Role of procalcitonin in predicting etiology in bacteremic patients: Report from a large single-center experience

Prognostic performance of IL-6 and IL-10 in febrile pediatric hematology/oncology patients with normal procalcitonin

INTRODUCTION

It is important to predict adverse outcomes in febrile children with hematology/oncology diseases. Procalcitonin (PCT) is a promising biomarker for the prediction of infection severity, but further studies have revealed its performance in excluding adverse outcomes of infection. IL-6 and IL-10 were reported to have a close association with those infection outcomes. The aim of the study was to investigate the performance of IL-6 and IL-10 in febrile pediatric hematology/oncology patients with normal PCT.

METHODS

This was a retrospective study conducted in a tertiary children's hospital in China over the past ten years. Inflammatory biomarkers, including IL-6, IL-10, PCT and C-reactive protein (CRP), were detected at the onset of infection. Separate analyses were conducted in patients with neutropenia and without neutropenia.

RESULTS

In total, 5987 febrile cases were enrolled. For patients with neutropenia, IL-6, IL-10 and PCT were significantly increased in patients with bloodstream infection (BSI), gram-negative bacteremia (GNB) and severe sepsis (SS), but only IL-6 and IL-10 were predictive of GNB and SS. For patients without neutropenia, IL-6, IL-10 and PCT were significantly increased in patients with BSI, GNB and SS, but no biomarkers were predictive of adverse outcomes. All biomarkers failed to exclude patients with fever of unknown origin or upper respiratory infection/bronchitis in patients with neutropenia.

CONCLUSIONS

IL-6 and IL-10 could be predictors for GNB and SS in febrile patients with neutropenia and had some association with unfavorable outcomes in febrile patients without neutropenia. All biomarkers failed to exclude patients with fever of unknown origin or upper respiratory infection/bronchitis.

Diagnostic usefulness of serum procalcitonin in patients with bacterial sepsis

Background

The Sequential Organ Failure Assessment (SOFA) score is used for the diagnosis of sepsis and involves clinical and laboratory parameters that may not be readily and/or timely available in most resource-poor settings. Procalcitonin (PCT) has its level changed in response to bacterial sepsis and its measurement costs only a fraction of the total cost of investigations required to calculate SOFA score. This study aims to determine the diagnostic usefulness of PCT in bacterial sepsis.

Materials and Methods

Ninety-nine participants were studied, divided into three groups: apparently healthy volunteers, those with bacterial infection without sepsis (SOFA score <2), and patients with bacterial sepsis (positive culture and SOFA ≥2). PCT level of each participant was measured and median group levels compared. Pearson's correlation was used to determine the correlation between serum PCT levels and SOFA scores in the sepsis group using a significance level of 5 percent (P < 0.05). Diagnostic usefulness of PCT was assessed using receiver operating characteristic (ROC).

Result

Positive correlation was found between serum PCT levels and SOFA scores among patients with sepsis r = 0.42, P = 0.016. At a concentration of ≥4.25 ng/ml, serum PCT as a surrogate for SOFA score had a sensitivity and specificity of 57.60% and 84.80%, respectively, for indicating sepsis. The area under the ROC curve (AUC) was 0.74 (95% CI {0.62 to 0.86}, P = 0.001).

Conclusion

Serum PCT concentration was significantly higher in bacterial sepsis compared to bacterial infection without sepsis and healthy state. PCT concentration demonstrated positive correlation with SOFA score in bacterial sepsis and can be used as surrogate for sepsis screening/monitoring in resource-poor settings.

The Role of Gut Microbiota in the Clinical Outcome of Septic Patients: State of the Art and Future Perspectives

Sepsis is a life-threatening multiple-organ dysfunction caused by a dysregulated host response to infection, with high mortality worldwide; 11 million deaths per year are attributable to sepsis in high-income countries. Several research groups have reported that septic patients display a dysbiotic gut microbiota, often related to high mortality. Based on current knowledge, in this narrative review, we revised original articles, clinical trials, and pilot studies to evaluate the beneficial effect of gut microbiota manipulation in clinical practice, starting from an early diagnosis of sepsis and an in-depth analysis of gut microbiota.

