Objective: To determine the diagnostic and prognostic value of soluble ST2 (sST2) in patients with sepsis.
Methods: A total of 113 critically ill patients were enrolled from the emergency department of the Beijing Chaoyang Hospital Jing Xi Branch. The venous blood levels of sST2 were measured using the AFIAS-6 dry fluorescence immunoassay analyzer. The patients were divided into sepsis group (76 cases) and non-sepsis group (37 cases) based on sepsis 3.0 diagnostic criteria. The sepsis group was further sub-divided into the non-survivor group (38 cases) and survivor group (38 cases) according to the survival outcomes after follow-up for 28 days. The vital signs, blood gas analysis, routine blood tests, liver and kidney function tests, procalcitonin (PCT), C-reactive protein (CRP), sST2, left ventricular ejection fraction (LVEF), and other basic characteristics of the patients were recorded. Further, the SOFA, qSOFA and APACHE Ⅱ scores of each patient were calculated. Statistical software SPSS 25.0 was used for statistical analysis. Independent sample t-test was used for comparisons of measurement data, while chi-square test was used for comparisons of counting data. Logistic regression analysis was used to evaluate the prognostic factors. Further, ROC curves were plotted to determine the predictive ability of sST2, lactic acid levels, SOFA and APACHE Ⅱ scores on survival.
Result: The serum sST2 levels in the sepsis group (125.00±60.32ng/ml) were significantly higher than in the non-sepsis group (58.55±39.03ng/ml) (P<0.05). The SOFA score (8.08±2.88), APACHE Ⅱ score (18.00±4.72), blood sST2 levels (168.06±36.75ng/ml) and lactic acid levels (2.89±3.28) in the non-survivor group were significantly higher than the survivor group (P<0.05). Multiple logistic regression analysis showed that sST2, SOFA score, APACHE Ⅱ score and lactic acid levels were independent risk factors for poor prognosis in patients with sepsis. The ROC curve analysis of the above indexes showed no significant differences between the AUC of sST2 (0.912) and the SOFA score (0.929) (z = 0.389, P = 0.697), or the APACHE Ⅱ score (0.933) (z = 0.484, P = 0.627). However, there was a significant difference between the AUC of sST2 (0.912) and lactic acid levels (0.768) (z = 2.153, P = 0.03).
Conclusion: Blood levels of sST2 shows a clinically diagnostic and prognostic value in sepsis. Further, sST2 shows a similar predictive ability as the SOFA and APACHE Ⅱ scores in determining the prognosis of sepsis patients. However, sST2 has a higher predictive ability than lactic acid levels in determining prognosis in sepsis.