Serological assessment of neutrophil elastase activity on elastin during lung ECM remodeling

Research output: Contribution to journalJournal articleResearchpeer-review

  • Jacob H. Kristensen
  • Morten A. Karsdal
  • Jannie M.B. Sand
  • Nicholas Willumsen
  • Claudia Diefenbach
  • Birte Svensson
  • Hägglund, Per Mårten
  • Diana J. Oersnes-Leeming

Background: During the pathological destruction of lung tissue, neutrophil elastase (NE) degrades elastin, one of the major constituents of lung parenchyma. However there are no non-invasive methods to quantify NE degradation of elastin. We selected specific elastin fragments generated by NE for antibody generation and developed an ELISA assay (EL-NE) for the quantification of NE-degraded elastin. Methods: Monoclonal antibodies were developed against 10 NE-specific cleavage sites on elastin. One EL-NE assay was tested for analyte stability, linearity and intra- and inter-assay variation. The NE specificity was demonstrated using elastin cleaved in vitro with matrix metalloproteinases (MMPs), cathepsin G (CatG), NE and intact elastin. Clinical relevance was assessed by measuring levels of NE-generated elastin fragments in serum of patients diagnosed with idiopathic pulmonary fibrosis (IPF, n = 10) or lung cancer (n = 40). Results: Analyte recovery of EL-NE for human serum was between 85% and 104%, the analyte was stable for four freeze/thaw cycles and after 24 h storage at 4°C. EL-NE was specific for NE-degraded elastin. Levels of NE-generated elastin fragments for elastin incubated in the presence of NE were 900% to 4700% higher than those seen with CatG or MMP incubation or in intact elastin. Serum levels of NE-generated elastin fragments were significantly increased in patients with IPF (137%, p = 0.002) and in patients with lung cancer (510%, p < 0.001) compared with age- and sex-matched controls. Conclusions: The EL-NE assay was specific for NE-degraded elastin. The EL-NE assay was able to specifically quantify NE-degraded elastin in serum. Serum levels of NE-degraded elastin might be used to detect excessive lung tissue degradation in lung cancer and IPF.

Original languageEnglish
Article number53
JournalBMC Pulmonary Medicine
Issue number1
Publication statusPublished - 3 May 2015

    Research areas

  • Biomarker, ECM, Elastin, IPF, Lung cancer, Neutrophil elastase

ID: 240157433