降钙素原对鉴别 G-菌与 G＋菌感染所致的脓毒症的诊断价值

Diagnostic value of procalcitonin in discriminating between gram-negative and gram-positive bacterial infection sepsis

目的：探讨降钙素原（procalcitonin,PCT）水平鉴别 G-菌与 G＋菌感染所致的脓毒症的诊断价值。方法收集2010年4月至2013年3月符合2001年华盛顿国际脓毒症定义会议制定的脓毒症标准且血培养阳性的脓毒症共103例患者,其中 G-菌感染组共59例,G＋菌感染组共44例,两组病例均在抗生素治疗前根据标准操作规程抽血,进行血培养和血 PCT、超敏 C 反应蛋白（hsCRP）的检测,分析 G-菌与 G＋菌组间 PCT、hsCRP 水平是否存在差异。结果 G-菌感染组 PCT [17（2.03,60.11）μg/L]高于 G＋菌感染组[0.46（0.14,2.27）μg/L],差异有统计学意义（P 〈0.01）；G-菌感染组 hsCRP [101（48.2,157.8）mg/L]同 G＋菌感染组[76.95（35.6,113.4）mg/L]比较差异无统计学意义（P 〉0.05）。使用 PCT 鉴别 G-菌与 G＋菌感染时,根据受试者工作特征（ROC）曲线,曲线下面积（AUC）为0.821（95% CI 0.735~0.907）,其 AUC 与 AUC=0.5比较差异有统计学意义（P 〈0.01）,当截断值取1.67μg/L 时,Youden 指数最大,为0.5351,敏感度为83.05%,特异度为70.45%。结论 PCT 在 G-菌感染时较 G＋菌感染升高更明显,对区分 G-菌和G＋菌感染有一定价值。

Objective To investigate the levels of procalcitonin to examine the diagnostic value of procalcitonin（PCT） in discriminating between Gram-negative （GN） and Gram-positive （GP） bacterial infection sepsis.Methods Patients with sepsis which was in line with the standard developed by the international septic defined Meeting 2001 whose blood culture were positive admitted between April 2010 and March 2013 were involved,a total of 103 patients.59 patients,blood culture were Gram-negative bacteria,while 44 patients,blood culture were Gram-negative bacteria.The two groups were determined serum PCT,hsCRP levels prior administered antimicrobial drug according to standard procedures.Then we analyzed the difference of PCT and the difference of hsCRP between the two groups. Results Procalcitonin levels were found to be markedly higher in patients with GN bacterium[1 7（2.03~60.1 1）μg/L]than in those with GP bacterium[0.46（0.14 ~ 2.27）μg/L],which was a statistically significant difference（P 〈0.01）.HsCRP levels were not found any statistically significant difference（P 〉0.05） between GN bacterium[101（48.2,1 57.8）mg/L]and GP bacterium[76.95（35.6,1 13.4）mg/L]. When using PCT levels as a biomarker to discriminate between the GN bacterium and GP bacterium,we found the area under the curve（AUC）was 0.821 （95% CI 0.735-0.907）,which was found a statistically significant difference（P 〈0.01） compared to area been 0.5.When taken 1.67 μg/L as a cutoff value of PCT,we found the largest Youden index （0.535）,the sensitivity was 83.05 and the specificity was 70.45. Conclusions Higher PCT levels are found in GN bacterium and it can play a role in discriminating between the GN bacterium and GP bacterium.