title: Correlation between levels of exhaled hydrogen sulfide and airway inflammatory phenotype in patients with chronic persistent asthma.
abstract: OBJECTIVE
  Endogenous hydrogen sulfide (H2 S) may be a biomarker of asthma severity and activity. However, the relationship between exhaled H2 S and airway inflammation phenotypes in asthma remains unclear. This study examined associations between endogenous H2 S and chronic airway inflammatory phenotypes in patients with chronic persistent asthma.
  
  
  METHODS
  One hundred forty-eight patients (47 males, 101 females, 47.4 ± 15.3 years old) with chronic persistent asthma were enrolled. Induced sputum cells were examined, and patients were grouped according to sputum inflammatory cell composition. Baseline demographics, Asthma Control Test (ACT) scores, spirometry data and H₂S levels in exhaled air and plasma were obtained for all patients.
  
  
  RESULTS
  The eosinophilic, neutrophilic, mixed granulocytic and paucigranulocytic inflammation groups included 57 (38.5%), 28 (18.9%), 23 (15.5%) and 40 (27%) subjects, respectively. The paucigranulocytic group had the best lung function, and patients with eosinophilic inflammation had lower ACT scores than patients with paucigranulocytic findings. In the eosinophilic group, lower exhaled H₂S were found and exhaled H2 S levels were negatively correlated with sputum eosinophil counts (R = -0.428, P < 0.01). Exhaled H2 S levels were positively correlated with percent of predicted forced expiratory volume in 1 s (R = 0.567, P < 0.01) and ACT score (R = 0.519, P < 0.01).
  
  
  CONCLUSIONS
  Exhaled H2 S may be a useful marker of airway inflammation in asthma.
authors.affiliation: Department of Respiratory Diseases, Peking University Third Hospital, Beijing, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.forename: Xinmao
authors.initials: X
authors.lastname: Wang
authors.forename: Yahong
authors.initials: Y
authors.lastname: Chen
authors.forename: Wanzhen
authors.initials: W
authors.lastname: Yao
mesh_terms: D000328:Adult; D001249:Asthma / Q000175:diagnosis / Q000378:metabolism / Q000503:physiopathology; D015415:Biomarkers / Q000032:analysis; D045853:Exhalation; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D006862:Hydrogen Sulfide / Q000032:analysis*; D007249:Inflammation / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide; D062072:Patient Acuity; D010641:Phenotype; D012129:Respiratory Function Tests; D012137:Respiratory System / Q000378:metabolism / Q000503:physiopathology; D013183:Sputum / Q000378:metabolism*; D013223:Statistics as Topic
chemical_list: D015415:Biomarkers; D009569:Nitric Oxide; D006862:Hydrogen Sulfide
keywords: airway inflammation; chronic persistent asthma; correlation; hydrogen sulfide; lung function