Chemotactic lipoxygenase products in sera from patients with psoriasis

Sera obtained from 12 patients with moderate to severe psoriasis were investigated for the presence of arachidonate lipoxygenase metabolites using reverse-phase high-performance liquid chromatography after extraction on silicic acid columns. Peaks which co-chromatographed with standards of synthetic leukotriene B4 (LTB4) were collected, and the material was tested for chemotactic activity. In the sera of 5 of the patients, chemotactic activity was demonstrable in these 'LTB4' peaks. Although minor peaks co-chromatographing with LTB4 were found in control sera, none of them contained chemotactic material. Isolated monocytes from the psoriasis patients showed enhanced chemotactic activity as compared to monocytes obtained from healthy controls. The results of our study support the view that abnormal 5-lipoxygenase activity is present in psoriasis. Further investigation is required to determine whether LTB4 is released from circulatory leukocytes or the skin.