title: Telomere length in interstitial lung diseases.
abstract: BACKGROUND
  Interstitial lung disease (ILD) is a heterogeneous group of rare diseases that primarily affect the pulmonary interstitium. Studies have implicated a role for telomere length (TL) maintenance in ILD, particularly in idiopathic interstitial pneumonia (IIP). Here, we measure TL in a wide spectrum of sporadic and familial cohorts of ILD and compare TL between patient cohorts and control subjects.
  
  
  METHODS
  A multiplex quantitative polymerase chain reaction method was used to measure TL in 173 healthy subjects and 359 patients with various ILDs, including familial interstitial pneumonia (FIP). The FIP cohort was divided into patients carrying TERT mutations, patients carrying SFTPA2 or SFTPC mutations, and patients without a proven mutation (FIP-no mutation).
  
  
  RESULTS
  TL in all cases of ILD was significantly shorter compared with those of control subjects (P range: .038 to < .0001). Furthermore, TL in patients with idiopathic pulmonary fibrosis (IPF) was significantly shorter than in patients with other IIPs (P = .002) and in patients with sarcoidosis (P < .0001). Within the FIP cohort, patients in the FIP-telomerase reverse transcriptase (TERT) group had the shortest telomeres (P < .0001), and those in the FIP-no mutation group had TL comparable to that of patients with IPF (P = .049). Remarkably, TL of patients with FIP-surfactant protein (SFTP) was significantly longer than in patients with IPF, but similar to that observed in patients with other sporadic IIPs.
  
  
  CONCLUSIONS
  The results show telomere shortening across all ILD diagnoses. The difference in TL between the FIP-TERT and FIP-SFTP groups indicates the distinction between acquired and innate telomere shortening. Short TL in the IPF and FIP-no mutation groups is indicative of an innate telomere-biology defect, while a stress-induced, acquired telomere shortening might be the underlying process for the other ILD diagnoses.
authors.affiliation: Center of Interstitial Lung Diseases, Department of Pulmonology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Reinier
authors.initials: R
authors.lastname: Snetselaar
authors.affiliation: Center of Interstitial Lung Diseases, Department of Pulmonology, University Medical Center Utrecht, Utrecht, The Netherlands; Division of Heart and Lung, University Medical Center Utrecht, Utrecht, The Netherlands. Electronic address: c.van.moorsel@antoniusziekenhuis.nl.
authors.forename: Coline H M
authors.initials: CHM
authors.lastname: van Moorsel
authors.affiliation: Center of Interstitial Lung Diseases, Department of Pulmonology, University Medical Center Utrecht, Utrecht, The Netherlands; Division of Heart and Lung, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Karin M
authors.initials: KM
authors.lastname: Kazemier
authors.affiliation: Center of Interstitial Lung Diseases, Department of Pulmonology, University Medical Center Utrecht, Utrecht, The Netherlands; Department of Clinical Chemistry, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Joanne J
authors.initials: JJ
authors.lastname: van der Vis
authors.affiliation: Center of Interstitial Lung Diseases, Department of Pulmonology, University Medical Center Utrecht, Utrecht, The Netherlands; Division of Heart and Lung, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Pieter
authors.initials: P
authors.lastname: Zanen
authors.affiliation: Department of Pathology, St. Antonius Hospital, Nieuwegein.
authors.forename: Matthijs F M
authors.initials: MFM
authors.lastname: van Oosterhout
authors.affiliation: Center of Interstitial Lung Diseases, Department of Pulmonology, University Medical Center Utrecht, Utrecht, The Netherlands; Division of Heart and Lung, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Jan C
authors.initials: JC
authors.lastname: Grutters
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D017563:Lung Diseases, Interstitial / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009154:Mutation; D016133:Polymerase Chain Reaction; D012313:RNA / Q000235:genetics*; D012189:Retrospective Studies; D019098:Telomerase / Q000235:genetics*; D016615:Telomere / Q000235:genetics*
chemical_list: D012313:RNA; D019098:Telomerase