Diagnostic values of neutrophil/lymphocyte ratio, platelet/lymphocyte ratio and procalcitonin in early diagnosis of bacteremia

Abstract

Abstract Objective The aim of this study is to investigate the diagnostic accuracy of complete blood count (CBC), C-reactive protein (CRP), and procalcitonin (PCT) levels, which can be used as a cultural alternative for the diagnosis of infection faster. Methods The patients were divided into two groups as bacteremia (n = 220) and nonbacteremia group (n = 812). The bacteremia group was divided into two subgroups as Gram-positive bacteria (n = 167) and Gram-negative bacteria (n = 53). Results PCT, CRP, red blood cell distribution width (RDW), platelet distribution width (PDW), neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR), and mean platelet volume (MPV) levels were significantly higher in patients with positive blood culture than non-patients. The serum PCT levels were 3.80 (0.83–37.68) and 0.43 (0.16–2.61) ng/mL, respectively (p < 0.001) in the patients with Gram-negative and Gram-positive bacterium. PCT at a cut-off value of 0.45 ng/mL for Gram-negative bacterium; sensitivity of 90% and specificity of 64%. Conclusions It is important that RDW, PDW, NLR, PLR, MPV values can be measured quickly, easily and cheaply by automatic hematological analysis. However, among the markers tested, PCT has the best diagnostic performance for Gram-negative bacteremia.