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

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

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'.

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.

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.