The early diagnostic value of different inflammatory factors in elderly female patients with blood stream infection

Objective To investigate the expression of different inflammatory variables, such as procalcitonin(PCT), C-reactive protein(CRP), D-dimer(DD), fibrinogen(FIB), white blood cell(WBC), neutrophils and platelet(PLT)in septic elderly female patients with bacterial bloodstream infection, in order to assess the early diagnostic value of these variables. Methods A total of 308 elderly female patients with systemic inflammatory response syndrome(SIRS)were enrolled for this prospective study in Beijing Hospital between January 2014 and December 2015.Patients were divided into the sepsis group(n=210)and non-sepsis group(n=98)based on the diagnostic criteria of sepsis.The early inflammatory variables in blood, including PCT, CRP, DD, FIB, WBC, neutrophils and PLT, were detected within 6 hours of bloodstream infection, and their correlations were analyzed.The receiver operating characteristic(ROC)curve of inflammatory variables for the diagnosis of bloodstream infection was plotted, and the area under ROC curve(AUC)was calculated and used to evaluate diagnostic value for bloodstream infection.The best diagnostic cut-off points were identified based on the best(largest)AUC and the best sensitivity and specificity of inflammatory variables for bloodstream infection. Results The levels of all the inflammatory variables were significantly higher in the sepsis group than in non-sepsis group(all P<0.05). Additionally, PCT and CRP were independent factors for diagnosis of blood stream infection.AUC of the combination of two biomarkers of PCT and CRP was 0.694 for diagnosis of sepsis, which was higher than the either biomarkers alone with AUC of 0.628 for PCT and 0.627 for CRP.The combination group of PCT and CRP showed better values of sensitivity, specificity, positive predictive, and negative predictive(86.2%, 59.1%, 65.1%, 81.3%), as compared with those used individually(63.4%, 58.2%, 60.3%, 61.4% for PCT; and 62.4%, 58.2%, 59.9%, 60.7% for CRP, respectively). Conclusions The combination assay of PCT and CRP enhances the diagnostic ability for bacterial bloodstream infection. Key words: Chemokines; Bacterial infections