Chemotactic responsiveness of eosinophils isolated from patients with inflammatory skin diseases

We determined the chemotactic responsiveness of peripheral eosinophilic granulocytes (eosinophils) isolated from patients with inflammatory dermatoses and healthy volunteers. Ten patients with atopic dermatitis, five patients with drug reactions, ten patients with psoriasis, and fourteen healthy volunteers were studied. Well characterized chemotaxins, the complement split product C5a, leukotriene B4 (LTB4), platelet activating factor (PAF), and N-formyl-methionyl-leucyl-phenylalanine (FMLP), were used as chemoattractants. Eosinophils from healthy volunteers showed strong migratory responses towards C5a and PAF but responded poorly to LTB4 and FMLP. When patients were grouped by disease severity, eosinophil chemotactic responses to PAF were significantly enhanced in severely affected patients (p less than 0.05); this was not true with C5a, LTB4 or FMLP. This enhanced eosinophil chemotaxis to PAF was not related to a specific disease. No correlation between eosinophil chemotactic activity and peripheral blood eosinophil count was observed. The increased responsiveness of circulating eosinophils towards PAF may be related to altered receptor expression during cutaneous inflammation.