title: Prognostic Role of Exhaled Breath Condensate pH and Fraction Exhaled Nitric Oxide in Systemic Sclerosis Related Interstitial Lung Disease.
abstract: BACKGROUND
  Interstitial lung disease (ILD) is one of the major causes of death in systemic sclerosis (SSc). This study investigated exhaled breath (EB) and exhaled breath condensate (EBC) biomarkers in patients with SSc and analyzed their role as a prognostic tool in SSc-related ILD.
  
  
  METHODS
  Fraction exhaled nitric oxide (FeNO) and exhaled carbon monoxide (eCO) measured in EB, together with pH, nitrite, nitrate and interleukin-6 levels measured in EBC were prospectively analyzed in 35 patients with SSc. Twelve patients had established ILD by chest high-resolution computed tomography (HRCT), and 23 patients showed no evidence of ILD. EB and EBC biomarkers were determined at inclusion, and pulmonary function tests were annually performed during 4 years of follow-up.
  
  
  RESULTS
  No differences at baseline biomarkers levels were found between groups. In all patients studied, low EBC pH levels were associated with a decreased diffusing capacity for carbon monoxide (DLCO) during follow-up. Low FeNO levels were correlated with lower forced vital capacity (FVC) at baseline, 4years of follow-up and with a decrease in FVC and DLCO during monitoring. Among ILD patients, high eCO levels were correlated with lower baseline FVC. In the global cohort, a worse progression-free survival was identified in patients with EBC pH values lower than 7.88 and FeNO levels lower than 10.75ppb (Log Rank P=.03 and P<.01, respectively).
  
  
  CONCLUSIONS
  EB and EBC could help to detect patients likely to present a deterioration on lung function during follow up.
authors.affiliation: Unitat de Malalties Autoimmunes Sistèmiques, Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, Barcelona, España. Electronic address: alguille@vhebron.net.
authors.forename: Alfredo
authors.initials: A
authors.lastname: Guillen-Del Castillo
authors.affiliation: Servei de Pneumologia, Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, Barcelona, España; Ciber de Enfermedades Respiratorias (CIBERES), España.
authors.forename: Sara
authors.initials: S
authors.lastname: Sánchez-Vidaurre
authors.affiliation: Unitat de Malalties Autoimmunes Sistèmiques, Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, Barcelona, España.
authors.forename: Carmen P
authors.initials: CP
authors.lastname: Simeón-Aznar
authors.affiliation: Servei de Pneumologia, Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, Barcelona, España; Ciber de Enfermedades Respiratorias (CIBERES), España.
authors.forename: María J
authors.initials: MJ
authors.lastname: Cruz
authors.affiliation: Unitat de Malalties Autoimmunes Sistèmiques, Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, Barcelona, España.
authors.forename: Vicente
authors.initials: V
authors.lastname: Fonollosa-Pla
authors.affiliation: Servei de Pneumologia, Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, Barcelona, España; Ciber de Enfermedades Respiratorias (CIBERES), España; Departament de Biologia Cel·lular, Fisiologia i Immunologia, Universitat Autònoma de Barcelona, Barcelona, España.
authors.forename: Xavier
authors.initials: X
authors.lastname: Muñoz
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000032:analysis; D001944:Breath Tests; D045853:Exhalation; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D017563:Lung Diseases, Interstitial / Q000209:etiology / Q000378:metabolism* / Q000401:mortality; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000032:analysis / Q000378:metabolism*; D011379:Prognosis; D011446:Prospective Studies; D012595:Scleroderma, Systemic / Q000150:complications / Q000378:metabolism* / Q000401:mortality; D015996:Survival Rate
chemical_list: D015415:Biomarkers; D009569:Nitric Oxide
keywords: Aire exhalado; Enfermedad pulmonar intersticial; Esclerosis sistémica; Exhaled breath; Interstitial lung disease; Nitric oxide; Systemic sclerosis; pH; Óxido nítrico