Cytokine Synthesis in Occupational Allergy to Caddisflies in Hydroelectric Plant Workers

Abstract

Background: Workers in hydroelectric plants appear to be readily sensitized to caddisfly allergens. This sensitization probably occurs de novo from occupational exposure. In some workers, sensitization occurs on a non-atopic background. Cytokine synthesis of IFN-γ, IL-5 and IL-13 in atopic and non-atopic caddisfly-allergic workers was examined to determine if responses were similar or different. Methods: Peripheral blood mononuclear cells were isolated from atopic caddisfly-allergic workers, non-atopic caddisfly-allergic workers and non-atopic caddisfly-exposed but non-allergic workers. Stimulation with caddisfly antigens was carried out and synthesis of IFN-γ, IL-5 and IL-13 was determined by sandwich ELISA. Results: Both caddisfly-allergic and non-allergic subjects responded to stimulation with caddisfly extract. The response in non-atopic caddisfly-non-allergic subjects was TH1 predominant, while that in atopic caddisfly-allergic subjects was TH2 predominant. The response in non-atopic caddisfly-allergic subjects was between that of the atopic caddisfly-allergic workers and the non-atopic caddisfly-non-allergic workers and the trend was to a TH2 response. Work-related symptoms were similarly intermediate between the atopic caddisfly-allergic and non-atopic caddisfly-non-allergic group. Differences were significant for IFN-γ/IL-5 ratios but not IFN-γ/IL-13 ratios for atopic and non-atopic caddisfly-allergic individuals, compared to non-atopic caddisfly-non-allergic workers. However, a linear relationship existed between IFN-γ synthesis and IL-5 and IL-13 synthesis in non-atopic caddisfly-allergic workers but not in atopic caddisfly-allergic subjects. Conclusions: Caddisfly allergy in hydroelectric workers may be a useful model for the development of allergy to a previously unencountered allergen, and points to some interesting differences between atopic and non-atopic subjects who become sensitized to environmental allergens.

Reported Cases and Diagnostics of Occupational Insect Allergy: A Systematic Review

“…A commercial caddis fly extract used in SPT was positive in 91% of employees who experienced work-related symptoms [186]. Another study on caddis fly allergy showed that peripheral blood mononuclear cells (PBMCs) of allergic workers produced more Th2 cytokines, although differences were not significant [187]. One additional case report established final confirmation of caddis fly allergenicity by a bronchial provocation test [188].…”

Indian Guidelines for Diagnosis of Respiratory Allergy

“…People whose professional activity is connected with insects, are usually sensitized to them. 311,[634][635][636][637][638][639][640][641][642][643][644][645] Risk factors for common housefly (Musca domestica) occurs in closed breeding rooms, livestock stables, barns, pharmaceutical industry and workers. 646 Bee keepers are exposed to honeybees (Apis mellifera).…”