Concentrations of eosinophil-derived neurotoxin in the blood and urine of patients with allergic diseases

ABSTRACTBackgroundIt has been reported that measurements of eosinophil-derived neurotoxin (EDN) may be useful to determine eosinophil activities in allergic diseases.MethodsSerum, plasma and urine concentrations of EDN in patients with allergic diseases were measured by enzyme-linked immunosorbent assay. Samples of blood and urine were obtained from the same patients when their symptoms were active and when patients were well. The number of eosinophils in peripheral blood was also counted.ResultsThe median concentrations of EDN in blood and urine and the number of eosinophils in peripheral blood from patients with active symptoms were all significantly higher compared with values obtained when patients were well. Compared with healthy control subjects, EDN concentrations in the serum, plasma and urine from asymptomatic asthmatic patients, as well as EDN concentrations in the serum and plasma from patients with mild atopic dermatitis and asymptomatic patients with seasonal allergic rhinitis, were significantly higher. Blood and urine concentrations of EDN in patients with active symptoms, but not urine concentrations of EDN from symptomatic patients with seasonal allergic rhinitis, were significantly increased compared with values obtained for healthy control subjects. The concentrations of EDN in the serum and plasma from bronchial asthmatic patients, serum from patients with atopic dermatitis and plasma from patients with mild atopic dermatitis correlated with the number of eosinophils in peripheral blood; however, the concentration of EDN in the serum correlated with the number of eosinophils from asymptomatic patients with seasonal allergic rhinitis.ConclusionsDetermination of blood and urinary concentrations of EDN is useful to monitor eosinophil activity in allergic diseases