Procalcitonin levels in bloodstream infections caused by different sources and species of bacteria

Development and Validation of a Novel Nomogram Model for Early Diagnosis of Anastomotic Leakage After Laparoscopic Colorectal Cancer Surgery

Background: This study aimed to investigate the clinical value of inflammatory factors for predicting anastomotic leakage (AL) after laparoscopic colorectal cancer surgery and establish a nomogram model to assess the probability of its occurrence. Patients and Methods: Data of 637 patients who underwent laparoscopic colorectal cancer surgery between June 2019 and June 2022 were collected. Differences in procalcitonin (PCT), C-reactive protein (CRP), and white blood cell (WBC) levels before surgery and on postoperative day (POD) 3 and 5 were compared between patients with and without AL (AL and non-AL groups, respectively). The diagnostic accuracy was determined using the area under the receiver operating characteristic curve (AUC), and a nomogram model was developed. Results: Post-operative AL occurred in 46 (7.2%) patients. Procalcitonin, CRP, and WBC levels on POD 3 and 5 were higher in the AL group than in the non-AL group. The AUCs of PCT, CRP, and WBC levels for predicting AL on POD 3 were 0.833, 0.757, and 0.756, respectively, which were better than those on POD 5 (AUC = 0.669, 0.581, and 0.588, respectively). The nomogram model for AL was developed based on five variables (PCT, CRP, WBC, American Society of Anesthesiologists [ASA] grade and comorbidities), and it had an AUC of 0.922. Calibration curves demonstrated that the nomogram had good fit. The Delong test showed that the AUC of the nomogram for predicting the probability of AL was higher than that of PCT alone (z = 2.311, p = 0.02). Conclusions: Procalcitonin measured on POD 3 seems to be a promising negative predictor of AL after laparoscopic colorectal cancer surgery. Furthermore, the nomogram model developed in our study, which utilizes a series of predictors that can be easily accessed, has demonstrated potential to further improve the prediction accuracy.

Plasma soluble suppression of tumorigenesis 2 measured in the emergency department for diagnosis and outcome prediction of sepsis: A single-center prospective study

BACKGROUND AND AIMS

The diagnostic and prognostic performance of soluble Suppression of Tumorigenicity 2 (sST2) in suspected septic patients presenting to the Emergency Department (ED) is largely unknown.

MATERIALS AND METHODS

Patients were included in this prospective study if there was high suspicion of sepsis. The plasma level of sST2 was measured during initial ED evaluation. Outcomes were the evaluation of (1) sST2 diagnostic performance (alone and in combination with procalcitonin [PCT]), and (2) sST2 ability to predict 30-day and 90-day all-cause mortality.

RESULTS

Among 569 patients included, 481 (84.5 %) had sepsis or septic shock. Plasma sST2 levels were more elevated in septic patients (159 [71-331] vs 50 [31-103] ng/mL, P < 0.001). The AUC of sST2 for sepsis diagnosis was lower than the AUC of PCT (0.76 vs 0.85, P = 0.03). The best cut-off for sST2 was 61.7 ng/mL, with a sensitivity of 79.9 % and a specificity of 70.6 %. sST2 was able to correctly reclassify septic patients with PCT <0.5 (NRI 28.9 % [P = 0.02]). sST2 level was an independent predictor of 30-day mortality in a model including clinical variables (aHR 2.03 [1.24-3.33], C-index 0.69).

CONCLUSION

sST2 could be a useful adjunct in diagnosing sepsis and in all-cause mortality prediction.

Early diagnosis of necrotizing fasciitis: Imaging techniques and their combined application

Necrotizing fasciitis is a clinical, surgical emergency characterized by an insidious onset, rapid progression, and a high mortality rate. The disease's mortality rate has remained high for many years, mainly because of its atypical clinical presentation, which prevents many cases from being diagnosed early and accurately, resulting in patients who may die from uncontrollable septic shock and multi-organ failure. But unfortunately, no diagnostic indicator can provide a certain early diagnosis of NF, and clinical judgement of NF is still based on the results of various ancillary tests combined with the patient's medical history, clinical manifestations, and the physician's experience. This review provides a brief overview of the epidemiological features of NF and then discusses the most important laboratory indicators and scoring systems currently employed to diagnose NF. Finally, the latest progress of several imaging techniques in the early diagnosis of NF and their combined application with other diagnostic indices are highlighted. We point out promising research directions based on an objective evaluation of the advantages and shortcomings of different methods, which provide a basis for further improving the early diagnosis of NF.

Severe Acute Bronchial Asthma with Sepsis: Determining the Status of Biomarkers in the Diagnosis of the Disease

Bronchial asthma is a widely prevalent illness that substantially impacts an individual's health standard worldwide and has a significant financial impact on society. Global guidelines for managing asthma do not recommend the routine use of antimicrobial agents because most episodes of the condition are linked to viral respiratory tract infections (RTI), and bacterial infection appears to have an insignificant impact. However, antibiotics are recommended when there is a high-grade fever, a consolidation on the chest radiograph, and purulent sputum that contains polymorphs rather than eosinophils. Managing acute bronchial asthma with sepsis, specifically the choice of whether or not to initiate antimicrobial treatment, remains difficult since there are currently no practical clinical or radiological markers that allow for a simple distinction between viral and bacterial infections. Researchers found that serum procalcitonin (PCT) values can efficiently and safely minimize antibiotic usage in individuals with severe acute asthma. Again, the clinical manifestations of acute asthma and bacterial RTI are similar, as are frequently used test values, like C-reactive protein (CRP) and white blood cell (WBC) count, making it harder for doctors to differentiate between viral and bacterial infections in asthma patients. The role and scope of each biomarker have not been precisely defined yet, although they have all been established to aid healthcare professionals in their diagnostics and treatment strategies.

2023 Update on Sepsis and Septic Shock in Adult Patients: Management in the Emergency Department

BACKGROUND

Sepsis/septic shock is a life-threatening and time-dependent condition that requires timely management to reduce mortality. This review aims to update physicians with regard to the main pillars of treatment for this insidious condition.

METHODS

PubMed, Scopus, and EMBASE were searched from inception with special attention paid to November 2021-January 2023.

RESULTS

The management of sepsis/septic shock is challenging and involves different pathophysiological aspects, encompassing empirical antimicrobial treatment (which is promptly administered after microbial tests), fluid (crystalloids) replacement (to be established according to fluid tolerance and fluid responsiveness), and vasoactive agents (e.g., norepinephrine (NE)), which are employed to maintain mean arterial pressure above 65 mmHg and reduce the risk of fluid overload. In cases of refractory shock, vasopressin (rather than epinephrine) should be combined with NE to reach an acceptable level of pressure control. If mechanical ventilation is indicated, the tidal volume should be reduced from 10 to 6 mL/kg. Heparin is administered to prevent venous thromboembolism, and glycemic control is recommended. The efficacy of other treatments (e.g., proton-pump inhibitors, sodium bicarbonate, etc.) is largely debated, and such treatments might be used on a case-to-case basis.

CONCLUSIONS

The management of sepsis/septic shock has significantly progressed in the last few years. Improving knowledge of the main therapeutic cornerstones of this challenging condition is crucial to achieve better patient outcomes.

Study on the performance of novel nanomaterials for detection of biomarkers such as PCT based on immunochromatography sensitivity

In this study, by comparing the UV-vis spectral characteristics of colloidal gold and colloidal gold enhancer, and their differences as immunochromatographic tracers in the qualitative detection of PCT, IL-6, Hp and quantitative determination of PCT performance, the factors that may affect the sensitivity were discussed. The results show that the absorbance at 520 nm of CGE diluted 20-fold and colloidal gold diluted 2-fold were comparable, and the sensitivity of CGE immunoprobe for qualitative detection of PCT, IL-6 and Hp was higher than that of colloidal gold immunoprobe, and the reproducibility and accuracy of both immunoprobes for quantitative detection of PCT were good. Indicating that the high sensitivity of CGE immunoprobe detection is mainly due to the absorption coefficient of CGE at 520 nm is about 10 times that of colloidal gold immunoprobe, CGE has stronger light absorption capacity and stronger quenching effect on rhodamine 6 G on the nitrocellulose membrane surface of the test strip.

Pcv-aCO2 and procalcitonin levels for the early diagnosis of bloodstream infections caused by gram-negative bacteria

BACKGROUND

The central venous-to-arterial carbon dioxide difference (Pcv-aCO₂) is a biomarker for tissue perfusion, but the diagnostic value of Pcv-aCO₂ in bacteria bloodstream infections (BSI) caused by gram-negative (GN) bacteria remains unclear. This study evaluated the expression levels and diagnostic value of Pcv-aCO₂ and procalcitonin (PCT) in the early stages of GN bacteria BSI.

