title: Bronchial mast cells are the dominating LTC4S-expressing cells in aspirin-tolerant asthma.
abstract: The increased bronchial production of leukotriene C4 (LTC4) in asthma is assumed to derive from infiltrating eosinophils expressing LTC4-synthase (LTC4S). Multicolor immunohistofluorescence examination of bronchial cryosections from 30 treated, untreated, or bronchial antigen-provoked aspirin-tolerant individuals with asthma and nine control subjects revealed that the dominating LTC4S-expressing cells were mast cells (> 80%), and not eosinophils. Whereas 95% of the mast cells expressed high levels of LTC4S, only 8-27% of the eosinophils expressed low levels. Image analysis revealed a significantly higher LTC4S expression levels in mast cells than in eosinophils. The bronchial mRNA levels for LTC4S did not correlate with the densities of LTC4S-positive eosinophils or mast cells. Treated individuals with asthma with more than 12% reversibility had significantly higher density of LTC4S-positive mast cells than those with less reversibility, and it correlated significantly with reduction in lung function (FEV1-predicted), both before and after salbutamol inhalation. Thus, mucosal mast cells, and not eosinophils, were the dominating LTC4S-containing cells in both untreated and treated aspirin-tolerant asthma. The density of LTC4S-positive mast cells correlated, moreover, with both the reduction in lung function and the degree of reversibility in treated asthma.
authors.affiliation: Institute of Oral Biology, University of Oslo, PB 1052, Blindern, 0316 Oslo, Norway. thalsten@odont.uio.no
authors.forename: Yiqing
authors.initials: Y
authors.lastname: Cai
authors.forename: Leif
authors.initials: L
authors.lastname: Bjermer
authors.forename: Trond S
authors.initials: TS
authors.lastname: Halstensen
mesh_terms: D000328:Adult; D000368:Aged; D001241:Aspirin / Q000009:adverse effects*; D001249:Asthma / Q000201:enzymology / Q000276:immunology / Q000378:metabolism*; D001980:Bronchi / Q000166:cytology* / Q000378:metabolism; D001985:Bronchial Provocation Tests; D004804:Eosinophils / Q000166:cytology / Q000378:metabolism; D005260:Female; D005982:Glutathione Transferase / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008407:Mast Cells / Q000166:cytology / Q000201:enzymology* / Q000378:metabolism; D008875:Middle Aged; D012044:Regression Analysis
chemical_list: D005982:Glutathione Transferase; C041116:leukotriene-C4 synthase; D001241:Aspirin