OBJECTIVE: To observe change in serum growth differentiation factor 11 (GDF11) and killer cell lectin-like receptor B1 (KLRB1), to construct a nomogram model for 28-day death in patients with septic shock, and to explore its predictive value. METHODS: A prospective observational study was conducted. The patients with septic shock admitted to the emergency intensive care unit (ICU) of Cangzhou Central Hospital from September 2023 to March 2025 were selected as the septic shock group, the patients with sepsis admitted to the emergency general ward during the same period were selected as the sepsis group, and healthy individuals undergoing physical examination during the same period were selected as the control group. On the day of hospital admission or physical examination for the research subjects, the levels of serum GDF11 and KLRB1 were detected by enzyme-linked immunosorbent assay (ELISA). The patients with septic shock were divided into survival and death groups based on their 28-day survival status. The patients' gender, age, past medical history, infection site, severity of illness, mechanical ventilation, blood purification, infection indicators, biochemical indicators, coagulation function indicators, and blood lactic acid (Lac) were collected. The clinical data of the patients with septic shock between the two groups with different prognoses were compared. Multivariate Logistic regression analysis was used to screen the risk factors for 28-day death in patients with septic shock, and bivariate Pearson correlation analysis was conducted. A nomogram model was constructed based on the risk factors for 28-day death in patients with septic shock. The discrimination and calibration of the nomogram model were evaluated using the receiver operator characteristic curve (ROC curve), Hosmer-Lemeshow goodness-of-fit test, and calibration curve. The clinical utility of the model was evaluated using clinical decision curve analysis (DCA). RESULTS: A total of 168 patients in the emergency ICU were enrolled in the septic shock group, 40 patients in the emergency general ward were enrolled in the sepsis group, and 40 healthy individuals were enrolled in the control group. Compared with the healthy control group, the serum GDF11 levels in the sepsis and septic shock groups were significantly increased (μg/L: 13.09±3.51, 19.28±5.36 vs. 4.17±0.92, both P < 0.05), and the serum KLRB1 levels were significantly decreased (ng/L: 57.36±11.28, 45.52±9.07 vs. 84.19±17.16, both P < 0.05), with more significant changes in the septic shock group (both P < 0.05). Among the 168 patients with septic shock, 96 survived and 72 died within 28 days. Compared with the survival group, the serum GDF11 level in the death group was significantly increased (μg/L: 24.24±4.81 vs. 15.56±4.62, P < 0.05), and the serum KLRB1 level was significantly decreased (ng/L: 28.53±8.69 vs. 58.26±9.45, P < 0.05). There were also statistically significant differences in sequential organ failure assessment (SOFA) score, acute physiology and chronic health evaluation II (APACHEII) score, procalcitonin (PCT), activated partial thromboplastin time (APTT), D-dimer, and Lac between the two groups. Multivariate Logistic regression analysis showed that SOFA score [odds ratio (OR) = 1.96, 95% confidence interval (95%CI) was 1.38-3.65), Lac (OR = 1.38, 95%CI was 1.09-2.01), GDF11 (OR = 1.54, 95%CI was 1.21-2.33) and KLRB1 (OR = 0.64, 95%CI was 0.41-0.78) were independent risk factors for 28-day death in patients with septic shock (all P < 0.05). Bivariate Pearson correlation analysis showed that SOFA score was significantly positively correlated with Lac and GDF11 (r value was 0.37 and 0.58, respectively, both P < 0.05), and significantly negatively correlated with KLRB1 (r = -0.72, P < 0.05). A nomogram model was constructed based on the risk factors for 28-day death in patients with septic shock. ROC curve analysis showed that the area under the ROC curve (AUC) of the nomogram model for predicting 28-day death in patients with septic shock was 0.963 (95%CI was 0.929-0.990), indicating that the model had good discrimination and predictive ability. The Hosmer-Lemeshow goodness-of-fit test (χ ² = 9.578, P = 0.295) and calibration curve indicated that the predicted values of the model were in good agreement with the actual values. DCA indicated that the model provided a high net benefit for clinical decision-making. CONCLUSIONS The serum GDF11 level was significantly increased and the KLRB1 level was significantly decreased in patients with septic shock. The nomogram model based on GDF11 and KLRB1 could more accurately evaluate the 28-day death of patients with septic shock.
Humans ; Shock, Septic/blood* ; Nomograms ; Prospective Studies ; Prognosis ; Male ; Female ; Middle Aged ; Aged ; Intensive Care Units