METHODS

Patients with BSI admitted to the intensive care unit at Guangdong Provincial People's Hospital between August 2014 and August 2017 were enrolled. Pcv-aCO₂ and PCT levels were evaluated in GN and gram-positive (GP) bacteria BSI patients.

RESULTS

A total of 132 patients with BSI were enrolled. The Pcv-aCO₂ (8.32 ± 3.59 vs 4.35 ± 2.24 mmHg p = 0.001) and PCT (30.62 ± 34.51 vs 4.92 ± 6.13 ng/ml p = 0.001) levels were significantly higher in the GN group than in the GP group. In the diagnosis of GN bacteria BSI, the area under the receiver operating characteristic curve (AUROC) for Pcv-aCO₂ was 0.823 (95% confidence interval (CI): 0.746-0.900). The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were 71.90%, 88.00%, 74.07% and 78.21%, respectively. The AUROC for PCT was 0.818 (95% CI: 0.745-0.890). The sensitivity, specificity, PPV and NPV were 57.90%, 94.67%, 71.93% and 74.67%, respectively.

CONCLUSIONS

Pcv-aCO₂ and PCT have similar and high diagnostic value for the early diagnosis of BSI caused by GN bacteria.

Severe Pneumonia Caused by Corynebacterium striatum in Adults, Seoul, South Korea, 2014–2019

Most (70.4%) cases were hospital-acquired, and 51.9% of patients were immunocompromised.

We investigated the proportion and characteristics of severe Corynebacterium striatum pneumonia in South Korea during 2014–2019. As part of an ongoing observational study of severe pneumonia among adult patients, we identified 27 severe C. striatum pneumonia cases. Most (70.4%) cases were hospital-acquired, and 51.9% of patients were immunocompromised. C. striatum cases among patients with severe hospital-acquired pneumonia (HAP) increased from 1.0% (2/200) during 2014–2015 to 5.4% (10/185) during 2018–2019, but methicillin-resistant Staphylococcus aureus (MRSA) infections among severe HAP cases decreased from 12.0% to 2.7% during the same timeframe. During 2018–2019, C. striatum was responsible for 13.3% of severe HAP cases from which bacterial pathogens were identified. The 90-day mortality rates were similarly high in the C. striatum and MRSA groups. C. striatum was a major cause of severe HAP and had high mortality rates. This pathogen is emerging as a possible cause for severe pneumonia, especially among immunocompromised patients.

Association of Procalcitonin with the Patient’s Infection Characteristics and Prognosis after Hematopoietic Stem Cell Transplantation

Objective

To study whether procalcitonin (PCT) is an important indicator of infection with or without agranulocytosis and to reveal whether PCT can distinguish between infected sites and affect prognosis after hematopoietic stem cell transplantation (HSCT).

Method

In the present study, 682 patients with HSCT were enrolled, and their clinical characteristics were noted. Their blood culture and inflammatory and biochemical indicators were studied. The patients were divided into respective groups according to the degree of agranulocytosis, type of bacterial infection, infected sites, and prognosis.

Results

The PCT, CRP, and D-dimer levels were significantly improved in patients with positive blood culture results compared to the case for those with negative blood culture results. The PCT level was the highest in the gram-negative group. The levels of PCT and D-dimer were significantly elevated in patients with infection and agranulocytosis after HSCT compared to those in the nonagranulocytosis cohort. Interestingly, no significant difference in the PCT level was observed among any of the eight foci. Lower PCT levels were associated with higher survival in patients with infection after HSCT.

Conclusion

Among patients that underwent HSCT, PCT levels were significantly elevated in those with infection and agranulocytosis, with the levels being specifically high in the gram-negative group. Moreover, lower PCT levels were associated with higher survival in patients with infection after HSCT.

Distinctions between Fournier's gangrene and lower extremity necrotising fasciitis: microbiology and factors affecting mortality

OBJECTIVES

In this study, we aimed to illustrate distinctions between Fournier's gangrene (FG) and lower extremity necrotising fasciitis (NF) and screen out possible risk factors of poor prognosis for each cohort.

METHODS

The medical records of qualified patients with NF admitted to the Second People's Hospital of Yibin from January 2016 to June 2021 were retrospectively reviewed. All participants were anatomically categorised into FG and lower extremity NF groups, and their baseline data and microbiological results were compared. Further comparisons of critical parameters were conducted between survivors and nonsurvivors within each group.

RESULTS

A total of 49 patients were included in the study with a median age of 58 years, and overall mortality was 20.4%. There were 18 patients with FG and 31 patients with lower extremity NF. A microbiology distinction was found-the predominance of gram-negative infection in FG and gram-positive infection in lower extremity NF. High Fournier's gangrene severity index scores (greater than 7), advanced age, procalcitonin and D-dimer value were identified as risk factors for FG, and the presentation of sepsis was an alarming indicator for lower extremity NF.

CONCLUSIONS

The distinction of microbiology might provide advice for appropriate antibacterial administrations. In addition, with practical prognostic predicting tools, clinicians might be able to identify patients at increased risk and intervene promptly to avoid unfavourable outcomes.

Association of Procalcitonin to Albumin Ratio with the Presence and Severity of Sepsis in Neonates

Purpose

Previous studies have demonstrated that procalcitonin and albumin have a close correlation with sepsis. However, the role of procalcitonin (PCT) to albumin (ALB) ratio (PAR) in sepsis was still unclear, especially in neonates. Thus, this study aimed to investigate the association between PAR and neonatal sepsis.

Patients and Methods

A total of 1,196 neonates with suspected sepsis were included in this study. Neonates were divided into control group and sepsis group, according to whether they were diagnosed with sepsis. Neonates with sepsis were further divided into mild sepsis and severe sepsis group according to the severity of sepsis. PAR was calculated as serum PCT (ng/mL)/ALB (mg/mL). All statistical analyses were performed using the statistical package SPSS 24.0, as appropriate.

Results

Compared with the control group, neonates with sepsis had a higher PAR. PAR also showed a significant gradual increase in the control, mild sepsis, and severe sepsis groups (P<0.001). Correlation analysis showed that there was a strong positive correlation between PAR and hsCRP, neonatal sequential organ failure assessment score (nSOFA), and prolonged length of hospital stay (P<0.001). On multiple logistic regression, higher PAR was independently associated with the presence and severity of neonatal sepsis. According to the receiver operating characteristic curve analysis, a PAR ≥0.065 had 64% sensitivity and 72% specificity in predicting the presence of neonatal sepsis (area under curve (AUC)=0.72, 95% CI=0.69–0.75, P<0.001) and a PAR≥0.070 had 69% sensitivity and 63% specificity in predicting the presence of severe sepsis (AUC=0.71, 95% CI=0.68–0.74, P<0.001).

Conclusion

PAR is significantly higher in neonates with sepsis and correlated with the severity of the disease. Increased PAR is an independent predictor useful for identifying the presence and severity of neonatal sepsis.

Specific patterns of vital sign fluctuations predict infection and enable sepsis diagnosis in pediatric burn patients

Early recognition of the clinical signs of bloodstream infection in pediatric burn patients is key to improving survival rates in the burn unit. The objective of this study was to propose a simple scoring criteria that used readily available temperature, heart rate (HR) and mean arterial pressure (MAP) data to accurately predict bloodstream infection in pediatric burn patients. A retrospective chart review included 100 patients admitted to the pediatric burn unit for >20% total body surface area (TBSA) burn injuries. Each patient had multiple blood culture tests, and each test was treated as a separate and independent “infection event” for analysis. The time at each blood culture draw was time 0 for that event, and temperature, HR and MAP data was collected for 24 hours after the blood culture was drawn. “Infection events” included in this study had at least six complete sets of temperature, HR and MAP data entries. Median temperature, HR and MAP, as well as mean fever spikes, HR spikes and MAP dips, were compared between infection group (positive blood cultures) and control group (negative blood cultures). These vital sign fluctuations were evaluated individually and as a combination of all three as timely predictors of bloodstream infection. In addition, we tested the prediction of Gram-negative bacteria versus Gram-positive or fungi present in blood cultures. Patients in the infection group had significantly higher median temperatures (p<0.001), mean fever spikes (p<0.001) and mean HR spikes (p<0.001), compared to the control group. Using the combination scoring criteria to predict bloodstream infection, the strongest predictive values in the 24-hour timeframe had high sensitivity (93%) and specificity (81%). The predictive test metric based on vital sign spikes predicted Gram-negative bacteria, but with limited sensitivity (57%) and specificity (44%). A simple scoring criteria using a combination of fever spikes, HR spikes and MAP dips predicted bloodstream infection in pediatric burn patients, and can be feasibly implemented in routine clinical care. There is also potential to use the predictive metric to detect a few select organisms based on vital signs, however further work is necessary to enhance accuracy to levels that would allow consideration for clinical use.