Changes of C-reactive protein and Procalcitonin after four weeks of treatment in patients with pulmonary TB

Objective

Tuberculosis (TB) remains a public health concern worldwide, affecting millions of people every year. Detailed characterization of disease pathophysiology is key to proper diagnosis, disease progression, or treatment follow-up and evaluation. The present study investigated C-reactive protein and Procalcitonin (PCT) as candidate markers of early treatment response and disease activity.

Methods

From September to December 2019, 21 HIV-negative consecutive TB patients were recruited, within the setting of the Gabonese TB specialized hospital and the National Laboratory of Public Health, in a prospective study. CRP and PCT levels were measured by chemiluminescence at diagnosis and 4 weeks following the initiation of anti-TB treatment.

Results

The mean concentration of CRP in TB patients was 114.7 mg/L (95 % CI: [83.8-145.6]) at diagnosis and 20.2 mg/L (95 % CI: [14.1-26.4]) 4 weeks following anti-TB treatment. The drop in CRP concentrations between diagnosis, and week 4 following anti-TB treatment showed was significant (p < 0.0001). The average concentration of PCT at the time of diagnosis was 0.3 ng/mL (95 % CI: [0.19-0.41]). PCT Concentration dropped below 0.05 ng/mL 4 weeks following the start of anti-TB treatment (p < 0.01).

Conclusion

CRP and PCT are potential TB biomarkers, each, carrying important keys. If the drop in both proteins may indicate a significant reduction of the Mtb burden, the maintenance of CRP above the inflammation threshold could indicate the presence of residual bacilli. However, the clinical translation of the present finding will require more investigation.

Epidemiology and Risk Factors of Community-Associated Bloodstream Infections in Zhejiang Province, China, 2017–2020

Purpose

Community-associated bloodstream infection (CA-BSI) is increasing in many community settings. However, the clinical significance and epidemiology of CA-BSI present in hospital admissions in China are not well established. In this work, we identified the risk factors in outpatients presenting with CA-BSI, and investigate the role of procalcitonin (PCT) and hypersensitive C-reactive protein (CRP) in diagnosing different types of the pathogen in patients with acute CA-BSI.

Methods

A retrospective study enrolling 219 outpatients with CA-BSI from The Zhejiang People's Hospital from January 2017 to December 2020 was performed. Susceptibility of the isolates obtained from these patients was examined. Subjecting receiver operating characteristic curves (ROC) were constructed to analyze the specificity and sensitivity of PCT, CRP, and WBC in determining infections caused by different bacterial genera. Risk factors for CA-BSI in the emergency setting were analyzed using essential information and simple identification of other pathogenic bacterial species through rapidly tested biomarkers.

Results

A total of 219 patients were included in the selection criteria, of which 103 were infected with Gram-positive bacteria (G+) and 116 with Gram-negative bacteria (G-). The PCT was significantly higher in the GN-BSI group than in the GP-BSI group, while no significant difference was observed between the two groups for CRP. Subjecting ROC curves were constructed to analyze WBC, CRP, and PCT, and the area under the curve (AUC) of the PCT in this model was 0.6661, with sensitivity = 0.798 and specificity = 0.489.

Conclusion

The PCT between the GP-BSI group and the GN-BSI group was significantly different. By combining the knowledge of clinicians and the clinical signs of patients, PCT should be utilized as a supplementary approach to initially determine pathogens and direct medication in the early stages of clinical practice.

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.

Microbiological and Clinical Findings of SARS-CoV-2 Infection after 2 Years of Pandemic: From Lung to Gut Microbiota

Early recognition and prompt management are crucial for improving survival in COVID-19 patients, and after 2 years of the pandemic, many efforts have been made to obtain an early diagnosis. A key factor is the use of fast microbiological techniques, considering also that COVID-19 patients may show no peculiar signs and symptoms that may differentiate COVID-19 from other infective or non-infective diseases. These techniques were developed to promptly identify SARS-CoV-2 infection and to prevent viral spread and transmission. However, recent data about clinical, radiological and laboratory features of COVID-19 at time of hospitalization could help physicians in early suspicion of SARS-CoV-2 infection and distinguishing it from other etiologies. The knowledge of clinical features and microbiological techniques will be crucial in the next years when the endemic circulation of SARS-CoV-2 will be probably associated with clusters of infection. In this review we provide a state of the art about new advances in microbiological and clinical findings of SARS-CoV-2 infection in hospitalized patients with a focus on pulmonary and extrapulmonary characteristics, including the role of gut microbiota.

