Umbilical cord plasma 25-hydroxyvitamin D concentration and immune function at birth: the Urban Environment and Childhood Asthma study

Abstract

Cite this as: A. Chi, J. Wildfire, R. McLoughlin, R. A. Wood, G. R. Bloomberg, M. Kattan, P. Gergen, D. R. Gold, F. Witter, T. Chen, M. Holick, C. Visness, J. Gern and G. T. O'Connor, Clinical & Experimental Allergy, 2011 (41) 842–850.SummaryBackground Recent studies have reported conflicting data on the association between maternal intake of vitamin D during pregnancy and asthma.Objective To assess the influence of prenatal vitamin D status on immune function at birth.Methods In an inner‐city birth cohort of 568 newborns, 520 of whom had at least one atopic parent, we measured the umbilical cord (UC) plasma concentration of 25‐hydroxyvitamin D (25(OH)D) and the cytokine responses of UC blood mononuclear cells (UCMCs) to stimuli including phytohaemagglutinin (PHA), lipopolysaccharide (LPS), and peptidoglycan. In a subset, the UCMC expression of regulatory T cell markers and the suppressive activity of CD4+CD25+UCMCs were measured.Results The 25th, 50th, and 75th percentiles of UC plasma 25(OH)D level were 15.0, 20.2, and 25.6 ng/mL, respectively. Most cytokine responses of UCMC were not correlated with UC 25(OH)D concentration; however, IFN‐γ release after LPS stimulation was weakly positively correlated with UC 25(OH)D concentration (r=0.11, P=0.01). PHA responses were not significantly correlated with 25(OH)D concentration. The UC plasma 25(OH)D concentration was inversely related to the number of CD25+ (r=−0.20, P=0.06), CD25Bright (r=−0.21, P=0.05), and CD25+FoxP3 (r=−0.29, P=0.06) cells as a proportion of CD4+ T cells in UC blood (r=−0.26, P=0.04) but not to the suppressive activity of CD4+CD25+cells (r=0.17, P=0.22).Conclusion and Clinical Relevance UC 25(OH)D concentration was not correlated with most UCMC cytokine responses to multiple stimuli. There was a suggestion of a weakly positive correlation with IFN‐γ release after LPS stimulation. The proportions of CD25+, CD25Bright, and CD25+FoxP3 cells to total CD4+ T cells were inversely correlated with UC 25(OH)D concentration. Our findings suggest that higher vitamin D levels at birth may be associated with a lower number of T‐regulatory cells. Vitamin D status in utero may influence immune regulation in early life.

Part of CIRS Nexus · Curated by Lauren Lowenstein, The Biotoxin Lady

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