Clinical review: the role of biomarkers in the diagnosis and management of community-acquired pneumonia

Serum activin A as a prognostic biomarker for community acquired pneumonia

BACKGROUND

It is essential to develop new biomarker with effective prognostic roles because of the unclear clinical use of the current community-acquired pneumonia (CAP) predictors.

AIM

To evaluate the association between serum activin A levels and prognosis in CAP patients.

METHODS

A total of 168 CAP individuals grouped according to the severity and prognosis of illness condition, and 48 healthy individuals as the control group were enrolled in this study. Circulating concentrations of activin A were measured using enzyme-linked immunoassays. The interaction between activin A levels and etiologies of CAP was determined. Based on the severity of CAP, 110 patients (65.48%) were categorized into group-I, 42 (25%) cases were grouped into group-II, and 16 (9.52%) cases were categorized into group-III.

RESULTS

Serum activin A levels were higher in patients with CAP than controls, but independent of etiology. Moreover, the scores of Pneumonia Severity Index (PSI) and CURB-65 positively correlated with the increasing levels of serum activin A, and were at their highest peak in individuals in group-III (P < 0.001). Combining activin A with CURB-65 or PSI was more effective in improving predictive property (P < 0.01). According to Cox proportional regression analysis, after adjusting clinical parameters, we confirmed that activin A showed a powerful predictive property for hospital mortality in CAP patients (P < 0.001).

CONCLUSION

Higher level of serum activin A was associated with poor prognosis of CAP. Activin A can be used as a more valuable biomarker of prognosis in CAP patients.

Early Diagnosis of Sepsis: The Role of Biomarkers and Rapid Microbiological Tests

Sepsis is a medical emergency resulting from a dysregulated response to an infection, causing preventable deaths and a high burden of morbidity. Protocolized and accurate interventions in sepsis are time-critical. Therefore, earlier recognition of cases allows for preventive interventions, early treatment, and improved outcomes. Clinical diagnosis of sepsis by clinical scores cannot be considered an early diagnosis, given that underlying molecular pathophysiological mechanisms have been activated in the preceding hour or days. There is a lack of a widely available tool enhancing preclinical diagnosis of sepsis. Sophisticated technologies for sepsis prediction have several limitations, including high costs. Novel technologies for fast molecular and microbiological diagnosis are focusing on bedside point-of-care combined testing to reach most settings where sepsis represents a challenge.

Can Biomarkers Correctly Predict Ventilator-associated Pneumonia in Patients Treated With Targeted Temperature Management After Cardiac Arrest? An Exploratory Study of the Multicenter Randomized Antibiotic (ANTHARTIC) Study

IMPORTANCE

Ventilator-associated pneumonia (VAP) frequently occurs in patients with cardiac arrest. Diagnosis of VAP after cardiac arrest remains challenging, while the use of current biomarkers such as C-reactive protein (CRP) or procalcitonin (PCT) is debated.

OBJECTIVES

To evaluate biomarkers' impact in helping VAP diagnosis after cardiac arrest.

DESIGN SETTING AND PARTICIPANTS

This is a prospective ancillary study of the randomized, multicenter, double-blind placebo-controlled ANtibiotherapy during Therapeutic HypothermiA to pRevenT Infectious Complications (ANTHARTIC) trial evaluating the impact of antibiotic prophylaxis to prevent VAP in out-of-hospital patients with cardiac arrest secondary to shockable rhythm and treated with therapeutic hypothermia. An adjudication committee blindly evaluated VAP according to predefined clinical, radiologic, and microbiological criteria. All patients with available biomarker(s), sample(s), and consent approval were included.

MAIN OUTCOMES AND MEASURES

The main endpoint was to evaluate the ability of biomarkers to correctly diagnose and predict VAP within 48 hours after sampling. The secondary endpoint was to study the combination of two biomarkers in discriminating VAP. Blood samples were collected at baseline on day 3. Routine and exploratory panel of inflammatory biomarkers measurements were blindly performed. Analyses were adjusted on the randomization group.

RESULTS

Among 161 patients of the ANTHARTIC trial with available biological sample(s), patients with VAP (n = 33) had higher body mass index and Acute Physiology and Chronic Health Evaluation II score, more unwitnessed cardiac arrest, more catecholamines, and experienced more prolonged therapeutic hypothermia duration than patients without VAP (n = 121). In univariate analyses, biomarkers significantly associated with VAP and showing an area under the curve (AUC) greater than 0.70 were CRP (AUC = 0.76), interleukin (IL) 17A and 17C (IL17C) (0.74), macrophage colony-stimulating factor 1 (0.73), PCT (0.72), and vascular endothelial growth factor A (VEGF-A) (0.71). Multivariate analysis combining novel biomarkers revealed several pairs with p value of less than 0.001 and odds ratio greater than 1: VEGF-A + IL12 subunit beta (IL12B), Fms-related tyrosine kinase 3 ligands (Flt3L) + C-C chemokine 20 (CCL20), Flt3L + IL17A, Flt3L + IL6, STAM-binding protein (STAMBP) + CCL20, STAMBP + IL6, CCL20 + 4EBP1, CCL20 + caspase-8 (CASP8), IL6 + 4EBP1, and IL6 + CASP8. Best AUCs were observed for CRP + IL6 (0.79), CRP + CCL20 (0.78), CRP + IL17A, and CRP + IL17C.

CONCLUSIONS AND RELEVANCE

Our exploratory study shows that specific biomarkers, especially CRP combined with IL6, could help to better diagnose or predict early VAP occurrence in cardiac arrest patients.

Current Diagnostic Techniques for Pneumonia: A Scoping Review

Community-acquired pneumonia is one of the most lethal infectious diseases, especially for infants and the elderly. Given the variety of causative agents, the accurate early detection of pneumonia is an active research area. To the best of our knowledge, scoping reviews on diagnostic techniques for pneumonia are lacking. In this scoping review, three major electronic databases were searched and the resulting research was screened. We categorized these diagnostic techniques into four classes (i.e., lab-based methods, imaging-based techniques, acoustic-based techniques, and physiological-measurement-based techniques) and summarized their recent applications. Major research has been skewed towards imaging-based techniques, especially after COVID-19. Currently, chest X-rays and blood tests are the most common tools in the clinical setting to establish a diagnosis; however, there is a need to look for safe, non-invasive, and more rapid techniques for diagnosis. Recently, some non-invasive techniques based on wearable sensors achieved reasonable diagnostic accuracy that could open a new chapter for future applications. Consequently, further research and technology development are still needed for pneumonia diagnosis using non-invasive physiological parameters to attain a better point of care for pneumonia patients.

New Guidelines for Severe Community-acquired Pneumonia

In 2023, the new European guidelines on severe community-acquired pneumonia, providing clinical practice recommendations for the management of this life-threatening infection, characterized by a high burden of mortality, morbidity, and costs for the society. This review article aims to summarize the principal evidence related to eight different questions covered in the guidelines, by also highlighting the future perspectives for research activity.

Metabolomics Study Revealing Purines as Potential Diagnostic Biomarkers of Acute Respiratory Distress Syndrome in Patients with Community─Acquired Pneumonia

Community-acquired pneumonia (CAP) is a significant threat to human health and the leading cause of acute respiratory distress syndrome (ARDS). We aimed to reveal the metabolic profiling whether can be used for assessing CAP with or without ARDS (nARDS) and therapeutic effects on CAP patients after treatment. Urine samples were collected at the onset and recovery periods, and metabolomics was employed to identify robust biomarkers. 19 metabolites were significantly changed in the ARDS relative to nARDS, mainly involving purines and fatty acids. After treatment, 7 metabolites in the nARDS and 14 in the ARDS were found to be significantly dysregulated, including fatty acids and amino acids. In the validation cohort, we observed that the biomarker panel consisted of N2,N2-dimethylguanosine, 1-methyladenosine, 3-methylguanine, 1-methyladenosine, and uric acid exhibited better AUCs of 0.900 than pneumonia severity index and acute physiology and chronic health evaluation II (APACHE II) scores between the ARDS and nARDS. Combining L-phenylalanine, phytosphingosine, and N-acetylaspartylglutamate as biomarkers for discriminating the nARDS and ARDS patients after treatment exhibited good AUCs of 0.811 and 0.821, respectively. The metabolic pathway and defined biomarkers may serve as crucial indicators for predicting the development of ARDS in CAP patients and for assessing therapeutic effects.

