Elevated levels of beta-D-glucan in bronchoalveolar lavage fluid in patients with farmer's lung in Miyazaki, Japan.
BACKGROUND
Farmers may be often exposed to beta-D-glucan in moldy hay, since straw for feed can be stored throughout the year.


OBJECTIVE
The aim of the present study was to clarify whether levels of beta-D-glucan, which modifies immune responses, are high in the respiratory tract in farmer's lung and whether beta-D-glucan participates in the pathogenesis of this condition.


METHODS
We measured beta-D-glucan levels in the bronchoalveolar lavage fluid (BALF) of 10 patients with farmer's lung, 4 with summer-type hypersensitivity pneumonitis (HP) and 10 healthy volunteers. Interleukin (IL)-8 and tumor necrosis factor (TNF)-alpha levels in BALF were measured by enzyme-linked immunosorbent assay (ELISA). We investigated the effects of beta-D-glucan on nuclear factor (NF)-kappaB activation and on the release of IL-8 and TNF-alpha from small airway epithelial cells (SAECs) in vitro.


RESULTS
beta-D-Glucan levels in the BALF of farmer's lung patients were increased compared to those in patients with summer-type HP and in healthy volunteers. Additionally, IL-8 levels in BALF were higher in farmer's lung than in summer-type HP, and TNF-alpha levels were equal in the two patient groups but raised compared to those in healthy volunteers. High, but not low, concentrations of beta-D-glucan were found to induce NF-kappaB activation in SAECs. IL-8 levels in the supernatant obtained from SAEC cultures were increased following the addition of beta-D-glucan in vitro.


CONCLUSIONS
BALF from farmer's lung patients showed high beta-D-glucan levels, which may enhance the expression and release of cytokines through NF-kappaB activation in respiratory epithelial cells.
Ashitani
Jun-Ichi
J
Division of Neurology, Respirology, Endocrinology and Metabolism, Third Department of Internal Medicine, Miyazaki University School of Medicine, Miyazaki, Japan. jashi2@fc.miyazaki-u.ac.jp
Kyoraku
Yuka
Y
Yanagi
Shigehisa
S
Matsumoto
Nobuhiro
N
Nakazato
Masamitsu
M
D000328:Adult; D000368:Aged; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry; D016022:Case-Control Studies; D016207:Cytokines / Q000378:metabolism*; D004847:Epithelial Cells / Q000378:metabolism*; D005203:Farmer's Lung / Q000378:metabolism*; D005260:Female; D006801:Humans; D016209:Interleukin-8 / Q000378:metabolism; D007564:Japan; D008297:Male; D008875:Middle Aged; D020545:Respiratory Mucosa / Q000378:metabolism*; D051996:Transcription Factor RelA / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D047071:beta-Glucans / Q000032:analysis / Q000378:metabolism*
D016207:Cytokines; D016209:Interleukin-8; D051996:Transcription Factor RelA; D014409:Tumor Necrosis Factor-alpha; D047071:beta-Glucans