Procalcitonin and C-reactive protein in differantiating to contamination from bacteremia

The Clinical Performance of Cell Population Data for Diagnosis of Bloodstream Infection in Cancer Patients

Background Bloodstream infection (BSI) induces a change in the number and morphology of blood cells. In this study, we compared cell population data (CPD) parameters between cancer patients with or without BSI to determine whether these parameters could serve as biomarkers of BSI. Methods Between April and June 2021, 43 BSI-negative and 22 BSI-positive cancer patients were enrolled in this study. We compared 18 CPD parameters and biomarkers between cancer patients with BSI-positive and BSI-negative. Results There were significant differences in the levels of several CPD parameters, including MO-WZ (p=0.040), MO-X (p<0.01), MO-Y (p=0.012), NE-SFL (p<0.01), and NE-WX (p=0.037), but not C-reactive protein (p=0.347) and procalcitonin (p=0.237) between BSI-positive and BSI-negative patients. The areas under the receiver-operating characteristic curves (AUCs) were above 0.7 for MO-X (0.762; 95% confidence intervals (CI): 0.624-0.901), NE-SFL (0.766; 95% CI: 0.625-0.880). And LY-WY (p=0.024) showed a significant difference between gram-negative and gram-positive BSI patients with high AUC (0.883; 95% CI: 0.703-1). Conclusion CPD parameters (MO-X and NE-SFL) provide additional information for discriminating between BSI-negative and BSI-positive BSI. And LY-WY provides useful information for discriminating between cancer patients with gram-negative BSI and gram-positive BSI.

Reliability of Admission Procalcitonin Testing for Capturing Bacteremia Across the Sepsis Spectrum: Real-World Utilization and Performance Characteristics, 65 U.S. Hospitals, 2008-2017

OBJECTIVES

Serum procalcitonin is often ordered at admission for patients with suspected sepsis and bloodstream infections (BSIs), although its performance characteristics in this setting remain contested. This study aimed to evaluate use patterns and performance characteristics of procalcitonin-on-admission in patients with suspected BSI, with or without sepsis.

DESIGN

Retrospective cohort study.

SETTING

Cerner HealthFacts Database (2008-2017).

PATIENTS

Adult inpatients (≥ 18 yr) who had blood cultures and procalcitonin drawn within 24 hours of admission.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Testing frequency of procalcitonin was determined. Sensitivity of procalcitonin-on-admission for detecting BSI due to different pathogens was calculated. Area under the receiver operating characteristic curve (AUC) was calculated to assess discrimination by procalcitonin-on-admission for BSI in patients with and without fever/hypothermia, ICU admission and sepsis defined by Centers for Disease Control and Prevention Adult Sepsis Event criteria. AUCs were compared using Wald test and p values were adjusted for multiple comparisons. At 65 procalcitonin-reporting hospitals, 74,958 of 739,130 patients (10.1%) who had admission blood cultures also had admission procalcitonin testing. Most patients (83%) who had admission day procalcitonin testing did not have a repeat procalcitonin test. Median procalcitonin varied considerably by pathogen, BSI source, and acute illness severity. At a greater than or equal to 0.5 ng/mL cutoff, sensitivity for BSI detection was 68.2% overall, ranging between 58.0% for enterococcal BSI without sepsis and 96.4% for pneumococcal sepsis. Procalcitonin-on-admission displayed moderate discrimination at best for overall BSI (AUC, 0.73; 95% CI, 0.72-0.73) and showed no additional utility in key subgroups. Empiric antibiotic use proportions were not different between blood culture sampled patients with a positive procalcitonin (39.7%) and negative procalcitonin (38.4%) at admission.

CONCLUSIONS

At 65 study hospitals, procalcitonin-on-admission demonstrated poor sensitivity in ruling out BSI, moderate-to-poor discrimination for both bacteremic sepsis and occult BSI and did not appear to meaningfully alter empiric antibiotic usage. Diagnostic stewardship of procalcitonin-on-admission and risk assessment of admission procalcitonin-guided clinical decisions is warranted.

Ambient temperature exposure causes lung function impairment: The evidence from Controlled Temperature Study in Healthy Subjects (CTSHS)

BACKGROUND

The effect of non-optimal ambient temperatures (low and high temperatures) on lung function and the underlying mechanisms remains unclear.

