Immunomodulating Effects of a Short-Term Oral Treatment with C 1821 in Untreated Cancer Patients: A Controlled Study

Abstract

C 1821 is a purified glycoprotein extract from Klebsiella pneumoniae serotype 2 (Laboratories Cassenne and Centre de Recherche Roussel UCLAF, Paris, France). Both gel filtration chromatography and ultracentrifugation of C 1821 yield a single peak. Its molecular weight is about 350,000. Chemical analysis has been performed by J. Montreuil and B. Fournet (Laboratory of Biological Chemistry, University of Lille I, France) and the compound is now chemically fairly well defined (manuscript in preparation). It is thought to be a component of the bacterial outer membrane. C 1821 has been found to enhance immune responses in animals when given orally and to modulate assays of human lymphocyte functions when added in vitro (1). The oral route of administration may be safely used in humans, as shown by toxicity studies. To study the immunomodulating properties of C 1821 further we entered upon a controlled trial on changes of in vivo and in vitro immune parameters after short-term oral administration of C 1821 in untreated cancer patients. In this small series of patients, no significant modifications of peripheral blood natural killer (NK) activity and lymphocyte subpopulation distribution were observed both at the start of the trial when compared to normal controls, and at the end of the trial which could be attributed to C 1821. Therefore, we will limit this presentation to the effects of C 1821 on delayed cutaneous hypersensitivity (DCH) to recall antigens and lymphocyte cyclic nucleotide levels.