title: Certain subphenotypes of aspirin-exacerbated respiratory disease distinguished by latent class analysis.
abstract: BACKGROUND
  Aspirin-exacerbated respiratory disease (AERD) is recognized as a distinct asthma phenotype. It usually has a severe course accompanied by chronic hyperplastic eosinophilic sinusitis with nasal polyps, blood eosinophilia, and increased concentrations of urinary leukotriene E4 (LTE4). More insightful analysis of individual patients shows this group to be nonhomogeneous.
  
  
  OBJECTIVE
  We sought to identify any likely subphenotypes in a cohort of patients with AERD through the application of latent class analysis (LCA).
  
  
  METHODS
  Clinical data from 201 patients with AERD (134 women) were collected from questionnaires. Standard spirometry, atopy traits, blood eosinophilia, and urinary LTE4 concentrations were evaluated. LCA was applied to identify possible AERD subphenotypes.
  
  
  RESULTS
  Four classes (subphenotypes) within the AERD phenotype were identified as follows: class 1, asthma with a moderate course, intensive upper airway symptoms, and blood eosinophilia (18.9% of patients); class 2, asthma with a mild course, relatively well controlled, and with low health care use (34.8% of patients); class 3, asthma with a severe course, poorly controlled, and with severe exacerbations and airway obstruction (41.3% of patients); and class 4, poorly controlled asthma with frequent and severe exacerbations in female subjects (5.0% of patients). Atopic status did not affect class membership. Patients with particularly intensive upper airway symptoms had the highest levels of blood eosinophilia and the highest concentrations of urinary LTE4.
  
  
  CONCLUSIONS
  LCA revealed unique AERD subphenotypes, thus corroborating the heterogeneity of this population. Such discrimination might facilitate more individualized treatment in difficult-to-treat patients.
authors.affiliation: Department of Internal Medicine, Jagiellonian University Medical College, Krakow, Poland. Electronic address: mmbochen@cyf-kr.edu.pl.
authors.forename: Grazyna
authors.initials: G
authors.lastname: Bochenek
authors.affiliation: Department of Internal Medicine, Jagiellonian University Medical College, Krakow, Poland.
authors.forename: Joanna
authors.initials: J
authors.lastname: Kuschill-Dziurda
authors.affiliation: Department of Epidemiology and Population Studies, Institute of Public Health, Jagiellonian University Medical College, Krakow, Poland.
authors.forename: Krystyna
authors.initials: K
authors.lastname: Szafraniec
authors.affiliation: Department of Internal Medicine, Jagiellonian University Medical College, Krakow, Poland.
authors.forename: Hanna
authors.initials: H
authors.lastname: Plutecka
authors.affiliation: Department of Internal Medicine, Jagiellonian University Medical College, Krakow, Poland.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Szczeklik
authors.affiliation: Department of Internal Medicine, Jagiellonian University Medical College, Krakow, Poland.
authors.forename: Ewa
authors.initials: E
authors.lastname: Nizankowska-Mogilnicka
mesh_terms: D000328:Adult; D000402:Airway Obstruction / Q000150:complications / Q000175:diagnosis*; D055963:Asthma, Aspirin-Induced / Q000145:classification / Q000150:complications / Q000175:diagnosis*; D002465:Cell Movement; D004804:Eosinophils / Q000473:pathology*; D005260:Female; D006801:Humans; D017999:Leukotriene E4 / Q000652:urine; D008297:Male; D008875:Middle Aged; D009298:Nasal Polyps / Q000150:complications / Q000175:diagnosis*; D012852:Sinusitis / Q000150:complications / Q000175:diagnosis*; D013147:Spirometry; D013223:Statistics as Topic
chemical_list: D017999:Leukotriene E4
keywords: AERD; Aspirin; Aspirin-exacerbated respiratory disease; Cysteinyl leukotriene; ED; Emergency department; ICU; Intensive care unit; LCA; LTE(4); Latent class analysis; Leukotriene E(4); NAEPP EPR3; NSAID; National Asthma Education and Prevention Program Expert Panel Report 3; Nonsteroidal anti-inflammatory drug; TENOR; The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens; aspirin-exacerbated respiratory disease; asthma phenotype; cysLT; latent class analysis; nonsteroidal anti-inflammatory drugs