Comparison of inflammatory events in skin sites with and without cutaneous late-phase reactions after prominent immediate IgE-mediated responses.

Abstract

A number of inflammatory events have been detected in skin chambers overlying sites of developing late-phase reactions (LPR) to pollen antigens in sensitive subjects. However, the pathogenic significance of such events is still unclear. We sought to compare inflammatory responses and cytokine levels in skin chambers that overlie sites of antigen challenge in individuals with and individuals without LPRs after immediate wheal responses of similar intensity. Early histamine releases at antigen sites were similar in eight subjects with LPR (+/+ group) and eight subjects without LPR (+/- group). However, histamine releases during hours 2 through 5 of antigen challenge were significantly greater in the +/+ subjects than in the +/- subjects. Total exuding leukocytes; percent eosinophils; and levels of eosinophil cationic protein, lactoferrin, and IL-8 were significantly greater at antigen versus buffer control challenge sites in both the +/+ and +/- groups, with no significant differences between the groups. IL-1 and IL-6 levels were not greater at antigen sites than at buffer sites. The only significantly greater antigen-induced response detected in +/+ subjects than in +/- subjects was in later histamine release, which is possibly a marker of other inflammatory responses because histamine itself does not induce LPRs. Other inflammatory events assessed may be somewhat greater in +/+ subjects, but not significantly so.