Human cystatin C: A new biomarker of idiopathic pulmonary fibrosis?
Article first published online: 25 NOV 2013
© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
PROTEOMICS - Clinical Applications
Special Issue: Proteases and Disease
Volume 8, Issue 5-6, pages 447–453, June 2014
How to Cite
Kasabova, M., Joulin-Giet, A., Lecaille, F., Saidi, A., Marchand-Adam, S. and Lalmanach, G. (2014), Human cystatin C: A new biomarker of idiopathic pulmonary fibrosis?. Prot. Clin. Appl., 8: 447–453. doi: 10.1002/prca.201300047
- Issue published online: 10 JUN 2014
- Article first published online: 25 NOV 2013
- Accepted manuscript online: 31 OCT 2013 04:07PM EST
- Manuscript Accepted: 14 SEP 2013
- Manuscript Revised: 4 SEP 2013
- Manuscript Received: 19 JUN 2013
- la Région Centre (France)
- Institut National de la Santé et de la Recherche Médicale (INSERM)
- Cystatin C;
- Lung fibrosis;
- Protease inhibitor
Human idiopathic pulmonary fibrosis (IPF) is a progressive interstitial lung disorder with a poor prognosis. The identification of a new and specific biomarker in bronchoalveolar lavage fluids (BALFs) may assist in the diagnosis of the disease.
Characterization of cysteine Cats and their endogenous inhibitor, cystatin C, was conducted by immunochemical analysis and measurement of endopeptidase activity of control (n = 11) and IPF (n = 25) BALFs (normalized conditions, 20 μg protein/assay).
Cathepsin (Cat) B was detected as proform and mature enzyme for both control and IPF samples, while Cats K, L, and S were found as zymogens with a strengthened staining in IPF BALFs. The overall endopeptidase activity related mainly to Cat B and did not vary significantly between control and IPF samples. Conversely a significant increase of immunoreactive cystatin C was measured in BALFs for each of three IPF grades.
Conclusions and clinical relevance
An excessive deposition of extracellular matrix proteins is the hallmark of fibrotic disorders. Cats are potent collagenases and might be essential for lung homeostasis. Taken together, increase of cystatin C in IPF BALFs may reflect abnormal regulation of proteolytic activity of Cats in lung, which in turn can promote the development of fibrosis.