PROCALCITONIN GUIDED ANTIBIOTIC STEWARDSHIP: A BALKAN EXPERT CONSENSUS STATEMENT

Sepsis as a consequence of infection is a frequent cause of death among critically ill patients. The most common sites of infection are lover respiratory tract, abdominal, urinary tract and catheter-associated blood stream infections. Early empiric, broad-spectrum therapy in those with severe sepsis and/or shock with the aim of reducing mortality may lead to antibiotic overuse, resistance and increased costs. Among numerous serum biomarkers, procalcitonin (PCT) has proved to be one of the most reliable ones in the diagnosis of sepsis. An important means of limiting antibiotic resistance is the antibiotic stewardship program, especially in intensive care units with critically ill patients and prevalence of multiple drug-resistant pathogens. The PCT-guided antibiotic stewardship was first started in Western Europe and Asia-Pacific countries, as well as in the United States. Considering that this method has proven to be effective in reducing antibiotic consumption while improving clinical outcome, a group of experts from the Balkan region decided to make their own recommendations and PCT protocol. When creating this protocol for initiation and duration of antibiotic treatment, they especially reviewed the literature for lower respiratory tract infection and sepsis. In the protocol, they have included the severity of illness, clinical assessment, and PCT levels. Developing a consensus on the clinical algorithm by eminent experts/specialists in various fields of medicine should enable clinicians to use PCT for initiation of antibiotic therapy and monitoring PCT to stop antibiotics earlier. It is crucial that the PCT-guided algorithm becomes an integral part of institutional stewardship program.

How to use biomarkers of infection or sepsis at the bedside: guide to clinicians

Sepsis is defined as a life-threatening organ dysfunction caused by a dysregulated host response to infection. In this context, biomarkers could be considered as indicators of either infection or dysregulated host response or response to treatment and/or aid clinicians to prognosticate patient risk. More than 250 biomarkers have been identified and evaluated over the last few decades, but no biomarker accurately differentiates between sepsis and sepsis-like syndrome. Published data support the use of biomarkers for pathogen identification, clinical diagnosis, and optimization of antibiotic treatment. In this narrative review, we highlight how clinicians could improve the use of pathogen-specific and of the most used host-response biomarkers, procalcitonin and C-reactive protein, to improve the clinical care of patients with sepsis. Biomarker kinetics are more useful than single values in predicting sepsis, when making the diagnosis and assessing the response to antibiotic therapy. Finally, integrated biomarker-guided algorithms may hold promise to improve both the diagnosis and prognosis of sepsis. Herein, we provide current data on the clinical utility of pathogen-specific and host-response biomarkers, offer guidance on how to optimize their use, and propose the needs for future research.

Myristoyl lysophosphatidylcholine is a biomarker and potential therapeutic target for community-acquired pneumonia

There is no gold standard for evaluating the severity of community-acquired pneumonia (CAP), and it is still based on a score. This study aimed to use the metabolomics method to find promised biomarkers in assessing disease severity and potential therapeutic targets for CAP. The result found that the metabolites in the plasma samples of CAP patients had significantly different between the acute phase and the remission phase, especially lysophosphatidylcholine (LPCs) in glycerophospholipids, whose levels are negatively linked to the severity of the disease. Subsequently, the two key metabolites of myristoyl lysophosphatidylcholine (LPC 14:0) and LPC 16:1 were screened. We analyzed the predictive performance of the two metabolites using Spearman-related analysis and ROC curves, and LPC14:0 showed more satisfactory diagnostic performance than LPC16:1. Then we explored the protective role and mechanism of LPC 14:0 in animal and cell models. The results showed that LPC 14:0 could inhibit the LPS-induced secretion of IL-1β, IL-6, and TNF-α, lower the ROS and MDA levels, and decreased the depletion of SOD and GSH, thereby reducing lung tissue and cell damage, such as down-regulating the protein level in BALF, lung W/D ratio, MPO activity, and apoptosis. We found that LPC 14:0 inhibited LPS-induced inflammatory response and oxidative stress, and the above protection was achieved by inhibiting LPS-induced activation of the NLRP3 inflammasome. LPC 14:0 may serve as a novel biomarker for predicting the severity of CAP. In addition, our exploration of the role of LPC 14:0 in animal and cellular models has reinforced its promise as a therapeutic target to improve the clinical efficacy for CAP.

N-myc and STAT interactor is a novel biomarker of severity in community-acquired pneumonia: a prospective study

Objectives

To tested the ability of N-myc and STAT interactor (NMI) levels in patients with community-acquired pneumonia (CAP) to predict the severity of the disease.

Methods

Prospective observational analysis of patients with CAP was performed. The NMI levels in serum of 394 CAP patients on admission were measured by immunoassay. Thirty-day mortality and intensive care unit (ICU) admission were set as clinical outcomes. The predicting value of NMI for clinical outcomes was determined by receiver operating characteristic curve and logistic regression analysis. The internal validity was assessed using cross-validation with bootstrap resampling.

Results

NMI was an independent risk factor for both 30-day mortality and admission to ICU for CAP patients. The area under curve (AUC) of NMI to predict mortality was 0.91 (95% CI: 0.86–0.96), and that to predict ICU admission was 0.92 (95% CI: 0.88–0.97), significantly higher than that of other biomarkers including procalcitonin and C-reactive protein. The proportion of clinical outcomes notably rose as NMI levels elevated (P < 0.001). The AUCs of the new score systems including NMI (N-PSI and N-CURB65 score) to predict outcomes were significantly higher than the original score systems.

Conclusions

NMI is a novel biomarker for predicting CAP severity superior to former biomarkers in 30-day mortality and ICU admission.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-02139-x.

Respiratory MUC5B disproportion is involved in severe community-acquired pneumonia

BACKGROUND

Mucus production is a process involved in the pathogenesis of Community-acquired pneumonia (CAP). The study is to determine Mucin 5B (MUC5B) protein concentration and its proportion in the bronchoalveolar lavage fluid (BALF) of CAP patients and evaluate its value to help assess disease severity.

METHODS

A total of 118 patients were enrolled in this cross-sectional study, including 45 with severe CAP (SCAP) and 73 with non-severe CAP (NSCAP). MUC5B concentration in BALF were determined by immunoblotting analysis. Total protein concentration of BALF was detected by Pierce BCA kit. Cytokines IL6, IL10, IFNγ, IL13, and IL17 in BALF were measured using commercial enzyme-linked immunosorbent assay (ELISA). Spearman's correlation analysis was applied to evaluate the relationships between MUC5B concentration or MUC5B/total protein ratio and the CURB-65 score, as well as cytokines. Logistic regression analysis was used to identify the independent factors associated with severe CAP. Receiver operating characteristic (ROC) curve was used to evaluate the assessment value of MUC5B/total protein ratio and other indexes for CAP severity.

RESULTS

MUC5B concentration in the BALF of NSCAP group was higher than that in SCAP group [NSCAP 13.56 µg/ml (IQR 5.92-25.79) vs. SCAP 8.20 µg/ml (IQR 4.97-14.03), p = 0.011]. The total protein concentration in the BALF of NSCAP group was lower than that in SCAP group [NSCAP 0.38 mg/ml (IQR 0.15-1.10) vs. SCAP 0.68 mg/ml (IQR 0.46-1.69), p = 0.002]. The MUC5B/total protein ratio was remarkably higher in NSCAP group than that in SCAP groups [NSCAP 3.66% (IQR 1.50-5.56%) vs. SCAP 1.38% (IQR 0.73-1.76%), p < 0.001]. MUC5B/total protein ratio was negatively correlated with total protein concentration (r_s = - 0.576, p < 0.001), IL6 (r_s = - 0.312, p = 0.001), IL10 (r_s = - 0.228, p = 0.013), IL13 (r_s = - 0.183, p = 0.048), IL17 (r_s = - 0.282, p = 0.002) and CURB-65 score (r_s = - 0.239, p = 0.009). Logistic regression identified that MUC5B/total protein ratio, IL6 level and CURB-65 score as independent variables related to CAP severity. ROC curve demonstrated best assessment value of MUC5B/total protein ratio for SCAP (AUC 0.803, p < 0.001), with a sensitivity of 88.9% and a specificity of 64.4%.

CONCLUSIONS

Respiratory MUC5B disproportion is related to CAP severity. MUC5B/total protein ratio may serve as an assessment marker and a potential therapeutic target for severe CAP.

A Broad Learning System to Predict the 28-Day Mortality of Patients Hospitalized with Community-Acquired Pneumonia: A Case-Control Study

This study was to conduct a model based on the broad learning system (BLS) for predicting the 28-day mortality of patients hospitalized with community-acquired pneumonia (CAP). A total of 1,210 eligible CAP cases from Chifeng Municipal Hospital were finally included in this retrospective case-control study. Random forest (RF) and an eXtreme Gradient Boosting (XGB) models were used to develop the prediction models. The data features extracted from BLS are utilized in RF and XGB models to predict the 28-day mortality of CAP patients, which established two integrated models BLS-RF and BLS-XGB. Our results showed the integrated model BLS-XGB as an efficient broad learning system (BLS) for predicting the death risk of patients, which not only performed better than the two basic models but also performed better than the integrated model BLS-RF and two well-known deep learning systems-deep neural network (DNN) and convolutional neural network (CNN). In conclusion, BLS-XGB may be recommended as an efficient model for predicting the 28-day mortality of CAP patients after hospital admission.

