Cytokines that are produced by mitogen-stimulated immune cells from pregnant women have been shown to be strongly associated with the development of asthma in their children — a relationship that was apparent in children of nonasthmatic mothers but not in children of asthmatic mothers — according to the results of an analysis published in the American Journal of Respiratory Cell and Molecular Biology.
In the Tucson Infant Immune Study, physician-diagnosed active asthma in children from birth though age 9, along with a history of asthma in their mothers, was assessed via questionnaires. The investigators measured cytokine production in supernatants from mitogen-stimulated peripheral blood immune cells collected both during and after pregnancy from mothers of children enrolled in the birth cohort study.
Maternal production of the cytokines interleukin-13 (IL-13), IL-4, IL-5, interferon-gamma (IFN-γ), IL-10, and IL-17 was not associated with the development of childhood asthma. In contrast, IFN-γ/IL-13 and IFN-γ/IL-4 ratios during pregnancy were related to a significantly decreased risk for childhood asthma (N=381; odds ratio [OR], 0.33; 95% CI, 0.17-0.66; P =.0017 and N=368; OR, 0.36; 95% CI, 0.18-0.71; P =.0031, respectively).
Moreover, the inverse relationships of these 2 ratios to the development of childhood asthma were apparent only in mothers without asthma (N=309; OR, 0.18; 95% CI, 0.08-0.42; P =.00007 and N=299; OR, 0.17; 95% CI, 0.07-0.39; P =.00003, respectively), and not in mothers with asthma (N=72 and N=69, respectively; P for interaction by maternal asthma =.036 and .002, respectively).
Paternal cytokine ratios, on the other hand, were not associated with the development of childhood asthma. Maternal cytokine ratios in mothers without asthma were not related to a child’s skin test reactivity, total immunoglobulin E level, physician-confirmed allergic rhinitis at age 5, or eczema in infancy.
The investigators concluded that this is most likely the first report of an immune indicator that is measurable during pregnancy and predictive of the risk for subsequent childhood asthma. The fact that cytokine profiles in pregnant nonasthmatic women are associated with the risk for asthma in their children, but not with the risk for allergy, implies that the process of asthma development begins in utero and is independent of allergy.
Rothers J, Stern DA, Lohman IC, et al. Maternal cytokine profiles during pregnancy predict asthma in children of nonasthmatic mothers [published online June 4, 2018]. Am J Respir Cell Mol Biol. doi:10.1165/rcmb.2017-0410OC