Inflammatory biomarkers are associated with aetiology and predict outcomes in community-acquired pneumonia: results of a 5-year follow-up cohort study

Endothelial Biomarkers Are Superior to Classic Inflammatory Biomarkers in Community-Acquired Pneumonia

Background: Complications in community-acquired pneumonia (CAP), including cardiovascular events (CVE), can occur during an acute episode and in the long term. We aimed to analyse the role of endothelial damage biomarkers (C-terminal endothelin-1 precursor fragment [CT-proET-1] and mid-regional pro-adrenomedullin [MR-proADM]), in contrast to classic inflammation markers (C Reactive Protein [CRP] and procalcitonin [PCT]) in patients admitted for CAP and their relationship with ICU admission, CVE and mortality in the short and long term; Methods: Biomarkers were analysed in 515 patients with CAP at day 1, 285 at day 5 and 280 at day 30. Traditional inflammatory biomarkers and endothelial damage biomarkers were measured. ICU admission, CVE and mortality (in-hospital and 1-year follow-up) were assessed using receiver operating characteristic (ROC) curve analysis and univariate logistic regression. Results: A statistically significant association was observed between initial, raised CT-proET-1 and MR-proADM levels, the need for ICU admission and the development of in-hospital CVE or in-hospital mortality. Both endothelial markers maintained a strong association at day 30 with 1-year follow-up CVE. At day 1, CRP and PCT were only associated with ICU admission. On day 30, there was no association between inflammatory markers and long-term CVE or death. The odds ratio (OR) and area under the curve (AUC) of endothelial biomarkers were superior to those of classic biomarkers for all outcomes considered. Conclusions: Endothelial biomarkers are better indicators than classic ones in predicting worse outcomes in both the short and long term, especially CVE. MR-proADM is the best biomarker for predicting complications in CAP.

The assessment of pentraxin 3: a diagnostic and prognostic biomarker in lower respiratory tract infections in children

BACKGROUND

Pentraxin 3 (PTX3) is an acute-phase reactant that is elevated in the plasma during inflammatory responses. We aimed to evaluate the utility of PTX3 as a clinical marker in children with lower respiratory tract infections (LRTIs) and the association between PTX3 and LRTIs severity.

METHODS

We included 60 patients admitted to Fayoum University Hospital with LRTIs fulfilling the WHO criteria for diagnosing LRTIs. We collected data on peak temperature, respiratory rate, heart rate, oxygen saturation upon admission, and length of hospital stay. The complete blood count (CBC), C-reactive protein (CRP) level, and PTX3 were measured upon admission.

RESULTS

PTX3 levels were significantly correlated with peak temperature, duration of hospital stay, the Pediatric Respiratory Severity Score (PRESS), total leucocytic count (TLC), CRP, and blood cultures.

CONCLUSION

PTX-3 represented the severity of the disease and predicted the prognosis. Pentraxin levels demonstrate a statistically significant sensitivity of (93.3%) and a specificity of (70%) at the cut-off value (of 8.84) with an area under the curve (90.7%) in the diagnosis of LRTIs.

Enhancing pneumonia prognosis in the emergency department: a novel machine learning approach using complete blood count and differential leukocyte count combined with CURB-65 score

BACKGROUND

Pneumonia poses a major global health challenge, necessitating accurate severity assessment tools. However, conventional scoring systems such as CURB-65 have inherent limitations. Machine learning (ML) offers a promising approach for prediction. We previously introduced the Blood Culture Prediction Index (BCPI) model, leveraging solely on complete blood count (CBC) and differential leukocyte count (DC), demonstrating its effectiveness in predicting bacteremia. Nevertheless, its potential in assessing pneumonia remains unexplored. Therefore, this study aims to compare the effectiveness of BCPI and CURB-65 in assessing pneumonia severity in an emergency department (ED) setting and develop an integrated ML model to enhance efficiency.

METHODS

This retrospective study was conducted at a 3400-bed tertiary medical center in Taiwan. Data from 9,352 patients with pneumonia in the ED between 2019 and 2021 were analyzed in this study. We utilized the BCPI model, which was trained on CBC/DC data, and computed CURB-65 scores for each patient to compare their prognosis prediction capabilities. Subsequently, we developed a novel Cox regression model to predict in-hospital mortality, integrating the BCPI model and CURB-65 scores, aiming to assess whether this integration enhances predictive performance.