An algorithm combining procalcitonin and lung ultrasound improves the diagnosis of bacterial pneumonia in critically ill children: The PROLUSP study, a randomized clinical trial

BACKGROUND

Lung ultrasound (LUS) and procalcitonin (PCT) are independently used to improve accuracy when diagnosing lung infections. The aim of the study was to evaluate the accuracy of a new algorithm combining LUS and PCT for the diagnosis of bacterial pneumonia.

METHODS

Randomized, blinded, comparative effectiveness clinical trial. Children <18 years old with suspected pneumonia admitted to pediatric intensive care unit were included, and randomized into experimental group (EG) or control group (CG) if LUS or chest X-Ray (CXR) were done as the first pulmonary image, respectively. PCT was determined. In patients with bacterial pneumonia, sensitivity, specificity, and predictive values of LUS, CXR, and of both combined with PCT were analyzed and compared. Concordance between the final diagnosis and the diagnosis concluded through the imaging test was assessed.

RESULTS

A total of 194 children, with a median age of 134 (interquartile range [IQR]: 39-554) days, were enrolled, 96 randomized into the EG and 98 into the CG. Bacterial pneumonia was diagnosed in 97 patients. Sensitivity and specificity for bacterial pneumonia diagnosis were 78% (95% confidence interval [CI]: 70-85) and 98% (95% CI: 93-99) for LUS, 85% (95% CI: 78-90) and 53% (95% CI: 43-62) for CXR, 90% (95% CI: 83-94) and 85% (95% CI: 76-91) when combining LUS and PCT, and 95% (95% CI: 90-98) and 41% (95% CI: 31-52) when combining CXR and PCT. The positive predictive value for LUS and PCT was 88% (95% C:I 79%-93%) versus 68% (95% CI: 60-75) for CXR and PCT. The concordance between the final diagnosis and LUS had a kappa value of 0.69 (95% CI: 0.62-0.75) versus 0.34 (95% CI: 0.21-0.45) for CXR, (p < 0.001).

CONCLUSIONS

The combination of LUS and PCT presented a better accuracy for bacterial pneumonia diagnosis than combining CXR and PCT. Therefore, its implementation could be a reliable tool for pneumonia diagnosis in critically ill children.

Severity Biomarkers in Puumala Hantavirus Infection

Annually, over 10,000 cases of hemorrhagic fever with renal syndrome (HFRS) are diagnosed in Europe. Puumala hantavirus (PUUV) causes most of the European HFRS cases. PUUV causes usually a relatively mild disease, which is rarely fatal. However, the severity of the infection varies greatly, and factors affecting the severity are mostly unrevealed. Host genes are known to have an effect. The typical clinical features in PUUV infection include acute kidney injury, thrombocytopenia, and increased vascular permeability. The primary target of hantavirus is the endothelium of the vessels of different organs. Although PUUV does not cause direct cytopathology of the endothelial cells, remarkable changes in both the barrier function of the endothelium and the function of the infected endothelial cells occur. Host immune or inflammatory mechanisms are probably important in the development of the capillary leakage. Several immunoinflammatory biomarkers have been studied in the context of assessing the severity of HFRS caused by PUUV. Most of them are not used in clinical practice, but the increasing knowledge about the biomarkers has elucidated the pathogenesis of PUUV infection.

PRO: Procalcitonin has clinical utility in children with community-acquired pneumonia

Procalcitonin (PCT) is a useful, albeit imperfect, diagnostic aid that can help clinicians make more informed decisions around antibiotic use in children with lower respiratory tract infections (LRTI), including community-acquired pneumonia (CAP). Recent data suggest that a very low PCT concentration has a high negative predictive value to identify a population of children at low risk of typical bacterial infections. Although the preponderance of data on the clinical utility of PCT in LRTI come from adult studies, the potential for benefit is likely greatest in paediatric CAP and other LRTIs where viral aetiologies predominate, yet antibiotics are frequently prescribed.

Which Biomarkers Can Be Used as Diagnostic Tools for Infection in Suspected Sepsis?

The diagnosis of infection in patients with suspected sepsis is frequently difficult to achieve with a reasonable degree of certainty. Currently, the diagnosis of infection still relies on a combination of systemic manifestations, manifestations of organ dysfunction, and microbiological documentation. In addition, the microbiologic confirmation of infection is obtained only after 2 to 3 days of empiric antibiotic therapy. These criteria are far from perfect being at least in part responsible for the overuse and misuse of antibiotics, in the community and in hospital, and probably the main drive for antibiotic resistance. Biomarkers have been studied and used in several clinical settings as surrogate markers of infection to improve their diagnostic accuracy as well as in the assessment of response to antibiotics and in antibiotic stewardship programs. The aim of this review is to provide a clear overview of the current evidence of usefulness of biomarkers in several clinical scenarios, namely, to diagnose infection to prescribe antibiotics, to exclude infection to withhold antibiotics, and to identify the causative pathogen to target antimicrobial treatment. In recent years, new evidence with "old" biomarkers, like C-reactive protein and procalcitonin, as well as new biomarkers and molecular tests, as breathomics or bacterial DNA identification by polymerase chain reaction, increased markedly in different areas adding useful information for clinical decision making at the bedside when adequately used. The recent evidence shows that the information given by biomarkers can support the suspicion of infection and pathogen identification but also, and not less important, can exclude its diagnosis. Although the ideal biomarker has not yet been found, there are various promising biomarkers that represent true evolutions in the diagnosis of infection in patients with suspected sepsis.

Blood leukocyte transcriptomes in gram-positive and gram-negative community-acquired pneumonia

BACKGROUND

Gram-positive and Gram-negative bacteria are the most common causative pathogens in community-acquired pneumonia (CAP) on the intensive care unit (ICU). The aim of this study was to determine whether the host immune response differs between Gram-positive and Gram-negative CAP upon ICU admission.

METHODS

Sixteen host response biomarkers providing insight in pathophysiological mechanisms implicated in sepsis and blood leukocyte transcriptomes were analysed in patients with CAP upon ICU admission in two tertiary hospitals in the Netherlands.

RESULTS

309 patients with CAP with a definite or probable likelihood (determined by predefined criteria) were included. A causative pathogen was determined in 74.4% of admissions. Patients admitted with Gram-positive CAP (n=90) were not different from those admitted with Gram-negative CAP (n=75) regarding demographics, chronic comorbidities, severity of disease and mortality. Host response biomarkers reflective of systemic inflammation, coagulation activation and endothelial cell function, as well as blood leukocytes transcriptomes, were largely similar between Gram-positive and Gram-negative CAP. Blood leukocyte transcriptomes were also similar in Gram-positive and Gram-negative CAP in two independent validation cohorts. On a pathogen-specific level, Streptococcus pneumoniae and Escherichia coli induced the most distinct host immune response.

CONCLUSION

Outcome and host response are similar in critically ill patients with CAP due to Gram-positive bacteria compared to Gram-negative bacteria.

Prognostic value of C-reactive protein to albumin ratio in patients resuscitated from out-of-hospital cardiac arrest

BACKGROUND

Despite major advances in basic and advanced life supports, patients who survived from out-of-hospital cardiac arrest (OHCA) have still poor prognosis. Several inflammatory parameters have been used to determine early and long-term prognosis in patients with OHCA. C-reactive protein-to-albumin ratio (CAR) is also a novel marker of systemic inflammation. To our knowledge, there is no study evaluating the clinical importance of CAR in OHCA patients.

AIMS

To evaluate the effect of CAR on in-hospital mortality in patients with OHCA.

METHODS

A total of 102 patients with OHCA were included in this study. The study population was divided into two groups as survivour (n = 43) and non-survivour (n = 59) during follow-up. Complete blood cell counts, biochemical and blood gas analyses were recorded for all patients. Neutrophil to lymphocyte ratio (NLR) was calculated as the ratio of neutrophil to lymphocyte. CAR was calculated as the ratio of C-reactive protein to the albumin.

RESULTS

NLR (P = .012), CAR (P < .001) and serum lactate level (P = .002) were significantly higher whereas lymphocyte (P = .008) and serum albumin (P < .001) were significantly lower in the non-survivour group compared with the survivour group. Multivariate logistic regression analysis showed that NLR (odds ratio [OR]: 1.044, 95% confidence interval [CI]: 1.044-1.437, P = .013), CAR (OR: 1.971, 95% CI: 1.327-2.930, P = .001) and lactate level (OR: 1.268, 95% CI: 1.095-1.469, P = .002) were independent predictors of in-hospital mortality.

