Is atopy a risk indicator of chronic obstructive pulmonary disease in dairy farmers?

Abstract

Allergic mechanisms related to environmental and occupational exposure have been suggested to contribute to the development of chronic obstructive pulmonary disease (COPD).

Objectives: To investigate the relationships between atopy markers, persistent airflow limitation (PAL) and occupational exposure in dairy farmers.

Methods: Clinical and biological (total IgE and 21 allergen specific IgE) markers of atopy were assessed in 101 dairy farmers with PAL (DF-PAL), 85 non-farmers with PAL (NF-PAL) (both groups were prospectively included from a screening program performed between 2011 and 2015), and matched controls, i.e. 98 farmers without PAL (DF-controls) and 89 non-farming subjects without PAL (NF-controls). Occupational exposure in farmers was estimated using a validated questionnaire.

Results: Prevalence of allergy history was significantly higher in DF-PAL and in NF-PAL than in controls. Polysensitization, and sensitization to seasonal and food allergens were more frequent in DF-PAL than in DF-controls, respectively: 13.8% vs 1% (adjusted odds ratio (aOR): 17.5 (2.2-134), 11.9% vs 3.1% (aOR: 4.4 (1.2-7.2) and 16.8% vs 4.1% (aOR: 5.2 (1.7-7.2)). The prevalence of atopy markers was similar between NF-PAL patients and NF-controls.

Conclusions: PAL in farmers is associated with a high rate of markers of atopy, supporting atopy as a risk indicator. Clinical trial registered with ClinicalTrials.gov (NCT02540408).

Keywords: Atopy; Chronic obstructive pulmonary disease; Farmers; Matthieu Veil-Picard and Thibaud Soumagne contributed equally to the work.; Occupational exposure; Specific IgE.

Conflict of interest statement

Dr. Roche reports grants and personal fees from Boehringer Ingelheim, Pfizer and Novartis, personal fees from Teva, GSK, AstraZeneca, Chiesi, Mundipharma, Cipla, Sano, Sandoz, 3 M, Zambon, outside the submitted work. Dr. Dalphin reports grants, personal fees and non-financial support from Novartis Pharma, GSK, Chiesi, Intermune, AstraZeneca, Boehringer ingelheim and non-financial support from Stallergenes, outside the submitted work.

Dr. Dalphin reports grants, personal fees and non-financial support from Novartis Pharma, personal fees and non-financial support from GSK, personal fees and non-financial support from Chiesi, personal fees and non-financial support from Intermune, personal fees and non-financial support from AstraZeneca, personal fees and non-financial support from Boehringer ingelheim, non-financial support from Stallergenes, outside the submitted work.

The other authors declare that they have no conflict of interest for the submitted work.

Figures

Fig. 1

Flow chart of participants included in the study. Subjects were recruited through a screening program set up by two national health insurance organizations. Inclusion criteria in the screening programs were: men or women aged 40 to 74 years, with no history of chronic respiratory disease including asthma and hypersensitivity pneumonitis. Abbreviations: COPD: chronic obstructive lung disease; DF: dairy farmer; NF: non farmer

Fig. 2

Frequency histogram of specific IgE among dairy-farmers and non-dairy-farmers’ patients COPD: chronic obstructive pulmonary disease; DF-COPD: dairy farmers with COPD; DF-control: dairy farmers in control group; NF- COPD: COPD in non-dairy farmers; NF-control: non-dairy farmers in control group.

Fig. 3

Comparison of odds ratios for markers of atopy among dairy-farmers and non-dairy-farmers (reference groups are patients without chronic obstructive pulmonary disease (COPD). All ORs were adjusted for age (continuous), gender (reference: female) and pack-years ( 15)