Predictive value of surveillance cultures for bacteremia caused by extended-spectrum beta-lactamase (ESBL)-producing Enterobacterales among patients with hematological diseases

PURPOSE

Due to the increasing prevalence of extended-spectrum beta-lactamase (ESBL)-producing Enterobacterales, empirical therapies with cefepime or piperacillin/tazobactam for hematology patients with febrile neutropenia have become ineffective. Carbapenems should be administered as soon as possible in such patients with ESBL bacteremia. If the surveillance culture results are consistent with the blood culture findings, the time to adequate treatment initiation can be shortened.

METHODS

All consecutive patients with Enterobacterales bacteraemia who were admitted from January 2013 to December 2018 at the hematology wards were enrolled in this study. Surveillance rectal swab and blood culture results were compared.

RESULTS

In total, 67 patients with Enterobacterales bacteremia underwent surveillance culture prior to the onset of infection. Regarding the presence or absence of ESBL-producing Enterobacterales, 64 (95.5%) patients had surveillance results concordant with blood culture results. The positive predictive value of surveillance culture for bacteremia caused by ESBL-producing Enterobacterales was 95.0%. Moreover, the negative predictive value of surveillance culture for bacteremia caused by non-ESBL-producing Enterobacterales was 95.7%.

CONCLUSION

The concordance rate between the surveillance rectal swab and blood cultures was highly acceptable. Surveillance rectal swab cultures are useful for identifying patients at high risk for ESBL bacteremia.

Use of infection biomarkers in the emergency department

The use of infection biomarkers in the emergency department is discussed in terms of their possible contributions to diagnostic-prognostic uncertainties, appropriate antibiotic treatments, and triage and follow-up planning. Procalcitonin (PCT), C-reactive protein (CRP), proadrenomedullin (proADM), and presepsin are among the most discussed infection biomarkers for use in the emergency department. Due to the variable sensitivity results and cutoff values, there are insufficient data to recommend the widespread use of CRP and procalcitonin (PCT) for the diagnosis and prognosis of infection in the emergency department. However, these biomarkers can be used for appropriate antibiotic use in selected infection groups, such as community-acquired pneumonia, especially to reduce unnecessary antibiotic prescribing. With its prognostic superiority over other biomarkers and its contribution to prognostic score systems in community-acquired pneumonia (CAP), proADM can be used to predict hospitalization, preferably within the scope of clinical studies. Although presepsin has been shown to have some advantages over other biomarkers to rule out sepsis, there are insufficient data for its clinical use in the emergency department.

The procalcitonin-to-cortisol ratio is a potential prognostic predictor in sepsis with abdominal source: a retrospective observational study

BACKGROUND

The aim of the study was to investigate the procalcitonin-to-cortisol ratio (P/C ratio) as a prognostic predictor among septic patients with abdominal source.

METHODS

We retrospectively enrolled 132 post-surgery patients between 18 and 90 years old with sepsis of the abdominal source. On the second day of sepsis onset, cortisol, procalcitonin (PCT), Acute Physiology and Chronic Health Evaluation (APACHE) II score, Sequential Organ Failure Assessment (SOFA) score, C-response protein (CRP), and other baseline characteristics were collected. In addition, the length of ICU stay, length of mechanical ventilation (MV) days, length of shock days, and 28-day mortality were also recorded. Univariate analysis was performed to screen potential risk factors. Stratified analysis was used to identify the interaction among the risk factors. Multivariate analysis was also utilized to demonstrate the relationship between the risk factors and mortality. The receiver operator characteristic (ROC) curve analysis was conducted to evaluate the risk factors. A restricted cubic spline (RCS) demonstrated the association between survival outcome and the P/C ratio variation.

RESULTS

A total of twenty-nine patients died, and 103 patients survived within 28 d. There were significant differences in cortisol, PCT, P/C ratio, interleukin (IL)-6, SOFA, and APACHE II scores between the survival and non-survival groups. No significant interaction was observed in the stratified analysis. Logistic regression analysis revealed that P/C ratio (P=0.033) was significantly related to 28-day mortality. Based on ROC curves, P/C ratio (AUC=0.919) had a higher AUC value than cortisol or PCT. RCS analysis depicted a positive relationship between survival possibility and P/C ratio decrement.

CONCLUSION

P/C ratio might be a potential prognostic predictor in septic patients with abdominal sources.

Clinical utility of procalcitonin and its association with pathogenic microorganisms

In this review, we summarize the relationship of PCT with pathogens, evaluate the clinical utility of PCT in the diagnosis of clinical diseases, condition monitoring and evaluation, and guiding medical decision-making, and explore current knowledge on the mechanisms by which pathogens cause changes in PCT levels. The lipopolysaccharides of the microorganisms stimulate cytokine production in host cells, which in turn stimulates production of serum PCT. Pathogens have different virulence mechanisms that lead to variable host inflammatory responses, and differences in the specific signal transduction pathways result in variable serum PCT concentrations. The mechanisms of signal transduction have not been fully elucidated. Further studies are necessary to ascertain the PCT fluctuation range of each pathogen. PCT levels are helpful in distinguishing between certain pathogens, in deciding if antibiotics are indicated, and in monitoring response to antibiotics.

A risk score for early predicting bloodstream infections in febrile obstetric patients: a pilot study

PURPOSE

Early prediction of bloodstream infections (BSI) among obstetric patients remains to be a challenge for clinicians. The objective of this study was to develop a risk score and assess its discriminative ability in febrile obstetric patients in a maternal intensive care unit (ICU).

METHODS

Between May 2015 and August 2020, a total of 497 febrile obstetric patients were categorized into BSI group (n = 276) and Non-BSI group (n = 221) based on the result of blood cultures. White blood cell count, C-reactive protein (CRP), procalcitonin (PCT), time of interval from amniorrhea to fever (IFAF) and maximum body temperature (T_max) were compared between the two groups. All patients were divided into training set (n = 298) and validation set (n = 199). The risk score was established using univariate and multivariate logistic regression from patients in the training set, and its discriminative ability was tested among patients in the validation set.

RESULTS

The levels of neutrophil, CRP, PCT, IFAF and T_max were significantly higher in BSI group than those in Non-BSI group. PROM, T_max, neutrophil and CRP acted as independent predictive factors for BSI in the training set. The area under the receiver operating characteristic curve of risk score for early prediction of BSI in the training, validation set and the whole population was 0.829 (95% CI 0.783-0.876), 0.848 (95% CI 0.792-0.903) and 0.838 (95% CI 0.803-0.873), respectively.

CONCLUSION

The risk score has a feasible discriminatory ability in early prediction of BSI in febrile obstetric patients.

Seeking diagnostic and prognostic biomarkers for childhood bacterial pneumonia in sub-Saharan Africa: study protocol for an observational study

INTRODUCTION

Clinically diagnosed pneumonia in children is a leading cause of paediatric hospitalisation and mortality. The aetiology is usually bacterial or viral, but malaria can cause a syndrome indistinguishable from clinical pneumonia. There is no method with high sensitivity to detect a bacterial infection in these patients and, as result, antibiotics are frequently overprescribed. Conversely, unrecognised concomitant bacterial infection in patients with malarial infections occur with omission of antibiotic therapy from patients with bacterial infections. Previously, we identified two combinations of blood proteins with 96% sensitivity and 86% specificity for detecting bacterial disease. The current project aimed to validate and improve these combinations by evaluating additional biomarkers in paediatric patients with clinical pneumonia. Our goal was to describe combinations of a limited number of proteins with high sensitivity and specificity for bacterial infection to be incorporated in future point-of-care tests. Furthermore, we seek to explore signatures to prognosticate clinical pneumonia.

METHODS AND ANALYSIS

Patients (n=900) aged 2-59 months presenting with clinical pneumonia at two Gambian hospitals will be enrolled and classified according to criteria for definitive bacterial aetiology (based on microbiological tests and chest radiographs). We will measure proteins at admission using Luminex-based immunoassays in 90 children with definitive and 160 with probable bacterial aetiology, and 160 children classified according to the prognosis of their disease. Previously identified diagnostic signatures will be assessed through accuracy measures. Moreover, we will seek new diagnostic and prognostic signatures through machine learning methods, including support vector machine, penalised regression and classification trees.

