Preliminary study of a challenge test to the patients with Japanese cedar pollinosis using an environmental exposure unit.
OBJECTIVE
Although clinical studies on pollinosis have been performed employing placebo-controlled double-blind comparative and field techniques, accurate evaluation is difficult because the scattering pollen count and climatic conditions vary between years and regions, leading to a bias in the results. Thus, we prepared a pollen challenge test unit (allergen challenge chamber: ACC) which facilitates quantitative pollen challenge at any time, and, so, the acquisition of objective data.


METHODS
The control of constant conditions and maintenance of specified pollen concentrations in ACC were investigated. In addition, the pollen distribution in ACC was measured while maintaining the level at 10,000 counts/m(3). The pollen levels were measured employing the aspiration and Durham methods, and the measured values were compared. Furthermore, whether symptoms are adequately induced in the chamber during the non-cedar pollen-scattering season was investigated in 14 volunteers with cedar pollinosis.


RESULTS
When the pollen level in ACC was set at 6000 counts/m(3) or higher, the rate of variation was +/-15%, within the adjustable range, and that of the pollen distribution in the chamber was within +/-20%. When the volunteers with cedar pollinosis were exposed to cedar pollen in ACC, pollinosis symptoms were induced, and challenge for 2 consecutive days significantly induced symptoms.


CONCLUSIONS
The temporal and spatial variations of the pollen level in ACC were small, facilitating stable pollen challenge, and pollinosis symptoms were induced in the volunteers with cedar pollinosis. The challenge chamber may be useful to judge the effects of therapy against pollinosis.
Ito
Kanako
K
Department of Otorhinolaryngology, Osaka Medical College, 2-7 Daigaku-cho, Takatsuki City, Osaka, Japan.
Terada
Tetsuya
T
Yuki
Ayumi
A
Ichihara
Takahiro
T
Hyo
Sawako
S
Kawata
Ryo
R
Takenaka
Hiroshi
H
Amano
Kentaro
K
Ishiguro
Takeshi
T
Ro
Toshitami
T
D032485:Cryptomeria / Q000276:immunology*; D003948:Diagnostic Techniques, Respiratory System; D004781:Environmental Exposure; D005260:Female; D006801:Humans; D007159:Immunologic Tests; D008297:Male; D015508:Nasal Obstruction / Q000209:etiology; D011537:Pruritus / Q000209:etiology; D006255:Rhinitis, Allergic, Seasonal / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D012621:Seasons; D012912:Sneezing; D013997:Time Factors; D055815:Young Adult