LAUSR

INTRODUCTION Short telomeres are recognized as risk factor for idiopathic pulmonary fibrosis (IPF). We aimed to assess the role of telomere length (TL) in fibrotic-Interstitial Lung Diseases (f-ILDs) associated with a usual interstitial pneumonia (UIP) pattern as well as in IPF acute exacerbation (IPF-AE). AIM AND METHODS TL was measured from peripheral white blood cells using a multiplex quantitative polymerase chain reaction in consecutive patients with f-ILDs, all presenting UIP pattern in the high-resolution chest-computed-tomography and compared to age-matched healthy controls. RESULTS Seventy-nine individuals were included (mean age 69.77 ± 0.72 years); 24 stable IPF, 18 IPF-AE, 10 combined pulmonary fibrosis and emphysema, 7 Rheumatoid arthritis-UIP-ILDs and 20 controls. TL in all patients was significantly shorter compared to controls [mean T/S ratio (SE) 0.77 (±0.05) vs 2.26 (±0.36), p < 0.001] as well as separately in each one of f-ILD subgroups. IPF-AE patients presented significantly shorter TL compared to stable IPF (p = 0.029). Patients with IPF and shorter than the median TL (0-0.72) showed reduced overall survival (p = 0.004). T/S < 0.72 was associated with increased risk for IPF-AE (OR = 30.787, 95% CI: 2.153, 440.183, p = 0.012) independent of age, gender, smoking and lung function impairment. A protective effect of TL was observed, as it was inversely associated with risk of death both in UIP-f-ILDs (HR = 0.174, 95%CI: 0.036, 0.846, p = 0.030) and IPF patients (HR = 0.096, 95%CI: 0.011, 0.849, p = 0.035). CONCLUSIONS Shorter TL characterizes different UIP f-ILDs. Although no difference was observed in TL among diverse UIP subgroups, IPF-AE presented shorter TL compared to stable IPF. Reduced overall survival and higher hazard ratio of death are associated with shorter TL in IPF.