Neutrophil function in psoriasis: effects of retinoids.

The present investigation focused on the oxidative response of polymorphonuclear neutrophil leukocytes in psoriasis, in particular pustular psoriasis and how this response was affected by different retinoid compounds. In the active phase of pustular psoriasis, the neutrophil chemiluminescence response to the chemotactic peptide f-met-leu-phe and to phorbol myristate acetate was enhanced and correlated to the development of pustules, whereas cells from psoriasis vulgaris patients showed normal chemiluminescence response. Retinoids, particularly tretinoin (= retinoic acid) and isotretinoin caused a pronounced inhibition of the chemiluminescence response only in primed neutrophils in vivo and in vitro, whereas etretinate and the metabolite Ro 10-1670 was less inhibitory. Retinoic acid furthermore inhibited the Fc-mediated phagocytosis, but did not affect C3bi-mediated phagocytosis. These data suggest that the antiinflammatory effect of retinoids may operate by affecting neutrophil activation and function.