Defective release of eosinophil chemotactic factor from peripheral leukocytes in patients with chronic urticaria.

Release of eosinophil chemotactic factor (ECF) and histamine was studied peripheral leukocytes of 16 normal and 12 ragweed allergic volunteers and compared to 15 patients with chronic urticaria. Cells were exposed to varying concentrations of anti-IgE or to ragweed antigen E in the case of allergic donors. Twelve of 15 patients with chronic urticaria showed defective release of ECF as well as histamine, while almost all normal and all allergic donors were able to release larger quantities of both mediators. Since the eosinophil is thought to have a modulating effect at sites of inflammation induced by anaphylactic mechanisms, the defective release of a factor attracting these cells may explain the persistence of symptoms in chronic urticaria.