Increased sensitivity of the chemoattractant-induced chemiluminescence in eosinophils isolated from atopic individuals.

Eosinophilia in peripheral blood is a common phenomenon associated with atopic condition. The present study illustrates the enhanced sensitivity of these eosinophils for formyl-methionyl-leucylphenylalanine (FMLP) and platelet-activating-factor (PAF) (measured as luminol-enhanced chemiluminescence) compared with eosinophils isolated from the peripheral blood of normal individuals. The PAF-induced chemiluminescence, which is peroxidase dependent and of extracellular origin, is inhibited by the PAF antagonist BN52021. The enhanced sensitivity of eosinophils isolated from atopic patients for FMLP and PAF might reflect a 'primed' state of these cells, relevant for the pathogenesis of atopic disease.