The effects of pregnancy on the exacerbation and development of maternal allergic respiratory disease

Abstract

The T-helper 2 (T_H2) bias associated with pregnancy may predispose the pregnant mother to the development or exacerbation of allergic disease. To determine the effects of pregnancy on pre-existing maternal sensitization, we sensitized BALB/c mice before breeding by two intratracheal aspiration (IA) exposures to the fungal allergen, Metarhizium anisopliae crude antigen (MACA). Some mice also received three IA exposures to MACA on gestational days 11, 15, and 19. After weaning, all mice were challenged IA with MACA before killing. To determine the effects of pregnancy on susceptibility to future sensitization, naïve parous and nulliparous BALB/c mice were sensitized by three IA exposures to MACA or to Hank’s buffered salt solution vehicle control. Pregnancy did not have a significant effect on individual inflammatory parameters (airway responsiveness to methacholine, total serum and bronchoalveolar lavage fluid (BALF) IgE, BALF total protein, lactate dehydrogenase activity, and total and differential cell counts) following allergen challenge in sensitized mice, regardless of post-breeding allergen exposure. In conclusion there was a weak inhibition of the overall response in mice exposed to allergen during pregnancy compared to identically treated nulliparous mice. In contrast, parous mice that did not encounter allergen post-breeding tended to have exacerbated responses. Parity had no significant impact on future susceptibility to sensitization.

Keywords::

• Asthma
• maternal asthma
• gestational exposure
• pregnancy
• mouse
• Metarhizium anisopliae

Acknowledgments

The authors would like to thank Debora Andrews, Elizabeth Boykin, James Lehmann, Judy Richards, Dr. Yong Joo Chung, and Dr. Michael Narotsky of U.S. EPA for technical and intellectual assistance. In addition, we would like to thank Drs. Robert Luebke, MaryJane Selgrade, and Christal Bowman for their critical review of the manuscript. This work was supported by UNC/EPA training agreement CR83323701.

Disclaimer: This research paper has been reviewed by the National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, and approved for publication. Approval does not signify that the contents necessarily reflect the views and policies of the agency, nor does mention of trade names or commercial products constitute endorsement or recommendation for use.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.