Bacterial Ventilator-Associated Pneumonia in COVID-19 Patients: Data from the Second and Third Waves of the Pandemic

During the coronavirus disease 2019 (COVID-19) pandemic, many patients requiring invasive mechanical ventilation were admitted to intensive care units (ICU) for COVID-19-related severe respiratory failure. As a matter of fact, ICU admission and invasive ventilation increased the risk of ventilator-associated pneumonia (VAP), which is associated with high mortality rate and a considerable burden on length of ICU stay and healthcare costs. The objective of this review was to evaluate data about VAP in COVID-19 patients admitted to ICU that developed VAP, including their etiology (limiting to bacteria), clinical characteristics, and outcomes. The analysis was limited to the most recent waves of the epidemic. The main conclusions of this review are the following: (i) P. aeruginosa, Enterobacterales, and S. aureus are more frequently involved as etiology of VAP; (ii) obesity is an important risk factor for the development of VAP; and (iii) data are still scarce and increasing efforts should be put in place to optimize the clinical management and preventative strategies for this complex and life-threatening disease.

Combined Use of Presepsin and (1,3)-β-D-glucan as Biomarkers for Diagnosing Candida Sepsis and Monitoring the Effectiveness of Treatment in Critically Ill Patients

New biomarker panel was developed and validated on 165 critically ill adult patients to enable a more accurate invasive candidiasis (IC) diagnosis. Serum levels of the panfungal biomarker (1,3)-β-D-glucan (BDG) and the inflammatory biomarkers C-reactive protein, presepsin (PSEP), and procalcitonin (PCT) were correlated with culture-confirmed candidemia or bacteremia in 58 and 107 patients, respectively. The diagnostic utility was evaluated in sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). BDG was the best marker for IC, achieving 96.6% sensitivity, 97.2% specificity, 94.9% PPV, and 98.1% NPV at a cut-off of 200 pg/mL (p ≤ 0.001). PSEP exhibited 100% sensitivity and 100% NPV at a cut-off of 700 pg/mL but had a lower PPV (36.5%) and low specificity (5.6%). Combined use of PSEP and BDG, thus, seems to be the most powerful laboratory approach for diagnosing IC. Furthermore, PSEP was more accurate for 28-day mortality prediction the area under the receiver operating characteristic curve (AUC = 0.74) than PCT (AUC = 0.31; PCT cut-off = 0.5 ng/mL). Finally, serum PSEP levels decreased significantly after only 14 days of echinocandin therapy (p = 0.0012). The probability of IC is almost 100% in critically ill adults with serum BDG and PSEP concentrations > 200 pg/mL and >700 pg/mL, respectively, defining a borderline between non-invasive superficial Candida colonization and IC.

The Interplay between Host Defense, Infection, and Clinical Status in Septic Patients: A Narrative Review

Sepsis is a life-threatening condition that arises when the body's response to an infection injures its own tissues and organs. Despite significant morbidity and mortality throughout the world, its pathogenesis and mechanisms are not clearly understood. In this narrative review, we aimed to summarize the recent developments in our understanding of the hallmarks of sepsis pathogenesis (immune and adaptive immune response, the complement system, the endothelial disfunction, and autophagy) and highlight novel laboratory diagnostic approaches. Clinical management is also discussed with pivotal consideration for antimicrobic therapy management in particular settings, such as intensive care unit, altered renal function, obesity, and burn patients.

2021 Guideline for the Management of COPD Exacerbations: Emergency Medicine Association of Turkey (EMAT) / Turkish Thoracic Society (TTS) Clinical Practice Guideline Task Force

Chronic obstructive pulmonary disease (COPD) is an important public health problem that manifests with exacerbations and causes serious mortality and morbidity in both developed and developing countries. COPD exacerbations usually present to emergency departments, where these patients are diagnosed and treated. Therefore, the Emergency Medicine Association of Turkey and the Turkish Thoracic Society jointly wanted to implement a guideline that evaluates the management of COPD exacerbations according to the current literature and provides evidence-based recommendations. In the management of COPD exacerbations, we aim to support the decision-making process of clinicians dealing with these patients in the emergency setting.

