Cord blood cytokines and acute lower respiratory illnesses in the first year of life.

OBJECTIVES: Little is known about the relation between cytokine profile at birth and acute lower respiratory illnesses in the first year of life. The purpose of this work was to examine the relation between cytokine secretions by cord blood mononuclear cells and acute lower respiratory illness in a birth cohort of 297 children.
METHODS: Cord blood mononuclear cells were isolated, and secretion of interferon-gamma, interleukin-13, interleukin-10, and tumor necrosis factor-alpha at baseline and in response to allergens (Blatella germanica 2 and Dermatophagoides farinae 1) and mitogen (phytohemagglutinin) were quantified using enzyme-linked immunosorbent assay. Acute lower respiratory illness was defined as a parental report of a diagnosis of bronchiolitis, pneumonia, bronchitis, and/or croup by a health care professional in the first year of life. Differences in the levels of cord blood cytokines between children with and without acute lower respiratory illness were examined using 2-sample Wilcoxon tests. Logistic regression models were used to examine the relation between various categories of cord blood cytokines and acute lower respiratory illness.
RESULTS: Median levels of interferon-gamma secreted by cord blood mononuclear cells in response to Blatella germanica 2 and Dermatophagoides farinae 1 were higher among children without acute lower respiratory illness as compared with children with acute lower respiratory illness. After adjustment for other covariates, the odds of acute lower respiratory illness was reduced among children in the top category (at or more than the median of detectable values) of interferon-gamma level, significantly so in response to Blatella germanica 2.
CONCLUSIONS: In a cohort of children from the general population, we found that upregulated interferon-gamma secretion at birth is associated with reduced risk of acute lower respiratory illness in the first year of life.