RESULTS

The predictive performance of the BCPI model and CURB-65 score for the 30-day mortality rate in ED patients and the in-hospital mortality rate among admitted patients was comparable across all risk categories. However, the Cox regression model demonstrated an improved area under the ROC curve (AUC) of 0.713 than that of CURB-65 (0.668) for in-hospital mortality (p<0.001). In the lowest risk group (CURB-65=0), the Cox regression model outperformed CURB-65, with a significantly lower mortality rate (2.9% vs. 7.7%, p<0.001).

CONCLUSIONS

The BCPI model, constructed using CBC/DC data and ML techniques, performs comparably to the widely utilized CURB-65 in predicting outcomes for patients with pneumonia in the ED. Furthermore, by integrating the CURB-65 score and BCPI model into a Cox regression model, we demonstrated improved prediction capabilities, particularly for low-risk patients. Given its simple parameters and easy training process, the Cox regression model may be a more effective prediction tool for classifying patients with pneumonia in the emergency room.

S100A9-/- alleviates LPS-induced acute lung injury by regulating M1 macrophage polarization and inhibiting pyroptosis via the TLR4/MyD88/NFκB signaling axis

Acute lung injury (ALI) is characterized by pulmonary diffusion abnormalities that may progress to multiple-organ failure in severe cases. There are limited effective treatments for ALI, which makes the search for new therapeutic avenues critically important. Macrophages play a pivotal role in the pathogenesis of ALI. The degree of macrophage polarization is closely related to the severity and prognosis of ALI, and S100A9 promotes M1 polarization of macrophages. The present study assessed the effects of S100A9-gene deficiency on macrophage polarization and acute lung injury. Our cohort study showed that plasma S100A8/A9 levels had significant diagnostic value for pediatric pneumonia and primarily correlated with monocyte-macrophages and neutrophils. We established a lipopolysaccharide (LPS)-induced mouse model of acute lung injury and demonstrated that knockout of the S100A9 gene mitigated inflammation by suppressing the secretion of pro-inflammatory cytokines, reducing the number of inflammatory cells in the bronchoalveolar lavage fluid, and inhibiting cell apoptosis, which ameliorated acute lung injury in mice. The in vitro and in vivo mechanistic studies demonstrated that S100A9-gene deficiency inhibited macrophage M1 polarization and reduced the levels of pulmonary macrophage chemotactic factors and inflammatory cytokines by suppressing the TLR4/MyD88/NF-κB signaling pathway and reversing the expression of the NLRP3 pyroptosis pathway, which reduced cell death. In conclusion, S100A9-gene deficiency alleviated LPS-induced acute lung injury by inhibiting macrophage M1 polarization and pyroptosis via the TLR4/MyD88/NFκB pathway, which suggests a potential therapeutic strategy for the treatment of ALI.

Nausea Predicts Bacteremia in Immunocompetent Patients with Pneumococcal Community-Acquired Pneumonia: Secondary Data Analysis from a Prospective Cohort

BACKGROUND

In pneumococcal community-acquired pneumonia (CAP), bacteremia is associated with increased mortality, but initial clinical severity scores frequently fail to identify bacteremic patients at risk. We have previously shown that gastrointestinal symptoms are common among patients admitted to the hospital with pneumococcal bacteremia. The aim of this study was to examine gastrointestinal symptoms and inflammatory responses in bacteremic and non-bacteremic pneumococcal CAP in a prospective cohort of immunocompromised and immunocompetent patients hospitalized with CAP.

METHODS

Logistic regression analysis was used to estimate the predictive value of gastrointestinal symptoms for pneumococcal bacteremia in patients with CAP. The Mann-Whitney test was used to compare inflammatory responses in patients with bacteremic vs. non-bacteremic pneumococcal CAP.

RESULTS

Eighty-one patients with pneumococcal CAP were included, of whom 21 (26%) had bacteremia. Immunocompetent patients with pneumococcal CAP had an odds ratio of 16.5 (95% CI 3.0-90.9, p = 0.001) for bacteremia if nausea was present, whereas no such association was found in the immunocompromised patients (OR 0.22, 95% CI 0.02-2.05, p = 0.18). The serum levels of C-reactive protein, procalcitonin and interleukin 6 were significantly higher in the patients with bacteremic pneumococcal CAP compared to non-bacteremic pneumococcal CAP patients (p < 0.001, p = 0.005, and p = 0.019, respectively).

