No abstract

The ECFS-CTN Standardisation Committee has undertaken this review of lung clearance index as part of the group's work on evaluation of clinical endpoints with regard to their use in multicentre clinical trials in CF. The aims were 1) to review the literature on reliability, validity and responsiveness of LCI in patients with CF, 2) to gain consensus of the group on feasibility of LCI and 3) to gain consensus on answers to key questions regarding the promotion of LCI to surrogate endpoint status. It was concluded that LCI has an attractive feasibility and clinimetric properties profile and is particularly indicated for multicentre trials in young children with CF and patients with early or mild CF lung disease. This is the first article to collate the literature in this manner and support the use of LCI in clinical trials in CF.

[1] Postfire changes in the local energy balance and soil chemistry may significantly alter rates of carbon turnover in organic-rich soils of boreal forests. This study combines field measurements of soil carbon uptake and emission along a 140-year chronosequence of burned black spruce stands to evaluate the timescales over which these disturbance effects operate. Soil CO 2 efflux increased as a function of stand age at a mean rate of 0.12 Mg C ha À1 yr À2 up to a maximum of 2.2 Mg C ha À1 yr À1 in the 140-year-old stand. During this same time period, organic soil horizons sequestered carbon and nitrogen at rates of 0.28-0.54 and 0.0076 Mg N ha À1 yr À1 , respectively. A mass balance model based on field measurements suggests that postfire changes in root and microbial respiration caused these soils to function as a net source of carbon for 7-15 years after fire, releasing between 1.8 and 11.0 Mg C ha À1 to the atmosphere (12.4-12.6% of total soil organic matter). These estimates are on the same order of magnitude as carbon losses during combustion and suggest that current models may underestimate the effect of fire on carbon emissions by a factor of 2.

The lung clearance index is repeatable and a more sensitive measure than FEV1 in the detection of abnormalities demonstrated on CT scan. The lung clearance index has the potential to be a useful clinical and research tool in patients with bronchiectasis.