title: Presence of IL-5 protein and IgE antibodies to staphylococcal enterotoxins in nasal polyps is associated with comorbid asthma.
abstract: BACKGROUND
  Nasal polyps often are associated with asthma. The phenotype of these patients is unknown.
  
  
  OBJECTIVE
  To identify the mucosal factors associated with asthma comorbidity, we analyzed the inflammatory patterns of nasal polyps.
  
  
  METHODS
  Nasal polyps from 70 Belgian patients, 34% with asthma, were analyzed for type of inflammation, T-cell cytokines, and IgE antibodies to Staphylococcus aureus enterotoxins. The same investigations were repeated in 93 Chinese patients with polyps, a group with a low asthma comorbidity rate (8%).
  
  
  RESULTS
  In Belgian patients with polyps, 54% of samples showed eosinophilic inflammation. A classification tree evaluation identified IL-5 as the main positive determinant. Enterotoxin IgE in tissue (37%) was associated with significantly increased total IgE and eosinophil cationic protein concentrations. Expression of enterotoxin IgE, total IgE at greater than 1,442 kU/L, and eosinophil cationic protein at greater than 17,109 μg/L in samples with a total IgE concentration of greater than 246 kU/L significantly predicted asthma (odds ratio, 5.8-13). Only 7.5% of the samples from Chinese patients with polyps showed eosinophilic inflammation. IL-5 was confirmed as a positive determinant of eosinophilic inflammation, and enterotoxin IgE in tissue (17% of patients) was associated with significantly increased total IgE and eosinophil cationic protein concentrations. The expression of IL-5 or total IgE at greater than 790 kU/L in samples with an IL-5 concentration of greater than 194 pg/mL significantly predicted comorbid asthma (odds ratio, 17.2-96).
  
  
  CONCLUSIONS
  Mucosal inflammation in nasal polyps orchestrated by T(H)2 cytokines and amplified by S aureus enterotoxins is characterized by an increased eosinophilic inflammation and formation of IgE antibodies. This phenotype is associated with comorbid asthma in white and Asian patients with nasal polyps.
authors.affiliation: Upper Airway Research Laboratory, Department of Oto-Rhino-Laryngology, Ghent University Hospital, Ghent, Belgium. claus.bachert@ugent.be
authors.forename: Claus
authors.initials: C
authors.lastname: Bachert
authors.forename: Nan
authors.initials: N
authors.lastname: Zhang
authors.forename: Gabriele
authors.initials: G
authors.lastname: Holtappels
authors.forename: Lizzy
authors.initials: L
authors.lastname: De Lobel
authors.forename: Paul
authors.initials: P
authors.lastname: van Cauwenberge
authors.forename: Shixi
authors.initials: S
authors.lastname: Liu
authors.forename: Ping
authors.initials: P
authors.lastname: Lin
authors.forename: Jean
authors.initials: J
authors.lastname: Bousquet
authors.forename: Kristel
authors.initials: K
authors.lastname: Van Steen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001249:Asthma / Q000453:epidemiology / Q000276:immunology* / Q000473:pathology; D002648:Child; D015897:Comorbidity; D004768:Enterotoxins / Q000276:immunology*; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology*; D007249:Inflammation / Q000276:immunology / Q000473:pathology; D015848:Interleukin-5 / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D009298:Nasal Polyps / Q000453:epidemiology / Q000276:immunology* / Q000473:pathology; D013211:Staphylococcus aureus / Q000276:immunology*; D055815:Young Adult
chemical_list: D004768:Enterotoxins; C508599:IL5 protein, human; D015848:Interleukin-5; D007073:Immunoglobulin E