LEUKOTRIENE-B4 IN ATOPIC-DERMATITIS - INCREASED SKIN LEVELS AND ALTERED SENSITIVITY OF PERIPHERAL-BLOOD T-CELLS

Employing a radioimmunoassay, de‐proteinated suction blister fluid from 12 patients with active atopic dermatitis appeared to contain higher levels of the pro‐inflammatory and immunomodulatory mediator leukotriene B4 (LTB4) than suction blister fluid from 12 non‐atopic individuals. Indirect support for the identity of the mediator was obtained by HPLC of pooled samples. Nylon wool enriched T cells from six patients with atopic dermatitis and six non‐atopic people preincubated with LTB4 (10−10 M−10−8 M) expressed no statistically significant suppression in co‐culture with mitogen stimulated autologous mononuclear cells, and there was no difference between atopic and non‐atopic T cells in this respect. In contrast, LTB4 induced a dose‐dependent reduction in the percentage of phenotypic Leu 2a (suppressor) cells leading to an increased helper/suppressor ratio in five atopic patients that was not observed in five non‐atopics. Elevated skin levels of LTB4 may initiate or amplify dermal inflammation, and abnormal T cell response to the mediator may account for the increased helper/suppressor ratio characteristic of patients with atopic dermatitis. Copyright © 1990, Wiley Blackwell. All rights reserved