Identification of TAT, PIC, tPAIC, and TM complex as biomarkers for prognosis and early evaluation of non-severe pneumonia and severe pneumonia diagnosis

Abstract Background Pneumonia is a major health problem and the most important causes of mortality in all age groups worldwide. We investigated new automation technology to detect plasma biomarkers, including thrombinantithrombin complex (TAT), α2-plasmininhibitor- plasmin complex (PIC), soluble thrombomodulin (sTM), and tissue plasminogen activator-inhibitor complex (tPAIC), and evaluated their diagnostic performance and prognostic value for severe pneumonia patients. Methods We collected 414 patients date with pneumonia. sTM, t-PAI·C, TAT, PIC were measured by qualitative chemiluminescence immunoassay performed on HISCL analyzers. Other laboratory tests were evaluated on the day of non-severe pneumonia and severe pneumonia diagnosis. Results There were significant differences in sTM, t-PAI·C, TAT, PIC (P < 0.0001), WBC (P = 0.023), PCT (P = 0.007) and IL-6 (P = 0.002) between the severe pneumonia and non-severe pneumonia groups, Logistic regression analysis showed that sTM (P = 0.001), t-PAI·C(P = 0.001), TAT(P = 0.022), PIC(P = 0.000) and APTT (P = 0.013) were independent risk factors for severe pneumonia. Logistic regression analysis showed that t-PAI·C(P = 0.006)was an independent risk factor for hospital mortality in severe pneumonia.The AUC of sTM combined with t-PAI·C, TAT and PIC on diagnosis of patients with severe pneumonia was 0.868 (95%CI: 0.837,0.899).Kaplan-Meier survival analysis with a log-rank test showed the in-hospital death rate of severe pneumonia was higher in the high TAT(≥ 5.58 ng/ mL) level than in group with low TAT(< 5.58 ng/ mL)level (log rank < 0.029). The same trend with high t-PAI·C was also found in severe pneumonia patients(log rank < 0.021). Conclusions Novel coagulation markers might be potential molecular markers for diagnosing and evaluating prognosis of severe pneumonia.