Irritant occupational exposure and specific-IgE sensitisation in the EGEA cohort

OBJECTIVES: The effect of occupational irritants on IgE sensitisation remains unknown. We investigated the association between occupational exposure to irritants and IgE sensitisation.

METHODS: The study included a cross-sectional analysis of 924 adult participants to the first follow-up of the Epidemiological study of the Genetics and Environment of Asthma (EGEA2) and a longitudinal analysis of 271 children recruited at EGEA1 and followed up to adulthood (EGEA2). Allergen-specific IgE sensitisation to 162 allergens was assessed by microarray technology. Lifetime occupational exposure to irritants was evaluated by the occupational asthma-specific job-exposure matrix. Adjusted regression models were performed to evaluate (1) cross-sectional associations between irritant exposures with the number and cluster-based profiles of sIgE sensitisation and (2) longitudinal associations between childhood sIgE sensitisation and occupational irritant exposures in adulthood to assess a potential 'healthy hire effect'.

RESULTS: Among adult-onset asthma participants, occupational exposure to irritants was associated with a lower number of sIgE sensitisation (adjusted mean ratio=0.63 (95% CI 0.39 to 1.02), p=0.06) and a lower risk of exhibiting house dust mite predominant and pollen/animal predominant sIgE sensitisation profiles (p=0.02 and 0.06 respectively). No association was observed in participants without asthma or with childhood-onset asthma. The longitudinal assessment showed no association.

CONCLUSION: This study, showing fewer sIgE sensitisations associated with occupational exposure to irritants in participants with adult-onset asthma but not in those with childhood-onset or no asthma, highlights the need to further explore the non-immunological mechanisms associated with exposure to respiratory irritants at work.