血清降钙素原在系统性自身免疫病患者细菌感染的诊断价值

Serum procalcitonin for diagnosis of bacterial infections in patients with systemic autoimmune diseases

目的探讨血清降钙素原(PCT)对系统性自身免疫病(SAID)病情活动与细菌感染鉴别诊断的意义,为临床诊断SAID患者细菌感染提供参考指标。方法回顾性分析2011年1月-2013年6月医院住院确诊为SAID且病历资料较完整的患者共287例,根据最终诊断的结果将患者分为细菌感染组103例和非感染组184例,比较两组患者血清PCT及C-反应蛋白(CRP)水平,数据采用SPSS 18.0软件进行统计分析。结果 SAID患者细菌感染组的PCT和CRP水平均显著高于非感染组,差异有统计学意义(P<0.05),但PCT诊断效能更高;PCT的最佳界值为0.215ng/ml,在此界值下其敏感性、特异性、阳性预测值、阴性预测值分别为90.3%、86.4%、78.8%、94.1%;脓毒血症组PCT水平显著高于非脓毒血症组(P<0.05);在有效的抗感染治疗后PCT水平显著下降(P<0.05)。结论在SAID病情活动与细菌感染的鉴别诊断中,PCT优于CRP;SAID细菌感染患者,血清PCT水平与感染严重程度相关,动态监测PCT水平可用于抗感染治疗效果的评价。

OBJECTIVE To study the role of serum procalcitonin （PCT） in differentiating bacterial infections in systemic autoimmune diseases （SAID） so as to provide reference for diagnosis of bacterial infection in SAID patients. METHODS A retrospective study was carried out for hospitalized SAID patients with complete and detailed medical records in the hospital from Jan. 2011 to Jun. 2013. Among a total of 287 SAID patients recruited in this study, there were 206 SLE patients, which were divided into the bacteria-infected group （n= 103） and the non-infected group （n= 184）. Serum PCT and C-reactive protein （CRP） levels＇ were compared between the two groups. The software SPSS 18.0 was used for statistical analysis of data. RESULTS The PCT and CRP levels were signitiiartly higher in the infected group than in the non-infected group （P〈0.05）, PCT showed higher efficiency for diagnosis. The optimum threshold for PCT was 0. 215 ng/ml. The sensitivity, specificity, positive prediction value and negative predication value were 90.3%, 86.4%, 78.8%, and 94.1% at this threshold. The serum PCT level was significantly higher for the septic patients than for non-septic ones （P〈0.05）. Serum PCT levels were significantly reduced after anti-bacterial treatment （P〈0.05）. CONCLUSION PCT is superior to CRP test in detecting superimposed bacterial infections in SAID patients. In SAID patients concurrent with bacterial infection, the levels of PCT are correlated with the severity of infections and can be used to monitor the response to antibiotic treatment.