摘要目的 探讨降钙素原(PCT)和C反应蛋白(CRP)在细菌感染性疾病诊断中的作用.方法 回顾性调查2120例临床病例中的PCT和CRP结果,应用受试者工作特征(ROC)曲线下面积评价PCT、CRP预测细菌感染的诊断能力,并计算和比较两者最佳截断点及其他几个截断点的敏感性、特异性、阳性预测值、阴性预测值、Youden指数和诊断准确率;同时对细菌感染患者中血清PCT与CRP进行相关分析.结果 PCT诊断细菌感染的AUC为0.957±0.016,诊断最佳界点为0.4 μg/L,此时灵敏度为90.0％,特异性为90.9％;CRP诊断细菌感染的AUC为0.712±0.04,诊断最佳界点为2.27 μgL,此时灵敏度为72.0％,特异性为57.3％.PCT与CRP曲线下面积比较,差异有统计学意义(P＜0.05).178例细菌感染性疾病患者血清中PCT与CRP无明显直线相关(r=0.322,P＞0.05).检测的2120例患者血清结果,CRP水平处于正常参考范围时(＜0.8 mg/L),PCT检测结果亦在正常参考范围(＜0.1 μg/L).结论 CRP作为预测细菌感染指标不理想;检测PCT具有快速、干扰因素少、特异性高等特点,对于细菌感染的诊断具有较高的临床价值.此外,对疑有细菌感染的患者,CRP检测正常时,可考虑暂不行PCT检测;结合PCT半衰期监测分析PCT变化,有利于准确判断疗效和评估病情.

abstractsObiective To study the value of procalcitonin (PCT) and C-reaction protein (CRP)in the diagnosis of bacterial infection.Methods PCT and CRP in 2120 patients were retrospectively analyzed.Receiver operating characteristic (ROC) curve was used to compare the diagnostic capacity between two indices.Correlation between PCT and CRP was analyzed among 178 patients with bacterial infection.Results Areas under ROC curve (AUC) were 0.957 ±0.016 for PCT and 0.712 ± 0.04 for CRP.There was statistical significance of the AUC for PCT and CRP.The optimum cutoff value for PCT was 0.4 μg/L,which had a sensitivity of 90.0％ and a specificity of 90.9％.The optimum cutoff value for CRP was 2.27mg/L,which had a sensitivity of 72.0％ and a specificity of 57.3％.In the 2120 patients,there was the situation which PCT was normal (＜0.1 μg/L) when CRP was normal (＜0.8 mg/L).Conclusions In prediction of bacterial infection,CRP was not good,but PCT had high clinical value because of rapid detection,less interference and high specificity.In suspected bacterial infection patients,PCT was considered not to be detected temporarily if CRP was normal.In this way,there was the economic value which the patient's medical costs may be Controlled and medical resources be saved.Combined with its half-life,monitoring and analyzing the PCT change is valuable for efficacy determination and assessment of the patients'conditions.