Role of Telomere Length in Survival of Patients with Idiopathic Pulmonary Fibrosis and Other Interstitial Lung Diseases

Abstract

Interstitial lung diseases (ILDs) constitute a group of more than 200 disorders, with idiopathic pulmonary fibrosis (IPF) being one of the most frequent. Telomere length (TL) shortening causes loss of function of the lung parenchyma. However, little is known about its role as a prognostic factor in ILD patients. With the aim of investigating the role of TL and telomerase activity in the prognosis of patients affected by ILDs, we analysed lung tissue samples from 61 patients. We measured relative TL and telomerase activity by conventional procedures. Both clinical and molecular parameters were associated with overall survival by the Kaplan–Meier method. Patients with IPF had poorer prognosis than patients with other ILDs (p = 0.034). When patients were classified according to TL, those with shortened telomeres reported lower overall survival (p = 0.085); differences reached statistical significance after excluding ILD patients who developed cancer (p = 0.021). In a Cox regression analysis, TL behaved as a risk-modifying variable for death associated with rheumatic disease (RD) co-occurrence (p = 0.029). Also, in patients without cancer, ferritin was significantly increased in cases with RD and IPF co-occurrence (p = 0.032). In relation to telomerase activity, no significant differences were detected. In conclusion, TL in lung tissue emerges as a prognostic factor in ILD patients. Specifically, in cases with RD and IPF co-occurrence, TL can be considered as a risk-modifying variable for death.