The predictive value of the expression of EZH2 on B lymphocyte subsets on the prognosis of septic patients / 中华急诊医学杂志

ABSTRACT

Objective:To investigate the dynamic expression of histone methyltransferase (enhance of zeste homolog 2, EZH2) in peripheral blood B lymphocytes (CD19 +B) and memory B lymphocytes (CD19 +CD27 +B) of septic patients and its value in predicting prognosis in sepsis. Methods:From June 2018 to January 2020, 48 septic patients in the Intensive Care Unit of Shanghai East Hospital were enrolled, and 40 healthy adult volunteers were recruited as healthy controls. Septic patients were divided into the non-survivors (18 cases) and the survivors (30 cases) according to whether the patients survived at 28 days. Blood samples were collected at day 1, 3 and 7, blood routine, IL-6 and blood gas analysis were collected, and SOFA and APACHE Ⅱ scores were counted. Flow cytometry was used to detect the positive rate and the mean fluorescence intensity of EZH2 on CD19 +B lymphocytes, and the positive rate of EZH2 on CD19 +CD27 +B lymphocytes at different time points. In the healthy controls, fasting was taken only once in the morning. ROC curve was drawn and the area under the curve (AUC) was calculated to evaluate the value of expression of EZH2 on CD19 +B lymphocytes and CD19 +CD27 +B lymphocytes in predicting the prognosis of septic patients. Results:(1) Compared with the healthy controls, the positive rate and average fluorescence intensity of EZH2 on CD19 +B lymphocytes and the positive rate of EZH2 expression on CD19 +CD27 +B lymphocytes were significantly increased at day 1, 2 and 3 in septic patients ( P<0.05). Over time, the expression of EZH2 in CD19 +B lymphocytes and CD19 +CD27 +B lymphocytes increased gradually ( P<0.05). (2) Compared with the survivors, the positive rate of EZH2 on CD19 +B lymphocytes of the non-survivors was increased at day 1, but the positive rate of EZH2 on CD19 +CD27 +B lymphocytes of the non-survivors was decreased at day 3 and 7 ( P<0.05). (3) The positive rate of EZH2 on CD19 +B lymphocytes, APACHE Ⅱ score, SOFA score and IL-6 level in septic patients at day 1 were independently associated with 28-day mortality. (4) The AUC of APACHEⅡ score was 0.907 (95% CI: 0.825-0.990), and the sensitivity and the specificity were 88.89% and 76.67%. The AUC of SOFA score was 0.831 (95% CI: 0.706-0.955), and the sensitivity and the specificity was 66.67% and 86.67%; The AUC of EZH2 positive rate on CD19 +B lymphocytes were 0.799 (95% CI: 0.657-0.941), and the sensitivity and specificity were 88.89% and 80.77%, respectively, the sensitivity was better than SOFA score, and the specificity was higher than APACHEⅡ score. Conclusions:The high expression of EZH2 on B lymphocytes in septic patients is associated with poor prognosis. Dynamic monitoring of EZH2 expression on B lymphocytes has certain predictive value for sepsis.