Elevated levels of tenascin-C in patients with cryptogenic organizing pneumonia.

OBJECTIVE Idiopathic interstitial pneumonias (IIPs) comprises a group of diffuse parenchymal lung diseases of unknown etiology with varying degrees of inflammation and fibrosis including cryptogenic organizing pneumonia (COP), idiopathic pulmonary fibrosis (IPF) and nonspecific interstitial pneumonia (NSIP). Tenascin-C is an extracellular matrix molecule that is expressed during wound healing in various tissues. The present study was aimed to investigate the role of tenascin-C in the pathogenesis of IIPs. METHODS We used enzyme-linked immunosorbent assays to measure levels of tenascin-C in serum and bronchoalveolar lavage fluid (BALF) from 17 patients with IPF, 12 with NSIP, 15 with COP and from 23 healthy individuals. RESULTS Serum levels of tenascin-C were significantly elevated in patients with COP compared with those in all other participants, whereas those in patients with IPF and NSIP were not significantly elevated compared with healthy individuals. The levels of tenascin-C in BALF from patients with COP and NSIP were significantly higher than those of healthy individuals. In addition, serum tenascin-C was significantly correlated with levels of serum C-reactive protein, which is a serum acute phase protein. CONCLUSION Systemic inflammation in the lung with IIPs might be associated with tenascin-C. These results suggest that tenascin-C is responsible for the pathogenesis of IIPs especially via inflammation, and that it might serve as a serum marker of COP.