 32 mg were uneffective.

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.