Antigen-induced local mediator release and cellular inflammatory responses in atopic subjects

We report comparisons of histamine release and neutrophil exudation in skin-window sites of 27 pollen-sensitive subjects challenged with antigen or buffer. More histamine was released within 30 min into appended collection chambers in antigen sites vs control sites. There were also more neutrophils adhering to membrane filters applied for 1 hr to the blister bases in antigen-challenged sites vs buffer sites. Comparison of skin-test extinction dilution titer, histamine release, and neutrophil accumulation in antigen-challenged sites in individual subjects showed that (1) there was no correlation between degrees of local histamine and neutrophil accumulation, (2) the increase in histamine but not in neutrophils correlated inversely with the concentration of antigen required to elicit a minimum wheal, and (3) both histamine and neutrophil increases were induced by antigen in a dose-dependent manner.