血清降钙素原和免疫炎性因子C反应蛋白、白介素-6、血清淀粉样蛋白A在脓毒血症中的诊断价值

Diagnostic Values of Procalcitonin,Interleukin-6,C Reactive Protein and Serum Amyloid A in Sepsis

目的评价血清降钙素原(PCT)、C反应蛋白(CRP)、白介素-6(IL-6)、血清淀粉样蛋白A(SAA)水平在脓毒血症中的诊断效能,确定其诊断临界值。方法选取2011年3～11月疑似脓毒血症感染者390例,根据临床感染病学标准分为脓毒血症组203例,非脓毒血症组187例,分别采用电化学发光法测定PCT、IL-6水平,速率散射比浊法测定CRP水平,定时散射比浊法测定SAA水平,采用ROC曲线比较上述指标的诊断价值。结果脓毒血症组中位PCT水平、中位CRP水平、中位IL-6水平、中位SAA水平均高于非脓毒血症组,差异具有统计学意义。PCT的曲线下面积(AUC)最大,为0.919(P<0.05),而CRP和IL-6分别为0.755(P<0.05)和0.784(P<0.05),SAA最低为0.645(P<0.05),4项指标联合AUC为0.892(P<0.05)。PCT的AUC大于其余3项指标(P<0.05),但与联合指标相比,差异无统计学意义。PCT的灵敏度、特异度、阳性预测值、阴性预测值、阳性似然比、阴性似然比、Youden指数优于CRP、IL-6和SAA。当PCT的最佳诊断点为1.18ng/mL时,灵敏度达84.7%,特异度达83.4%,Youden指数为0.681,阴、阳性预测值分别为64.1%和75.8%,阴、阳性似然比分别为0.18和5.10。ICU脓毒血症患者中位PCT水平高于其他医疗单元,差异有统计学意义(P<0.05)。结论 PCT作为诊断脓毒血症的早期指标,诊断效能优于传统免疫炎性因子CRP、IL-6、SAA,经济效应优于4项指标联合,可作为早期独立辅助诊断脓毒血症的可靠指标。

Objective To evaluate the diagnostic values of procalcitonin （PCT）, C reactive protein （CRP）, interleukin-6 （IL-6）, serum amyloid A （SAA） in septic patients. Methods This study totally enrolled 390 patients who were admitted to West China Hospital, Sichuan University from March to November 2011 with septic manifestation. The patients were divided into sepsis group （n=203） and non-sepsis group （n= 187） according to clinical infectious disease standard. PCT and IL-6 were measured by automatic electrochemiluminescence （ECL） analyser. CRP was measured by rate immunonephelometric analyser, SAA was measured by fixed time nephelometric method. The diagnostic powers of these four biomakers were constructed by receiver operating characteristics （ROC） curves. Results There were statistically significant differences on the values of PCT, CRP, IL-6, SAA between sepsis group and non-sepsis group. PCT had an AUC value of 0. 919 （P〈0.05） which was higher than that of CRP, IL-6, and SAA （P〈0.05）. CRP performed with an AUC of 0. 755 （P〈0.05）, IL-6 with an AUC of 0. 786 （P〈0.05）,and SAA with the lowest AUC of 0. 645 （P〈0.05）. The combination AUC was 0. 892（P〈0.05） and there was no statistically significant difference when compared to PCT. As an early diagnostic indicator of sepsis, the cut-off value of PCT was 1.18 ng/mL, with sensitivity of 84.7%, specific of 83.4%, while Youden index was 0. 681, positive predict value was 64.1%, negative predict value was 75.8 %, positive likelihood ratio was 5.10, negative likelihood ratio was 0.18, respectively. A statistically significant difference was available on the value of PCT in septic patients between ICU and non-ICU. Conclusion PCT as an early independent biomarker for sepsis is superior to immune inflammatory biomarkers （CRP, IL-6, SAA）, also is better than the combination of these four biomarkers for economic effect.