ETHICS AND DISSEMINATION

Ethics approval has been obtained from the Gambia Government/Medical Research Council Unit The Gambia Joint Ethics Committee (protocol 1616) and the institutional review board of Boston University Medical Centre (STUDY00000958). Study results will be disseminated to the staff of the study hospitals, in scientific seminars and meetings, and in publications.

TRIAL REGISTRATION NUMBER

H-38462.

Evaluation of the Diagnostic and Prognostic Value of CSF Presepsin Levels in Patients with Postneurosurgical Ventriculitis/Meningitis

Aim

To evaluate the diagnostic and prognostic value of CSF presepsin levels in patients with postneurosurgical ventriculitis/meningitis (PNVM).

Methods

We conducted a case-control study to achieve our aims. First, we prospectively enrolled patients who had undergone neurosurgery in Beijing Tiantan Hospital from June to November 2020 and measured the CSF levels of 8 biomarkers, including presepsin and other meningitis biomarkers. The diagnostic and prognostic accuracies of presepsin levels were evaluated by determining the values for the area under the receiver operating characteristic curve (AUC).

Results

Two hundred thirty-nine patients were enrolled in this study; 34 were diagnosed with confirmed ventriculitis/meningitis (cVM), 138 were classified as probable ventriculitis/meningitis (pVM), and the others were rejected ventriculitis/meningitis (rVM). Presepsin levels effectively diagnose cVM and predict the outcomes of patients with PNVM, with thresholds of 1257.4 pg/mL and 1276.2 pg/mL and AUCs of 0.746 and 0.825, respectively. Furthermore, a joint analysis with CSF lactate (C-Lac) levels shows that the AUCs of the two markers increased to 0.856 and 0.872, respectively.

Conclusion

The rapid diagnosis and prediction of the clinical outcome is important in neurosurgery. CSF presepsin levels are an impressive diagnostic and prognostic biomarker for meningitis, and when combined with C-Lac, they indeed improve the diagnostic and predictive efficiency of PNVM.

Serum biomarkers to differentiate Gram-negative, Gram-positive and fungal infection in febrile patients

Introduction. Contamination of specimens and overuse of broad spectrum antibiotics contribute to false positives and false negatives, respectively. Therefore, useful and applicable biomarkers of bacteremia are still required.Hypothesis/Gap Statement. IL-6 can be used as a serum biomarker to discriminate among bacterial infections and fungal infections in febrile patients with a bloodstream infection.Aim. We aimed to evaluate the diagnostic efficiency of neutrophil/lymphocyte ratio (NLR), procalcitonin (PCT) and interleukin-6 (IL-6) in discriminating Gram-negative (G^-) bacteria from Gram-positive (G⁺) bacteria and fungi in febrile patients.Methodology. A total of 567 patients with fever were evaluated. Serum levels of IL-6, PCT, NLR and CRP were compared among a G^- group (n=188), a G⁺ group (n=168), a fungal group (n=38) and a culture negative group (n=173). Sensitivity, specificity, Yuden's index and area under the Receiver operating characteristic (ROC) curve (AUC) were obtained to analyse the diagnostic abilities of these biomarkers in discriminating bloodstream infection caused by different pathogens.Results. Serum IL-6 and PCT in the G^- group increased significantly when compared with both the G⁺ group and fungal group (P <0.05). AUC of IL-6 (0.767, 95 % CI:0.725-0.805) is higher than AUC of PCT (0.751, 95 % CI:0.708-0.796) in discriminating the G^- group from G⁺ group. When discriminating the G^- group from fungal group, the AUC of IL-6 (0.695, 95 % CI:0.651-0.747) with a cut-off value of 464.3 pg ml^-1 was also higher than the AUC of PCT (0.630, 95 % CI:0.585-0.688) with a cut-off value of 0.68 ng ml^-1. Additionally, AUC of NLR (0.685, 95 % CI:0.646-0.727) in discriminating the fungal group from G⁺ group at the cut-off value of 9.03, was higher than AUC of IL-6, PCT and CRP.Conclusion. This study suggests that IL-6 could be used as a serum biomarker to discriminate among bacterial infections and fungal infections in febrile patients with a bloodstream infection. In addition, NLR is valuable to discriminate fungal infections from Gram-positive infections in febrile patients with a bloodstream infection.

Utility of Routine Laboratory Biomarkers to Detect COVID-19: A Systematic Review and Meta-Analysis

No routine laboratory biomarkers perform well enough in diagnosing COVID-19 in isolation for them to be used as a standalone diagnostic test or to help clinicians prioritize patients for treatment. Instead, other diagnostic tests are needed. The aim of this work was to statistically summarise routine laboratory biomarker measurements in COVID-19-positive and -negative patients to inform future work. A systematic literature review and meta-analysis were performed. The search included names of commonly used, routine laboratory tests in the UK NHS, and focused on research papers reporting laboratory results of patients diagnosed with COVID-19. A random effects meta-analysis of the standardized mean difference between COVID-19-positive and -negative groups was conducted for each biomarker. When comparing reported laboratory biomarker results, we identified decreased white blood cell, neutrophil, lymphocyte, eosinophil, and platelet counts; while lactate dehydrogenase, aspartate aminotransferase, and alanine aminotransferase were elevated in COVID-19-positive compared to COVID-19-negative patients. Differences were identified across a number of routine laboratory biomarkers between COVID-19-positive and -negative patients. Further research is required to identify whether routine laboratory biomarkers can be used in the development of a clinical scoring system to aid with triage of patients.

C-reactive protein predicts complications in community-associated S. aureus bacteraemia: a cohort study

Background

Staphylococcus aureus (S. aureus) bacteraemia is increasingly acquired from community settings and is associated with a mortality rate of up to 40% following complications. Identifying risk factors for complicated S. aureus bacteraemia would aid clinicians in targeting patients that benefit from expedited investigations and escalated care.

Methods

In this prospective observational cohort study, we aimed to identify risk factors associated with a complicated infection in community-onset S. aureus bacteraemia. Potential risk factors were collected from electronic medical records and included: - patient demographics, symptomology, portal of entry, and laboratory results.

Results

We identified several potential risk factors using univariate analysis. In a multiple logistic regression model, age, haemodialysis, and entry point from a diabetic foot ulcer were all significantly protective against complications. Conversely, an unknown entry point of infection, an entry point from an indwelling medical device, and a C-reactive protein concentration of over 161 mg/L on the day of admission were all significantly associated with complications.

Conclusions

We conclude that several factors are associated with complications including already conducted laboratory investigations and portal of entry of infection. These factors could aid the triage of at-risk patients for complications of S. aureus bacteraemia.

Simultaneous Quantitative Detection of IL-6 and PCT Using SERS magnetic immunoassay with sandwich structure

Sepsis is a systemic inflammatory response syndrome caused by infection. The mortality rate is as high as 30%-50%. Early diagnosis and treatment can significantly improve the mortality of patients with sepsis. Therefore, we have developed a SERS-based magnetic immunoassay method that uses the principle of sandwich method to quantitatively detect Interleukin 6 (IL-6) and Procalcitonin (PCT). In this article, two different Raman reporter molecules are embedded in the middle of the Au@Ag shell and coupled with the tracer antibody to form a SERS immunoprobe. Biotin was coupled with capture antibody to form a sandwich structure when participating in the immune response. Streptavidin and biotin systems have extremely high binding affinity. The sandwich structure is quickly captured by SA magnetic beads and then applied with a magnetic field to enrich the magnetic beads. Finally, simultaneous quantitative detection is achieved by the intensity of the two Raman reporter characteristic peaks on the solution magnetic beads. IL-6 and PCT showed a good relationship between 0-1000 pg ml^-1and 0-20 ng ml^-1, respectively, and the limits of detection were 0.54 pg ml^-1and 0.042 ng ml^-1, respectively. The recovery rate was between 89.8% and 104.2%, both intra-assay and inter-assay CV were ≤20%. No cross-reaction with C-reactive protein (100μg ml^-1), showing good specificity. This method provides a new technical reference for the clinical detection of sepsis biomarkers.

Usefulness of serum procalcitonin for necrotizing fasciitis as an early diagnostic tool

INTRODUCTION

While the early diagnosis of necrotizing fasciitis (NF) is crucial and could lead to a favorable outcome, it is difficult to differentiate NF from cellulitis, resulting in delay for the appropriate treatment.

