Serum concentration of macrophage-derived chemokine may be a useful inflammatory marker for assessing severity of atopic dermatitis in infants and young children

Chemokines are responsible for the trafficking of leukocytes to sites of inflammation. Serum chemokine levels were previously shown to be increased in adult patients with atopic dermatitis (AD). We tested whether serum concentrations of chemokines, including macrophage-derived chemokine (MDC), thymus and activation-regulated chemokine (TARC), eotaxin (EOX), interferon gamma inducible protein 10 (IP-10) and monocyte chemotactic protein 1 (MCP-1), are useful inflammatory markers for assessing AD severity in infants and young children. To investigate this, we assessed the severity of AD clinically using the SCORing Atopic Dermatitis (SCORAD) index system. Serum chemokine concentrations were determined by sandwich enzyme immunoassay. Twenty AD patients with a median age of 2.1 years [interquartile range (IQR): 0.6-4.2] were recruited. Their SCORAD score was 23.5 (12.5-33.5). Serum concentrations of MDC, TARC, EOX, IP-10 and MCP-1 were 2551 (1978-3935), 1469 (1125-3070), 68 (57-85), 126 (101-226) and 518 (419-614) pg/ml, respectively. Serum MDC levels correlated with SCORAD (r = 0.608, p = 0.004) and its extent (r = 0.629, p = 0.003) and intensity (r = 0.557, p = 0.011) components. Serum TARC concentration showed weaker correlation with extent (r = 0.474, p = 0.035) and intensity (r = 0.465, p = 0.039) of skin involvement but not SCORAD. The median serum levels of MDC (3131 vs. 2394 pg/ml; p = 0.031) and EOX (80 vs. 61 pg/ml; p = 0.046) were also higher in children with moderate as compared with mild AD. The other chemokines did not correlate with AD severity. In conclusion, our results suggest that serum MDC concentration may be a useful inflammatory marker for assessing AD severity in infants and young children.