Vitamin D Supplementation Attenuates Asthma Development Following Traffic-Related Particulate Matter Exposure
Journal of Allergy and Clinical Immunology, DOI: https://doi.org/10.1016/j.jaci.2018.04.042
Paige Bolcas, BS, Eric Brandt, PhD, Zhonghua Zhang, PhD, Jocelyn Biagini Myers, PhD, Brandy Ruff, BS, Gurjit K. Khurana Hershey, MD, PhD, MD, PhD Gurjit K. Khurana Hershey PhD Gurjit K. Khurana Hershey Gurjit.Hershey at cchmc.org
Supplement mice with Vitamin D during pregnancy or after
Background
Recent literature suggests that children who are vitamin D deficient are uniquely susceptible to the effects of traffic-related air pollution (TRAP) exposure. This is highly significant because large segments of the population reside in zones of high TRAP exposure.
Objective
To determine whether vitamin D supplementation mitigates the impact of TRAP exposure on asthma development, asthma exacerbation, and/or airway inflammation, and to determine the timing of vitamin D supplementation that confers maximal health benefit.
Methods
Using established mouse models of asthma, we examined the impact of pre-and post-natal vitamin D supplementation on asthma development as well as the utility of vitamin D as a treatment for established asthma in the context of diesel-exhaust particle (DEP) exposure.
Results
DEP and allergen co-exposure resulted in increased airway hyperresponsiveness (AHR) and accumulation of pathogenic Th2/Th17 cells in the lungs of vitamin D deficient mice compared to control mice. Prenatal and postnatal vitamin D supplementation significantly attenuated the development of AHR, and decreased pulmonary accumulation of Th2/Th17 cells following co-exposure to TRAP and allergen, but not allergen alone. Restoration of normal vitamin D status had no impact on AHR once asthma was already established.
Conclusions
Our data establish that vitamin D confers protection against asthma development specifically in the context of TRAP exposure. While vitamin D replacement did not reverse established asthma, restoration of normal vitamin D status in early life significantly attenuated the development of AHR in DEP-exacerbated allergic asthma and reduced lung Th2/Th17 cells, which portend the development of severe asthma.
Clinical Implications
Early vitamin D supplementation may be an effective preventive strategy for the development of TRAP-induced asthma.