降钙素原C-反应蛋白及病原体检测对下呼吸道感染的诊断价值

目的探讨降钙素原(PCT)、C-反应蛋白(CRP)及呼吸道感染病原体抗体联合细菌培养在下呼吸道感染诊断中的诊断价值。方法将119例下呼吸道感染者分为细菌感染组(75例)与非细菌病原体感染组(44例),同期健康体检者60例为健康对照组。采用酶联荧光分析及速率散射比浊法测定PCT及CRP,采用荧光免疫分析检测呼吸道感染病原体抗体,同时对患者的痰及血液进行培养。结果细菌感染组的PCT及CRP水平均高于非细菌病原体感染组及健康对照组(P<0.01)。以PCT>0.5ng/mL、CRP>8.0mg/L为阈值,PCT及CRP的敏感性分别为89.3%和84.0%(二者比较,P>0.05)与非细菌病原体感染组及健康对照组比较差异有统计学意义(P<0.01),PCT对细菌感染诊断的特异度为88.4%高于CRP的78.8%(P<0.05);痰培养和血培养联合检测可提高细菌的阳性检出率(41.3%);下呼吸道细菌感染诊断实验的敏感度依次为:PCT与CRP大于细菌培养。呼吸道感染病原体抗体对于非细菌病原体感染组的阳性检出率为56.8%。结论 PCT及CRP适宜细菌感染的早期诊断,PCT的特异度高于CRP;同时联合呼吸道感染病原体抗体检查及细菌培养对于下呼吸道感染的诊断与鉴别诊断具有重要的价值。

Diagnostic value of procalcitonin C-reactive protein and pathogens detection in lower respiratory tract infections

Objective To investigate the diagnostic value of measurement of serum PCT,CRP and the pathogens antibody of respiratory tract infection and culture of bacteria.Methods 119 patients with lower respiratory tract infection were divided into two group,75 patients with bacterial infection and 44 patients with non-bacteria infection,and 60 healthy people were included.All serum samples were measured of PCT（by Brahms PCT-Q）,CRP（by using immunity-turbidity method）and the antibody of pathogens for respiratory tract infection.All patients were cultured for bacteria in phlegm and blood.Results The levels of PCT and CRP in bacterial infection group were higher than those in non-bacteria infection group and healthy controls（P〈0.01）.The PCT〉 0.5 ng/mL,CRP〉 8.0 mg/L as the threshold,the sensitivity of PCT and CRP were 89.3 % and 84.0 %,with significant difference（P〉 0.05）,and compared with non-bacterial pathogens group and the healthy control one,the difference was statistically significant（P〈0.01）.The specificity of PCT for the diagnosis of bacterial infection was 88.4 %,which was higher than that of CRP（78.8 %）,with significant difference（P〈0.05）;Joint detection of sputum culture and blood culture on bacteria increased the positive rate（41.3%）;The sensitivity of diagnostic tests for lower respiratory tract infections by PCT and CRP was higher than bacterial culture.The positive detection rate of respiratory tract infection pathogens antibody for non-bacterial pathogen infection was 56.8 %.Conclusion PCT and CRP are suitable for the early diagnosis of bacterial infection,and sensitivity of PCT is higher than that of CRP.Combined detection with pathogens antibody of respiratory tract infection and bacterial culture on diagnosis and differential diagnosis of lower respiratory tract infection has important value.