Differential Aerosol Challenge Studies in Byssinosis

Cotton textile mill workers with conditions diagnosed as byssinosis or not byssinosis by a modified Medical Research Council (MRC) questionnaire were challenged with extracts of cotton dust fractionated by filter membrane dialysis, and volatilization. Byssinotic subjects responded with a significant decrease in FEV_1.0 and with clinical symptoms to the inhalation of whole raw cotton extract and nonvolatile, nondialyzable cotton extract compared to saline, volatile extract, and dialyzable extract. Subjects without byssinosis responded the same to saline as to all other extracts. Comparison of responses of byssinotic and nonbyssinotic subjects showed no statistically significant differences with any extract. It was concluded that the active agent in cotton dust is water soluble, filterable at 0.22μ, nonvolatile at 40C, and nondialyzable but may not be active only in that group of patients identified as byssinotic by questionnaire.