Plasma Thrombomodulin Levels are Associated with Endothelial Injury in Patients with Bacterial Infections

Endothelial injury is the key to the occurrence and development of bacterial infections. The aim of this study was to discuss the relationship between the molecular marker of endothelial damage, thrombomodulin (TM), and infectious disease severity, and prognosis.

From January 2017 to April 2018, 296 patients with bacterial infections and 163 controls were recruited from our hospital. The concentrations of thrombomodulin and other routine coagulation and inflammatory factors were quantified.

Plasma levels of thrombomodulin were obviously increased in infection group compared with control group (8.30 (7.23 - 9.68) vs. 15.83 (10.60 - 22.20) TU/mL, p < 0.001) and logistic regression analysis showed that the thrombomodulin was an independent risk factor for bacterial infection (OR, 1.189 (1.079 - 1.311)). In the infection group, patients with elevated thrombomodulin levels (> 75th percentile of its distribution, n = 71) experienced a higher level of coagulation factors (p < 0.05) and inflammatory factors (p < 0.05) than patients with levels below this cutoff. Multiple linear regression analysis showed that there was a positive correlation among the plasma thrombomodulin and D-dimer, white blood cells, and procalcitonin (β coefficient = 0.590, 0.220, and 0.208, p = 0.004, 0.027, and 0.025, respectively). With the increase of severity of disease, thrombomodulin levels gradually rose (13.58 ± 0.47 TU/mL vs. 25.07 ± 2.01 TU/mL vs. 31.34 ± 2.56 TU/mL, respectively, p < 0.001). Furthermore, there was an abnormal increase of plasma thrombomodulin in patients with bacterial infections and poor prognosis (p < 0.05). The area under curve of thrombomodulin as diagnosis for organ failure and non-survivor was 0.867 and 0.778, respectively.

Plasmatic level of thrombomodulin could be considered as a diagnostic tool for bacterial infections. An increase in thrombomodulin plasmatic level was associated with poor outcome.