CONCLUSIONS

In immunocompetent patients hospitalized with pneumococcal CAP, nausea may be a predictor of bacteremia. Bacteremic pneumococcal CAP patients display an increased inflammatory response compared to non-bacteremic pneumococcal CAP patients.

Overruling of Procalcitonin-Guided Antibiotics for Lower Respiratory Tract Infections in Primary Care: Ancillary Study of a Randomized Controlled Trial

BACKGROUND

Lower respiratory tract infections (LRTIs) in primary care are a promising target for antibiotic stewardship. A clinical trial in Switzerland showed a large decrease in antibiotic prescriptions with procalcitonin guidance (cut-off < 0.25 µg/L) compared with usual care. However, one-third of patients with low procalcitonin at baseline received antibiotics by day 28.

AIM

To explore the factors associated with the overruling of initial procalcitonin guidance.

DESIGN AND SETTING

Secondary analysis of a cluster randomized trial in which patients with an LRTI were included.

METHOD

Using the characteristics of patients, their disease, and general practitioners (GPs), we conducted a multivariate logistic regression, adjusted for clustering.

RESULTS

Ninety-five out of 301 (32%) patients with low procalcitonin received antibiotics by day 28. Factors associated with an overruling of procalcitonin guidance were: a history of chest pain (adjusted OR [aOR] 1.81, 95% confidence interval 1.03-3.17); a prescription of chest X-ray by the GP (aOR 4.65, 2.32-9.34); a C-reactive protein measured retrospectively above 100 mg/L (aOR 7.48, 2.34-23.93, reference ≤ 20 mg/L); the location of the GP practice in an urban setting (aOR 2.27, 1.18-4.37); and the GP's number of years of experience (aOR per year 1.05, 1.01-1.09).

CONCLUSIONS

Overruling of procalcitonin guidance was associated with GPs' socio-demographic characteristics, pointing to the general behavioral problem of overprescription by physicians. Continuous medical education and communication training might support the successful implementation of procalcitonin point-of-care tests aimed at antibiotic stewardship.

C-Reactive Protein as a Predictor of Survival and Length of Hospital Stay in Community-Acquired Pneumonia

Introduction: Community-acquired pneumonia (CAP) presents high mortality rates and high healthcare costs worldwide. C-reactive protein (CRP) has been widely used as a biomarker for the management of CAP. We evaluated the performance of CRP threshold values and ΔCRP as predictors of CAP survival and length of hospital stay. Methods: A total of 173 adult patients with CAP were followed for up to 30 days. We measured serum CRP levels on days 1, 4, and 7 (D1, D4, and D7) of hospitalization, and their variations between different days were calculated (ΔCRP). A multivariate logistic regression model was created with CAP 30-day survival and length of hospital stay as dependent variables, and absolute CRP values and ΔCRP, age, sex, smoking habit (pack-years), pO2/FiO2 ratio on D1, WBC on D1, and CURB-65 score as independent variables. Results: A total of six patients with CAP died (30-day mortality 3.47%). No difference was found in CRP levels and ΔCRP between survivors and non-survivors. Using a cut-off level of 9 mg/dL, the AUC (95% CI) for the prediction of survival of CRP on D4 and D7 were 0.765 (0.538−0.992) and 0.784 (0.580−0.989), respectively. A correlation between CRP values on any day and length of hospital stay was found, with it being stronger for CRPD4 and CRPD7 (p < 0.0001 and p = 0.0024, respectively). A reduction of CRP > 50% from D1 to D4 was associated with 4.11 fewer days of hospitalization (p = 0.0308). Conclusions: CRP levels on D4 and D7, but not ΔCRP, could fairly predict CAP survival. A reduction of CRP > 50% by the fourth day of hospitalization could predict a shorter hospital stay.

