چکیده (انگلیسی):

Background: Minimal persistent inflammation (MPI) contributes to hyperreactivity in allergic rhinitis.
However, little is known regarding whether pre-onset activation of eosinophils and mast cells is present
or not in Japanese cedar pollinosis (JCP). Furthermore, a prophylactic effect of intranasal corticosteroids
on such MPI in JCP has not been investigated.
Methods: We designed a double-blinded, randomized, placebo-controlled, crossover trial. Twenty patients
with JCP were examined outside the pollen season (UMIN000008410). Nasal provocation with
paper discs containing extracts of Japanese cedar pollen was performed once a day for 3 consecutive
days. Onset of nasal symptoms was monitored over 15 min after each provocation. The levels of
eosinophil cationic protein (ECP) and tryptase in nasal secretions were examined. Fluticasone furoate
nasal spray or placebo treatment was started one day before the first provocation.
Results: In the placebo group, 25% of the patients showed onset of nasal symptoms following provocation
on the first day. In addition, 75% and 68% of the patients showed symptom onset on the second and
third day of provocation, respectively. After the first provocation, the levels of ECP and tryptase in nasal
secretions were significantly increased. These increases were seen not only in symptomatic but also in
asymptomatic subjects in response to provocation, and the levels were similar between these subjects.
Prophylactic treatment with fluticasone significantly suppressed the increase in nasal ECP and tryptase
associated with repeated provocations.
Conclusions: These results suggest that pre-onset activation of eosinophils and mast cells is present in
experimental JCP, and that prophylactic treatment with intranasal corticosteroids has the potential to
control such activation.