Serum biomarkers in ILA and familial Early ILD.

<bold>Introduction:</bold> Interstitial lung abnormalities(ILA) are incidental findings at thorax computed tomography in asymptomatic patients that could progress and could be sporadic (ILA) or with a genetic substrate(EARLY interstitial lung disease(ILD)). <bold>Aims:</bold> The aim of this study was to analyze serum biomarkers and clinical behavior of subjects with ILA(incidental sporadic mild ILD) with healthy controls(Control-ILA) and subjects with mild ILD with a 1st degree familial ILD(EARLY familial ILD) and without it (familial control-EARLY). <bold>Methods:</bold> Serum levels of KL6,GAL3,CCL18,SPD and αKlotho were quantified by ELISA.Demographic,genetic and pulmonary function tests(PFT) including FVC,TLC,DLCO and 6-minute walking test were evaluated.Correlations were performed between serum biomarkers and functional parameters.Parametric and non-parametric statistical tests were used.p<0.05 was considered statistically significant. <bold>Results:</bold> ILA patients were older than EARLY ones with a higher proportion of males and less smokers than their controls in both groups.TLC was diminished in ILA compared with their controls (p<0.05).DLCO was decreased in ILA and EARLY compared with their controls (p<0.05).The majority of ILA patients showed MUC5B polymorphism(rs357059509), while telomeric alterations, MUC5B and variants of uncertain significance(VUS) were observed in EARLY patients.Regarding baseline serum biomarkers,ILA had increased KL6, SPD and α-Klotho compared to their controls, while EARLY had increased KL6 and decreased α-Klotho(p<0.05).A negative correlation between SPD and FVC was observed in EARLY subjects. <bold>Conclusions:</bold> KL6 and αKlotho in both groups and SPD in ILA are the most altered biomarkers in our cohort.This different profile could impact on ILD progression.