Role of soluble triggering receptors expressed on myeloid cells-1 and 25-hydroxy vitamin D as early diagnostic markers of neonatal Ventilator-associated pneumonia: A prospective cohort study

BACKGROUND

Ventilator-associated pneumonia (VAP) is one of the most common causes of nosocomial pneumonia in ventilated neonates. Nevertheless, its diagnosis is challenging due to the nonspecific clinical parameters and the lack of sensitive biomarkers. The main objective of this study was to compare soluble triggering receptors expressed on myeloid cells-1 (sTREM-1) and 25-hydroxy vitamin D as early predictors of neonatal VAP.

METHODS

This prospective cohort study included 85 ventilated neonates divided into the VAP group (n = 33) and the non-VAP group (n = 52). sTREM-1 levels in the endotracheal aspirate (ETA) and serum 25-hydroxy vitamin D levels were measured on the third and seventh days following mechanical ventilation. The Ethical and Research Committee approved the study at Tanta University Hospitals, Egypt (with the Approval code: 32751/12/18).

RESULTS

The sTREM-1 cutoff value of >0.46 and >0.44 ng/ml at 3 and 7 days had a sensitivity of 93.94% and 96.97%, a specificity of 92.31% and 100%, and an area under the receiver operating characteristic curve (AUC) of 0.963 and 0.993, respectively, to predict the development of neonatal VAP. A serum 25-hydroxy vitamin D cutoff value of ≤17.5 ng/ml at 3 and 7 days had a sensitivity of 90.91% and 81.82%, a specificity of 75% and 78.85%, and area under the curve of 0.877 and 0.939, respectively.

CONCLUSION

Both sTREM-1 in ETA and serum 25-hydroxy vitamin D could be used as early predictors of neonatal VAP, but sTREM-1 appears more useful.

Diagnostic Accuracy of Procalcitonin upon Emergency Department Admission during SARS-CoV-2 Pandemic

INTRODUCTION

Procalcitonin is a marker for bacterial diseases and has been used to guide antibiotic prescription. Procalcitonin accuracy, measured at admission, in patients with community-acquired pneumonia (CAP), is unknown in the current severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic.

OBJECTIVES

To evaluate the diagnostic accuracy of procalcitonin to assess the need for antibiotic treatment in patients with CAP presenting to the emergency department during the SARS-CoV-2 pandemic.

METHODS

We performed a real-world diagnostic retrospective accuracy study of procalcitonin in patients admitted to the emergency department. Measures of diagnostic accuracy were calculated based on procalcitonin results compared to the reference standard of combined microbiological and radiological analysis. Sensitivity, specificity, positive and negative predictive values, and area under (AUC) the receiver-operating characteristic (ROC) curve were calculated in two analyses: first assessing procalcitonin ability to differentiate microbiologically proven bacteria from viral CAP and then clinically diagnosed bacterial CAP from viral CAP.

RESULTS

When using a procalcitonin threshold of 0.5 ng/mL to identify bacterial etiology within patients with CAP, we observed sensitivity and specificity of 50% and 64.1%, and 43% and 82.6%, respectively, in the two analyses. The positive and negative predictive values of a procalcitonin threshold of 0.5 ng/mL to identify patients for whom antibiotics should be advised were 46.4% and 79.7%, and 48.9% and 79% in the two analyses, respectively. The AUC for the two analyses was 0.60 (95% confidence interval [CI] 0.52-0.68) and 0.62 (95% CI, 0.55-0.69).

CONCLUSIONS

Procalcitonin measured upon admission during the SARS-CoV-2 pandemic should not guide antibiotic treatment in patients with CAP.

The Potential Use of Saliva as a Biofluid for Systemic Inflammatory Response Monitoring in Children with Pneumonia

OBJECTIVE

To investigate the levels of C-reactive protein, procalcitonin, calprotectin, interleukin 1 beta (IL-1β), IL-6, and tumor necrosis factor-alpha (TNF-α) in both saliva and serum in children with community-acquired pneumonia and to compare the saliva response with the systemic response.

METHODS

Forty hospitalized children with community-acquired pneumonia aged between 1 mo and 15 y; and 40 healthy controls were included. Both serum and saliva samples were collected on admission and at the time of discharge.