METHODS

Forty-three (20 males, 23 females) healthy non-obese volunteers with an average of 23.9 years participated in the controlled temperature study. All volunteers underwent three temperature exposures in a sequence (moderate [18 °C], low [6 °C], and high [30 °C] temperatures) lasting 12 h with air pollutants controlled. lung function parameters (forced vital capacity [FVC], forced expiratory volume in 1 s [FEV₁], and peak expiratory flow [PEF]) were determined in each exposure. Blood and urine samples were collected after each exposure and assayed for inflammatory markers [C-reactive protein (CRP), procalcitonin (PCT), platelet-lymphocyte ratio (PLR), and neutrophil-lymphocyte ratio (NLR)] and oxidative damage markers [protein carbonylation (PCO), 4-hydroxy-2-nominal-mercapturic acid (HNE-MA), 8-iso-prostaglandin-F_2α (8-isoPGF_2α), and 8-hydroxy-2-deoxyguanosine (8-OHdG)]. Mixed-effects models were constructed to assess the changes of the above indexes under low or high temperatures relative to moderate temperature, and then the repeated measures correlation analyses were performed.

RESULTS

Compared with moderate temperature, a 2.20% and 2.59% net decrease in FVC, FEV₁, and a 5.68% net increase for PEF were observed under low-temperature exposure, while a 1.59% net decrease in FVC and a 7.29% net increase in PEF under high-temperature exposure were found (all P < 0.05). In addition, low temperature elevated inflammatory markers (PCT, PLR, and NLR) and oxidative damage markers (8-isoPGF_2α, 8-OHdG), and high temperature elevated HNE-MA. Repeated measures correlation analyses revealed that PCT (r = -0.33) and NLR (r = -0.31) were negatively correlated with FVC and HNE-MA (r = -0.35) and 8-OHdG (r = -0.31) were negatively correlated with the FEV₁ under low-temperature exposure (all P < 0.05).

CONCLUSION

Non-optimal ambient temperatures exposure alters lung function, inflammation, and oxidative damage. Inflammation and oxidative damage might be involved in low temperature-related lung function reduction.

Routine laboratory biomarkers used to predict Gram-positive or Gram-negative bacteria involved in bloodstream infections

This study evaluated routine laboratory biomarkers (RLB) to predict the infectious bacterial group, Gram-positive (GP) or Gram-negative (GN) associated with bloodstream infection (BSI) before the result of blood culture (BC). A total of 13,574 BC of 6787 patients (217 BSI-GP and 238 BSI-GN) and 68 different RLB from these were analyzed. The logistic regression model was built considering BSI-GP or BSI-GN as response variable and RLB as covariates. After four filters applied total of 320 patients and 16 RLB remained in the Complete-Model-CM, and 4 RLB in the Reduced-Model-RM (RLB p > 0.05 excluded). In the RM, only platelets, creatinine, mean corpuscular hemoglobin and erythrocytes were used. The reproductivity of both models were applied to a test bank of 2019. The new model presented values to predict BSI-GN of the area under the curve (AUC) of 0.72 and 0.69 for CM and RM, respectively; with sensitivity of 0.62 and 0.61 (CM and RM) and specificity of 0.67 for both. These data confirm the discriminatory capacity of the new models for BSI-GN (p = 0.64). AUC of 0.69 using only 4 RLB, associated with the patient's clinical data could be useful for better targeted antimicrobial therapy in BSI.

C-Reactive Protein Monitoring and Clinical Presentation of Fever as Predictive Factors of Prolonged Febrile Neutropenia and Blood Culture Positivity after Autologous Hematopoietic Stem Cell Transplantation-Single-Center Real-Life Experience

BACKGROUND

Febrile neutropenia (FN) is a medical emergency that requires urgent evaluation, timely administration of empiric broad-spectrum antibiotics and careful monitoring in order to optimize the patient's outcome, especially in the setting of both allogeneic and autologous hematopoietic stem cell transplant (ASCT).

METHODS

In this real-life retrospective study, a total of 49 consecutive episodes of FN were evaluated in 40 adult patients affected by either multiple myeloma (thirty-eight) or lymphoma (eleven), following ASCT, with nine patients having fever in both of the tandem transplantations.

