Proinflammatory action of Exhaled Breath Condensate in children with severe asthma: Predictive value for exacerbations.

<bold>Background:</bold> severe exacerbations (SE) are the most relevant complication in severe asthma (SA), predicting them is a main goal. Exhaled Breath Condensate (EBC) contains active molecules. EBC of asthmatic children affect cell cultures in a different way than EBC of healthy children. <bold>Aims:</bold> assess whether EBC from children with SA exhibits proinflammatory activity in human respiratory epithelium cell cultures (HREC) and if this activity predict SE. <bold>Methods:</bold> prospective study in two Pulmonology Departments. Children undergo selected measurements: anthropometry, evaluation of inhaler technique and treatment adherence, ACT, screening for SDB (PSQ), pre and post β2 spirometry, FeNO, and history of SE (ATS/ERS 2009: at least 3 days of sistemic steroids) in the previous year. A sample of EBC was collected (TurboDECCS) and added to HREC. Patients were followed every two months and SE were recorded. The association between SE and the proinflammatory action of EBC on cell cultures, as well as the rest of clinical and functional variables, were estimated. Data from each hospital were analyzed separately since the study was carried out in different periods of respiratory virus circulation. <bold>Results:</bold> Hospital 1=44 children (30% EBC samples induce IL-6 liberation by HREC; 73% has SE in the previous year and 59% has SE in the posterior six months). Hospital 2=70 children (46% of EBC samples induce IL-6 liberation; 51% has SE in the previous year and 27% has SE in the posterior six months). The only predictor for SE in both groups is the history of SE in the previous year (Hospital 1 OR 13; Hospital 2 OR 6). <bold>Conclusion:</bold> previous SE was the unique common predictive factor for SE.