Abstract
Phthalates are plastic softeners used in commercial products that become widespread environmental contaminants. Epidemiological studies suggest an association between phthalate exposure and respiratory diseases. DBP is found in high concentrations in indoor air. We hypothesize that DBP inhalation prior to allergen inhalation will affect lung function, recruitment and activation of immune cells in the lower airway.
A controlled, double-blind, crossover study enrolled 16 allergen-sensitized participants. Recruitment was balanced for airway hyper-responsiveness status (AHR = methacholine provocative concentration causing a 20% fall in FEV1 (PC20) ≤ 16 mg/ml), allergen inhaled and exposure order. Participants were exposed to control air or DBP (120µg/m3) for 3 hours, followed by an inhaled allergen challenge. The area under the curve (AUC), measured as FEV1 % drop from baseline was calculated. A methacholine test was performed the following day. Bronchoalveolar lavage was acquired at 24 hours.
Exposure to DBP augmented the AUC compared to control air (p=0.032). Non-AHR participants were the drivers of the DBP effect on the increased AUC (p=0.012), decreased methacholine PC20 (p=0.057) and decreased FEV1 20 hours post-exposure (p=0.018). Moreover, DBP exposure increased the recruitment of macrophages (p=0.05) and their expression of CD206 (p=0.05), a receptor that aids phagocytosis and antigen presentation. The presence of M2 macrophages increased (p=0.09) whereas M1 and Th1 cells decreased (p=0.08 and p=0.07) with DBP exposure.
DBP exposure affects allergen-induced lung function, as well as recruitment and activation of lower airway immune cells.
Footnotes
Cite this article as: European Respiratory Journal 2019; 54: Suppl. 63, PA1992.
This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).
- Copyright ©the authors 2019