[Evaluation of serum thrombomodulin in patients with interstitial pneumonia]

We encountered a 63-year-old man whose dry cough due to interstitial pneumonia had been successfully with an anti-thrombin drug, argatroban, which was given to treat exacerbated Buerger's disease. We therefore prospectively evaluated fibrinogen, fibrin-degradating product D-dimer, thrombin anti-thrombin III complex, and plasmin anti-plasmin complex in patients with interstitisal lung diseases. In a preliminary study, we found that some patients actually had elevated levels of these markers. These findings suggested that increased coagulability was involved in the pathophysiology of interstitial pneumonia. In this study, we measured the levels of serum-soluble thrombomodulin as a marker of endothelial cell damages that lead to hemostasis. We found that serum levels of thrombomodulin were high in about 35% of patients with sarcoidosis, interstitial pneumonia associated with collagen diseases, or idiopathic interstitial pneumonia. Furthermore, these levels decreased as the patients' conditions improved. Although further evaluation is needed, these results suggest that endothelial cell damage and hemostasis are involved in the pathophysiology of interstitial pneumonia.