Effects of UVB treatment on neutrophil function in psoriatic patients and healthy subjects

To evaluate if whole body UVB irradiation has effects on the neutrophil function, eleven patients with mild to moderate psoriasis and 14 healthy subjects were treated with whole body UVB irradiation 3 times weekly for 4 weeks. Eight healthy untreated subjects served as controls. After 2 weeks of treatment the individual change of phagocytosis measured by the ingestion of IgG-coated particles was related to the pre-treatment value both in the psoriatic patients and healthy subjects (p less than 0.05 and p less than 0.001, respectively). Similar results were obtained for ingestion of IgG-C3b-coated particles. Thus, the change in phagocytic rate seemed to be dependent on the functional activity before treatment. UV irradiation of PMNs in vitro did not influence the phagocytic rate. After 4 weeks of UV treatment the healthy subjects showed a significant decrease in the rate of phagocytosis of IgG-C3b particles (p less than 0.02) and of the serum chemokinetic activity (p less than 0.01). In the psoriatic patients the mean chemokinetic activity in heated sera was decreased after 2 weeks (p less than 0.02). There appeared to be no relation between improvement of psoriasis and changes in PMN function. In an untreated group of healthy subjects no significant changes in neutrophil function were found. The results indicate that there is a change in PMN function during UVB treatment. The degree of change seems to vary, not only between individuals but possibly also between groups, e.g. healthy subjects compared with psoriatic patients.