血浆DNA浓度对急诊重症监护室休克患者预后的预测价值

Prognostic value of circulating cell - free DNA in patients with shock admitted to Emergency Intensive Care Unit

目的探讨血浆DNA浓度对急诊重症监护室（EICU）休克患者病情及预后的预测价值。方法采用前瞻性、随机对照方法，选择2012—06-2013—12期间人住我院EICU休克患者共69例，分别于入室0、24h采取外周静脉血，应用实时荧光定量PCR技术定量检测血浆DNA浓度，同时测定血乳酸，以及24h内急性生理学和慢性健康状况评分Ⅱ（APACHEⅡ评分）；另选取30例体检者为健康对照组。随访28天生存率，比较28天存活组和死亡组之间不同时相点血浆DNA、乳酸浓度以及24hAPACHEⅡ评分对病情及预后的评估价值。结果患者入室0h血浆DNA浓度7．66×10^5（1．61×10^5～2．06×10^6）pg／mL和24h血浆DNA浓度3．91×10^5（3．47×10^4-3．88×10^6）pg／mL，均明显高于健康对照组[9．09×10^3（4．77×10^3～8．97×10^4）pg／mL，P〈0．05]。人室0、24h存活组与死亡组患者血浆DNA浓度分别为2．85×10^5（7．20×10^4-9．35×10^5）pg／mLvs1．91×10^6（7．81×10^5-4．60×10^7）pg／mL、5．74×10^4（1．12×10^4～5．97×10^5）pg/mLV83．82×10^6（1．66×10^6-9．27×10^6）pg／mL，差异均有统计学意义（P〈0．05）。入室0h的血浆DNA曲线下面积为0．822（0．707～0．937），特异度为71．9％，敏感度为75％，最佳截断值为8．11×10^5pg／mL；入室24h的血浆DNA曲线下面积为0．861（0．759—0．963），特异度为87．5％，敏感度为80％，最佳截断值为1．39×10^6pg／mL。多元Logistic回归分析显示，24h血浆DNA和24h血乳酸分别是预测休克患者28天死亡率的独立危险因素。结论入室24h血浆DNA和24h血乳酸可作为判断休克患者的独立预测因子，且血浆DNA预测价值明显高于乳酸。

Objective Our investigation was to explore the chnical prognosis value of plasma cell - free DNA （cf - DNA） in shock patients admission to Emergency Intensive Care Unit （EICU）. Methods A prospective observational study of 69 consecutive patients with shock of the First Affiliate Hospital of Anhui Medical University in the EICU. The cf - DNA was measured by real - time quantitative PCR assay for the 13 - globin gene in blood samples drawn at study admission and 24 h later, while the value of lactate at admission and 24 h post - admission were detected and the Acute Physiology and Chronic Health Evaluation Ⅱ （ APACHEⅡ ） scores within 24 h among these patients were investigated. A control group containing 30 patients matched in age and gender were also included in the meantime. End point of this study was 28 - d mortality rate. Clinical data including cf - DNA, blood lactate and APACHE Ⅱ scores at 0 h, 24 h after admission in survivors and non - survivors respectively. Results The median cell- free DNA concentrations from patients serum were statistically significantlyhigher in patient died of shock at admission and 24 h post - admission （ median, 1.91 × 10^6 pg/mL; interquartile range （IQR）, 7.81 × 10^5 to 4.60 × 10^7, and 3.82 × 10^6 pg/mL, IQR 1.66 × 10^6 to 9.27× 10^6, respectively） than in patients survived shock （median 2.85 × 10^5 pg/mL, IQR 7.20 × 10^4 to 9. 35× 10^5 ; and 5.74 × 10^4 pg/mL, IQR 1.12 × 10^4 to 5.97× 10^5, respectively, P 〈 0.05）. Both the median cf-DNA levels of 0 h and 24 h were also higher in patients than those in controls （9.09 × 10^3 pg/mL, IQR ： 4.77 × 10^3 to 8.97 ×10^4 ）. Using receiver operating curve （ROC） analysis, the best cut - off values of cf - DNA at admission and 24 h later for predicting 28 - day mortality were 8.11 × 10^5 pg/mL （ sensitivity 75%, specificity 71.9% ） and 1.39 × 10^6 pg/mL （ sensitivity 80%, specificity 87. 5% ）, based on the calculated areas under the curve （AUCs） of 0.822 （95% CI 0.707 to 0. 937）, 0.861 （95% CI 0. 759 to 0.963）, respectively. In Logistic regression analysis, both cf- DNA at 24 h after admission and lactate at 24 h later were independently associated with 28 - day mortality （P 〈 0.05）. Conclusion Circulating level of cf - DNA at 24 h after admission is significantly higher in patients died of shock in EICU than patients survived and the predictive power is higher than that of the lactate value at 24 h post - admission.