Bepotastine besilate OD tablets suppress nasal symptoms caused by Japanese cedar pollen exposure in an artificial exposure chamber (OHIO Chamber).

OBJECTIVE: To investigate the efficacy and safety of bepotastine, we conducted a randomized, investigator-blind, placebo-controlled and parallel study to evaluate the allergic symptoms and the cognitive function of the subjects with Japanese cedar (JC) pollinosis in response to JC pollen exposure in an artificial exposure chamber. METHODS: Twenty-four volunteers with JC pollinosis were enrolled in this study. The subjects were randomly divided into two groups: a bepotastine group and a placebo group (12 subjects each). Subjects received either a 10-mg bepotastine OD (orally disintegrating) tablet or a placebo 10 min before entering the chamber for a 3-h exposure. The nasal and ocular symptoms were evaluated by each patient at regular intervals. The amount of nasal discharge was measured and the number of sneezes recorded. To evaluate the cognitive function, a digit cancellation test (D-CAT), in which the subjects have to eliminate certain numbers within a fixed time, was conducted. RESULTS: Twelve subjects in the placebo group developed nasal and/or ocular symptoms, whereas six subjects in the bepotastine group showed none of the symptoms during exposure. Mean secretion weights and number of sneezes were significantly lower in the bepotastine group than in the placebo group. In D-CAT, no deterioration of work performance was observed in the bepotastine group. No adverse effects were observed in either group. CONCLUSION: Bepotastine treatment is effective and well tolerated in patients with allergen-induced symptoms exposed to JC pollen in an exposure chamber.

Validation study of the OHIO Chamber in patients with Japanese cedar pollinosis.

BACKGROUND: An artificial exposure chamber (OHIO Chamber), which allows dispersal of a fixed concentration of Japanese cedar (JC) pollen under stable conditions, was constructed. This study was conducted to identify the exposure conditions assuring validity of the clinical tests conducted using this chamber. METHODS: Twenty-four adult patients with JC pollinosis were exposed to different concentrations of JC pollen: 0 (only during the summer period), 4,000, 8,000 and 12,000 grains/m3, and the nasal and ocular symptoms were self-assessed during a 4-hour period of exposure. The amount of nasal discharge was measured and the sneezing frequency was recorded. This study was conducted twice during the summer and winter periods, i.e. non-pollen seasons. The reproducibility of the symptoms between the two seasons was assessed. RESULTS: None of the subjects developed any symptom at the pollen concentration of 0 grains/m3. No significant differences in the time to the onset of symptoms were found between the summer and winter study, regardless of the pollen concentration. There were no significant differences between the summer and winter study in the total symptom score and total nasal symptom score at any pollen concentration, suggesting the very favorable reproducibility of symptoms. CONCLUSIONS: Efficient and reproducible results are obtained in patients exposed to JC pollen in the OHIO Chamber. The results suggest the conditions of JC pollen exposure have scientific validity and the OHIO Chamber has the potential to contribute significantly to basic and clinical studies of JC pollinosis.

Preliminary study on Japanese cedar pollinosis in an artificial exposure chamber (OHIO Chamber).

BACKGROUND: A pollen exposure chamber (OHIO Chamber) was built in central Tokyo, Japan, in order to study seasonal allergic rhinitis (SAR). Since satisfactory outcomes were obtained from the controlled pollen exposure at the chamber, we conducted preliminary studies in volunteers with SAR. METHODS: Ten volunteers with SAR sensitive to Japanese cedar (JC) pollen were enrolled in this study. In order to investigate the intranasal and intraocular pollen number, volunteers were initially exposed to a low concentration of JC (2500 grains/m3) for at most 1 hour in this chamber. Before and after the exposure, nasal cavities and eyes were washed with 100ml and 25 ml of saline, respectively. Nasal and eye washing solutions were collected and the number of JC pollen was counted. After 3 hours the volunteers were subsequently exposed to a moderate concentration of JC (4500 grains/m3) for 2 hours. Subjective nasal and ocular symptoms were recorded and the amount of nasal secretion was measured during the allergen exposure periods. RESULTS: During the initial exposure, all volunteers except one stayed in the chamber for 1 hour without any nasal or ocular symptoms. The number of pollen in the nose and eyes was 249.2 +/- 120.9 and 13.6 +/- 13.6 grains, respectively. During the subsequent 2-hour exposure to JC pollen, nasal and ocular symptoms developed gradually in a time dependent manner in all the volunteers except one. CONCLUSIONS: This is the first clinical study using Japanese cedar pollen under well-controlled conditions in the OHIO chamber in which the induction of allergic symptoms was observed. The OHIO chamber will be useful for studying allergic rhinitis in Japan.