Breath tests cover the fraction of nitric oxide in expired gas (F_ENO), volatile organic compounds (VOCs), variables in exhaled breath condensate (EBC) and other measurements. For EBC and forF_ENO, official recommendations for standardised procedures are more than 10 years old and there is none for exhaled VOCs and particles. The aim of this document is to provide technical standards and recommendations for sample collection and analytic approaches and to highlight future research priorities in the field. For EBC andF_ENO, new developments and advances in technology have been evaluated in the current document. This report is not intended to provide clinical guidance on disease diagnosis and management.Clinicians and researchers with expertise in exhaled biomarkers were invited to participate. Published studies regarding methodology of breath tests were selected, discussed and evaluated in a consensus-based manner by the Task Force members.Recommendations for standardisation of sampling, analysing and reporting of data and suggestions for research to cover gaps in the evidence have been created and summarised.Application of breath biomarker measurement in a standardised manner will provide comparable results, thereby facilitating the potential use of these biomarkers in clinical practice.

In asthma, the acute increment of airway responsiveness caused by exposure to allergen is associated with influx of eosinophils into the airways. The relationship between chronic airway hyperresponsiveness and airway inflammation is unclear, as they do not change consistently following long-term anti-inflammatory treatments. We studied 71 patients with chronic asthma and allergic sensitizization to perennial allergens. Airway responsiveness was determined by inhalation of methacholine, and airway inflammation was quantified by induced sputum (n = 28) or bronchoalveolar lavage (n = 43) and bronchial biopsy (n = 20). The relationships between airway responsiveness and the numbers of different inflammatory cells were assessed by multiple regression analysis. No significant correlations were found between the degree of airway responsiveness and the numbers of inflammatory cells in sputum or bronchoalveolar lavage or bronchial biopsy. By contrast, baseline lung function was inversely related to the numbers of eosinophils and directly related to the numbers of macrophages. The eosinophil cationic protein contents of either sputum or bronchoalveolar lavage were significantly correlated with the percentages of eosinophils but not with airway responsiveness. We suggest that other factors (e.g., airway wall remodeling or autonomic dysfunction) may be responsible for most of the interindividual variability of airway responsiveness in asthma.

Linezolid is used off-label to treat multidrug-resistant tuberculosis (MDR-TB) in absence of systematic evidence. We performed a systematic review and meta-analysis on efficacy, safety and tolerability of linezolid-containing regimes based on individual data analysis.12 studies (11 countries from three continents) reporting complete information on safety, tolerability, efficacy of linezolid-containing regimes in treating MDR-TB cases were identified based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Meta-analysis was performed using the individual data of 121 patients with a definite treatment outcome (cure, completion, death or failure).Most MDR-TB cases achieved sputum smear (86 (92.5%) out of 93) and culture (100 (93.5%) out of 107) conversion after treatment with individualised regimens containing linezolid (median (inter-quartile range) times for smear and culture conversions were 43.5 (21–90) and 61 (29–119) days, respectively) and 99 (81.8%) out of 121 patients were successfully treated. No significant differences were detected in the subgroup efficacy analysis (daily linezolid dosage ≤600 mgversus>600 mg). Adverse events were observed in 63 (58.9%) out of 107 patients, of which 54 (68.4%) out of 79 were major adverse events that included anaemia (38.1%), peripheral neuropathy (47.1%), gastro-intestinal disorders (16.7%), optic neuritis (13.2%) and thrombocytopenia (11.8%). The proportion of adverse events was significantly higher when the linezolid daily dosage exceeded 600 mg.The study results suggest an excellent efficacy but also the necessity of caution in the prescription of linezolid.

Large studies on bedaquiline used to treat multidrug-resistant (MDR-) and extensively drug-resistant tuberculosis (XDR-TB) are lacking. This study aimed to evaluate the safety and effectiveness of bedaquiline-containing regimens in a large, retrospective, observational study conducted in 25 centres and 15 countries in five continents.428 culture-confirmed MDR-TB cases were analysed (61.5% male; 22.1% HIV-positive, 45.6% XDR-TB). MDR-TB cases were admitted to hospital for a median (interquartile range (IQR)) 179 (92–280) days and exposed to bedaquiline for 168 (86–180) days. Treatment regimens included, among others, linezolid, moxifloxacin, clofazimine and carbapenems (82.0%, 58.4%, 52.6% and 15.3% of cases, respectively).Sputum smear and culture conversion rates in MDR-TB cases were 63.6% and 30.1%, respectively at 30 days, 81.1% and 56.7%, respectively at 60 days; 85.5% and 80.5%, respectively at 90 days and 88.7% and 91.2%, respectively at the end of treatment. The median (IQR) time to smear and culture conversion was 34 (30–60) days and 60 (33–90) days. Out of 247 culture-confirmed MDR-TB cases completing treatment, 71.3% achieved success (62.4% cured; 8.9% completed treatment), 13.4% died, 7.3% defaulted and 7.7% failed. Bedaquiline was interrupted due to adverse events in 5.8% of cases. A single case died, having electrocardiographic abnormalities that were probably non-bedaquiline related.Bedaquiline-containing regimens achieved high conversion and success rates under different nonexperimental conditions.