RESULTS

Calculated differences between values for each serum and salivary parameter on admission and before discharge named delta (Δ) values were used for correlation analysis. Salivary Δ values of each parameter were moderately/strongly correlated with their corresponding serum Δ levels [IL-1β ÷ (r = 0.554, p < 0.001); IL-6 ÷ (r = 0.484, p = 0.002); PCT ÷ (r = 0.737, p < 0.001); TNF-α ÷ (r = 0.587, p < 0.001); CRP ÷ (r = 0.703, p < 0.001); and calprotectin ÷ (r = 0.774, p < 0.001)].

CONCLUSIONS

This study will evaluate the reflection of systemic changes in saliva and the efficacy of saliva in pediatric patients with pneumonia. Results will highlight saliva potential use as a biofluid for systemic monitoring in this patient group.

Neutrophil-Dependent Immunity During Pulmonary Infections and Inflammations

Rapid recruitment of neutrophils to an inflamed site is one of the hallmarks of an effective host defense mechanism. The main pathway through which this happens is by the innate immune response. Neutrophils, which play an important part in innate immune defense, migrate into lungs through the modulation actions of chemokines to execute a variety of pro-inflammatory functions. Despite the importance of chemokines in host immunity, little has been discussed on their roles in host immunity. A holistic understanding of neutrophil recruitment, pattern recognition pathways, the roles of chemokines and the pathophysiological roles of neutrophils in host immunity may allow for new approaches in the treatment of infectious and inflammatory disease of the lung. Herein, this review aims at highlighting some of the developments in lung neutrophil-immunity by focusing on the functions and roles of CXC/CC chemokines and pattern recognition receptors in neutrophil immunity during pulmonary inflammations. The pathophysiological roles of neutrophils in COVID-19 and thromboembolism have also been summarized. We finally summarized various neutrophil biomarkers that can be utilized as prognostic molecules in pulmonary inflammations and discussed various neutrophil-targeted therapies for neutrophil-driven pulmonary inflammatory diseases.

Assessment of antiphospholipid antibodies and calprotectin as biomarkers for discriminating mild from severe COVID-19

BACKGROUND

To explore the association of thrombo-inflammatory biomarkers with severity in coronavirus disease (COVID-19), we measured antiphospholipid antibodies (aPL) and calprotectin in sera of COVID-19 patients.

METHODS

Anticardiolipin antibodies (aCL) and anti-β2-glycoprotein I antibodies were measured using enzyme-linked immunosorbent assay (ELISA) and multiplex flow immunoassay (MFIA) in hospitalized COVID-19 patients (N = 105) and healthy controls (N = 38). Anti-phosphatidylserine/prothrombin antibodies, calprotectin, and C-reactive protein (CRP) levels were also measured. We assessed the potential correlation between calprotectin levels and various laboratory parameters that were measured during the hospitalization period. After stratifying COVID-19 patients into two groups by their oxygenation status or acute respiratory distress syndrome presentation, the discriminatory performance of each biomarker was evaluated.

RESULTS

A high proportion of COVID-19 patients (29.5%, 31/105) had low aCL IgM titers that were detectable by ELISA but mostly below the detection limit of MFIA. Calprotectin levels in severe groups of COVID-19 were significantly higher than those in non-severe groups, while CRP levels revealed no significant differences. Serum calprotectin levels showed strong to moderate degree of correlation with other routinely used parameters including peak levels of CRP, ferritin, procalcitonin, BUN, and neutrophil-to-lymphocyte ratio, but a negative correlation with minimal lymphocyte count and CD4⁺ T cells. The discriminatory performance was highest for calprotectin in discriminating severe groups of COVID-19.

CONCLUSIONS

Serum calprotectin levels were significantly elevated in severe COVID-19 cases. The prevalence of clinically significant aPL did not differ. The link between calprotectin and inflammatory pathway in COVID-19 may help improve the management and outcomes of COVID-19 patients.