CONCLUSIONS

We have demonstrated for the first time that CAR was an independent predictor of in-hospital mortality in OHCA patients.

Lipid profiles and differential lipids in serum related to severity of community-acquired pneumonia: A pilot study

This study aimed to characterize the lipidomic responses to community-acquired pneumonia (CAP) and provide new insight into the underlying mechanisms of pathogenesis and potential avenues for diagnostic and therapeutic treatments. This study was performed from January 2017 to October 2018. Lipidomic profiles were generated using ultra high-performance liquid chromatography with tandem mass spectrometry (UHPLC-MS/MS) platform. Spearman's rank correlation test and multiple linear regression analysis were applied to explore the correlation between changes in the relative abundance of lipids and clinical parameters. Kaplan-Meier methods were used to build 30-day survival curves. From the UHPLC-MS/MS results, a total of 509 and 195 lipid species were detected in the positive and negative ionization mode respectively. Positive ionization covered six lipid classes (glycerol-phospholipids, glycerolipids, sphingolipids, sterol-lipids, prenol-lipids, and fatty acid), whilst negative ionization covered three (glycerol-phospholipids, sphingolipids, fatty acid). Four lipids were selected as targets: PC (16:0_18:1), PC (18:2_20:4), PC (36:4), and PC (38:6). The relative increase of the areas under the curves for all four lipids were superior to the pneumonia severity index and CURB-65 (confusion, urea, respiratory rate, blood pressure, and age ≥65 years old) for discriminating severe CAP from CAP. Decreasing relative levels of PC (18:2_20:4), PC (38:6), and PC (36:4) were negatively related to fraction of inspiration O2; Changes in the relative abundance of PC (16:0_18:1) and PC (18:2_20:4) had significantly linear relationship with procalcitonin. Patients with an elevated level of PC (16:0_18:1) had significantly longer duration of hospital stays. As the relative abundance of PC (18:2_20:4), PC (36:4), and PC (38:6) decreased, the length of hospitalization days and 30-day mortality rate increased significantly (all log-rank p<0.05). Therefore, using the UHPLC-MS/MS platform's serum lipidomic approach can help reveal changes in lipid abundance during CAP and establish lipid profiles related to disease severity.

DAMPs and RAGE Pathophysiology at the Acute Phase of Brain Injury: An Overview

Early or primary injury due to brain aggression, such as mechanical trauma, hemorrhage or is-chemia, triggers the release of damage-associated molecular patterns (DAMPs) in the extracellular space. Some DAMPs, such as S100B, participate in the regulation of cell growth and survival but may also trigger cellular damage as their concentration increases in the extracellular space. When DAMPs bind to pattern-recognition receptors, such as the receptor of advanced glycation end-products (RAGE), they lead to non-infectious inflammation that will contribute to necrotic cell clearance but may also worsen brain injury. In this narrative review, we describe the role and ki-netics of DAMPs and RAGE at the acute phase of brain injury. We searched the MEDLINE database for “DAMPs” or “RAGE” or “S100B” and “traumatic brain injury” or “subarachnoid hemorrhage” or “stroke”. We selected original articles reporting data on acute brain injury pathophysiology, from which we describe DAMPs release and clearance upon acute brain injury, and the implication of RAGE in the development of brain injury. We will also discuss the clinical strategies that emerge from this overview in terms of biomarkers and therapeutic perspectives

A randomized trial to compare procalcitonin and C-reactive protein in assessing severity of sepsis and in guiding antibacterial therapy in Egyptian critically ill patients

BACKGROUND

Procalcitonin (PCT) and C-reactive protein (CRP) are the main used biomarkers for sepsis and in guiding antibiotic therapy, although PCT high cost limits its use in developing countries.

OBJECTIVE

Comparing between PCT and CRP in assessing severity of sepsis and in guiding antibacterial therapy in critically ill patients.

METHODS

In a prospective randomized study, 60 patients were included from an Egyptian Intensive Care Unit. Patients were divided into CRP and PCT groups. CRP and PCT were measured at baseline and on days 4 and 7. Validity, sensitivity, and specificity of both biomarkers and their correlation with sepsis scores (Acute Physiology and Chronic Health Evaluation II (APACHE II) and Sepsis-related Organ Failure Assessment (SOFA)) were evaluated. Antibacterial continuation at days 4 and 7 was assessed.

RESULTS

The diagnostic accuracy, specificity, and sensitivity of PCT were higher than CRP (80.79% vs 69.45%, 36% vs 28.7%, 87.6% vs 72.4%, respectively). PCT levels were significantly correlated with APACHE II score (P ≤ 0.0001) and SOFA score (P = 0.005), while CRP levels were not correlated with APACHEII and SOFA scores,(P > 0.05). PCT was associated with less antibacterial exposure (33% stopped their antibiotics on day 4 versus 6% in CRP, P = 0.009). Only 33% continued their antibacterial regimen in PCT group after 7 days versus 83% in CRP group (*P ≤ 0.0001).

CONCLUSION

PCT is a more accurate diagnostic and prognostic biomarker than CRP in patients with sepsis. PCT significantly shortened patients' exposure to antibacterial therapy and hospital length of stay.

Prediction value of procalcitonin combining CURB-65 for 90-day mortality in community-acquired pneumonia

Background: Due to its high mortality rate, immediate and reliable severity assessment and accurate prediction of prognosis at hospital admission is critical for the management of community-acquired pneumonia (CAP) patients.Methods: Consecutive patients with primary diagnosis of CAP and hospitalized at our hospital from January 2013 to December 2015 were screened for this retrospective study. Demographic information, clinical and laboratory examination, severity model scoring, and 90-day outcomes were studied. Area under the curve (AUC) of receiver operating characteristic curve (ROC) was analyzed to compare the predictive value of different prognostic scoring methods.Results: 2099 CAP patients with a median age of 60 (IQR 44.0-73.0) years-old were included in this study. Median length of stay was 10 days (IQR 8.0-13.0). The all-cause 90-day mortality was found in 2.19% (46/2099) of all patients. PCT was identified as an independent predictor for the prognosis of CAP patients. CURB-65 in combination with PCT outperformed other predictive methods in 90-day mortality with the optimal AUC of 0.900 and Youden's Index of 0.706.Conclusions: PCT is a good marker for the assessment of severity and 90-day mortality of CAP patients. The combination of PCT and CURB-65 was more accurate than other prognostic models in predicting 90-day mortality.

Risk Factors Affecting Clinical Outcome in Patients with Carbapenem-Resistant K. pneumoniae: A Retrospective Study

Background

The increased prevalence of carbapenem-resistant K. pneumoniae (CRKP) poses a great threat worldwide. Early identification of CRKP in patients is paramount. Moreover, fully understanding the risk factors affecting clinical outcome and actively providing targeted treatment can improve the cure rate of patients with CRKP. Therefore, our study aimed to describe the clinical characteristics and identify the risk factors affecting clinical outcomes in patients with CRKP.

Material/Methods

From January 2016 to September 2017, CRKP strains and clinical data from 97 hospitalized patients were collected. We first performed an antibiotic susceptibility test on CRKP strains using the Kirby-Bauer disc agar diffusion method. Logistic regression analysis was then performed to analyze risk factors.

Results

According to clinical outcome, among the 97 CRKP patients, 67 were in the effective group and 30 patients were in the noneffective group. Risk factors found to correlate with poor clinical outcome in patients with CRKP included ICU admission, arteriovenous catheterization, indwelling gastric tube, indwelling urethral catheter, tracheal intubation, mechanical ventilation, hypoproteinemia, and exposure to carbapenems. Multivariate analysis showed that hypoproteinemia (OR: 2.83, p=0.042), presence of an indwelling gastric tube (OR: 4.54, p=0.005), and exposure to carbapenems (OR: 2.77, p=0.045) negatively affected clinical outcome in patients with CRKP.

Conclusions

Adverse risk factors correlated with poor clinical outcomes in patients with CRKP were determined. This could be of help in identifying high-risk patients with whom clinicians should take extra precautions and adjust therapeutic strategy to supplement conventional basic treatment with additional measures.

Outcome prediction using the Mortality in Emergency Department Sepsis score combined with procalcitonin for influenza patients

BACKGROUND

Severe influenza is often associated with bacterial coinfection and can trigger sepsis, which increases the severity, complexity and mortality of the disease. To determine an effective method for predicting 28-day mortality of emergency department (ED) patients with influenza, we investigated the Mortality in Emergency Department Sepsis (MEDS) score, procalcitonin (PCT) and other relevant biomarkers.

