Presence of the inflammatory cytokines IL-1, TNF, and IL-6 in preparations of monoclonal antibodies.

Abstract

We have detected significant levels of IL-1, TNF and IL-6 in ascitic fluid from mice injected with different hybridomas. Each of these murine cytokines is active on a wide range of both human and murine target cells, and all are involved in inflammatory responses in vivo. We could not detect TNF or IL-1 in culture supernatant from the hybridoma line, used to generate the ascites; however, one out of ten did produce high levels of IL-6. These cytokines can interfere in many in vitro systems where monoclonal antibodies are used as diluted ascitic fluid to inhibit their ligands. A potentially more serious problem could arise with monoclonal antibodies used for therapy, in vivo diagnosis, or as ex vivo reagents. The use of monoclonal antibodies derived from culture supernatants is, therefore, obviously preferable to use of ascitic fluid for clinical applications, however, even with supernatant it cannot be assumed that cytokines are not present. Cytokine levels should, therefore, be monitored in all starting solutions and if present, their clearance during purification should be determined.