RT Journal Article SR Electronic T1 LSC Abstract – Increased oxidative stress leads to telomere shortening in children with alpha-1 antitrypsin deficiency JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP PA896 DO 10.1183/13993003.congress-2016.PA896 VO 48 IS suppl 60 A1 Sara Pastor A1 Amparo Escribano A1 Silvia Castillo A1 Ana Reula A1 María Mercedes Navarro-García A1 Francisco Sanz A1 Estrella Fernandez-Fabrellas A1 Pilar Codoñer-Franch A1 Francisco Jose Dasi Fernandez YR 2016 UL http://erj.ersjournals.com/content/48/suppl_60/PA896.abstract AB Background: Oxidative stress (OS) is involved in the pathophysiology of AATD (Escribano A. et al. Thorax 2015; 70:82-3). In addition, it has been shown that OS accelerates telomere shortening which is associated to higher emphysema risk in COPD patients.Rationale and aims: Since AATD is characterised by chronic OS, we hypothesise that telomere shortening would be accelerated in AATD patients and would be associated with higher risk of developing lung disease. This study is aimed to assess the OS profile, the enzymatic antioxidant defence mechanisms and telomere length (TL) in children with AATD and to study its association with AAT phenotypes.Methods: OS parameters, the activity of the main antioxidant enzymes and TL were prospectively measured in fifty-one children diagnosed with alpha-1 antitrypsin deficiency and thirty-eight control individuals.Results: AATD patients showed higher GSSG/GSH ratio (p=0.001; p<0.0001, respectively), malondialdehyde (p=0.004; p<0.0001), 8-OHdG (p<0.0001; p<0.0001) and oxidized proteins (p=0.01; p=0.002) than the control group, while total (p<0.0001; p<0.0001) and reduced glutathione levels (p <0.0001; p<0.0001) were decreased. Catalase activity was decreased (p=0.003; p<0.001) leading to the accumulation of H2O2 (p=0.04; p=0.001), which would explain the high levels of OS observed. TL is decreased in patients with AATD compared to control subjects (p<0.001).Conclusions: Increased OS lead to accelerated telomere shortening in AATD patients. An association between OS, TL and risk of developing lung/liver disease is observed.Funding: SEPAR 2013 and ISCIII (PI14/02162) grants.This abstract has been presented previously at the European Respiratory Society's Lung Science Conference in March 2016.