METHODS

We conducted a retrospective, observational, monocentric study, and the endpoint was 28-day mortality. Independent predictors were identified and a new combination predictive model was created both by logistic regression, and the model was evaluated by a receiver operating characteristic (ROC) curve.

RESULTS

A total of 364 consecutive ED admitted patients with influenza were enrolled and 45 patients died within 28 days. For predicting 28-day mortality, the MEDS score and PCT were independent predictors with adjusted odds ratio of 1.318 (95% CI 1.206-1.439) and 1.038 (95% CI 1.010-1.065), and with AUCs of 0.817 (95% CI 0.756-0.878) and 0.793 (95% CI 0.725-0.861), respectively. The new combination of the MEDS score with PCT significantly improved the efficacy for predicting 28-day mortality with an AUC of 0.857 (95% CI 0.809-0.905), and was superior to the SOFA score with an AUC of 0.837 (95% CI 0.779-0.894).

CONCLUSION

The MEDS score and PCT, especially when combined, perform well for predicting mortality of ED admitted patients with influenza.

Circulating sphingosine-1-phosphate as a prognostic biomarker for community-acquired pneumonia

Early determination of the severity of Community-Acquired Pneumonia (CAP) is essential for better disease prognosis. Current predictors are suboptimal, and their clinical utility remains to be defined, highlighting the need for developing biomarkers with efficacious prognostic value. Sphingosine-1-phosphate (S1P) is a bioactive sphingolipid with a documented regulatory role in immune defense and maintenance of endothelial barrier integrity. For early diagnose of CAP and recognition of severe CAP patients, we conduct this pilot study to access the potential utility of the circulating S1P in an Emergency department setting. In the prospective study, plasma S1P levels were quantified in healthy controls and patients with CAP. Also, their discriminating power was assessed by receiver operating characteristic analysis. The association between S1P levels and disease severity indices was assessed by Spearman correlation and logistic regression tests. Patients with CAP had significantly higher plasma S1P levels than healthy individuals (CAP: 27.54 ng/ml, IQR = 14.37-49.99 ng/ml; Controls: 10.58 ng/ml, IQR = 4.781-18.91 ng/ml; p < 0.0001). S1P levels were inversely correlated with disease severity in patients with CAP. Based on multivariate logistic regression analysis, the plasma S1P concentrations showed significant predicting power for mortality (OR: 0.909; CI: 0.801-0.985; p < 0.05), intensive care unit admission (OR: 0.89; CI: 0.812-0.953; p < 0.005) and long hospital stay (OR: 0.978; CI: 0.961-0.992; p < 0.005). Interestingly, significantly elevated levels of S1P were noted in patients who received methylprednisolone treatment during hospitalization. These results suggest that S1P may be associated with the pathogenesis of CAP and may have prognostic utility in CAP and its therapy, especially in the Emergency Department setting.

Systemic interleukins levels in community-acquired pneumonia and their association with adverse outcomes

Introduction: Community-acquired pneumonia (CAP) is still one of the major causes of morbidity and mortality worldwide. Pro-inflammatory and anti-inflammatory interleukins have been studied to elucidate the role that inflammation plays in its pathogenesis. The aim of this study is to investigate inflammation in CAP, by analyzing in dynamic, serum levels of six interleukins (IL) and their predictive value regarding adverse outcomes.

Materials and methods: Forty adult patients with CAP, admitted in the Teaching Hospital of Infectious Diseases, Cluj-Napoca, Romania from December 2015 to February 2017, were enrolled in this study. Serum levels of pro-inflammatory: IL1β, TNF-α, IL-6, anti-inflammatory: IL-10 and IL-4, along with IL-17A were analyzed in dynamic, on day 1 and day 4.The receiver – operator curves (ROC) were used to analyze the outcome prediction of IL.

Results: Serum levels of IL-1β, IL-6, TNF-α and IL-10 have decreased significantly in dynamic, while IL-4 increases. IL-17A has acted like a pro-inflammatory cytokine. We have found a correlation between IL-6 and IL-10 (r=0.429, p=0.000), IL-6 and IL-17A (r=0.295, p=0.008) and IL-10 and IL-17A (r=0.475, p=0.000). Out of 40 patients, 9 had adverse outcomes, consisting in 9 relapses from which 1 died. IL-6 discriminates alone between adverse and favorable outcomes. With multivariate analysis and multiple regression of all combined IL, we have found that there is a predictive model regarding adverse outcomes.

Conclusion: IL-10 and IL-17A behave like pro-inflammatory cytokines. IL-6 is a predictive marker for adverse outcomes alone. All IL studied together have an impact on adverse outcomes.

Is Interleukin-6 a better predictor of successful antibiotic therapy than procalcitonin and C-reactive protein? A single center study in critically ill adults

Background

The aim of this study was to evaluate whether Interleukin-6 (IL-6) could be a faster indicator of treatment success in adults with severe sepsis and septic shock compared to procalcitonin (PCT) and C-reactive protein (CRP).

Methods

Data from adult patients with severe sepsis and septic shock managed at the medical intensive care unit (ICU) of the University Hospital Leipzig between September 2009 and January 2012 were analyzed retrospectively. Values for CRP, PCT and IL-6 on admission as well as after 24 and 48–72 h were collected. Antibiotic therapy was defined as clinically successful if the patient survived ICU stay.

Results

A total of 328 patients with severe sepsis and septic shock with adequate data quality were included. After 48–72 h, the median IL-6 was significantly lower in survivors than in non-survivors (114.2 pg/ml vs. 746.6 pg/ml; p < 0.001), while there was no significant difference for PCT (5.6 vs. 4.9 ng/ml; p = 0.586) and CRP (158.5 mg/l vs. 172.4 mg/l; p = 0.988).

Conclusions

The results of this study suggest that IL-6 is better than PCT and CRP in predicting the treatment success in predominantly non-surgical sepsis in the first 48–72 h.

Funding and policy incentives to encourage implementation of point-of-care C-reactive protein testing for lower respiratory tract infection in NHS primary care: a mixed-methods evaluation

OBJECTIVES

Utilisation of point-of-care C-reactive protein testing for lower respiratory tract infection has been limited in UK primary care, with costs and funding suggested as important barriers. We aimed to use existing National Health Service funding and policy mechanisms to alleviate these barriers and engage with clinicians and healthcare commissioners to encourage implementation.

DESIGN

A mixed-methods study design was adopted, including a qualitative survey to identify clinicians' and commissioners' perceived benefits, barriers and enablers post-implementation, and quantitative analysis of results from a real-world implementation study.

INTERVENTIONS

We developed a funding specification to underpin local reimbursement of general practices for test delivery based on an item of service payment. We also created training and administrative materials to facilitate implementation by reducing organisational burden. The implementation study provided intervention sites with a testing device and supplies, training and practical assistance.

RESULTS

Despite engagement with several groups, implementation and uptake of our funding specification were limited. Survey respondents confirmed costs and funding as important barriers in addition to physical and operational constraints and cited training and the value of a local champion as enablers.

CONCLUSIONS

Although survey respondents highlighted the clinical benefits, funding remains a barrier to implementation in UK primary care and appears not to be alleviated by the existing financial incentives available to commissioners. The potential to meet incentive targets using lower cost methods, a lack of policy consistency or competing financial pressures and commissioning programmes may be important determinants of local priorities. An implementation champion could help to catalyse support and overcome operational barriers at the local level, but widespread implementation is likely to require national policy change. Successful implementation may reproduce antibiotic prescribing reductions observed in research studies.

C-reactive protein and procalcitonin profile in ventilator-associated lower respiratory infections

PURPOSE

Ventilator-associated tracheobronchitis (VAT) has been suggested as an intermediate process between tracheobronchial colonization and ventilator-associated pneumonia (VAP) in patients receiving mechanical ventilation. The aim of this study was to evaluate the ability of C-reactive protein (CRP) and procalcitonin (PCT) to differentiate between VAT and VAP.

METHODS

Pre-planned analysis of the prospective multinational TAVeM database, performed on 2960 patients receiving mechanical ventilation for >48 h, including 689 patients with VA-LRTI. Patients with the diagnosis of VAT or VAP microbiologically documented and with one measurement of CRP and/or PCT on the day of diagnosis were included.

RESULTS

Four hundred and four patients (mean age 63 years, 298 men, ICU mortality 40%) were studied, 207 with VAT and 197 with VAP. On the day of infection diagnosis, the median CRP was elevated in both groups but significantly higher in VAP (18 mg/dL vs. 14 mg/dL, p = .001). Median PCT was also significantly higher in VAP (2.1 ng/dL vs. 0.64 ng/d L, p < .001). Both biomarkers could not help distinguish between VAT and VAP.

