Plasma and Urinary Soluble Thrombomodulin in Newborns with Respiratory Distress Syndrome and Chronic Lung Disease

Abstract

Thrombomodulin (TM), which is mainly present on the surface membrane of endothelial cells, plays an important role in the prevention of thrombosis. It is also present in a free form, named soluble TM (sTM), in circulating blood and urine. Plasma sTM has recently attracted considerable attention as a marker of protease damage to endothelium. We previously reported the plasma and urine levels of sTM in neonates, infants and children, and showed a good correlation between plasma and urinary sTM levels in healthy children. In this study, we investigated sTM levels in newborns with respiratory distress syndrome (RDS) and chronic lung disease (CLD). Plasma and urinary sTM levels in patients with RDS at birth were not significantly elevated as compared to those in healthy neonates. They were found to be remarkably higher in patients with CLD (plasma sTM 1-6 Ms : CLD ; 21.7 ± 7.2 TU/ml, nonCLD ; 14.9± 3.5 TU/ml p< 0.001, urinary sTM 1-6 Ms : CLD ; 280.3 ±126.3 TU/mgCr, nonCLD ; 132.8 ± 37.3 TU/mgCr p< 0.05). These data suggest that CLD in newborns may be evaluated with serial measurements of plasma and urinary sTM.