Urine eosinophil protein X (EPX) is an in vitro parameter of inflammation in atopic dermatitis of the adult age.

Abstract

Eosinophils are important effector cells in several atopic diseases. The levels of eosinophil granule-derived mediators (ECP, EPX) in serum and body fluids have been proven to be correlated with disease activity in atopic respiratory diseases and atopic dermatitis. The study aimed to demonstrate an interrelationship between urine EPX and disease activity in adult patients with atopic dermatitis. We determined urine EPX concentration, serum ECP concentration, and peripheral blood eosinophil count in 40 adult patients with mild to severe atopic dermatitis and compared it with the disease activity as assessed with the SCORAD index. Urine EPX and serum ECP concentrations were significantly higher in patients with severe atopic dermatitis than in patients with mild or moderate disease (median values 123.5 vs 78.3 microg/mmol creatinine, P<0.0001; 25.4 vs 14.9 microg/l, P<0.0001, respectively). We found a significant correlation between urine EPX levels, serum ECP levels, and the SCORAD (r=0.36, P<0.0001 and 0.34, P<0.0001, respectively). Urine EPX is a useful in vitro parameter of inflammation in atopic dermatitis of the adult age.