CONCLUSION

Although PCT and CRP presented lower values in VAT as compared to VAP, there was a marked overlap of both biomarkers values in both VA-LRTI not allowing adequate discrimination.

Plasma levels of mid-regional pro-adrenomedullin in sepsis are associated with risk of death

BACKGROUND

Identifying Intensive Care Unit (ICU) patients with sepsis and predicting the risk of death are unmet clinical needs.

METHODS

Prospective observational single-center study of 120 consecutive ICU patients with suspected severe sepsis at Jerez Hospital. Epidemiological, clinical, laboratory data and MR-proADM, Procalcitonin (PCT) and C-reactive protein (CRP) levels were recorded at ICU admission and follow-up.

RESULTS

At ICU discharge, 104 patients were diagnosed with severe sepsis and 39 died. Plasma MR-proADM was highly indicative of sepsis: 4.05 nmol/L vs. of 0.309 nmol/L (P<0.001), with area under the ROC curve (AUC-ROC) was 0.947. At 48 hours following admission, the median MR-proADM levels in surviving sepsis patients fell to 1.65 nmol/L but remained higher in the non-survivors (2.475 nmol/L) (P=0.04). On day 5 the levels fell to 1.36 nmol/L in surviving sepsis patients vs. 3.42 nmol/L in the non-survivors (P<0.001). On day 5 the survivors showed greater MR-proADM clearance (62.7% vs. 21.2%). The AUC-ROC on day 5 was 0.825, PCT 0.725 and CRP 0.700. The AUC-ROC to MR-proADM clearance on day 5 was 0.734. In a multivariable model, MR-proADM levels at 48 hours and on day 5 and clearance on day 5 following admission were statistically significant predictive factors of mortality.

CONCLUSIONS

In clinical practice, in ICU patients admitted with SIRS and organ dysfunction, an MR-proADM cut-off point of 1.425 nmol/L helps to identify those with sepsis. An MR-proADM value above 5.626 nmol/L 48 hours after admission was associated with a high risk of death.

Mid-Regional Pro-Adrenomedullin (MR-proADM) as a Biomarker for Sepsis and Septic Shock: Narrative Review

Early identification and diagnosis of sepsis and septic shock is vitally important; despite appropriate management, mortality and morbidity rates remain high. For this reason, many biomarkers and screening systems have been investigated in accordance with the precision medicine concept. A narrative review was conducted to assess the role of mid-regional pro-adrenomedullin (MR-proADM) as a biomarker for sepsis and septic shock. Relevant studies were collected via an electronic PubMed, Web of Science, and The Cochrane Library search. The review focused on both diagnosis and prognosis in patients with sepsis and septic shock and specifically in subpopulations of patients with sepsis and septic shock with burns or malignant tumors. No exclusion criteria regarding age, sex, intensive care unit admission, follow-up duration, or co morbidities were used so as to maximize sensitivity and due to lack of randomized controlled trials, opinion paper and reviews were also included in this review. A total of 22 studies, one opinion paper, and one review paper were investigated. MR-proADM levels were found to be useful in assessing patients’ initial evolution and become even more useful during follow-up with increased area under curve values in the mortality prognosis by exceeding values of 0.8 in the data shown in several studies. These results also improve along with other biomarkers or severity scores and especially correlate with the organ failure degree. The results of this study indicate that MR-proADM is a good biomarker for the diagnosis and prognosis of sepsis and septic shock patients as well as for organ failure. Although several publications have discussed its role as a biomarker for pneumonia, its value as a biomarker for sepsis and septic shock should now be assessed in randomized controlled trials and more collaborative prospective studies with larger patient samples.

Serum procalcitonin levels can be used to differentiate between inflammatory and non-inflammatory diarrhea in acute infectious diarrhea

In this study, we assess the possibility of using procalcitonin levels to differentiate between inflammatory diarrhea and non-inflammatory diarrhea in acute infectious diarrhea.We reviewed the records of 1176 patients who had symptoms of diarrhea, fever (≥37.8 °C), and abdominal pain between March 2011 and May 2015. After applying exclusion criteria, a sample of 514 patients was considered for study. The patient sample was divided into Group A and Group B for inflammatory diarrhea and non-inflammatory diarrhea, respectively. The assessment involved comparing the laboratory characteristics with the clinical characteristics of the groups.The characteristics of Group A, such as white blood cell (WBC), C-reactive protein (CRP), absolute neutrophil count (ANC), and procalcitonin levels, were relatively higher than those of Group B (P < .001 for Group A). A receiver operator characteristic (ROC) analysis revealed that the highest area-under-the-curve (AUC) value of procalcitonin (0.797; 95% confidence interval [CI] [0.760, 0.831]; P < .001), could be used to differentiate between the 2 groups. Procalcitonin exhibited a sensitivity and a specificity of 87.03% and 68.75%, respectively, at a 0.08 ng/mL cut-off level.Procalcitonin was a good candidate biomarker of inflammatory diarrhea than other inflammatory markers.

Association of serum procalcitonin and C-reactive protein levels with CURB-65 criteria among patients with community-acquired pneumonia

Background

The concentration of diagnostic markers such as inflammatory biomarkers including procalcitonin (PCT) and C-reactive protein (CRP) increases in bacterial infections. The aim of this study was to compare serum PCT and CRP levels with CURB-65 ranking, in the patients with community-acquired pneumonia (CAP).

Patients and methods

In a cross-sectional study, 93 hospitalized patients with a definite diagnosis of CAP, considering inclusion and exclusion criteria, were enrolled. Serum PCT and CRP levels and their relations with CURB-65 criteria were assessed.

Results

The mean serum levels of PCT and CRP were 3.64±12.32 ng/mL and 75.01±51.93 mg/L, respectively. There was a statistically significant association between CURB-65 criteria and serum levels of PCT (P=0.0001) and CRP (P=0.007), which means that the concentration of these two inflammatory biomarkers increased with an increase in the score of CURB-65 criteria. Moreover, there was a statistically significant association between the serum level of PCT and the outcomes of the disease (P<0.001).

Conclusion

According to the results, the serum level of PCT or CRP is a strong prognostic factor for evaluating severity of CAP and is a suitable factor for the CURB-65 criteria in the decision making of whether a patient with CAP in the ICU should be admitted.

Metabolic profiles in community-acquired pneumonia: developing assessment tools for disease severity

Background

This study aimed to determine whether community-acquired pneumonia (CAP) had a metabolic profile and whether this profile can be used for disease severity assessment.

Methods

A total of 175 individuals including 119 CAP patients and 56 controls were enrolled and divided into two cohorts. Serum samples from a discovery cohort (n = 102, including 38 non-severe CAP, 30 severe CAP, and 34 age and sex-matched controls) were determined by untargeted ultra-high-performance liquid chromatography with tandem mass spectrometry (LC-MS/MS)-based metabolomics. Selected differential metabolites between CAP patients versus controls, and between the severe CAP group versus non-severe CAP group, were confirmed by targeted mass spectrometry assays in a validation cohort (n = 73, including 32 non-severe CAP, 19 severe CAP and 22 controls). Pearson’s correlation analysis was performed to assess relationships between the identified metabolites and clinical severity of CAP. The area under the curve (AUC), sensitivity and specificity of the metabolites for predicting the severity of CAP were also investigated.

Results

The metabolic signature was markedly different between CAP patients and controls. Fifteen metabolites were found to be significantly dysregulated in CAP patients, which were mainly mapped to the metabolic pathways of sphingolipid, arginine, pyruvate and inositol phosphate. The alternation trends of five metabolites among the three groups including sphinganine, p-Cresol sulfate, dehydroepiandrosterone sulfate (DHEA-S), lactate and l-arginine in the validation cohort were consistent with those in the discovery cohort. Significantly lower concentrations of sphinganine, p-Cresol sulfate and DHEA-S were observed in CAP patients than in controls (p < 0.05). Serum lactate and sphinganine levels were positively correlated with confusion, urea level, respiratory rate, blood pressure, and age > 65 years (CURB-65), pneumonia severity index (PSI) and Acute Physiology and Chronic Health Evaluation II (APACHE II) scores, while DHEA-S inversely correlated with the three scoring systems. Combining lactate, sphinganine and DHEA-S as a metabolite panel for discriminating severe CAP from non-severe CAP exhibited a better AUC of 0.911 (95% confidence interval 0.825–0.998) than CURB-65, PSI and APACHE II scores.

Conclusions

This study demonstrates that serum metabolomics approaches based on the LC-MS/MS platform can be applied as a tool to reveal metabolic changes during CAP and establish a metabolite signature related to disease severity.

Trial registration

ClinicalTrials.gov, NCT03093220. Registered retrospectively on 28 March 2017.

Electronic supplementary material

The online version of this article (10.1186/s13054-018-2049-2) contains supplementary material, which is available to authorized users.

