Interleukin-6 and procalcitonin as biomarkers in mortality prediction of hospitalized patients with community acquired pneumonia

Abstract

INTRODUCTION:Community acquired pneumonia (CAP) may present as life-threatening infection with uncertain progression and outcome of treatment. Primary aim of the trial was determination of the cut-off value of serum interleukin-6 (IL-6) and procalcitonin (PCT) above which, 30-day mortality in hospitalized patients with CAP, could be predicted with high sensitivity and specificity. We investigated correlation between serum levels of IL-6 and PCT at admission and available scoring systems of CAP (pneumonia severity index-PSI, modified early warning score-MEWS and (Confusion, Urea nitrogen, respiratory rate, Blood pressure, ≥65 years of age-CURB65).METHODS:This was prospective, non-randomized trial which included 101 patients with diagnosed CAP. PSI, MEWS and CURB65 were assessed on first day of hospitalization. IL-6 and PCT were also sampled on the first day of hospitalization.RESULTS:Based on ROC curve analysis (AUC ± SE = 0.934 ± 0.035; 95%CI(0.864-1.0); P = 0.000) hospitalized CAP patients with elevated IL-6 level have 93.4% higher risk level for lethal outcome. Cut-off value of 20.2 pg/ml IL-6 shows sensitivity of 84% and specificity of 87% in mortality prediction. ROC curve analysis confirmed significant role of procalcitonin as a mortality predictor in CAP patients (AUC ± SE = 0.667 ± 0.062; 95%CI(0.546-0.789); P = 0.012). Patients with elevated PCT level have 66.7% higher risk level for lethal outcome. As a predictor of mortality at the cut-off value of 2.56 ng/ml PCT shows sensitivity of 76% and specificity of 61.8%.CONCLUSIONS:Both IL-6 and PCI are significant for prediction of 30-day mortality in hospitalized patients with CAP. Serum levels of IL6 correlate with major CAP scoring systems.

Utilization of serum procalcitonin as a biomarker in the diagnosis and treatment of children with bacterial hospital-acquired pneumonia

“…Compared to other earlier studies that used bacterial serology or blood culture for the diagnosis of pediatric pneumonia, or studies that used PCT assay that has relatively lower detection limits, our study successfully detected PCT concentrations in a wider range, and thus atypical and viral pneumonia can be distinguished from typical bacterial pneumonia [23]. To date, in spite of multiple pieces of evidence supporting the diagnostic and prognostic values for PCT, many studies have reported various prognostic factors for inflammatory diseases in adults or elderly patients [24][25][26]. However, only a few studies have assessed the role of PCT as a prognostic factor in pediatric pneumonia patients.…”

Cold-inducible RNA-binding protein might determine the severity and the presences of major/minor criteria for severe community-acquired pneumonia and best predicted mortality

“…Moreover, IL-6 levels have been shown to have a good correlation with various clinical severity scores (e.g. PSI) [ 30 ]. Admission CRP < 100 mg/L has reduced risk for 30-day mortality, need for mechanical ventilation and/or inotropic support, and complicated pneumonia.…”

Prognostic value of procalcitonin in hospitalized patients with lower respiratory tract infections

“…When examining the use of PCT for the prognostic prediction of hospitalized patients with respiratory infections, a cohort study from 2014 involving 101 hospitalized patients with CAP found results similar to those of the aforementioned studies; it showed that PCT had low to moderate accuracy for predicting 30-day mortality in this group of patients, with an AUC value of 0.66 (95%CI, 0.54 - 0.78; p ≤ 0.012) The best cutoff value found, 2.56ng/mL, presented a sensitivity of 76% and a specificity of 61.8% for predicting mortality. ( 35 ) Another prospective study involving 170 hospitalized patients with CAP showed the superior performance of initial PCT levels in predicting survival at 30 days (AUC for mortality, 0.8; 95%CI, 0.7 - 0.9), although it used a semiquantitative method to measure PCT. The accuracy of PCT was higher than that of other markers, including CRP; however, it was less accurate than the CURB-65 (AUC 0.88) and PSI (AUC 0.89) scores.…”