PATIENTS AND METHODS

For the purpose of examining which diagnostic tools could correctly differentiate NF from cellulitis, we conducted this case-control study. We retrospectively reviewed all patients who were diagnosed with NF at our institute during 2014-2019. The patients who were diagnosed with cellulitis were randomly selected during the study period as the control group. The severity of NF is evaluated by serum-procalcitonin (PCT), LRINEC score, NTSI assessment and SIARI score.

RESULTS

A total of 25 NF patients were enrolled in this study. The median age was 68 years (range 39-79) and 18 (72%) were male. Comparing NF and cellulitis groups, NF group showed a higher LRINEC score and serum PCT than cellulitis group did, even though there was no statistical significance in serum PCT. With respect to the diagnostic value for differentiating NF from cellulitis, the area under the ROC curve for of serum PCT and LRINEC scores were 0.928 [95% confidential interval (CI) 0.864-0.992, p < 0.001] and 0.846 (95% CI 0.757-0.936, p < 0.001). The appropriate serum-PCT cutoff value was 1.0 and had a sensitivity of 88%, a specificity of 89%, a positive predictive value of 81%, and a negative predictive value of 93%.

CONCLUSION

Serum-PCT could be a useful diagnostic marker for differentiating diagnosis of NF from cellulitis.

Predictive performance of critical illness scores and procalcitonin in sepsis caused by different gram-stain bacteria

OBJECTIVES

To compare the early and late predictive values of several critical illness scores (CISs) and biomarkers in sepsis-3 patients with bloodstream infections (BSIs) and to identify the prognostic value of procalcitonin (PCT) for different gram-stain bacteria infections.

METHODS

Patients with at least one positive blood culture within 24h of emergency department admission and with a final diagnosis of sepsis/septic shock were enrolled. CISs were calculated based on the first parameters on the day of admission. The receiver operating characteristics curve was used to analyze the predictive value of CISs and biomarkers for early and late mortality.

RESULTS

Of 834 enrolled patients with sepsis-3, death occurred in 214 patients within 28 days and in 273 patients within 60 days. Compared with biomarkers, CISs showed a significantly higher area under the curve (AUC) in the prediction of early and late mortality (p<0.01), especially for patients with GNB infection. The Sequential Organ Failure Assessment score showed a higher AUC for predicting early mortality than the Mortality in Emergency Department Sepsis score (p=0.036). Compared with GNB infections, the AUC values of the PCT for gram-positive bacteria (GPB) infections were higher for predicting early or late mortality; PCT showed higher AUC than high-sensitivity C-reactive protein and white blood cells for predicting early mortality (p<0.05).

CONCLUSIONS

CISs were more advantageous in the assessment of early and late prognosis, especially for patients with GNB infections; however, for sepsis with GPB infection, PCT can be used for the prediction of early mortality.

Risk factors and diagnostic markers for Escherichia coli bloodstream infection in older patients

OBJECTIVE

To investigate risk factors for Escherichia coli (E. coli) bloodstream infection (BSI) in older patients and the diagnostic accuracy of laboratory parameters.

METHODS

The electronic medical records of patients aged 60 years and above who were admitted with a serious condition were extracted. Propensity score matching (PSM) was used to ensure that the included patients had similar baseline clinical features. Multiple regression analysis was used to identify risk factors for E. coli BSI and extended-spectrum β-lactamase (ESBL)-producing E. coli BSI. Receiver operating characteristic (ROC) curve analysis was performed to determine the diagnostic utility of relevant laboratory indicators.

RESULTS

After PSM, 508 patients were included: 254 patients with E. coli BSI and 254 control patients. Bile duct stone (adjusted odds ratio [aOR] 5.131), kidney stone (aOR 3.678), and urinary system infection (aOR 3.173) were independent risk factors for E. coli BSI. Prior exposure to cephems (aOR 3.782) and drainage tube placement (aOR 2.572) were independent risk factors for ESBL-producing E. coli BSI. Serum procalcitonin (PCT) yielded the highest area under the curve (0.783) and the best cut-off value (1.3 ng/ml).

CONCLUSION

Bile duct stone, kidney stone, and urinary system infection must be detected and treated early, in order to prevent E. coli BSI in older patients. Further, administration of cephems and invasive procedures must be undertaken with caution, in order to reduce the risk of BSI with ESBL-producing E. coli. Finally, serum PCT level has potential as diagnostic marker for E. coli BSI in older individuals.

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.

Diagnostic Accuracy of Biomarkers for Early-Onset Neonatal Bacterial Infections: Evaluation of Serum Procalcitonin Reference Curves

To date, no clinical studies have compared the accuracy of serum procalcitonin (PCT) reference curves. We aimed to validate the diagnostic accuracy of previously reported serum PCT reference curves and to determine which biomarkers among a cut-off value over the 95th percentile in the serum PCT reference curve, white blood cell (WBC) count, and C-reactive protein (CRP) and immunoglobulin M (IgM) levels, have the highest diagnostic accuracy for early-onset neonatal bacterial infections. This retrospective cohort study assessed 16 preterm and 23 term infants with suspected bacterial infections within 72 h after birth. Each infant group was divided into two subgroups: confirmed- and non-infection. The diagnostic accuracy was determined using the Youden index. The reference curves by Fukuzumi et al. in preterm and term infants had the highest Youden indexes: 1.000 and 0.324, respectively. Among preterm infants, the Youden index for PCT was 1.000. Among term infants, the Youden index for a combination of PCT, CRP, and WBC and/or IgM was 1.000. In conclusion, a serum PCT level over the 95th percentile on the reference curve for preterm infants and a combination of PCT and CRP levels with WBC count and/or IgM levels for term infants provided sufficient diagnostic accuracy.

Plasma procalcitonin levels remain low at the onset of gram-positive bacteremia regardless of severity or the presence of shock: A retrospective analysis of patients with detailed clinical characteristics

OBJECTIVES

Procalcitonin (PCT) is an early diagnosis marker of sepsis/bacteremia. However, some reports refer to its lower responsiveness to gram-positive bacteremia. We retrospectively evaluated the PCT values at the onset of bacteremia in relation to severity index.

METHODS

Patients with bacteremia caused by two gram-negative bacteria (46 E. coli and 50 Klebsiella pneumoniae) and three gram-positive bacteria (45 S. aureus, 56 S. epidermidis, and 10 S. mitis) were studied. The plasma PCT and C-reactive protein (CRP) levels were compared between species and different Sequential Organ Failure Assessment (SOFA) score groups.

RESULTS

The median PCT level was higher in gram-negative than in gram-positive bacteremia in overall (13.09 vs. 0.50 ng/mL, p < 0.0001), in SOFA score≥4 group (28.85 vs.1.72 ng/mL, p < 0.0001) and in SOFA<4 group (2.64 vs. 0.42 ng/mL, p < 0.0001). Only 46%, and 11% of patients showed PCT ≥0.5 ng/mL in S. epidermidis, and S. mitis bacteremia, respectively. PCT was significantly better than CRP in discriminating gram-negative from gram-positive bacteremia (AUCROC; 0.828 and 0.634, p < 0.001), but it was low in Staphylococcus epidermidis bacteremia regardless of SOFA scores.

CONCLUSIONS

PCT levels are lower in gram-positive bacteremia regardless of SOFA scores or the presence of shock. The conventional sepsis cutoff of 0.5 ng/mL may overlook certain proportions of gram-positive bacteremia.

Procalcitonin Perplexity - Prolonged Idiopathic Elevation in Pleomorphic Sarcoma: A Case Report and Review of the Literature

Historically, elevations in procalcitonin (PCT) have been implicated in medullary thyroid cancer and neuroendocrine tumors. More recently, the trending of PCT has been suggested as a monitor of infection to assess the presence, clearance and eradication of infection, especially in cancer patients. Its increase serves as a marker of bacterial infections. During homeostasis it is produced by most tissues in the body at an extremely low level (<.01 ng/mL) and is often induced by bacterial endotoxins. In cancer patients additional factors influence these levels. Metastasis in particular is linked with relatively higher PCT levels.

We present a case of an afebrile patient with undifferentiated pleomorphic sarcoma who underwent 25 cycles of radiation therapy and presented one month later with elevated procalcitonin, lactic acid, and leukocytosis. All infectious work up was negative. Findings were incidental after a hospital visit for dehydration. Leukocytosis and lactic acidosis resolved after four days into the hospitalization. Procalcitonin, however, remained elevated over four months in the range of 2-5 ng/mL. The patient has no findings of metastatic disease. To our knowledge, there has never been a report in the literature describing a prolonged elevation of procalcitonin in a patient with a non-metastatic sarcoma without any signs of infection or any other underlying cause.