Biomarker Value in the Diagnosis of Community-Acquired Pneumonia with Concomitant Chronic Heart Failure

The diagnosis of community-acquired pneumonia (CAP) with chronic heart failure (CHF) is associated with objective difficulties. Our case–control study aims to establish whether established serum inflammatory biomarkers are relevant to the diagnosis of CAP in patients with CHF. Seventy inpatients with previously diagnosed CHF and suspected non-severe CAP were recruited and then stratified into two subgroups with confirmed and rejected diagnosis of CAP. C-reactive protein (CRP), procalcitonin (PCT), tumor necrosis factor α (TNFα), interleukin-6 (IL-6) and brain natriuretic peptide (BNP) were measured. The value of biomarkers was determined using logistic regression, and their discriminatory efficacy was assessed by analyzing receiver operating characteristic (ROC) curves. Significantly higher levels of CRP 50.0 (35.5–98.5) mg/L, PCT 0.10 (0.05–0.54) ng/mL and IL-6 46.1(21.4–150.3) pg/mL in cases were identified as compared to the control group—15.0 (9.5–25.0) mg/L, 0.05 (0.05–0.05) ng/mL and 13.6 (9.5; 25.0) pg/mL, respectively. The Area Under the ROC Curve (95% CI) was the highest for CRP—0.91 (0.83–0.98), followed by PCT—0.81 (0.72–0.90) and IL-6—0.81 (0.71–0.91). A CRP value of >28.5 mg/L had an optimal sensitivity and specificity ratio (85.7/91.4%). In conclusion, the measurement of serum CRP, PCT and IL-6 levels can be useful for the diagnosis of CAP in patients with CHF. CRP showed optimal diagnostic utility in this population.

Calprotectin: An Ignored Biomarker of Neutrophilia in Pediatric Respiratory Diseases

Calprotectin (CP) is a non-covalent heterodimer formed by the subunits S100A8 (A8) and S100A9 (A9). When neutrophils become activated, undergo disruption, or die, this abundant cytosolic neutrophil protein is released. By fervently chelating trace metal ions that are essential for bacterial development, CP plays an important role in human innate immunity. It also serves as an alarmin by controlling the inflammatory response after it is released. Extracellular concentrations of CP increase in response to infection and inflammation, and are used as a biomarker of neutrophil activation in a variety of inflammatory diseases. Although it has been almost 40 years since CP was discovered, its use in daily pediatric practice is still limited. Current evidence suggests that CP could be used as a biomarker in a variety of pediatric respiratory diseases, and could become a valuable key factor in promoting diagnostic and therapeutic capacity. The aim of this study is to re-introduce CP to the medical community and to emphasize its potential role with the hope of integrating it as a useful adjunct, in the practice of pediatric respiratory medicine.

Hepcidin and Ferritin Predict Microbial Etiology in Community-Acquired Pneumonia

Background

Iron is crucial for survival and growth of microbes. Consequently, limiting iron availability is a human antimicrobial defense mechanism. We explored iron and iron-related proteins as potential biomarkers in community-acquired pneumonia and hypothesized that infection-induced changes in these potential biomarkers differ between groups of pathogens and could predict microbial etiology.

Methods

Blood samples from a prospective cohort of 267 patients with community-acquired pneumonia were analyzed for hepcidin, ferritin, iron, transferrin, and soluble transferrin receptor at admission, clinical stabilization, and a 6-week follow-up. A total of 111 patients with an established microbiological diagnosis confined to 1 microbial group (atypical bacterial, typical bacterial, or viral) were included in predictive analyses.

Results

High admission levels of ferritin predicted atypical bacterial versus typical bacterial etiology (odds ratio [OR], 2.26; 95% confidence interval [CI], 1.18–4.32; P = .014). Furthermore, hepcidin and ferritin predicted atypical bacterial versus viral etiology (hepcidin: OR = 3.12, 95% CI = 1.34–7.28, P = .008; ferritin: OR = 2.38, 95% CI = 1.28–4.45, P = .006). The findings were independent of C-reactive protein and procalcitonin.

Conclusions

Hepcidin and ferritin are potential biomarkers of microbial etiology in community-acquired pneumonia.

Predicting 30-day mortality of patients with pneumonia in an emergency department setting using machine-learning models

OBJECTIVE

This study aimed to confirm the accuracy of a machine-learning-based model in predicting the 30-day mortality of patients with pneumonia and evaluating whether they were required to be admitted to the intensive care unit (ICU).