RESULTS

Febrile neutropenia occurred a median of 7 days from ASCT. Median duration of FN was 2 days, with 25% of population that had fever for at least four days. Ten patients had at least one fever spike superior to 39 °C, while the median number of daily fever spikes was two. Twenty patients had positive blood cultures with XDR germs, namely Pseudomonas aeruginosa and Klebsiella pneumoniae, present in seven cases. ROC analysis of peak C-reactive protein (CRP) values was conducted based on blood culture positivity and a value of 12 mg/dL resulted significant. Onset of prolonged fever with a duration greater than 3 days was associated with the presence of both a peak number of three or more daily fever spikes (p = 0.02) and a body temperature greater than 39 °C (p = 0.04) based on odds ratio (OR). Blood culture positivity and peak CRP values greater than 12 mg/dL were also associated with prolonged fever duration, p = 0.04, and p = 0.03, respectively. The probability of blood culture positivity was also greater in association with fever greater than 39 °C (p = 0.04). Furthermore, peak CRP values below the cut-off showed less probability of positive blood culture (p = 0.02).

CONCLUSIONS

In our study, clinical characteristics of fever along with peak CRP levels were associated with a higher probability of both prolonged fever duration and positive blood culture, needing extended antibiotic therapy.

Procalcitonin kinetics to guide sequential invasive-noninvasive mechanical ventilation weaning in patients with acute exacerbation of chronic obstructive pulmonary disease and respiratory failure: procalcitonin's adjunct role

How to identify the optimum switch point of sequential invasive and noninvasive ventilation is the focus of clinical attention on the patients suffering from acute exacerbation of chronic obstructive pulmonary disease (AECOPD) complicated by acute respiratory failure (ARF). This study aims to explore the clinical significance of taking the change rate of procalcitonin (PCT) as identifying the timing of weaning on the mechanical ventilation for the patients of AECOPD followed by ARF as a complication. There were altogether 140 patients of AECOPD complicated with ARF, who were randomly selected and divided into a study group and a control group respectively. A change rate of serum PCT level exceeding 50% was taken as the switch point selection of tracheal intubation removal for the patients of the study group, while the ‘pulmonary infection control (PIC) window’ was done for those in the control group. With CRP, IL-6, TNF-a, PaCO_2, PaO_2, and Lac having been detected before and after treatment to them all, clinical indexes were obtained and compared between these two groups. The CRP, TNF-a, and IL-6 levels of the patients in the study group after treatment (p < 0.05) were lower than those in the control group. There was no significant difference in PaCO_2, PaO_2, and Lac between these two groups before and after treatment (p > 0.05). Even so, some other indexes available for the study group of patients were found to be lower than those for the control group (p < 0.05) in the following aspects: duration of invasive ventilation support, total time of mechanical ventilation support, incidence rate of ventilator-associated pneumonia, 48-hour reintubation rate, incidence rate of upper gastrointestinal bleeding, hospitalization time of critical respiratory illness, total hospitalization time, RICU treatment cost, total treatment cost, and mortality. It is preferable to take the change rate of PCT level exceeding 50% as the switch point of weaning time in sequential mechanical ventilation rather than the PIC window.

Abbreviations

AECOPD: acute exacerbation of chronic obstructive pulmonary disease; ARF: acute respiratory failure; PCT: procalcitonin; PaO₂: the oxygen partial pressure; PaCO₂: the partial pressure of carbon dioxide; TNF-a: serum tumor necrosis factor-a; IL-6: interleukin-6; CRP: serum C-reactive protein; PIC window: pulmonary infection control window; RICU: respiration and intensive care unit

Biomarkers in pediatric sepsis: a review of recent literature

Sepsis remains the leading cause of death in infants and children worldwide. Prompt diagnosis and monitoring of infection is pivotal to guide therapy and optimize outcomes. No single biomarker has so far been identified to accurately diagnose sepsis, monitor response and predict severity. We aimed to assess existing evidence of available sepsis biomarkers, and their utility in pediatric population. C-reactive protein and procalcitonin remain the most extensively evaluated and used biomarkers. However, biomarkers related to endothelial damage, vasodilation, oxidative stress, cytokines/chemokines and cell bioproducts have also been identified, often with regard to the site of infection and etiologic pathogen; still, with controversial utility. A multi-biomarker model driven by genomic tools could establish a personalized approach in future disease management.

Serum procalcitonin and C-reactive protein in the evaluation of bacterial infection in generalized pustular psoriasis

Background

There is an obvious need for more prompt and specific biomarkers of bacterial infections in generalized pustular psoriasis patients.

Objective

The aim of this study was to evaluate the diagnostic properties and define appropriate cut-off values of procalcitonin and C-reactive protein in predicting bacterial infection in generalized pustular psoriasis patients.

Methods

Sixty-four generalized pustular psoriasis patients hospitalized from June 2014 to May 2017 were included in this retrospective study. The values of procalcitonin, C-reactive protein, details of infection, and other clinical parameters were analyzed.