The elevation of PCT has been noted in patients who suffered burns, trauma, minor and major surgery, and cardiogenic shock in addition to infection. Increases have served as signs of worsening patient outcomes and elevated rate of complications. Trending PCT can help in appropriated antibiotic use as it has been shown to decrease antibiotic use by 2.4 days. PCT trends have been increasing in value making idiopathic elevations found in combination undifferentiated pleomorphic sarcoma an important addition to the literature.

Marked Elevation in Serum Procalcitonin Levels Do Not Correlate With Severity of Disease or Mortality in Hospitalized Patients: A Retrospective Study

Background:

Bacteremia and sepsis are significant contributors to the morbidity, mortality, and economic burden of health care systems worldwide. Procalcitonin has been identified as a potentially useful marker of disease and severity in sepsis. However, the assumption that greater procalcitonin levels correlate with greater burden of disease has not been adequately studied.

Methods:

A retrospective chart review of adult patients admitted to an urban teaching hospital with suspected sepsis was undertaken to test the association of elevated procalcitonin (>30 ng/mL) with other markers of sepsis (lactic acid, white blood cell count, percent bands), severity of disease (Sequential Organ Failure Assessment [SOFA] and Acute Physiology and Chronic Health Evaluation–II [APACHE II] scores), and mortality.

Results:

In total, 168 patients were identified over 18 months (42% ward, 11% Stepdown, 44% medical intensive care unit [MICU], 2% surgical intensive care unit (STICU), 1% gynecology [GYN]). The Spearman correlation analysis showed that serum procalcitonin level did not correlate with SOFA (P = .238) or APACHE II (P = .918) scores on admission, and did not correlate with survival (Kruskal-Wallis test, P = .937). However, higher serum procalcitonin levels were associated with patients who had positive blood cultures (Kruskal-Wallis test, P = .0016 for Gram-positive and P = .0007 for Gram-negative bacteria). Lactic acid levels on admission strongly correlated with SOFA APACHE II (the Spearman correlation, P < .0001 for both) and mortality (P = .0001 for both).

Conclusions:

Higher serum procalcitonin levels above 30 ng/mL failed to correlate with indicators of sepsis, severity of disease (SOFA and APACHE II scores), and mortality but were associated with positive blood cultures. Lactic acid levels did show correlation to both severity of disease and mortality. Serum procalcitonin levels >30 ng/mL do not appear to correlate with the severity of disease in a sample of patients with markedly elevated initial procalcitonin levels.

Serum Procalcitonin Level Is Associated with Positive Blood Cultures, In-hospital Mortality, and Septic Shock in Emergency Department Sepsis Patients

This study examines the accuracy of initial and subsequent serum procalcitonin (PCT) levels in predicting positive blood cultures, in-hospital mortality, and development of septic shock in emergency department (ED) patients with severe sepsis. This study includes all patients who presented to our ED with an admission diagnosis of severe sepsis over a period of nine months. The median initial PCT was 0.58 ng/mL, interquartile range (IQR) 0.16-5.39. The median subsequent serum PCT was 2.1 ng/mL, with an IQR of 0.3-11.1. The PCT trend over the initial three hours increased in 67% of the study population. Blood cultures were positive in 38% of the cohort. The median maximum PCT in those with a negative blood culture was 1.06 ng/mL compared to 4.19 ng/mL in those with a positive blood culture (p=0.0116). Serum PCT levels >2.0 ng/mL display significant correlation with positive blood cultures, in-hospital mortality, and development of septic shock and as such may serve as a biomarker for more serious infections.

Biomarkers of inflammation and the etiology of sepsis

Sepsis is characterized as a life-threatening organ dysfunction syndrome that is caused by a dysregulated host response to infection. The main etiological causes of sepsis are bacterial, fungal, and viral infections. Last decades clinical and preclinical research contributed to a better understanding of pathophysiology of sepsis. The dysregulated host response in sepsis is complex, with both pathogen-related factors contributing to disease, as well as immune-cell mediated inflammatory responses that can lead to adverse outcomes in early or advanced stages of disease. Due to its heterogenous nature, clinical diagnosis remains challenging and sepsis-specific treatment options are still lacking. Classification and early identification of patient subgroups may aid clinical decisions and improve outcome in sepsis patients. The initial clinical presentation is rather similar in sepsis of different etiologies, however, inflammatory profiles may be able to distinguish between different etiologies of infections. In this review, we summarize the role and the discriminating potency of host-derived inflammatory biomarkers in the context of the main etiological types of sepsis.

Gram-negative septic thrombosis in critically ill patients: A retrospective case-control study

BACKGROUND

Data on septic thrombosis caused by Gram-negative bacilli (GN-ST) in intensive care unit (ICU) patients are currently limited.

METHODS

The aim of this retrospective case-control study (matched 1:3) performed over a 15-month period on ICU patients with bacteraemia, associated (cases) or not (controls) with GN-ST, was to assess 30-day mortality and clinical/microbiological features of GN-ST.

RESULTS

During the study period, 16 patients with GN-ST and 48 controls were analyzed. Polytrauma was the cause of ICU admission in 12 (75%) cases and 22 (46%) controls (p = 0.019). In no case of septic thrombosis was surgical debridement performed. The site of venous thrombosis was more frequently in the lower limbs, associated with bone fracture in nine out of 12 (75%) cases. The median duration of bacteraemia (22 days vs 1 day; p < 0.001) and time to clinical improvement (15 days vs 4 days; p < 0.001) were significantly longer in cases than in controls. On analysis of the receiver operating characteristics (ROC) curve, bacteraemia >72 h was significantly associated with GN-ST (area under the curve (AUC) 0.95, sensitivity 0.996 and specificity 0.810; p < 0.001). Finally, 30-day mortality was 20% in cases and 67% in controls (p < 0.001).

CONCLUSIONS

Critically ill patients with GN-ST showed specific clinical features. Despite delayed bacteraemia clearance, targeted antibiotic therapy plus anticoagulation usually provided clinical improvement and a low 30-day mortality rate.

Follow-up blood cultures in Gram-negative bacilli bacteremia: are they needed for critically ill patients?

BACKGROUND

Gram-negative bacilli bacteremias (GNB-Bs) represent a major cause of morbidity and mortality in Intensive Care Unit (ICU) patients. Aim of this study was to investigate the role of follow-up blood cultures (FUBCs) and the clinical significance of persistent bacteremia (PB) in these settings.

METHODS

We retrospectively analyzed clinical data and outcome of GNB-Bs that occurred in ICU patients over a span of 1 year. In particular we sought information on development and clinical details of PB, defined as repeatedly positive FUBCs after ≥96 hours of appropriate antibiotic treatment and ≥48 hours after removal of endovascular devices.

RESULTS

Among 307 ICU patients, 69 (22.4%) developed 107 GNB-Bs. Of these, 78 (73%) could be eventually analyzed: 50 of 78 (64.1%) were non-PBs from 26 patients and 28 of 78 (35.9%) were PBs from 23 patients. Duration of fever and bacteremia, time to procalcitonin normalization and weaning from vasopressors were longer in episodes of PBs than non-PBs (P=0.04, P<0.001, P=0.02 and P=0.004, respectively). Primary bacteremia was more frequent in non-PBs than in PBs (29 of 50, 58% vs. 3/28, 10.7%, P=0.0001), whereas septic thrombus infection (STI) was the source of infection in 14 of 28 (50%). Finally, clinical features and 30-day mortality did not differ between patients with PB and those who developed only non-PB episodes.

CONCLUSIONS

Among our ICU patients, more than one third of GNB-Bs for which FUBCs were performed resulted PB. This condition is often associated with the presence of STI; therefore, FUBCs seem useful for the optimal management of GNB in this clinical setting.

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

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.

Diagnostic Accuracy of Procalcitonin Compared to C-Reactive Protein and Interleukin 6 in Recognizing Gram-Negative Bloodstream Infection: A Meta-Analytic Study

Objective

Gram-negative bloodstream infections (GNBSIs), especially those caused by antibiotic-resistant species, have become a public health challenge. Procalcitonin (PCT) showed promising potential in early diagnosis of GNBSI; however, little was known about its performance under different clinical settings. We here systematically assessed the diagnostic accuracy of PCT in recognizing GNBSI and made direct comparisons with C-reactive protein (CRP) and interleukin 6 (IL-6).

