Objective: To determine the prevalence of respiratory symptoms among workers processing herring and assess ex vivo cytokine release in response to agents at their workplace.
Methods: We applied a questionnaire, and performed skin prick testing and pulmonary investigations in 36 workers at two herring factories, using 31 municipal workers as controls. In a whole blood assay (WBA), venous blood from the subjects was incubated with lipopolysaccharide (LPS), beta(1,3)-glucan or sterile-filtered, fish constituents such as skin and rinsing water. We determined the IL-1beta and IL-8 release in the plasma by chemiluminescence ELISA.
Results: Among smoking fish-factory workers the forced vital capacity (FVC) was higher (per cent predicted 92.0 vs 85.0; P=0.028) than among municipal workers. Fish rinsing water induced WBA IL-8 release to higher levels than LPS and glucan. Among non-smokers the induced IL-1beta release for rinsing water ( P=0.007) and the IL-8 release for skin ( P=0.001) and meat ( P=0.003) were higher in fish-factory workers than in municipal workers. The IL-1beta release for rinsing water ( P=0.028) and skin ( P=0.041) was higher among non-smokers than among smokers, and so was the IL-8 release for rinsing water ( P=0.008).
Conclusions: Assessing the cytokine release by use of the WBA we identified substances in the occupational environment with a pro-inflammatory potential comparable to that of LPS. The cytokine release for fish constituents was highest among non-smoking fish-factory workers. The results suggest a priming effect of the work exposure.