Effects of psoriatic sera on the generation of oxygen intermediates by normal polymorphonuclear leucocytes.

The effects of psoriatic sera were investigated on the generation of oxygen intermediates (OIs) by normal polymorphonuclear leucocytes (PMNs). Although increased superoxide generation was noted, a further respiratory burst of the PMns was significantly suppressed. Since superoxide dismutase (SOD) and catalase activities of the sera assayed in the xanthine-xanthine oxidase system were comparable to the controls, it still remains obscure why this dissociation occurs. It is suggested that increased generation of superoxide anion from the PMNs may be another facet of PMN activation which plays an important role in the psoriatic process.