LATE-PHASE RESPONSE IN NASAL-MUCOSA CLOSELY CORRELATED WITH IMMEDIATEPHASE REACTION AND HYPERREACTIVITY TO HISTAMINE

It has been suggested that the onset of the late phase response (LPR) and hyperreactivity to non-specific stimuli occurs in the lower airway . However, its relationship in the nose has not yet been studied. This study was designed to examine the mechanism of LPR and the relationsh ip between LPR and hyperreactivity. A total of 25 Japanese cedar polli nosis patients participated in this study. On the first visit, the fre quency of sneezes, weight of nasal discharge, and the nasal airway res istance (NAR) were time-dependently measured without antigen challenge . The histamine reactivity was observed after 12 h. The same protocol was used during the second to fourth visits. The frequency of sneezes, weight of nasal discharge, and NAR were measured continuously for 12 h after antigen challenge, and nasal reactivity to histamine was obser ved. The percent change of NAR during immediate phase response (IR) an d during LPR showed a significant correlation. The frequency of sneeze s and weight of nasal discharge induced by histamine were both signifi cantly higher in the positive than in the negative LPR group. These re sults suggest that the chemical mediators and inflammatory cells induc ing nasal swelling during IR cause, directly or indirectly, nasal swel ling during LPR, and induce hyperreactivity to histamine.