title: Eosinophil-derived neurotoxin in childhood asthma: correlation with disease severity.
abstract: BACKGROUND
  Eosinophil numbers and eosinophil cationic protein (ECP) levels have been proposed as markers of disease activity; however, the usefulness of eosinophil-derived neurotoxin (EDN)--another eosinophil granular protein--as a marker in pediatric asthma has not been established.
  
  
  OBJECTIVE
  The authors compared the concentrations of blood eosinophil counts (TECs), serum ECP, and serum EDN to asthma symptom severity in young children.
  
  
  METHODS
  Forty-three young children with asthma (Asthma group: mean age, 2.9 years; range, 1.4-5.0 years) were evaluated during both the acute and stable phases of disease. Asthma severity was measured using a symptom-scoring technique, and serum eosinophil indices (EDN and ECP levels and TECs) were determined. Nineteen age-matched controls (Control group: mean age, 2.7 years; range, 1.0-5.0 years) were used for comparison.
  
  
  RESULTS
  Levels of serum EDN, serum ECP, and TECs were significantly higher in children with acute asthma compared with Controls (p < .0001). However, in stable asthma only EDN and ECP levels differed significantly when compared to Controls (p < .0001 and p < .001, respectively). When comparing acute and stable phases, EDN and TECs differed significantly (p < .0001), whereas ECP did not. Symptom scores correlated significantly with EDN (r = 0.850, p < 0.0001), ECP (r = 0.374, p < 0.01) and TECs (r = 0.457, p < 0.01) in acute asthma patients. When symptom scores were divided into three subgroups based on severity, only EDN levels showed significant differences amongst the three groups.
  
  
  CONCLUSIONS
  These findings suggest that serum EDN is a useful marker for identifying disease activity in children with asthma. EDN levels may better reflect disease severity than ECP levels or total eosinophil counts.
authors.affiliation: Asthma and Allergy Center, Department of Pediatrics, Inje University Sanggye Paik Hospital, Seoul, Korea.
authors.forename: Chang-Keun
authors.initials: CK
authors.lastname: Kim
authors.forename: Zak
authors.initials: Z
authors.lastname: Callaway
authors.forename: Rachel
authors.initials: R
authors.lastname: Fletcher
authors.forename: Young Yull
authors.initials: YY
authors.lastname: Koh
mesh_terms: D001249:Asthma / Q000097:blood* / Q000175:diagnosis*; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D002675:Child, Preschool; D018450:Disease Progression; D004797:Enzyme-Linked Immunosorbent Assay; D047150:Eosinophil Cationic Protein / Q000097:blood* / Q000378:metabolism; D047208:Eosinophil-Derived Neurotoxin / Q000097:blood* / Q000378:metabolism; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D011237:Predictive Value of Tests; D011336:Probability; D011379:Prognosis; D012016:Reference Values; D018570:Risk Assessment; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric
chemical_list: D015415:Biomarkers; D047208:Eosinophil-Derived Neurotoxin; D047150:Eosinophil Cationic Protein