PURPOSE OF THE STUDY.
To determine whether having siblings affects the airway immune response in healthy neonates, a characteristic that could be attributed to an underlying immune modulatory pathway.
Five hundred seventy-one 1-month-old, asymptomatic neonates from the Copenhagen Prospective Studies on Asthma in Childhood 2010 (COPSAC2010) birth cohort were studied.
Unstimulated airway mucosal lining fluid was sampled via the nose at 1 month of age. A variety of cytokines and chemokines were assayed by multiplex array, high-sensitivity enzyme-linked immunosorbent assay. Mediator profiles were grouped into Type I, Type 2, Type 17, and T regulatory responses. The association between airway mediator levels and the presence of siblings was investigated by using conventional statistics and principal component analysis.
Neonates with siblings had higher levels of airway immune mediators, predominately in the Type 1 and Type 17 categories. There was a highly significant difference between neonates with and without siblings (P > 10−10), which persisted after adjustment for potential confounding variables, such as pathogenic airway bacteria and viruses (P < .0001). With increasing time from the previous childbirth, the immune responses skewed toward the levels found in neonates without siblings.
The results of this study show that there is an immune modulatory effect of having siblings that leads to more enhanced Type 1 and Type 17 responses versus Type 2 responses. This appears to reflect possible in utero priming because the observed effect decreased with increased time from the previous childbirth. Such responses could have a role in risk for later development of asthma and allergy.
The researchers in this study lay the foundation for future analysis to determine whether the cytokine and chemokine phenotype for the 20 mediators examined in the neonatal cohort affects the long-term development of asthma and/or allergy. The microbiome and/or exposome mentioned in the discussion may also have a determining role.
- Copyright © 2017 by the American Academy of Pediatrics