Summer Newborns May Be Least Likely To Develop Allergic Disorders

Professor of Pediatrics Hans Bisgaard, MD, DMSc Copenhagen Prospective Studies on Asthma in Childhood Herlev and Gentofte Hospital, University of Copenhagen, Denmark.

Prof. Bisgaard

MedicalResearch.com Interview with:
Professor of Pediatrics Hans Bisgaard, MD, DMSc

Copenhagen Prospective Studies on Asthma in Childhood
Herlev and Gentofte Hospital,
University of Copenhagen, Denmark

Medical Research: What is the background for this study?

Prof. Bisgaard: Birth season has been reported to be a risk factor for several immune-mediated diseases, although the critical season varies depending on the disease. Autoimmune diseases are generally associated with spring births, whereas asthma and allergies are more common among subjects born in fall and winter. Because many of these diseases, such as asthma, rheumatoid arthritis, and multiple sclerosis, have an underlying immune-mediated pathology, we hypothesized that this association might be mediated by differential changes in neonatal immune phenotype and function with birth season. We therefore sought to investigate the influence of season of birth on neonatal immunity by a combined analysis of immune cells subsets from cord blood and inflammatory mediators in the airways of neonates from the Copenhagen Prospective Study on Asthma in Childhood (COPSAC) 2010 birth cohort.

Medical Research: What are the main findings?

Prof. Bisgaard: We found a birth season–related fluctuation in neonatal immune cell subsets and in early-life airway mucosal immune function. The seasonal airway immune pattern was associated with the number of activated and regulatory T cells in cord blood whereas it was independent of concomitant presence of pathogenic airway microbes. Specifically, summer newborns presented with the lowest levels of all cell types and mediators and thereby seem to display the most quiescent immune status. Fall births presented mainly with an enhanced type 2 profile (eosinophils and IL-13), along with high TNF-a, IL-12p70, IL-10, and IL-2 levels, suggesting recent immune activation; whereas winter newborns had the highest levels of most cell types and mediators, including an anti-bacteria/ fungi–associated type 17 response (neutrophils, IL-17, and IL-1b), an antiviral response (pDCs and NK cells), increased eosinophil counts and an IL-5–mediated type 2 response. These season-linked immune profiles were similar to the known immune pathology of type 2 immune-mediated diseases associated with the fall and winter birth seasons, suggesting that immune function in early life might be biased toward the trajectory to later disease development.

Medical Research: What should clinicians and patients take away from your report?

Prof. Bisgaard: Our results show that birth season fluctuations seems to affect neonatal immune development and result in differential potentiation of cord blood immune cells and early airway mucosal immune function.We speculate that the observed birth season–related changes in neonatal immunology might affect the risk for later development of immune-mediated diseases because the risks of several inflammatory diseases are reported to associate with birth season.

Medical Research: What recommendations do you have for future research as a result of this study?

Prof. Bisgaard: Replication in other mother-child cohorts. We hope that this study will direct future research in immunological diseases towards the commonalities of these and look into risk factors in early life or even prenatally

Citation:

Season of birth shapes neonatal immune function

Thysen, Anna Hammerich et al.

Journal of Allergy and Clinical Immunology
November 12, 2015

DOI: http://dx.doi.org/10.1016/j.jaci.2015.08.041

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Professor of Pediatrics Hans Bisgaard, MD, DMSc (2015). Summer Newborns May Be Least Likely To Develop Allergic Disorders