Methods

PubMed, Embase, ISI Web of Knowledge, and Scopus were searched from inception to March 15th, 2019. Area under the summary receiver operating characteristic curve (AUC), pooled sensitivity, specificity, and diagnostic odds ratio (DOR) were calculated. Hierarchical summary receiver operating characteristic (HSROC) model was used for the investigation of heterogeneity and for comparisons between markers.

Results

25 studies incorporating 50933 suspected BSI episodes were included. Pooled sensitivity and specificity for PCT were 0.71 and 0.76, respectively. The overall AUC was 0.80. The lowest AUCs were found in patients with febrile neutropenia (0.69) and hematological malignancy (0.69). The highest AUC was found in groups using electrochemiluminescence immunoassay (0.87). In direct comparisons, PCT showed better overall performance than CRP with the AUC being 0.85 (95% CI 0.81–0.87) for PCT and 0.78 (95% CI 0.74–0.81) for CRP, but the relative DORs varied with thresholds between PCT and CRP (p < 0.001). No significant difference was found either in threshold (p < 0.001). No significant difference was found either in threshold (p < 0.001). No significant difference was found either in threshold (

Conclusions

PCT was helpful in recognizing GNBSI, but the test results should be interpreted carefully with knowledge of patients' medical condition and should not serve as the only criterion for GNBSI. Further prospective studies are warranted for comparisons between different clinical settings.

A Bayesian decision support sequential model for severity of illness predictors and intensive care admissions in pneumonia

Background

Community-acquired pneumonia (CAP) is one of the leading causes of morbidity and mortality in the USA. Our objective was to assess the predictive value on critical illness and disposition of a sequential Bayesian Model that integrates Lactate and procalcitonin (PCT) for pneumonia.

Methods

Sensitivity and specificity of lactate and PCT attained from pooled meta-analysis data. Likelihood ratios calculated and inserted in Bayesian/ Fagan nomogram to calculate posttest probabilities. Bayesian Diagnostic Gains (BDG) were analyzed comparing pre and post-test probability. To assess the value of integrating both PCT and Lactate in Severity of Illness Prediction we built a model that combined CURB65 with PCT as the Pre-Test markers and later integrated the Lactate Likelihood Ratio Values to generate a combined CURB 65 + Procalcitonin + Lactate Sequential value.

Results

The BDG model integrated a CUBR65 Scores combined with Procalcitonin (LR+ and LR-) for Pre-Test Probability Intermediate and High with Lactate Positive Likelihood Ratios. This generated for the PCT LR+ Post-test Probability (POSITIVE TEST) Posterior probability: 93% (95% CI [91,96%]) and Post Test Probability (NEGATIVE TEST) of: 17% (95% CI [15–20%]) for the Intermediate subgroup and 97% for the high risk sub-group POSITIVE TEST: Post-Test probability:97% (95% CI [95,98%]) NEGATIVE TEST: Post-test probability: 33% (95% CI [31,36%]) . ANOVA analysis for CURB 65 (alone) vs CURB 65 and PCT (LR+) vs CURB 65 and PCT (LR+) and Lactate showed a statistically significant difference (P value = 0.013).

Conclusions

The sequential combination of CURB 65 plus PCT with Lactate yielded statistically significant results, demonstrating a greater predictive value for severity of illness thus ICU level care.

Serum procalcitonin as an independent diagnostic markers of bacteremia in febrile patients with hematologic malignancies

Background

Serum procalcitonin (PCT) and C-reactive protein (CRP) are biomarkers of infection. In patients with hematologic disorders with or without hematopoietic stem cell transplantation (HSCT), it is difficult to distinguish bloodstream infections from aseptic causes of febrile episodes. The objective of this study was to investigate diagnostic values of PCT and CRP in predicting systemic bacterial infection in patients with hematologic malignancies.

Methods

Clinical and laboratory data of 614 febrile episode cases from 511 patients were analyzed. Febrile episodes were classified into four groups: (1) culture-positive bacterial infection by Gram-positive cocci (GPC), (2) culture-positive bacterial infection by Gram-negative bacilli (GNB), (3) fungal infection, and (4) viral infection or a noninfectious etiology.

Results

Of 614 febrile cases, systemic bacterial infections were confirmed in 99 (16.1%) febrile episodes, including 38 (6.2%) GPC and 61 (9.9%) GNB infections. PCT levels were significantly higher in GNB infectious episodes than those in febrile episodes caused by fungal infection (0.58 ng/mL (95% CI: 0.26–1.61) vs. 0.22 ng/mL (0.16–0.38), P = 0.047). Bacterial infectious episodes showed higher PCT and CRP levels than non-bacterial events (PCT: 0.49 (0.26–0.93) ng/mL vs. 0.20 (0.18–0.22) ng/mL, P < 0.001; CRP: 76.6 (50.5–92.8) mg/L vs. 58.0 (51.1–66.5) mg/L, P = 0.036). For non-neutropenic febrile episodes, both PCT and CRP discriminated bacteremia from non-bacteremia. However, in neutropenic febrile episodes, PCT only distinguished bacteremia from non-bacteremia. In non-neutropenic episode, both PCT and CRP showed good diagnostic accuracy (AUC: 0.757 vs. 0.763). In febrile neutropenia, only PCT discriminated bacteremia from non-bacterial infection (AUC: 0.624) whereas CRP could not detect bacteremia (AUC: 0.500, 95% CI: 0.439–0.561, P > 0.05).

Conclusions

In this single-center observational study, PCT was more valuable than CRP for discriminating between bacteremia and non-bacteremia independent of neutropenia or HSCT.

Procalcitonin for predicting catheter-associated bloodstream infection: A meta-analysis

OBJECTIVE

The predictive accuracies of procalcitonin (PCT) in the diagnosis of catheter-associated bloodstream infection (CABSI) vary widely. This meta-analysis aimed to explore the predictive value of PCT for CABSI.

METHODS

We searched PubMed, EMBase, Web of Science, ScienceDirect, Cochrane Library, and studies published up to 10 March 2019. Odds ratios (ORs) with 95% confidence intervals (95%CIs) were calculated to evaluate PCT predictive value using Stata 14.0 software.

RESULTS

The meta-analysis was composed of 7 studies, consisting of 347 subjects. Pooled analysis demonstrated that a high PCT was significantly correlated with CABSI (pooled OR = 23.36, 95%CI 12.43-43.91, P < .001) and medium heterogenicity (I = 36.9%, P = .147). The pooled sensitivity and specificity were 85% (95%CI 0.76-0.91) and 89% (95%CI 0.68-0.97), respectively. Although Begg funnel plot (P = .007) indicated the presence of publication bias among the included studies, the stability of the pooled outcomes was verified by the trim-and-fill method. Furthermore, sensitivity analyses did not show important differences in effect estimation.

CONCLUSION

PCT is an effective predictor of CABSI. However, high-quality randomized controlled trials are needed to determine whether PCT could predict CABSI.

Serum human neutrophil lipocalin: An effective biomarker for diagnosing bacterial infections

BACKGROUND

Human neutrophil lipocalin (HNL) is used as a novel biomarker for infections. However, only a few studies have focused on the usefulness of HNL. The purpose of this study was to evaluate the diagnostic efficiency of HNL for identifying bacterial infections and to compare HNL with procalcitonin (PCT) and C-reactive protein (CRP).

METHODS

Hospital patients with acute infections of bacterial origin (n = 439), viral origin (n = 71), and healthy volunteers (n = 67) were included in the study. The infection status of each patient was verified using microbiological, serological, and PCR testing. Additionally, CRP, HNL, and PCT levels were measured by established methods.

RESULTS

In distinguishing bacterial and viral infections, area under the curve (AUC) analysis showed that, with a value of 0.81 (95% CI, 0.76-0.86), HNL was superior to CRP at 0.73 (0.68-0.79) and PCT at 0.64 (0.58-0.70). Interestingly, the combination of HNL, PCT, and CRP improved the diagnostic potential significantly with an AUC of 0.86 (0.82-0.90, P < 0.05). Furthermore, when comparing different infection site subgroups with healthy patients, HNL levels were higher in all bacterial groups, albeit to widely varying degrees (P < 0.0001), and HNL reached a higher level in bloodstream and abdominal infections. CRP levels showed the same trend as HNL levels. PCT levels were significantly increased in bloodstream infections, abdominal infections, and in bacterial pneumonia (P < 0.0001), while no significant differences were found in soft tissue (P = 0.4378) or urinary tract infections (P = 0.423). There was no difference in HNL and CRP levels between patients with Gram-negative bacterial (GNB) or Gram-positive bacterial infections. However, compared with controls, PCT was only increased in GNB-infected patients.

