血清降钙素原在鉴别细菌性感染与自身免疫性疾病活动期中的应用价值

Clinical Value of Serum Procalcitonin in the Differential Diagnosis of Bacterial Infection and Disease Flares in Patients with Autoimmune Diseases

目的:探讨血清降钙素原(procalcitonin,PCT)在鉴别诊断自身免疫性疾病活动期与细菌感染中的应用价值。方法:选择析深圳市保健办2011年1月-2012年3月收治的30例自身免疫性疾病活动期和34例细菌感染患者为研究对象,测定其血清C反应蛋白(C-reactive protein,CRP)和PCT的水平。结果:感染组患者CRP水平为(0.1162±0.0873)g/L,PCT水平(2.37±7.02)×10-3g/L,自身免疫活动期患者CRP水平(0.0639±0.0687)g/L,PCT浓度(0.09±0.08)×10-3g/L。ROC曲线下面积(AUC)和95%可信区间(CI)分别为0.75和0.86,0.61-0.83和0.74-0.94,差异具有统计学意义(P<0.05)。CRP联合PCT水平预测的AUC为0.82,其与单独PCT水平相比没有显著性差别(P=0.74)。CRP的最佳临界值为0.0722 g/L,灵敏度为73.5%,特异性为69.2%;PCT的最佳临界值为0.09×10-3g/L,其灵敏度为82.1%,特异性为72.5%。结论:在鉴别活动期自身免疫疾病患者与细菌感染时,PCT的灵敏度与特异性比CRP高,但其联合CRP对此类诊断并无显著意义。

Objective： To explore the application value of serum Procalcitonin （PCT） in the differential diagnosis of bacterial in- fection and disease flares in patients with autoimmune diseases. Methods： 30 cases of autoimmune disease patients with disease flares and 34 cases of patients with infections hospitalized in Shenzhen Health Care Center from January 2011 to March 2012 were collected, the serum C-reactive protein （CRP） and PCT levels were measured. Results： The serum CRP and PCT levels in the infection group was （0.1162± 0.0873）g/L and （2.37± 7.02）× 10^-3g/L respectively. For the disease flare group, CRP and PCT were （0.0639：1： 0.0687）g/L and （0.09± 0.08）× 10^-3g/L. The area under the ROC curve for CRP and PCT were respectively 0.75 （0.61-0.83） and 0.86 （0.74-0.94）, which showed a significant difference （P〈0.05）. The predicted AUC for the CRP and PCT levels combined was 0.82, which was not significantly different compared to the PCT level alone （P=0.74）. The best cut-off value for CRP was 0.0722 g/L, with a sensitivity of 73.5% and a specificity of 69.2%. The best cut-off value for PCT was 0.09ng/mL, with a sensitivity of 82.1% and a specificity of 72.5%. Conclusions： The PCT had higher sensitivity and specificity compared to the CRP in distinguishing bacterial infections and disease flares in autoim- mune disease patients, but CRP level had no additive value when it was combined with the PCT in the differential diagnosis of bacterial infections and disease flares.