Diagnostic Accuracy of Procalcitonin, Neutrophil-to-Lymphocyte Ratio, and C-Reactive Protein in Detection of Bacterial Infections and Prediction of Outcome in Nonneutropenic Febrile Patients with Lung Malignancy

Abstract

Background. Procalcitonin (PCT), C-reactive protein (CRP), and neutrophil-to-lymphocyte ratio (NLR) have emerged as important markers of inflammation, and these markers, especially PCT and CRP, have been studied in patients with neutropenia. This study was designed to evaluate their value in differentiating infectious fever from tumor fever (TF) and to investigate their role in assessing outcomes in nonneutropenic lung cancer patients (NNLCPs). Methods. This retrospective clinical study included 588 febrile NNLCPs between January 2019 and December 2019. The levels of PCT, CRP, and conventional inflammatory markers, including white blood cells (WBC) and neutrophils (NEU), were measured. NLR was defined as the ratio of the absolute neutrophil count to the absolute lymphocyte count. Patients’ clinical and bacteriological data were recorded. Results. This study included 311 NNLCPs with bacterial infections and 277 with TF. Inflammatory markers such as PCT, CRP, WBC, and NEU levels and NLR were significantly higher in patients with bacterial infections than in those with TF (p < 0.0001). However, PCT level was the best predictor of bacterial infections, with an area under the curve (AUC) of 0.874, followed by CRP level (AUC = 0.855) and NLR (AUC = 0.792) (p < 0.0001). Additionally, PCT level was significantly elevated in patients with bacterial infections with progressive disease after radiotherapy and chemotherapy (p < 0.01). Conclusions. The present study demonstrated the superiority of PCT over CRP and NLR in the diagnosis of febrile patients with bacterial infections. Additionally, PCT can be used to assess the clinical outcomes and cancer progression in NNLCPs.

Usefulness of procalcitonin (PCT), C-reactive protein (CRP), and white blood cell (WBC) levels in the differential diagnosis of acute bacterial, viral, and mycoplasmal respiratory tract infections in children

“…6 mL elbow venous blood was collected and injected into the coagulant tube and the anticoagulant tube containing ethylene diamine tetraacetic acid. The serum PCT level was detected by electrochemiluminescence immunometric assay, and the level not exceeding 0.5 ng/mL was considered normal [ 10 ]. The CRP and WBC level was measured by immunoturbidimetry assay and flow cytometry, respectively.…”

Comparison of sPLA2IIA performance with high-sensitive CRP neutrophil percentage PCT and lactate to identify bacterial infection

“…The bacterial infection is defined as a clinical bacterial infection or positive bacterial cultures (sputum, body fluids, blood, et cetera). However, the exclusion criteria were immunosuppressed patients, in either case, oncologic patients 15 – 19 , partially treated with antibiotics before ED presentation, preexisting liver cirrhosis 20 – 23 and end-stage renal failure who required regular dialysis 24 – 26 , or sterile inflammatory disease. The research was approved by the Universiti Kebangsaan Malaysia (UKM) ethical review board (ethic code FF-2015-322) and carried out according to Good Clinical Practice guideline.…”

Relationship between changes in the course of COVID-19 and ratio of neutrophils-to-lymphocytes and related parameters in patients with severe vs. common disease

“…Procalcitonin (PCT), C-reactive protein (CRP) and the neutrophil-to-lymphocyte ratio (NLR) have all been shown to serve as important markers of inflammation [ 6 ]. These markers, in particular, PCT and CRP, have been studied in patients with neutropenia.…”