Value of combined detection of serum PCT and IL-6 in diagnosis of pulmonary infection

Objective To explore the clinical value of combination detection of serum procalcitonin(PCT)and interleukin-6(IL-6)in the diagnosis of pulmonary infection.Methods The patients with pulmonary infection in our hospital from October 2013 to May 2014 were collected,including 32 cases of bacterial infection and 28 cases of nonbacterial infection;at the same time and the serum samples in 35 healthy subjects as control group were collected.The expression levels of serum PCT in each group was detected by the dry-immunofluorescence quantitation method,and the levels of serum IL-6was detected by the electrochemical fluorescence quantitative method.And the diagnostic value of the combined detection of PCT and IL-6in pulmonary infection was analyzed.Results The levels of PCT and IL-6in the bacterial infection group were significantly higher than those in the healthy control group and the non-bacterial infection group(F=21.71,F=39.09,P0.05).However,the non-bacterial infection group and the healthy control group had no statistical difference in serum PCT and IL-6levels(P0.05).The area under the ROC curves(AUCROC)of serum PCT for diagnosing bacterial infection was 0.787(95%CI:0.559-0.999)and which of IL-6was 0.934(95%CI:0.829-0.999).In PCT0.5ng/mL and IL-6120.0pg/mL as the cut off values respectively,the sensitivity,specificity,positive predictive value and negative predictive value of the combined detection of PCT and IL-6in diagnosing pulmonary infection were 87.5%,98.4%,95.6%and 94.7%respectively,which were significantly higher than those of single PCT or IL-6detection.Conclusion The combination detection of serum PCT and IL-6has higher sensitivity and higher specificity in diagnosing pulmonary infection and can be used in the assisted diagnosis of pulmonary infection.