Association between Thymosin beta-4, acute kidney injury, and mortality in patients with sepsis: An observational cohort study.

BACKGROUND: Sepsis is a systemic inflammatory response syndrome, associated with high risk of acute kidney injury (AKI) and in-hospital mortality. Thymosin beta-4 (Tβ4) is an actin-sequestering protein that can prevent inflammation in several tissues. Thus, we studied the role of Tβ4 in sepsis. METHODS: The Tβ4 concentrations were prospectively measured in 191 patients within 6 h of the intensive care units (ICU) admission with diagnosis of sepsis. The cohort was divided into Tβ4 concentration tertiles: 1.19-7.11 ng/ml (n = 64), 7.12-11.01 ng/ml (n = 64), and 11.02-28.10 ng/ml (n = 63). RESULTS: Of 191 patients, 92 patients developed AKI, 24 of whom received continuous renal replacement therapy (CRRT), 29 patients died within 7 days, and 53 patients died within 28 days. Lower Tβ4 stages were correlated with poor prognosis, including AKI(odds ratio [OR], 2.102 per stage lower; 95% confidence interval [CI], 1.448 to 3.050; P < 0.001), CRRT(OR, 2.346 per stage lower; 95% CI, 1.287 to 4.276; P = 0.005), 7-day mortality(OR, 1.755 per stage lower; 95% CI, 1.050 to 2.935; P = 0.032), and 28-day mortality(OR, 1.821 per stage lower; 95% CI, 1.209 to 2.743; P = 0.004). Kaplan-Meier analysis also demonstrated that patients with lower Tβ4 stages had a high risk of AKI and death. In addition, the area under the curve (AUC) of Tβ4 for predicting AKI, CRRT, 7-day mortality, and 28-day mortality were, respectively, 0.702 (95% CI 0.628-0.776), 0.717 (95% CI 0.592-0.842), 0.694 (95% CI 0.579-0.808), and 0.682 (95% CI 0.598-0.767). CONCLUSIONS: Lower Tβ4 stages are associated with higher odds of poor prognosis in ICU patients with sepsis.