Elevated umbilical cord serum TARC/CCL17 levels predict the development of atopic dermatitis in infancy

Background Thymus-and-activation-regulated chemokine (TARC; CCL17) is related to both allergy and pregnancy, but the relationships of maternal and umbilical cord blood CCL17 to atopic dermatitis (AD) development have not yet been examined. Objective Seventy paired full-term and normal vaginal delivery newborns and their mothers were enrolled in this study. Methods To elucidate the pathogenesis and fetomaternal inheritance of AD in infancy, CCL17, IFN-gamma-inducible protein 10 kDa (IP-10; CXCL10), soluble HLA-G (sHLA-G), IgE and eosinophil counts were examined using sera from 70 paired umbilical cord and maternal blood samples. Results Serum CCL17 (r(s) = 0.340, P<0.001) and sHLA-G (r(s) = 0.600, P<0.001) levels showed high correlations between umbilical cord and maternal blood. Umbilical cord serum levels of CCL17 from neonates destined to develop AD in infancy were higher than in those from neonates who showed no signs of AD during infancy (median 1586.9 vs. 819.6 pg/mL, P<0.001). Serum levels of CCL17 were higher in mothers with AD than in those without AD (median 909.6 vs. 214.1 pg/mL, P<0.001). High umbilical cord serum levels of CCL17 were associated with infantile AD development even in 62 neonates born to mothers without AD (median 1514.4 vs. 740.6 pg/mL, P<0.001) and 38 neonates born to mothers with no allergies (median 1624.2 vs. 740.6 pg/mL, P<0.001). The summary estimates for umbilical cord serum CCL17 in the diagnosis of infantile AD were: sensitivity 85.7% (95% confidence interval: 72.8-98.7), specificity 73.8% (60.5-87.1), positive predictive value 68.6% (53.2-84.0) and negative predictive value 88.6% (78.0-99.1). Conclusion and Clinical Relevance These findings suggest that the umbilical cord blood CCL17 may be involved in the pathogenesis of infantile AD and in fetomaternal inheritance. Serum levels of CCL17 from umbilical cord blood may be a predictive marker for AD in infancy.