Results

Receiver operating characteristic curve analysis generated similar areas (p = 0.051) under the curve for procalcitonin 0.896 (95% CI 0.782–1.000) and C-reactive protein 0.748 (95% CI 0.613–0.883). A cut-off value of 1.50 ng/mL for procalcitonin and 46.75 mg/dL for C-reactive protein gave the best combination of sensitivity (75.0% for procalcitonin, 91.7% for C-reactive protein) and specificity (100% for procalcitonin, 53.8% for C-reactive protein). Procalcitonin was significantly positively correlated with C-reactive protein levels both in the infected (r = 0.843, p = 0.040) and non-infected group (r = 0.799, p = 0.000).

Study limitations

The sample size and the retrospective design are limitations.

Conclusions

The serum levels of procalcitonin and C-reactive protein performed equally well to differentiate bacterial infection from non-infection in generalized pustular psoriasis patients. The reference value of procalcitonin and C-reactive protein applied to predicting bacterial infection in most clinical cases may not be suitable for generalized pustular psoriasis patients. C-reactive protein had better diagnostic sensitivity than procalcitonin; however, the specificity of procalcitonin was superior to that of C-reactive protein.

Ability of procalcitonin to differentiate true bacteraemia from contaminated blood cultures in an emergency department

OBJECTIVES

To analyse and compare the ability of procalcitonin (PCT), C-reactive protein (CRP) and leukocytes to differentiate true bacteraemia from contaminated blood cultures in patients seen in the emergency department (ED) for an episode of infectious disease.

METHODS

Observational, retrospective and descriptive analytical study of all blood cultures with positive growth extracted in an ED in adult patients (≥18 years) during 2016 and 2017. The follow-up was carried out over a 30-day period to calculate the predictive power and the prognostic performance for true bacteraemia.

RESULTS

A total of 266 blood cultures with positive growth were included in the study. Out of these, 154 (57.9%) were considered true bacteraemia and 112 (42.1%) were considered to be contaminated blood cultures. The area under the Receiver Operating Characteristic curve (AUC-ROC) for PCT to predict true bacteraemia was 0.983 (95% CI: 0.972-0.994; P<0.001) and, considering a cut-off value of≥0.43 ng/ml, PCT achieved 94% sensitivity, 91% specificity, positive predictive value of 94%, and negative predictive value of 92%. The AUC-ROC obtained for CRP was 0.639 (95% CI: 0.572-0.707, P<.001), for leukocytes of 0.693 (95% CI: 0.630-0.756, P<.001) and for immature leukocytes (>10% bands) of 0.614 (95% CI: 0.547-0.682, P<.001). The mean values for PCT were 3.44 (SD 6.30) ng/ml in true bacteraemia vs. 0.16 (SD 0.18) ng/ml in contaminated blood cultures (P<.001).

CONCLUSIONS

In blood cultures with positive growth extracted in an ED, PCT achieves the best prognostic performance of true bacteraemia vs. contaminated blood cultures, better than CRP and leukocytes.

Procalcitonin-guided diagnosis and antibiotic stewardship revisited

Several controlled clinical studies have evaluated the potential of the infection biomarker procalcitonin (PCT) to improve the diagnostic work-up of patients with bacterial infections and its influence on decisions regarding antibiotic therapy. Most research has focused on lower respiratory tract infections and critically ill sepsis patients. A clinical utility for PCT has also been found for patients with urinary tract infections, postoperative infections, meningitis, and patients with acute heart failure with possible superinfection (i.e., pneumonia). In these indications, PCT levels measured on hospital admission were found to substantially reduce the initiation of antibiotic treatment in low-risk situations (i.e., bronchitis, chronic obstructive pulmonary disease exacerbation). For more severe infections (i.e., pneumonia, sepsis), antibiotic stewardship by monitoring of PCT kinetics resulted in shorter antibiotic treatment durations with early cessation of therapy. Importantly, these strategies appear to be safe without increasing the risk for mortality, recurrent infections, or treatment failures. PCT kinetics also proved to have prognostic value correlating with disease severity (i.e., pancreatitis, abdominal infection) and resolution of illness (i.e., sepsis). Although promising findings have been published in these different types of infections, there are a number of limitations regarding PCT, including suboptimal sensitivity and/or specificity, which makes a careful interpretation of PCT in the clinical context mandatory. This narrative review aims to update clinicians on the strengths and limitations of PCT for patient management, focusing on research conducted within the last 4 years.