Risk stratification and prediction value of procalcitonin and clinical severity scores for community-acquired pneumonia in ED

OBJECTIVE

Community-acquired pneumonia (CAP) is a common presentation to the emergency department (ED) and has high mortality rates. The aim of our study is to investigate the risk stratification and prognostic prediction value of precalcitonin (PCT) and clinical severity scores on patients with CAP in ED.

METHODS

226 consecutive adult patients with CAP admitted in ED of a tertiary teaching hospital were enrolled. Demographic information and clinical parameters including PCT levels were analyzed. CURB65, PSI, SOFA and qSOFA scores were calculated and compared between the severe CAP (SCAP) and non-severe CAP (NSCAP) group or the death and survival group. Receiver-operating characteristic (ROC) curves for 28-day mortality were calculated for each predictor using cut-off values. Logistic regression models and area under the curve (AUC) analysis were performed to compare the performance of predictors.

RESULTS

Fifty-one patients were classified as SCAP and forty-nine patients died within 28days. There was significant difference between either SCAP and NSCAP group or death and survival group in PCT level and CURB65, PSI, SOFA, qSOFA scores (p < 0.001). The AUCs of the PCT and CURB65, PSI, SOFA and qSOFA in predicting SCAP were 0.875, 0.805, 0.810, 0.852 and 0.724, respectively. PCT is superior in predicting SCAP and the models combining PCT and SOFA demonstrated superior performance to those of PCT or the CAP severity score alone. The AUCs of the PCT and CURB65, PSI, SOFA and qSOFA in predicting 28-day mortality were 0.822, 0.829, 0.813, 0.913 and 0.717, respectively. SOFA achieved the highest AUC and the combination of PCT and SOFA had the highest superiority over other combinations in predicting 28-day mortality.

CONCLUSION

Serum PCT is a valuable single predictor for SCAP. SOFA is superior in prediction of 28-day mortality. Combination of PCT and SOFA could improve the performance of single predictors. More further studies with larger sample size are warranted to validate our results.

Cytokine kinetic profiles in children with acute lower respiratory tract infection: a post hoc descriptive analysis from a randomized control trial

OBJECTIVES

Standard inflammatory markers and chest radiography lack the ability to discriminate bacterial from non-bacterial lower respiratory tract infection (LRTI). Cytokine profiles may serve as biomarkers for LRTI, but their applicability to identify aetiology, severity of disease and need for antibiotic prescription in children remains poorly defined. Objectives were to determine the cytokine kinetic profiles over 5 days in paediatric patients with LRTI, to investigate the relationship between cytokine patterns, and clinical and laboratory variables.

METHODS

We included patients aged 1 month to 18 years, with febrile LRTI and three consecutive cytokines measurements on days 1, 3 and 5 of a randomized controlled trial (ProPAED study). We evaluated differences in cytokine concentrations between days and associations with clinical and laboratory variables.

RESULTS

A total of 181 patients (median age 4.1 years) were included; 72/181 (40%) received antibiotics. Serum concentrations of interferon (IFN)-γ, interleukin (IL)-1ra, IL-6, IL-10, IFN-γ-inducible protein (IP)-10 and tumor necrosis factor-α were elevated on day 1 and decreased subsequently, with the greatest decline between day 1 and 3 (by -8 to >-94%). Procalcitonin (PCT) and C-reactive protein (CRP) values showed a protracted decrease with the most prominent reduction in concentrations between days 3 and 5. Significantly elevated IL-6 concentrations were associated with hospital admission, antibiotic treatment, and prolonged antibiotic treatment. Bacteraemic LRTI patients had higher concentrations of IL-1ra (p <0.0055) and IL-6 (p <0.0055) on day 1.

CONCLUSIONS

We observed an earlier decrease of elevated cytokines compared to PCT or CRP. Both pro- and anti-inflammatory cytokines may serve as markers for severity of LRTI.

Prognostic performance of MR-pro-adrenomedullin in patients with community acquired pneumonia in the Emergency Department compared to clinical severity scores PSI and CURB

AIM

(i) evaluate the performance of MR-pro-ADM in reflecting the outcome and risk for CAP patients in the emergency department, and (ii) compare the prognostic performance of MR-pro-ADM with that of clinical scores PSI and CURB65.

METHODS

Observational prospective, single-center study in patients with suspected community acquired pneumonia (CAP). Eighty one patients underwent full clinical and laboratory assessment as by protocol, and were followed up a 28 days. Primary endpoints measured were: death, death at 14 days, non-invasive mechanical ventilation (NIMV), endotracheal intubation (EI), ICU admission, overall hospital stay >10 days, emergency department stay >4 days. The discriminative performance of MR-pro-ADM and clinical scores was assessed by AUROC analysis.

RESULTS

The distribution for MR-pro-ADM followed an upward trend, increasing with the increase of both PSI (p<0.001) and CURB65 (p<0.001) classes. However, the difference between MRproADM values and score classes was significant only in the case of CURB65 classes 0 and 1 (p = 0.046), 2 (p = 0.013), and 3 (p = 0.011); and with PSI classes 5, 3 (p = 0.044), and 1 (p = 0.020). As to the differences among variables for the six end-points, MR-pro-ADM values in the two groups selected for each considered end-point differed in a statistically significant manner for all endpoints. Both PSI and CURB65 differed significantly for all end-points, except for stay in the ED longer than 4 days and the hospital stay longer than 10 days and endotracheal intubation (only PSI classes differed with statistical significance). ROC analyses evidenced that MR-pro-ADM values gave the greatest AUC for the prediction of death, endotracheal intubation, hospital stay >10 days and DE stay >4 days, compared to the PSI and CURB (though difference not statistically significant). For each endpoint measured, the best thresholds values for Mr-pro-ADM were: 1.6 (specificity 76.5%; sensitivity 77.8%) for death; 2.5 (specificity 88.9%; sensitivity 80.0%) for death at 14 days; 1.5 (specificity 77.0%; sensitivity 87.5%) for NIMV; 2.4 (specificity 88.7%; sensitivity 83.3%) for endotracheal intubation; 0.9 (specificity 53.5%; sensitivity 70.6%) for DE stay greater than 4 days; 1.9 (specificity 82.1%; sensitivity 55.3%) for hospital stay greater than 10 days. The AUC for the combination of MR-pro-ADM and PSI was 81.29% [63.41%-99.17%], but not in a statistically significant manner compared to the AUCs of the single predictors. Conversely, the AUC for the combination of MR-pro-ADM and CURB65 was 87.58% [75.54%-99.62%], which was significantly greater than the AUC of CURB65 (p = 0.047) or PSI (p = 0.017) alone.

CONCLUSIONS

The present study confirms that assessment of MR-pro-ADM levels in CAP patients in addition to CURB scores increases the prognostic accuracy of CURB alone and may help rule out discrepancies arising from flawed clinical severity classification. With particular reference to patients scoring in the upper classes of CURB and PSI, MR-pro-ADM values provided additional information towards a better risk stratification of those patients. In particular, our results pointed towards two MR-pro-ADM threshold values that appear to predict with a good degree of accuracy the patient's need for non-invasive mechanical ventilation, endotracheal intubation, or intensive care. This aspect, however, deserves further investigation.

Systemic cytokines and chemokines on admission of children hospitalized with community-acquired pneumonia

Community-acquired pneumonia (CAP) is the main cause of death in children under-5 years worldwide and Streptococcus pneumoniae is the most common bacterial agent. However, it is difficult to identify pneumococcal infection among children with CAP. We aimed to assess association between any cytokine/chemokine and pneumococcal infection in childhood CAP. Furthermore, we evaluated the diagnostic value of cytokine/chemokine for pneumococcal infection. This prospective study was conducted at an Emergency Room, in Salvador, Brazil. Children <5-years-old hospitalized with CAP in a 21-month period were evaluated. On admission, clinical and radiological data were collected along with biological samples to investigate 20 etiological agents and determine serum cytokines (interleukin (IL)-8, IL-6, IL-10, IL-1β, IL-12, TNF-α, IL-2, IL-4, IL-5, γ-interferon), and chemokines (CCL2, CCL5, CXCL9, CXCL10) concentration. From 166 patients with etiology detected, pneumococcal infection was detected in 38 (22.9%) cases among which the median IL-6(pg/ml) was 31.2 (IQR: 12.4-54.1). The other 128 cases had other causative agents detected (Haemophilus influenzae, Moraxella catarrhalis, atypical bacteria and viruses) with the median IL-6 concentration being 9.0 (IQR: 4.1-22.0; p < 0.001). The area under the ROC curve for IL-6 to predict pneumococcal CAP was 0.74 (95%CI: 0.65-0.83; p < 0.001). By multivariate analysis, with pneumococcal CAP as dependent variable, IL-6 was an independent predictor for pneumococcal infection (OR = 5.56; 95%CI: 2.42-12.75, cut-off point = 12.5 pg/ml; p = 0.0001). The negative predictive value of IL-6 under 12.5 pg/ml for pneumococcal infection was 90% (95%CI: 82-95%). Independently significant difference was not found for any other cytokines/chemokines. Serum IL-6 concentration on admission is independently associated with pneumococcal infection among children under-5 years hospitalized with CAP.

