MONOCYTE RESPONSIVENESS AND A T-CELL SUBTYPE PREDICT THE EFFECTS INDUCED BY COTTON DUST EXPOSURE

The aim of the study was to evaluate whether peripheral cellular param eters could predict susceptibility to decreased lung function and asso ciated symptoms, in response to a single exposure to cotton dust. Prev iously nonexposed subjects (n = 42) inhaled an aerosol of cotton dust in a model cardroom during a period of 5 h. The subjects were examined before the exposure for FEV(1), procoagulant activity (PCA) in blood mononuclear cells (BMNC), and serum IgE antibodies against a pool of i nhalant antigens. Blood lymphocytes were typed into the helper/inducer (CD4+) and cytotoxic/suppressor (CD8+)T cells in combination with sur face markers subdividing these populations. A questionnaire was used t o identify atopic and nonatopic subjects. Immediately after exposure, the subjects were tested for FEV(1) and PCA, and symptoms were recorde d with a questionnaire. The dust exposure induced a decrease in FEV(1) that was larger for the atopic group, but did not change the PCA in B MNC. The decrease in FEV(1) was positively related to the preexposure PCA in both atopics and nonatopics. Symptoms from the airways after th e exposure were reported to the same extent in the atopic and nonatopi c group, and the subject group reporting chest tightness had a larger preexposure PCA. The atopic group had a larger proportion of blood CD8 + T lymphocytes negative for the monoclonal antibody anti-S6f1 (CD8+S6 F1-), and in this group the decrease in FEV(1) was significantly relat ed to the proportion of this cell type. Also, in the atopic group, the proportion of CD8+S6F1- cells correlated positively with the preexpos ure PCA, and a negative correlation was found for this cell and serum levels of IgE. The findings suggest that functional changes induced by an inflammatory response in the airways are related to cell reactivit y and function in both atopic and nonatopic subjects.