title: Exhaled nitric oxide and carbon monoxide in lung transplanted patients.
abstract: BACKGROUND
  Exhaled nitric oxide (eNO) and carbon monoxide (eCO) are markers of pulmonary inflammation associated with acute graft rejection and lung infections in lung transplant (LTX) recipients. Regarding eNO and eCO levels in LTX patients affected by bronchiolitis obliterans syndrome (BOS), published data are discordant.
  
  
  OBJECTIVE
  We aim to evaluate eNO at multiple flows, alveolar concentration of nitric oxide (CalvNO), maximum conducting airway wall flux (J'awNO) and eCO levels in LTX patients to assess the potential role of these parameters in BOS evaluation.
  
  
  METHODS
  Fractional exhaled nitric oxide (FeNO), CalvNO and J'awNO were analysed in 30 healthy subjects and 27 stable LTX patients (12 BOS patients). Pulmonary function tests were performed after eNO and eCO assessment. Receiver operating characteristic (ROC) curves were conducted to evaluate diagnostic accuracy for BOS of eNO parameters.
  
  
  RESULTS
  LTX patients reported higher values of FeNO at flow rates of 50 (p < 0.01), 150 (p < 0.05), 350 ml/s (p < 0.001), and CalvNO (p < 0.0001) than healthy controls. BOS patients showed higher FeNO at flow rates of 150 (p < 0.05) and 350 ml/s (p < 0.01) and CalvNO (p < 0.001) than non-BOS patients. CalvNO reported a remarkable diagnostic accuracy for BOS (AUC: 0.82). There were no significant differences of eCO levels between LTX patients and healthy controls.
  
  
  CONCLUSIONS
  LTX patients affected by BOS showed higher levels of FeNO 150 and 350, and CalvNO than non-BOS LTX patients, probably due to chronic airway inflammation and fibrotic remodelling. CalvNO may be a potential biomarker of BOS in LTX patients.
authors.affiliation: Department of Medical and Surgical Sciences and Neurosciences, Respiratory Disease and Lung Transplantation Section, Le Scotte Hospital, Viale Bracci 16, Siena, Italy. Electronic address: paolocameli88@gmail.com.
authors.forename: P
authors.initials: P
authors.lastname: Cameli
authors.affiliation: Department of Medical and Surgical Sciences and Neurosciences, Respiratory Disease and Lung Transplantation Section, Le Scotte Hospital, Viale Bracci 16, Siena, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Bargagli
authors.affiliation: Department of Medical and Surgical Sciences and Neurosciences, Respiratory Disease and Lung Transplantation Section, Le Scotte Hospital, Viale Bracci 16, Siena, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Fossi
authors.affiliation: Department of Medical and Surgical Sciences and Neurosciences, Respiratory Disease and Lung Transplantation Section, Le Scotte Hospital, Viale Bracci 16, Siena, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Bennett
authors.affiliation: Thoracic Surgery, University Hospital Careggi, Largo Brambilla 3, Firenze, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Voltolini
authors.affiliation: Department of Medical and Surgical Sciences and Neurosciences, Respiratory Disease and Lung Transplantation Section, Le Scotte Hospital, Viale Bracci 16, Siena, Italy.
authors.forename: R M
authors.initials: RM
authors.lastname: Refini
authors.affiliation: Department of Medical and Surgical Sciences and Neurosciences, UOC Thoracic Surgery, Le Scote Hospital, Viale Bracci 16, Siena, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Gotti
authors.affiliation: Department of Medical and Surgical Sciences and Neurosciences, Respiratory Disease and Lung Transplantation Section, Le Scotte Hospital, Viale Bracci 16, Siena, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Rottoli
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000378:metabolism; D001944:Breath Tests / Q000379:methods; D001989:Bronchiolitis Obliterans / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D002248:Carbon Monoxide / Q000378:metabolism*; D016022:Case-Control Studies; D045853:Exhalation / Q000502:physiology; D005260:Female; D006801:Humans; D016040:Lung Transplantation / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000378:metabolism*; D012129:Respiratory Function Tests
chemical_list: D015415:Biomarkers; D009569:Nitric Oxide; D002248:Carbon Monoxide
keywords: Biomarker; Bronchiolitis obliterans syndrome; Lung transplantation; Nitric oxide