Management of community-acquired pneumonia in immunocompetent adults: updated Swedish guidelines 2017

Based on expert group work, Swedish recommendations for the management of community-acquired pneumonia in adults are here updated. The management of sepsis-induced hypotension is addressed in detail, including monitoring and parenteral therapy. The importance of respiratory support in cases of acute respiratory failure is emphasized. Treatment with high-flow oxygen and non-invasive ventilation is recommended. The use of statins or steroids in general therapy is not found to be fully supported by evidence. In the management of pleural infection, new data show favourable effects of tissue plasminogen activator and deoxyribonuclease installation. Detailed recommendations for the vaccination of risk groups are afforded.

Biomarker-guided antibiotic therapy-strengths and limitations

Biomarkers as C-reactive protein (CRP) and procalcitonin (PCT) emerged as tools to help clinicians to diagnose infection and to properly initiate and define the duration of antibiotic therapy. Several randomized controlled trials, including adult critically ill patients, showed that PCT-guided antibiotic stewardship was repeatedly associated with a decrease in the duration of antibiotic therapy with no apparent harm. There are however some relevant limitations in these trials namely the low rate of compliance of PCT-guided algorithms, the high rate of exclusion (without including common clinical situations and pathogens) and the long duration of antibiotic therapy in control groups. Such limitations weakened the real impact of such algorithms in the clinical decision-making process and strengthened the concept that the initiation and the duration of antibiotic therapy cannot depend solely on a biomarker. Future efforts should address these limitations in order to better clarify the role of biomarkers on the complex and multifactorial issue of antibiotic management and to deeply understand its potential effect on mortality.

Exhaled Breath Metabolomics for the Diagnosis of Pneumonia in Intubated and Mechanically-Ventilated Intensive Care Unit (ICU)-Patients

The diagnosis of hospital-acquired pneumonia remains challenging. We hypothesized that analysis of volatile organic compounds (VOCs) in exhaled breath could be used to diagnose pneumonia or the presence of pathogens in the respiratory tract in intubated and mechanically-ventilated intensive care unit patients. In this prospective, single-centre, cross-sectional cohort study breath from mechanically ventilated patients was analysed using gas chromatography-mass spectrometry. Potentially relevant VOCs were selected with a p-value < 0.05 and an area under the receiver operating characteristics curve (AUROC) above 0.7. These VOCs were used for principal component analysis and partial least square discriminant analysis (PLS-DA). AUROC was used as a measure of accuracy. Ninety-three patients were included in the study. Twelve of 145 identified VOCs were significantly altered in patients with pneumonia compared to controls. In colonized patients, 52 VOCs were significantly different. Partial least square discriminant analysis classified patients with modest accuracy (AUROC: 0.73 (95% confidence interval (CI): 0.57–0.88) after leave-one-out cross-validation). For determining the colonization status of patients, the model had an AUROC of 0.69 (95% CI: 0.57–0.82) after leave-one-out cross-validation. To conclude, exhaled breath analysis can be used to discriminate pneumonia from controls with a modest to good accuracy. Furthermore breath profiling could be used to predict the presence and absence of pathogens in the respiratory tract. These findings need to be validated externally.

Differences in inflammatory marker patterns for adult community-acquired pneumonia patients induced by different pathogens

INTRODUCTION

The inflammatory marker patterns of community-acquired Pneumonia (CAP) induced by different microorganisms in adult patients remained unclear.

OBJECTIVES

We aim to explore the inflammatory marker patterns of adult CAP patients induced by different pathogens.

METHODS

Adult CAP patients with definite etiologies were enrolled from September 2010 to June 2012. They were divided into three groups according to the causative pathogens: typical bacteria, Mycoplasma pneumoniae (MP), and viruses. Twenty-seven cytokines and bactericidal/permeability-increasing protein (BPI) levels of serum collected within 7 days onset in these groups were compared.

RESULTS

One hundred twenty-four cases were enrolled for serum detection and analysis, including 10 typical bacterial pneumonia patients, 56 cases with MP pneumonia and 58 with viral pneumonia. Three kinds (PDGF-BB, IP-10, RANTES) of 27 cytokines and BPI levels were significantly elevated in patients with acute pneumonia than healthy controls. Distinct inflammatory marker patterns were released by different pathogens: typical bacterial pneumonia patients had highest levels of BPI, IL-6, IL-8, IL-1rα; while patients caused by MP presented higher levels of PDGF-BB, IL-17A, G-CSF than those caused by viruses. Rhinovirus owned a higher inflammatory response level than the other viruses. The area under the curve (AUC) of PDGF-BB to differentiate MP and virus infection was biggest, which was 0.708.

CONCLUSION

Distinct inflammatory marker patterns were released by different pathogens during acute pneumonia. Significantly increased level of PDGF-BB was observed in acute pneumonia for the first time. It showed a better ability to differentiate MP and virus infection.

Economic evaluation of procalcitonin-guided antibiotic therapy in acute respiratory infections: a Chinese hospital system perspective

Background:

Cost-impact models have indicated that in the USA, the use of antibiotic stewardship protocols based on procalcitonin (PCT) levels for patients with suspected acute respiratory tract infection results in cost savings. Our objective was to assess the cost impact of adopting PCT testing among patients with acute respiratory infections (ARI) from the perspective of a typical hospital system in urban China.

Methods:

To conduct an economic evaluation of PCT testing versus usual care we built a cost-impact model based on a previously published patient-level meta-analysis data of randomized trials including Chinese sites. The data were adapted to the China setting by applying the results to mean lengths of stay, costs, and practice patterns typically found in China. We estimated the annual ARI visit rate for the typical hospital system (assumed to be 1650 beds) and ARI diagnosis.

Results:

In the inpatient setting, the costs of PCT-guided care compared to usual care for a cohort of 16,405 confirmed ARI patients was almost 1.1 million Chinese yuan (CNY), compared to almost 1.8 million CNY for usual care, resulting in net savings of 721,563 CNY to a typical urban Chinese hospital system for 2015. In the ICU and outpatient settings, savings were 250,699 CNY and 2.4 million CNY, respectively. The overall annual net savings of PCT-guided care was nearly 3.4 million CNY.

Conclusions:

Substantial savings are associated with PCT protocols of ARI across common China hospital treatment settings mainly by direct reduction in unnecessary antibiotic utilization.

Interpreting Laboratory Tests in Infection: Making Sense of Biomarkers in Sepsis and Systemic Inflammatory Response Syndrome for Intensive Care Unit Patients

Sepsis and severe sepsis are leading causes of death in the United States and the most common causes of death among critically ill patients in noncoronary intensive care units. Diagnosis of infection and sepsis is a subjective clinical judgment based on the criteria for systemic inflammatory reaction, which is highly sensitive, not specific, and often misleading in intensively treated patients. Biomarkers are emerging as adjuncts to traditional diagnostic measures. No biomarkers have sufficient specificity or sensitivity to be routinely used in clinical practice, but they can aid in the diagnosis and treatment of infection versus inflammation.

Serum procalcitonin and C-reactive protein kinetics as indicators of treatmentoutcome in hospitalized patients with community-acquired pneumonia

BACKGROUND/AIM

There has been growing interest in the use of serum procalcitonin (PCT) and C-reactive protein (CRP) in patients with community-acquired pneumonia (CAP). The aim of this study was to investigate whether an assessment of fever, leukocyte count, and serum CRP and PCT levels on admission and during follow-up (day 3) provides any information about the clinical outcome in hospitalized patients with CAP.

MATERIALS AND METHODS

Patients with a diagnosis of CAP who were admitted to and followed at four university hospitals were evaluated retrospectively using the Turkish Thoracic Society Pneumonia Database.

RESULTS

A total of 103 hospitalized CAP patients (57 males, mean age: 61.5 ± 16.7 years) were enrolled in the study. Treatment failure (TF) was observed in 20 patients (19.4%). Pneumonia Severity Index scores, serum CRP levels, and PCT levels on admission were significantly higher in the TF group. There were significant decreases in CRP and PCT levels between admission day and day 3 in the treatment success group.

CONCLUSION

In patients with CAP, the body temperature and leukocyte count on admission do not predict outcome. Monitoring levels of CRP and PCT may be useful as a predictor of treatment outcome.