BLOOD INTERLEUKIN-8 PRODUCTION IS INCREASED IN CHEMICAL WORKERS WITH BRONCHITIC SYMPTOMS

Chemical exposure may result in respiratory conditions such as chronic bronchitis, bronchial hyperresponsiveness, and chronic airway obstruc tion. Clinical studies have shown that during the course of disease, c ytokine networks are changed. In order to study the relationship betwe en blood cytokines and respiratory symptoms in an occupational setting , we investigated 106 chemical workers during a routine yearly medical examination in 1995. Lung function was measured with flow volume curv es and impedance using the forced oscillation technique (FOT). Smoking status and respiratory symptoms were determined by questionnaires. Cy tokines were selected on biological plausibility and measured both in a whole blood assay (TNF-alpha, IL-8) and in serum (IL-4, IL-5, IL-6, IFN-gamma). The hypothesis is that blood levels of TNF-alpha and IL-8 are increased in bronchitis, while serum levels of IL4, IL-5 are incre ased and IFN-gamma is decreased in asthmatic workers. Spontaneous IL-8 release was significantly higher in workers with bronchitis (P < 0.05 ) or chronic bronchitis (P < 0.01) compared to workers without those r espiratory symptoms, also after correction for age, pack-years, and bl ood lymphocyte numbers of compared to a matched control group. No corr elation was present between specific cytokines and asthmatic symptoms. These data suggest that blood IL-8 may be considered as a useful mark er for bronchitis. (C) 1991 Wiley-Liss, Inc.