Urinary Eosinophil-derived Neurotoxin Concentrations in Patients with Atopic Dermatitis: A Useful Clinical Marker for Disease Activity

ABSTRACTBackgroundIt has been reported that measurements of eosinophil-derived neurotoxin (EDN) may be useful for identifying eosinophil activities in allergic diseases including atopic dermatitis.MethodsEDN concentrations in the urine were measured by enzyme-linked immunosorbent assay, and the number of eosinophils in the peripheral blood was counted in 30 patients with atopic dermatitis. The severity of atopic dermatitis was graded on the criteria proposed by Rajka and Langeland. The disease activity was assessed by each patient on a visual analogue scale (VAS).ResultsUrinary concentrations of EDN in patients with atopic dermatitis showed a significant positive correlation with disease severity. Urine EDN concentrations also correlated with VAS scores for itching, skin condition, overall skin symptoms and total VAS score, but not with the VAS score for skin dryness. Urinary EDN concentrations did not correlate with the number of eosinophils in the peripheral blood.ConclusionsThe urinary EDN concentration in patients with atopic dermatitis is a useful clinical marker for monitoring disease activity.