TY - JOUR T1 - Longitudinal assessment of Lung Clearance Index as a marker of disease progression in a cohort of children with cystic fibrosis and normal spirometry JF - European Respiratory Journal JO - Eur Respir J DO - 10.1183/13993003.congress-2020.4315 VL - 56 IS - suppl 64 SP - 4315 AU - Jacquelyn Spano AU - Sean Ryan AU - Carlos Milla Y1 - 2020/09/07 UR - http://erj.ersjournals.com/content/56/suppl_64/4315.abstract N2 - Objectives: The lung clearance index at 2.5 of starting concentration (LCI2.5) from Nitrogen multiple breath washout (MBW) has demonstrated sensitivity to early lung disease in Cystic Fibrosis (CF). Our study aims to evaluate if the LCI2.5 can identify lung disease progression in children with CF with normal lung function by spirometry.Methods: We have enrolled 57 children with CF (mean age 10.3 + 3, range 6 - 18 years; 22 boys, 35 girls) into a longitudinal study that evaluates spirometry, MBW and patient reported outcomes at clinical encounters. Our main endpoint is FEV1 decline over one year.Results: At baseline these children demonstrated normal parameters (mean FVC 99.2 + 20 %-pred., FEV1 94 + 21 %-pred., FEV1/FVC ratio 0.84 + 0.12; BMI 61 + 24 %-ile), with no significant differences between boys and girls (p > 0.25 for all). However, by LCI there was evidence for airway disease (Mean 9.4 units + 2.6) and with no differences between boys and girls (p = 0.5).At baseline modest correlation was found between LCI and FEV1%-pred. (r 0.45, p = 0.001). During follow up, on average no significant change in FEV1 was noted (p = 0.57). However, there was an inverse correlation between baseline LCI and FEV1 decline (-2.5 %-pred./year for every unit of LCI2.5, p= 0.0001) and between change in LCI2.5 and FEV1 decline (-2.0 %-pred./year for every unit of increase in LCI2.5, p < 0.0001).Conclusion: The LCI2.5 from MBW identifies children with subsequent decline in FEV1. One unit increase in LCI seems to be a strong indicator of lung disease activity.Funding Source: US CFF MILLA17A0FootnotesCite this article as: European Respiratory Journal 2020; 56: Suppl. 64, 4315.This abstract was presented at the 2020 ERS International Congress, in session “Respiratory viruses in the "pre COVID-19" era”.This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only). ER -