Clinical applications of bronchoalveolar lavage, induced sputum, fractional exhaled nifric oxide and exhaled breath condensate in inflammatory disorders
| Bronchoalveolar lavage | Induced sputum | Fractional exhaled nitric oxide | Exhaled breath condensate | |
| Standardisation | ERS 1–3 | ERS 4 | ATS/ERS 5 | ATS/ERS 6 |
| Reproducibility and validity | Reproducibility assessed and methodology validated in normal subjects and disease status (mainly ILD) | Reproducibility assessed and methodology validated in normal subjects and disease status (mainly asthma, COPD) | Reproducibility assessed and methodology validated in normal subjects and asthma | Data available for some mediators |
| Nature of sample | Biological fluid containing cells and acellular components | Biological fluid containing cells and acellular components | Exhaled air containing NO gas | Biological fluid containing acellular components |
| Biomarker(s) | Differential cell count, specialised markers¶ | Total and differential cell count specialised markers¶ | NO ppb | pH, various mediators |
| Feasibility: facilities and equipment needed | Thoracic endoscopy, basic cellular lab, outsourcing for specialised analyses | Pulmonary function lab, ultrasonic aerosol, basic cellular lab, outsourcing for specialised analyses | NO analyser | EBC condenser, pH analyser, HPLC or MS |
| Time for evaluation | 1 working day+ | 1 working day+ | Online | Online§, days to weeks |
| Main field of application# | ILD, exposure to toxic substances | All airway diseases, ILD, exposure to toxic substances | Asthma and allergic diseases | COPD, asthma allergy, infections, exposure to toxic substances |
| Clinical applications | In the diagnostic process of sarcoidosis, IPF and other ILDs 7–9 | As an additional method to manage asthma 10–15 | As an additional method to manage asthma. 15–20 | NA |
ERS: European Respiratory Society; ATS: American Thoracic Society; ILD: interstitial lung diseases; COPD: chronic obstructive pulmonary disease; NO: nitric oxide; EBC: exhaled breath condensate; HPLC: high performance liquid chromatography; MS: mass spectrometry; IPF: idiopathic pulmonary fibrosis; NA: not available. #: only applications related to inflammatory markers in lung and airway diseases of adult patients are reported; ¶: specialised markers can be diagnostic in bronchoalveolar lavage (e.g. CD1+ cells in histiocytosis X, mineralogic assays for assessing exposure) and in sputum (e.g. asbestos bodies); +: 90 mins is usually sufficient for an expert team to obtain the results, 1 working day is intended for a report in clinical practice; §: online evaluation in EBC is only for pH and H2O2 determination.