[Clinical significance of serum interleukin-18 concentration in the patients with atopic dermatitis].

BACKGROUND

Interleukin (IL)-18, a potent inducer of interferon gamma (IFN-gamma), is known to have a role in diseases involving type-2 T helper cell responses including atopic dermatitis. In this study, we aimed to determine the clinical significance of serum IL-18 level in the patients with atopic dermatitis.

METHODS

Serum concentration of IL-18, IFN-gamma, IgE, and blood eosinophil were measured in the patients with atopic dermatitis and healthy control subjects, and their association with the clinical score of the disease was analysed.

RESULTS

Serum concentrations of IL-18 were significantly elevated in patients with atopic dermatitis compared to the healthy controls (332 pg/mL vs 151 pg/mL, P<0.05). Serum levels of IL-18 (r=0.41, P=0.001), eosinophil (r=0.36, P=0.003), and IgE (r=0.32, P=0.009) correlated with clinical scores in the patients. Also, multiple regression analysis indicated that serum IL-18 and IgE levels were independent predictors for the clinical score of atopic dermatitis (r2=0.25, beta=0.39, P=0.001 and beta=0.32, P=0.009).

CONCLUSIONS

Our results confirmed a significant correlation between the concentration of serum IL-18 and the severity of atopic dermatitis. Although serum IL-18 concentration reflects the disease severity, its usefulness as a clinical test needs to be further investigated, because its additive benefit over those of conventional blood tests is not evident so far.