title: Simultaneously elevated exhaled nitric oxide and serum-eosinophil cationic protein relate to recent asthma events in asthmatics in a cross-sectional population-based study.
abstract: We have reported that increased fraction of exhaled nitric oxide (FeNO), a measure of TH2-driven airway inflammation, and blood eosinophil count, a marker of systemic eosinophil inflammation, correlated with asthma attacks in a population-based study.
  
  
  
  To investigate the relation between simultaneously elevated FeNO and serum eosinophil cationic protein (S-ECP) levels and asthma events among asthmatics.
  
  
  
  Measurements of FeNO (elevated ≥ 25 ppb) and S-ECP (elevated ≥ 20 ng/mL) were performed in 339 adult asthmatics. Asthma events (attacks and symptoms) were self-reported.
  
  
  
  Simultaneously normal S-ECP and FeNO levels were found in 48% of the subjects. Subjects with simultaneously elevated S-ECP and FeNO (13% of the population) had a higher prevalence of asthma attacks in the preceding 3 months than subjects with normal S-ECP and FeNO (51% vs. 25%, P = 0.001). This was not found for subjects with singly elevated S-ECP (P = 0.14) or FeNO (P = 0.34) levels. Elevated S-ECP and FeNO levels were independently associated with asthma attacks in the preceding 3 months after adjusting for potential confounders (OR (95% CI) 4.2 (2.0-8.8).
  
  
  
  Simultaneously elevated FeNO and S-ECP levels were related to a higher likelihood of asthma attacks in the preceding 3 months. This indicates that there is a value in measuring both FeNO and systemic eosinophilic inflammation in patients with asthma to identify individuals at high risk of exacerbations.
  
  
  
  FeNO and S-ECP are markers for inflammation in asthma, but are dependent on different inflammatory pathways and weakly correlated. Simultaneous measurements of both offer better risk characterization of adult asthmatics.
authors: Department of Medical Sciences: Lung-, Allergy- and Sleep Research, Uppsala University, Uppsala, Sweden.
authors: I
authors: 0000-0002-0198-2718
authors: I
authors: Mogensen
authors: Department of Women's and Children's Health, Uppsala University, Uppsala, Sweden.
authors: K
authors: K
authors: Alving
authors: Department of Women's and Children's Health: Clinical Paediatrics, Karolinska Institute, Stockholm, Sweden.
authors: A
authors: A
authors: Bjerg
authors: Department of Women's and Children's Health, Uppsala University, Uppsala, Sweden.
authors: M P
authors: MP
authors: Borres
authors: Department of Women's and Children's Health: Clinical Paediatrics, Karolinska Institute, Stockholm, Sweden.
authors: G
authors: G
authors: Hedlin
authors: Department of Public Health and Clinical Medicine: Occupational Medicine, Umeå University, Umeå, Sweden.
authors: J
authors: J
authors: Sommar
authors: Experimental Asthma and Allergy Research Unit: Institute of Environmental Medicine, Karolinska Institute, Stockholm, Sweden.
authors: S-E
authors: SE
authors: Dahlén
authors: Department of Medical Sciences: Lung-, Allergy- and Sleep Research, Uppsala University, Uppsala, Sweden.
authors: C
authors: C
authors: Janson
authors: Department of Medical Sciences: Clinical Physiology, Uppsala University, Uppsala, Sweden.
authors: A
authors: A
authors: Malinovschi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001249:Asthma / Q000175:diagnosis* / Q000188:drug therapy / Q000453:epidemiology / Q000378:metabolism*; D015415:Biomarkers; D003430:Cross-Sectional Studies; D018450:Disease Progression; D047150:Eosinophil Cationic Protein / Q000097:blood*; D004804:Eosinophils / Q000276:immunology / Q000378:metabolism; D045853:Exhalation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000378:metabolism*; D016017:Odds Ratio; D011159:Population Surveillance; D012129:Respiratory Function Tests; D012882:Skin Tests; D013548:Sweden / Q000453:epidemiology; D063189:Symptom Assessment; D055815:Young Adult
chemical_list: D015415:Biomarkers; D009569:Nitric Oxide; D047150:Eosinophil Cationic Protein
keywords: asthma; clinical immunology; epidemiology