Increased monocyte chemotaxis towards leukotriene B4 and platelet activating factor in patients with inflammatory dermatoses.

In vitro monocyte chemotaxis towards leukotriene B4(LTB4) and platelet activating factor (PAF) was studied with cells from 51 patients with various inflammatory dermatoses and 12 normal volunteers. Monocytes from normal subjects responded poorly to LTB4 (10(-8)-10(-12) M) and PAF (10(-6)-10(-10) M), and cells from patients with urticaria pigmentosa and vericella were even less responsive, while monocytes from patients with severe psoriasis and atopic eczema exhibited markedly enhanced chemotaxis. These changes persisted during high dose therapy with oral steroids, but returned to normal with healing of the skin lesions. Pre-incubation of monocytes with histamine, LTB4, PAF, lymphokines or sera from patients and normal controls did not result in enhanced chemotaxis of the cells. The chemotactic activity of monocytes did not correlate with that of neutrophils in the same patients (r = 0.08). Altered monocyte chemotaxis in patients with inflammatory dermatoses is therefore a reversible process that is related to the severity of the cutaneous inflammation but is not limited to a specific disease.