定量与半定量检测血清降钙素原在细菌感染诊断中的应用价值评价

目的评价定量与半定量方法检测血清降钙素原（PCT）对细菌感染性疾病诊断的应用价值。方法选取186例入院疑为细菌感染的患者,分别采用化学发光定量法和胶体金免疫结合半定量法检测患者血清PCT含量,并采用Kappa一致性检验评价两种方法检测结果的一致性,ROC曲线分析其对细菌感染诊断的敏感度及特异度。结果非感染组、局部细菌感染组血清PCT均未升高,脓毒血症组PCT显著升高,细菌感染性全身炎症反应综合征（SIRS）组血清PCT轻中度升高,组间比较差异有统计学意义（P〈0.05）。定量与半定量检测PCT结果总体一致性较好（Kappa检验,K=0.77）,以PCT≥0.5ng/mL为阳性诊断界点,ROC分析表明定量方法的敏感度98.9%、特异度92.6%均高于半定量方法的92.6%、88.4%。结论检测血清PCT水平对全身细菌感染诊断具有良好的敏感度和特异度,定量法检测结果客观、精确,对于处于阳性临界值或需要监测疗效的患者,定量检测PCT是首选方法。

Evaluation of the clinical performance of quantitative and semi-quantitative detection of serum procalcitonin for the diagnosis of bacterial infection

Objective To evaluate the clinical performance of quantitative and semi-quantitative detection of serum procalcitonin（PCT）for the diagnosis of bacterial infection.Methods 186cases of hospitalized patients with suspected bacterial infection were enrolled and detected for serum levels of PCT using quantitative assay of chemiluminescence and semi-quantitative immunochromatographic assay respectively.Kappa consistency test was used to estimate the consistency between the two methods.The diagnostic sensibility and specificity for bacterial infections of the two methods were evaluated using ROC analys.Results The levels of PCT in sepsis group and bacterial systemic inflammatory response syndrome（SIRS）group were significantly higher than those in noninfection group and local bacterial infection group（P〈0.05）.The PCT results of quantitative assay showed good consistency with semi-quantitative assay（Kappa test,K=0.77）.With a PCT cutoff value of 0.5ng/mL,ROC curves analysis showed that quantitative assay had a higher sensitivity（98.9%）and specificity（92.6%）than that of semi-quantitative assay.Conclusion Serum PCT is a better diagnostic and discriminative biomarker of systemic bacterial infection.The results of PCT quantitative assays are more objective and accurate.Quantitative assay might be a good choice when serum PCT closes to positive cutoff value or would be needed to reflect the efficacy of antibiotics.