ePS06.4 Upper airway infection and inflammation in CF and healthy controls during exacerbation and stable phases

Objectives Upper airway (UAW) infections are common in CF patients with nasal congestion, impaired climate function and reduced quality of life. Moreover, by postnasal drip, infections can descend to the lungs. Actually, there are no data comparing UAW infection and inflammation in CF and healthy controls in stable phases and during exacerbation. Methods We collected epithelial lining fluid from 49 CF patients and 38 healthy controls by nasal lavage in stable phases and during UAW infection. Microbiological (only CF cohort), cytological and immunological analyses (NE/IL-6/IL-8/IL-1β/MMP-9/TIMP-1) were performed. Results During UAW infection all measured inflammatory mediators increased in both, CF patients and the control cohort. Whereas levels of IL-6 and IL-8 were significantly higher in CF under stable conditions compared to healthy controls, the levels of the control cohort exceeded those of CF patients during infection. Age-stratified analyses showed higher releases of mediators during acute UAW infection in CF patients ≤12 years, especially for MMP-9, IL-8 and TIMP-1. These findings were not present in controls. Conclusion In CF patients, chronic inflammation with higher values of inflammatory mediators compared to healthy controls was observed. However, the increase of inflammation during UAW infection is not higher in CF compared to healthy controls. In contrast, for all measured parameters except TIMP-1 a weaker increase was observed in CF, suggesting a deregulation of the immune system in CF with a decreased ability of mediator release. This hypothesis is also supported by the observation of higher releases of MMP-9, TIMP-1 and IL-8 in younger CF patients.