CONCLUSION

HNL detection can help diagnose patients with infectious diseases, and the diagnostic efficacy of HNL is not affected by the infected site or by pathogenic bacterial species. The combination of HNL, PCT, and CRP has a superior performance at identifying bacterial infections compared with traditional biomarkers.

The clinical value of IL-3, IL-4, IL-12p70, IL17A, IFN-γ, MIP-1β, NLR, P-selectin, and TNF-α in differentiating bloodstream infections caused by gram-negative, gram-positive bacteria and fungi in hospitalized patients: An Observational Study

Early differential diagnosis of bloodstream infections (BSIs) caused by different sources and species of bacteria in hospitalized patients is crucial for the timely targeted interventions including appropriate use of antibiotics. The aim of this study was to identify 9 biomarkers for the early differentiation of gram-negative-bloodstream infection (GN-BSI), gram-positive (GP)-BSI, and fungal-BSI.A prospective study was conducted for a total of 390 inpatients who underwent blood culture in the Chinese PLA General Hospital from September 2015 to March 2018. Patients with positive culture of a single pathogen were divided into GN-BSI, GP-BSI, and Fungal-BSI groups, and a culture-negative disease control group was also established. The serum levels of macrophage inflammatory protein 1β (MIP-1β), tumor necrosis factor α (TNF-α), interleukin (IL)-3, interferon (IFN)-γ, IL-17A, IL-4, IL-12p70, and P-selectin were detected and the NLR was calculated from routine blood test. Receiver-operating characteristic analysis was used to determine the efficacy of various indicators in the differential diagnosis of BSIs. Prediction and validation experiments on clinical patient samples (263 cases) were also performed.The level of IL-3 in the GP-BSI group was significantly higher than those in the other 3 groups. The level of IFN-γ in the fungal-BSI group was significantly higher than those in the other 3 groups. NLR, MIP-1β, TNF-α, IL-17A, and IL3 exhibited some efficacy when distinguishing between GN-BSI and GP-BSI and NLR had the largest area under curve (AUC) (0.728), followed by MIP-1β with an AUC of 0.679. IFN-γ and IL-3 exhibited some value in differential diagnosis between GN-BSI and Fungal-BSI. IL-3, MIP-1β, TNF-α, IFN-γ, NLR, IL-17A, and IL-4 exhibited some value in distinguishing fungal-BSI and GP-BSI, with IL-3 had the largest AUC (0.722), followed by MIP-1β with an AUC of 0.703.NLR and MIP-1β may be valuable in differentiating GN-BSI from GP-BSI in hospitalized patients. IFN-γ and IL-3 may be helpful in differential diagnosis GN-BSI and fungal-BSI. IL-3 and MIP-1β exhibited some diagnostic efficacy in distinguishing fungal-BSI and GP-BSI. Additionally, IL-3 with high serum level may be a marker for GP-BSI and IFN-γ with high serum level may be a valuable marker for the prediction of Fungal-BSI. The utility of these biomarkers to predict BSIs owing to different pathogens in hospitalized patients needs to be assessed in further studies.

Procalcitonin versus C-reactive protein: review of kinetics and performance for diagnosis of neonatal sepsis

Procalcitonin (PCT) and C-reactive protein (CRP) are commonly used biomarkers, but their diagnostic advantage for neonatal early-onset (EOS) or late-onset (LOS) sepsis is controversial. In a comprehensive literature review we found significant heterogeneity between studies in sample timing, cut-off values, consideration of blood culture results for sepsis classification, and definition of EOS versus LOS. We identified 39 studies directly comparing PCT with CRP, but only four in very low birth weight (VLBW) neonates. The mean sensitivity for EOS, LOS, and EOS + LOS was 73.6%, 88.9%, and 76.5% for PCT, compared to 65.6%, 77.4%, and 66.4% for CRP, respectively. Mean specificity of PCT and CRP was 82.8% versus 82.7% for EOS, 75.6% versus 81.7% for LOS, and 80.4% versus 91.3% for EOS + LOS. More studies directly comparing both biomarkers for EOS and LOS, especially in extremely and very-low-birth-weight infants, are needed to determine their clinical value for guidance of antibiotic therapy in neonatal sepsis.

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

BACKGROUND

Procalcitonin (PCT) is routinely used for an early recognition of severe infections and for promoting appropriate use of antibiotics. However, limited data correlating values of PCT with etiology of infection has been reported.

METHODS

During 2016, all positive blood cultures (BC) were retrospectively extracted in a 1100-beds Italian tertiary-care hospital. PCT and C-reactive protein (CRP) values were recorded within 24h from BC collection. Primary endpoint of the study was to investigate the correlation between PCT and CRP values and the occurrence of bloodstream infections (BSI) caused by bacteria or fungi.

RESULTS

During the study period, 1296 positive BC were included: 712 (54.9%) due to Gram-positive (GP), 525 (40.5%) due to Gram-negative (GN) strains, and 59 (4.6%) caused by fungi. Among GN isolates, enterobacteriaceae were reported in 453 (86.3%) cases. PCT values were higher in patients with GN etiology (26.1±14.2ng/mL) compared to GP (6.9±4.5) and fungi (3.3±2.4). Mean values for CRP in GN, GP, and fungi were not different. Receiver Operating Characteristic (ROC) curves showed an area under curve (AUC) of 0.71 for PCT and 0.51 for CRP among GN isolates; an AUC of 0.7 for PCT and 0.52 for CRP among enterobacteriaceae. Lower AUC for PCT were reported for GP and fungi.

CONCLUSIONS

PCT showed moderate performance in early detection (within 24h) of Gram-negative infections, especially those caused by enterobacteriaceae. Further prospective studies are mandatory to confirm these observations.

Occult bacteraemia in cardiac implantable electronic device patients: a review of diagnostic workflow and mandatory therapy

: Cardiac implantable electronic device (CIED) implantation has greatly increased, with an associated exponential increase in CIED infections (CDIs). Cardiac device related infective endocarditis (CDRIE) has high morbidity and mortality: approximately 10-21%. Therefore, a prompt diagnosis and radical treatment of CDRIE are needed; transvenous lead extraction (TLE) is the mainstay for the complete healing, even if associated with wide logistic problems, high therapeutic costs and high mortality risk for patients. Some criticisms about the value of Duke criteria and their limitations for the diagnosis of CDRIE are known. The significance of classic laboratory data, transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE), considered in the Duke score, are reviewed and critically discussed in this article, with regard to the specific field of the diagnosis of CDI. The need for new techniques for achieving the diagnostic reliability has been well perceived by physicians, and additional techniques have been introduced in the new European Society of Cardiology (ESC) and British Heart Rhythm Society (BHRS) guidelines on infective endocarditis. These suggested techniques, such as 18-Fluorodeoxyglucose PET/computed tomography (FDG-PET/CT), white blood cell PET (WBC PET) and lung multislice CT (MSCT), are also discussed in the study. This short review is intended as an extensive summary of the diagnostic workflow in cases of CDI and will be useful for readers who want to know more about this issue.

Procalcitonin levels in candidemia versus bacteremia: a systematic review

Background

Procalcitonin (PCT) is a biomarker used to assess systemic inflammation, infection, and sepsis and to optimize antimicrobial therapies. Its role in the in the differential diagnosis between candidemia and bacteremia is unclear. The aim of this systematic review was to summarize the current evidence about PCT values for differentiating candidemia from bacteremia.

Methods

PubMed and EMBASE were searched for studies reporting data on the diagnostic performance of serum PCT levels in intensive care unit (ICU) or non-ICU adult patients with candidemia, in comparison to patients with bacteremia.

Results

We included 16 studies for a total of 45.079 patients and 785 cases of candidemia. Most studies claimed to report data relating to the use of PCT values for differentiating between candidemia and bacteremia in septic patients in the intensive care unit. However, the studies identified were all retrospective, except for one secondary analysis of a prospective dataset, and clinically very heterogeneous and involved different assessment methods. Most studies did show lower PCT values in patients with candidemia compared to bacteremia. However, the evidence supporting this observation is of low quality and the difference seems insufficiently discriminative to guide therapeutic decisions. None of the studies retrieved actually studied guidance of antifungal treatment by PCT. PCT may improve diagnostic performance regarding candidemia when combined with other biomarkers of infection (e.g., beta-d-glucan) but more data is needed.

Conclusions

PCT should not be used as a standalone tool for the differential diagnosis between candidemia and bacteremia due to limited supporting evidence.

Electronic supplementary material

The online version of this article (10.1186/s13054-019-2481-y) contains supplementary material, which is available to authorized users.