The enhanced monocyte and neutrophil chemotaxis in psoriasis is normalized after treatment with psoralens plus ultraviolet A and anthralin.

The chemotactic activity of purified monocytes and neutrophils was studied in twenty-two psoriatic patients prior to the initiation of psoralens plus ultraviolet A (PUVA) or anthralin therapy and during the treatment. Patients with untreated, active psoriasis had increased chemotactic response of their monocytes and neutrophils to N-formyl-methionyl-leucyl-phenylalanine. Plasma from untreated psoriasis patients had an enhanced chemotactic activity toward neutrophils from persons without psoriasis. Treatment with PUVA or anthralin resulted in a progressive clearing of psoriatic lesions and in a significant depression of leukocyte chemotaxis 2 weeks after the start of the respective therapy. The chemotactic activity of both monocytes and neutrophils was normalized after 4 weeks of anthralin therapy and after 6 weeks of PUVA treatment. The chemotaxis-enhancing properties of plasma from psoriasis patients returned to normal values already after 2 weeks of treatment.