title: Total serum IgE levels in a large cohort of patients with severe or difficult-to-treat asthma.
abstract: BACKGROUND
  Limited data are available on levels of IgE in large cohorts of patients with severe or difficult-to-treat asthma.
  
  
  OBJECTIVE
  To examine IgE levels and disease in patients from The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens (TENOR) study.
  
  
  METHODS
  From January 2001 to October 2001, 4,923 patients were screened for inclusion in the study. Of these, 4,756 patients 6 years or older with severe or difficult-to-treat asthma were enrolled and completed a baseline study visit. Total serum IgE levels were measured at the baseline visit and are summarized by geometric means.
  
  
  RESULTS
  The mean total IgE level of the population is 106.6 IU/mL (95% confidence interval, 101.5-112.0 IU/mL). Children (6-12 years old) and adolescents (13-17 years old) have higher mean IgE levels than adults (> or =18 years old) (P < .001). Males have a higher mean IgE level than females (P < .001). IgE levels are higher among nonwhite patients than white patients (P < .001). Current smokers have higher IgE levels than past smokers or never smokers (P < .001). Among children, patients with severe asthma have a higher mean IgE level (280.2 IU/mL) than patients with moderate (145.8 IU/mL) or mild (137.8 IU/mL) asthma (P < .001). Among adults, patients with childhood-onset asthma have higher IgE levels (124.3 IU/mL [n = 1,348]) than patients with adult-onset asthma (65.7 IU/mL [n = 1,956]) (P < .001).
  
  
  CONCLUSIONS
  In patients with severe or difficult-to-treat asthma from the TENOR study, higher total IgE levels were observed in males, children, smokers, nonwhite racial/ethnic groups, and adults with childhood-onset disease. In addition, IgE levels are associated with asthma severity among younger patients.
authors.affiliation: University of Virginia, Charlottesville, Virginia, USA.
authors.forename: Larry
authors.initials: L
authors.lastname: Borish
authors.forename: Bradley
authors.initials: B
authors.lastname: Chipps
authors.forename: Yamo
authors.initials: Y
authors.lastname: Deniz
authors.forename: Sheila
authors.initials: S
authors.lastname: Gujrathi
authors.forename: Beiyao
authors.initials: B
authors.lastname: Zheng
authors.forename: Chantal M
authors.initials: CM
authors.lastname: Dolan
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001249:Asthma / Q000097:blood* / Q000276:immunology / Q000503:physiopathology; D002648:Child; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood*; D008297:Male; D008875:Middle Aged; D012737:Sex Factors; D012907:Smoking
chemical_list: D007073:Immunoglobulin E