PCT检测在全身和局部细菌感染诊断中的临床应用

The clinical application of PCT in the diagnosis of systemic and local bacterial infections

目的评价血清降钙素原(PCT)定量检测在全身和局部细菌感染诊断中的临床应用价值。方法采用美国临床实验室标准化协会(CLSI)颁布的EP15-A2文件验证罗氏Cobas E601电化学发光免疫检测系统(简称Cobas E601)检测PCT的精密度和准确度,保证仪器条件符合实验要求。收集全身和局部细菌感染住院患者697例,联合分析患者血培养、痰培养、中段尿培养和脑脊液培养数据及其血清PCT结果,比较全身感染和局部感染及不同部位感染患者血清PCT的变化趋势,并分析革兰阳性球菌和革兰阴性杆菌感染机体PCT的表达差异情况。结果 Cobas E601检测PCT具有良好的重复性,总变异系数(CV)<3.59%,与定值校准品的偏差<5.0%,符合临床检测要求。血清PCT水平在全身和局部感染患者中均升高,且全身感染患者PCT水平明显高于局部感染患者(P<0.05);在局部感染中,呼吸系统、泌尿系统和神经系统感染组间血清PCT水平差异无统计学意义(P>0.05)。在全身感染中,革兰阴性杆菌感染患者血清PCT水平高于革兰阳性球菌感染患者(P<0.05);在局部感染中,此2类细菌感染患者血清PCT水平差异无统计学意义(P>0.05)。结论血清PCT水平在全身感染和局部感染患者样本中均升高,在局部感染中不能通过血清PCT水平鉴别革兰阴性杆菌和革兰阳性球菌的感染。

Objective To evaluate the clinical application significance of serum procalcitonin(PCT) quantitation determination in the diagnosis of systemic and local bacterial infections. Methods The Clinical and Laboratory Standards Institute(CLSI) EP15-A2 document was employed to verify the precision and accuracy of PCT determination by Roche Cobas E601 chemiluminescence analyzer(Cobas E601) and ensure instrument conditions being complied with the requirement of experiment. A total of 697 patients with systemic and local bacterial infections were enrolled. The results of serum PCT determination,blood culture,sputum culture,middle-urine culture and cerebrospinal culture were used to compare the change trends of serum PCT for systemic and local bacterial infections and for different-part infections. The difference of PCT in Gram-positive cocci and Gram-negative bacilli infections was analyzed. Results Cobas E601 had good repeatability,and the total coefficient of variation(CV) was < 3. 59%. The fixed calibration bias was < 5. 0% and met the clinical determination requirements. For serum PCT,there was significance for systemic and local bacterial infections with having increasing serum PCT level(P < 0. 05). For local bacterial infection,there was no statistical significance for respiratory system,urinary system and nervous system infections(P > 0. 05). For systemic bacterial infection,there was higher serum PCT level for patients with Gram-negative bacilli infection than with Grampositive cocci infection(P < 0. 05). For local bacterial infection,there was no statistical significance for patients with Gram-negative bacilli infection and Gram-positive cocci infection(P > 0. 05). Conclusions In patients with systemic and local bacterial infections,serum PCT level has high expression,and serum PCT level can not identify local bacterial infection Gram-negative bacilli and Gram-positive cocci infections.