Chemiluminescence in microamounts of whole blood for investigation of the human phagocyte oxidative metabolism function.

The present study was undertaken in order to investigate more precisely the chemiluminescence (CL) phenomenon and thus the generation of oxygen-free radical products by polymorphonuclear granulocytes (PMN) and monocytes (MN) as takes place in whole blood. A luminol-dependent photometric assay previously devised in our laboratory was used to simultaneously evaluate the CL production by resting cells and cells stimulated by a series of particulate and soluble surface-stimulating agents: latex particles, opsonized zymosan, phorbolmyristate acetate and concanavalin A. In order to quantify the overall light-quenching effect of blood on light emission and subsequently to determine the actual CL output by PMN and MN present in whole blood, Pholad luciferin was used as a constant source of light. This approach allowed the observation that CL production by cells in whole blood was of a much higher order than that of isolated cells. Application of this CL assay to investigate oxygen-free radical production in patients suffering from chronic granulomatous disease and related phagocytic cell disorders permitted the early and accurate diagnosis of such genetic disorders. Of great interest were the preliminary results obtained in patients with inflammatory diseases showing a marked discrepancy between background CL emission from whole blood and isolated cells. In conclusion, this investigation of PMN and MN oxidative metabolism in whole blood allows for the precise evaluation of CL production by phagocytic cells in an in vitro situation which closely mirrors their in vivo environment. Such advantages encourage its widespread application in both human and experimental physiopathology in order to further elucidate the in vivo role of oxygen-free radicals in the mechanisms of host resistance against pathogens.