Correlation analysis of microRNA-126 expression in peripheral blood lymphocytes with apoptosis and prognosis in patients with sepsis

Abstract

To analyze the relationship between the expression of microRNA-126 (miR-126) in peripheral blood lymphocytes with apoptosis and prognosis in patients with sepsis, and to explore its potential regulatory mechanism. Thirty patients with general infection and 20 patients with sepsis admitted to the department of intensive care unit (ICU) of the First Affiliated Hospital of Bengbu Medical College from January to December 2019 were enrolled. Peripheral blood was taken to separate lymphocytes, and the expressions of miR-126 and caspase-3 were detected by reverse transcription-polymerase chain reaction (RT-PCR). At the same time, the liver and kidney function and other laboratory indexes were measured, and the sequential organ failure assessment (SOFA) and acute physiology and chronic health evaluation II (APACHE II) scores were calculated. The 28-day prognosis was observed. Pearson method was used to analyze the correlation between miR-126 and caspase-3, APACHE II score. Receiver operating characteristic (ROC) curve was used to analyze the predictive value of miR-126 on prognosis; at the same time, according to the best cut-off value of miR-126 in predicting prognosis, the patients were divided into two groups, and the 28-day Kaplan-Meier survival curve was drawn. The expression of miR-126 in peripheral blood lymphocytes of patients with sepsis was lower than that of patients with general infection [miR-126 mRNA (2-ΔΔCt): 1.239±0.134 vs. 1.599±0.110, P < 0.01], while the expression of caspase-3 and APACHE II score were significantly increased [caspase-3 mRNA (2-ΔΔCt): 1.172±0.132 vs. 0.901±0.143, APACHE II: 19.75±3.74 vs. 12.63±3.94, both P < 0.01]. Pearson correlation analysis showed that the expression of miR-126 was negatively correlated with the expression of caspase-3 (r = -0.678, P < 0.001) and APACHE II score (r = -0.581, P < 0.001). ROC curve analysis showed that the area under the ROC curve (AUC) for predicting the prognosis by miR-126 expression in peripheral blood lymphocytes was 0.823 (P < 0.001). When the best cut-off value was 1.395, the sensitivity was 75.0%, the specificity was 71.4%, the positive predictive value was 81.1%, the negative predictive value was 63.6%, the positive likelihood ratio was 2.622, and the negative likelihood ratio 0.350. In addition, the patients were divided into high miR-126 group (miR-126 > 1.395, n = 31) and low miR-126 group (miR-126 ≤ 1.395, n = 19) according to the best cut-off value of miR-126. Kaplan-Meier survival curve analysis showed that the 28-day cumulative survival rate of high miR-126 group was higher than that of low miR-126 group (Log-Rank: χ2 = 11.702, P = 0.001). miR-126 in peripheral blood lymphocytes of patients with sepsis may affect immune status by promoting apoptosis of lymphocytes, and its expression level can reflect the severity and prognosis of sepsis.