Liu Fei, Wang Qian, Zeng Fang-yin, Zhang Peng
Department of Clinical Laboratory, Nanfang Hospital, Southern Medical University, Guangzhou, China.
Nan Fang Yi Ke Da Xue Xue Bao. 2010 Mar;30(3):614-6, 619.
To evaluate the value of procalcitonin (PCT) detection in the diagnosis of local infection and sepsis.
PCT, C-reactive protein (CRP), white blood cell count (WBC), neutrophil ratio (neu%) and lymphocyte ratio (lym%) were measured in patients with negative or positive blood culture test. The receiver operating characteristic (ROC) curves were constructed for PCT CRP, WBC, neu%, lym%, and the diagnostic model using SPSS software. Based on the binary logistic regression model, the predictors or probabilities were obtained and applied to establish the empirical and binormal model of the ROC curves to compare the area under the curve (AUC).
A highly significant difference in PCT concentrations was noted between the two groups (chi(2)=52.52, P<0.001), and the diagnostic criteria at <2 of the ROC curves resulted in the greatest Youden index with a sensitivity of 63.3% and specificity of 86.8%. The AUC of PCT, CRP, WBC, neu% and lym% were 0.700, 0.765, 0.636, 0.618 and 0.648, respectively; the combined predicted ROC AUC was 0.776. The maximum Youden index was acquired at the optimal cutoff point of 0.566 with a diagnosis sensitivity and specificity of 63.8% and 84.7%, respectively.
The PCT level is a valuable predictor for a rapid and reliable early diagnosis of sepsis. The diagnostic model based on the laboratory parameters, using the combined predictors of PCT, CRP and lym%, can be a useful means for predicting early-onset sepsis.
评估降钙素原(PCT)检测在局部感染和脓毒症诊断中的价值。
对血培养试验阴性或阳性的患者测定PCT、C反应蛋白(CRP)、白细胞计数(WBC)、中性粒细胞比例(neu%)和淋巴细胞比例(lym%)。使用SPSS软件构建PCT、CRP、WBC、neu%、lym%的受试者工作特征(ROC)曲线以及诊断模型。基于二元逻辑回归模型,获得预测因子或概率,并应用于建立ROC曲线的经验和双正态模型,以比较曲线下面积(AUC)。
两组间PCT浓度存在高度显著差异(χ² = 52.52,P < 0.001),ROC曲线<2时的诊断标准产生最大约登指数,敏感性为63.3%,特异性为86.8%。PCT、CRP、WBC、neu%和lym%的AUC分别为0.700、0.765、0.636、0.618和0.648;联合预测ROC AUC为0.776。在最佳截断点0.566处获得最大约登指数,诊断敏感性和特异性分别为63.8%和84.7%。
PCT水平是脓毒症快速可靠早期诊断的有价值预测指标。基于实验室参数的诊断模型,使用PCT、CRP和lym%的联合预测因子,可作为预测早发性脓毒症的有用手段。