Clinical and microbiological characteristics of patients with bacteremia and normal procalcitonin

Procalcitonin is a biomarker of bacterial infection used to guide antimicrobial therapy. However, emerging studies have highlighted bacteremic patients with low procalcitonin, potentially limiting its clinical utility. Here, we conducted an observational, retrospective study analyzing clinical and microbiological parameters of adult patients with bacteremia and procalcitonin <2 ng/mL. High proportions of patients required intensive care (31.2%) with vasopressor (14.9%) or ventilatory (17.7%) support, developed renal injury (30.7%), or had in-hospital mortality (14.4%). When divided into subgroups by procalcitonin level, patients with procalcitonin 0.5 to 2.0 ng/mL had significantly higher rates of in-hospital mortality, vasopressor requirement, and renal injury than those with procalcitonin <0.5 ng/mL. Altogether, bacteremic patients had significant morbidity and mortality despite low procalcitonin. While subgroup analysis suggested that higher procalcitonin may correlate with illness severity, a more sensitive procalcitonin cutoff did not eliminate patients with significant disease. Procalcitonin-based algorithms may not be clinically appropriate for management of bacteremia.

Combined procalcitonin and hemogram parameters contribute to early differential diagnosis of Gram-negative/Gram-positive bloodstream infections

Background

Hemogram parameters and procalcitonin (PCT) play auxiliary roles in the diagnosis and outcome of sepsis. However, it is not clear whether these indicators can quickly distinguish bacterial classification or guide the choice of empirical antibiotics.

Methods

We retrospectively enrolled 381 patients with bloodstream infections (BSI), divided into Gram‐positive bloodstream infections (GP‐BSI) and Gram‐negative bloodstream infections (GN‐BSI). Demographic parameters, hemogram parameters, and PCT were recorded and compared between the two groups.

Results

The mean platelet volume (MPV), platelet distribution width (PDW), and PCT in the GN‐BSI group were significantly higher than those in the GP‐BSI group, while the platelet count (PLT), plateletcrit, platelet count‐to‐white blood cell count ratio (PWR), platelet count‐to‐neutrophil count ratio (PNR), platelet count‐to‐PCT ratio (PLT/PCT), and mean platelet volume‐to‐PCT ratio (MPV/PCT) were significantly lower in the GN‐BSI group. Multivariate stepwise logistic regression analysis revealed that the independent predictors of GN‐BSI were MPV, PWR, and PCT. The areas under the curve (AUC) for this prediction model was 0.79, with sensitivity =0.75 and specificity =0.71.

Conclusions

There were significant differences in terms of PCT, platelet parameters, and platelet‐related index‐PCT ratio between GN‐BSI and GP‐BSI. Combined PCT and hemogram parameters are more conducive to the early differential diagnosis of bacterial classification of BSI.

Future Biomarkers for Infection and Inflammation in Febrile Children

Febrile patients, suffering from an infection, inflammatory disease or autoimmunity may present with similar or overlapping clinical symptoms, which makes early diagnosis difficult. Therefore, biomarkers are needed to help physicians form a correct diagnosis and initiate the right treatment to improve patient outcomes following first presentation or admittance to hospital. Here, we review the landscape of novel biomarkers and approaches of biomarker discovery. We first discuss the use of current plasma parameters and whole blood biomarkers, including results obtained by RNA profiling and mass spectrometry, to discriminate between bacterial and viral infections. Next we expand upon the use of biomarkers to distinguish between infectious and non-infectious disease. Finally, we discuss the strengths as well as the potential pitfalls of current developments. We conclude that the use of combination tests, using either protein markers or transcriptomic analysis, have advanced considerably and should be further explored to improve current diagnostics regarding febrile infections and inflammation. If proven effective when combined, these biomarker signatures will greatly accelerate early and tailored treatment decisions.

