Psoriatic sera decrease responses of stimulated granulocytes from normal and psoriatic subjects.

Previous studies have demonstrated alterations in polymorphonuclear leukocyte (PMNL) function in patients with psoriasis, but results have been variable. In this study we attempted to determine whether functional changes in PMNL from psoriatics represented an intrinsic cellular defect or a response to factors in serum. We evaluated the effect of the continuous presence of autologous and heterologous serum on lysozyme release and superoxide anion (O2-) generation by psoriatic and normal PMNL exposed to a soluble or particulate phagocytic stimulus. There were no differences in O2- generation or lysozyme release between normal and psoriatic PMNL without serum. However, in the presence of 10% autologous serum, these responses were significantly decreased for psoriatic PMNL (p less than .001). The results were not time-dependent and did not correlate with the extent of psoriatic involvement. The data support the hypothesis that serum factors exist in patients with psoriasis that may affect PMNL functions. The presence or absence of such factors could explain, in part, the differences between the various investigations of PMNL function in psoriasis.