血清降钙素原和C-反应蛋白对AECOPD细菌感染的诊断价值

Value of serum procalcitonin and C-reactive protein in diagnosing bacterial infection in patients with acute exacerbation of chronic obstructive pulmonary disease

目的探讨血清降钙素原（PCT）和C-反应蛋白（CRP）对慢性阻塞性肺疾病急性加重（AECOPD）细菌感染的诊断价值。方法选取70例AECOPD患者为研究对象，治疗前检测其血清PCT和CRP水平，并进行诱导痰细菌定量培养，治疗后再次进行血清PCT和CRP水平测定。以痰中的下呼吸道病原菌（PMM）浓度≥10^7CFU／ml作为诊断AECOPD细菌感染的金标准，将AECOPD患者70例分为细菌感染组39例和非细菌感染组31例。比较2组患者血清PCT和CRP水平的变化及临床意义。结果治疗前AECOPD患者PCT和CRP均显著高于治疗后（P〈0．05），细菌感染组PCT水平高于非细菌感染组（P〈0．05），2组CRP比较无明显差异（P〉0．05）。以PCT〉0．5ng／ml，CRP〉10mg／L为阳性阈值，PCT和CRP诊断AECOPD细菌感染的敏感度分别为94．9％、89．7％，特异度分别为87．1％、67．7％，PCT特异度高于CRP（P〈0．05），敏感度无明显差异（P〉0．05）。采用Kappa分析PCT和CRP与痰培养诊断AECOPD细菌感染的-致性，Kappa值分别为0．92、0．58，一致性均较高。结论PCT和CRP是诊断AECOPD细菌感染较好的炎性反应指标，而PCT更具临床价值。

Objective To investigate the clinical value of serum procalcitonin （PCT） and C reactive protein （CRP） in diagnosing bacterial infection in patients with acute exacerbation of chronic obstructive pulmonary disease （AECOPD）. Methods A total of 70 patients with AECOPD were enrolled. The level of serum PCT and CRP were detected before and after treatment. Quantitative sputum culture was performed before treatment. PMMs were only regarded as significant if they reached a growth of≥10^7CFU/ml, indicating the presence of bacterial infection,70 patients with AECOPD was divided into bacterial infecton group（ n = 39） and non-bacterial infection group（ n = 31 ）, the changes of serum PCT and CRP levels were com- pared. Results The levels of PCT and CRP in AECOPD before treatment was obviously higher than those after treatment （ P 〈 0.05 ）. Before treatment, the level of PCT for patients of bacterial infection group was obviously higher than nonbacterial infection group （ P 〈0.05）, but CRP was no difference between the two groups （ P 〉0.05）. The sensitivity of PCT（ 〉0.5ng/ml as positive threshold） and CRP（ 〉 10 mg/L as positive threshold） were 94.8% and 89.7%, respectively, with the specificity being 87.1% and 67.7% respectively in the determination of bacterial infection. Specificity of PCT was higher compared with CRP （ P 〈 0.05 ）, but sensitivity with no difference （ P 〉 0.05 ）. Kappa analysis was used to analyze consis- tency in the diagnosis of bacterial infection. The Kappa value was 0.92 between the PCT and sputum culture, 0.58 between the CRP and sputum culture. Conclusion The PCT and CRP are sensitive index for inflammatory reaction in patients with AECOPD, especially in the determination of bacterial infection, PCT maybe has more clinical value.