Delta-Procalcitonin and Vitamin D Can Predict Mortality of Internal Medicine Patients with Microbiological Identified Sepsis

Background: The management of septic patients hospitalized in Internal Medicine wards represents a challenge due to their complexity and heterogeneity, and a high mortality rate. Among the available prognostic tools, procalcitonin (PCT) is considered a marker of bacterial infection. Furthermore, an association between vitamin D deficiency and poor sepsis-related outcomes has been described. Objectives: To evaluate the prognostic accuracy of two consecutive PCT determinations (Delta-PCT) and of vitamin D levels in predicting mortality in a population of patients with microbiological identified sepsis admitted to Internal Medicine wards. Methods: This is a sub-analysis of a previous prospective study. A total of 80 patients had at least two available consecutive PCT determinations, while 63 had also vitamin D. Delta-PCT was defined as a reduction of PCT > 50% after 48 h, >75% after 72 h, and >85% after 96 h. Mortality rate at 28- and 90-days were considered as main outcome. Results: Mortality rate was 18.7% at 28-days and 30.0% at 90-days. Baseline PCT levels did not differ between survived and deceased patients (28-days: p = 0.525; 90-days: p = 0.088). A significantly higher proportion of survived patients showed Delta-PCT (28-days: p = 0.002; 90-days: p < 0.001). Delta-PCT was associated with a lower 28-days (p = 0.007; OR = 0.12, 95%CI 0.02–0.46) and 90-days mortality (p = 0.001; OR = 0.17, 95%CI 0.06–0.48). A significantly higher proportion of deceased patients showed severe vitamin D deficiency (28-days: p = 0.047; 90-days: p = 0.049). Severe vitamin D deficiency was associated with a higher 28-days (p = 0.058; OR = 3.95, 95%CI 1.04–19.43) and 90-days mortality (p = 0.054; OR = 2.94, 95%CI 1.00–9.23). Conclusions: Delta-PCT and vitamin D represent two useful tests for predicting prognosis of septic patients admitted to Internal Medicine wards.

Recent molecules in the treatment of severe infections caused by ESBL-producing bacteria

Introduction: The widespread increase in resistance to β-lactam antibiotics in Enterobacterales currently represents one of the main threats to human health worldwide. The primary mechanisms of resistance are the production of β-lactamase enzymes that are able to hydrolyze β-lactams.Areas covered: we summarize the most recent advances regarding the main characteristics and spectrum of activity of new available antibiotics and strategies for the treatment of ESBL-producing Enterobacterales infections.Expert opinion: ESBL-producing strains are recognized as a worldwide challenge in the treatment of both hospital- and community-acquired infections. Data from the literature point out the high mortality associated with severe infections due to ESBL strains, especially in patients who developed severe sepsis or septic shock, together with the importance of the source of infection and indicators of severity, as determinants of the patient's outcome. Carbapenems are currently considered the first-line therapy, although the diffusion of resistant strains is an evolving problem and is mandatory the introduction in clinical practice of new drug regimens and treatment strategies, based on clinical data, local epidemiology, and microbiology. As a possible carbapenem-sparing strategy, ceftolozane-tazobactam and ceftazidime-avibactam appear the best-available carbapenem-sparing therapies. The definitive role of new drugs should be definitively assessed.

Procalcitonin as a predictor of early antibiotic treatment failure in patients with gram-negative bloodstream infections caused by urinary tract infections

We retrospectively evaluated whether initial procalcitonin (PCT) levels can predict early antibiotic treatment failure (ATF) in patients with gram-negative bloodstream infections (GN-BSI) caused by urinary tract infections from January 2018 to November 2019. Early ATF was defined as the following: (1) hemodynamically unstable or febrile at Day 3; (2) the need for mechanical ventilation or continuous renal replacement therapy at Day 3; (3) patients who died within 3 days (date of blood culture: Day 0). The study included 189 patients; 42 showed early ATF. Independent risk factors for early ATF were initial admission to the intensive care unit (odds ratio: 7.735, 95% confidence interval: 2.567-23.311; P < 0.001) and PCT levels ≥30 ng/mL (odds ratio: 5.413, 95% confidence interval: 2.188-13.388; P < 0.001). Antibiotic factors were not associated with early ATF. Initial PCT levels may be helpful to predict early ATF in these patients.