METHODS

The study conducted a retrospective analysis of pneumonia patients at an emergency department (ED) in Seoul, Korea, from January 1, 2016 to December 31, 2017. Patients aged 18 years or older with a pneumonia registry designation on their electronic medical record were enrolled. We collected their demographic information, mental status, and laboratory findings. Three models were used: the pre-existing CURB-65 model, and the CURB-RF and Extensive CURB-RF models, which were machine-learning models that used a random forest algorithm. The primary outcomes were ICU admission from the ED or 30-day mortality. Receiver operating characteristic curves were constructed for the models, and the areas under these curves were compared.

RESULTS

Out of the 1,974 pneumonia patients, 1,732 patients were eligible to be included in the study; from these, 473 patients died within 30 days or were initially admitted to the ICU from the ED. The area under receiver operating characteristic curves of CURB-65, CURB-RF, and extensive-CURB-RF were 0.615 (0.614-0.616), 0.701 (0.700-0.702), and 0.844 (0.843-0.845), respectively.

CONCLUSION

The proposed machine-learning models could predict the mortality of patients with pneumonia more accurately than the pre-existing CURB-65 model and can help decide whether the patient should be admitted to the ICU.

Procalcitonin and C-reactive protein perform better than the neutrophil/lymphocyte count ratio in evaluating hospital acquired pneumonia

Background

The relationship between biomarkers and hospital-acquired pneumonia (HAP) is understudied, especially in severe cases admitted to the intensive care unit (ICU). Compared with community-acquired pneumonia (CAP), HAP might have different traits regarding biomarkers due to the previous history in hospitals.

Methods

A total of 593 adult patients were enrolled in this retrospective cohort study to determine the neutrophil/lymphocyte count ratio (NLCR), procalcitonin (PCT), C-reactive protein (CRP) and serum lactate level upon admission to the ICU. According to diagnosis, patients were divided into two groups: non-infection and HAP. Discriminant analysis was performed based on better outcomes of diagnostic performance and severity evaluation. The diagnostic performance of each individual biomarker was assessed by constructing receiver operating characteristic (ROC) curves and calculating the area under each ROC curve (AUROC). Multivariable analysis was also applied to determine the most appropriate prognostic factors.

Results

NLCR, PCT and CRP were markedly different between the non-infection and HAP groups. NLCR had a worse ability to discriminate severe infection (AUROC 0.626; 95% CI 0.581–0.671) than conventional markers such as CRP (0.685, 95% CI 0.641–0.730) and PCT (0.661, 95% CI 0.615–0.707). In addition, the AUROC of composite biomarkers, especially the combination of NLCR, CRP and WBC, was significantly greater than that of any single biomarker.

Conclusions

NLCR was not comparable to conventional single biomarkers, such as CRP and PCT, for diagnosing or evaluating the severity of HAP. Composite biomarkers that have good accessibility, especially the combination of NLCR, CRP and WBC, could help with early diagnosis and severity evaluation.

Biomarkers in Community-Acquired Pneumonia (Cardiac and Non-Cardiac)

Community-acquired pneumonia (CAP) remains the first cause of morbidity and mortality worldwide due to infection. Several aspects such as severity and host response are related to its clinical course and outcome. Beyond the acute implications that the infection provokes in the host, pneumonia also has long-term negative consequences. Among them, cardiovascular complications and mortality are the most outstanding. Therefore, an adequate recognition and stratification of the risk of complications and mortality is crucial. Many biomarkers have been studied for these reasons, considering that each biomarker mirrors a different aspect. Moreover, the clinical application of many of them is still being deliberated because of their limitations and the heterogeneity of the disease. In this review, we examine some of the most relevant biomarkers that we have classified as cardiac and non-cardiac. We discuss some classic biomarkers and others that are considered novel biomarkers, which are mainly involved in cardiovascular risk.

[The new comprehension of pulmonary infections]

Epidemiological data on the distribution of mostly bacterial pathogens are still the basis for empirical treatment recommendations on respiratory infections. Because of the dynamic technological developments in molecular multiplexing and sequencing procedures, the spectrum of potential pathogens is increased and challenges the current dogma of virulence and pathogenicity of certain pathogens. Classical pathogens of the lungs are thereby not questioned but are increasingly placed in a context that reflects co-infections with viruses and changes of the local microbiome in more depth. Recent data indicate that integration of this novel information is required for a better understanding of the seasonal differences in the frequency of particular lung infections and to find new approaches to risk stratification of patients. This becomes most obvious in the subgroup of immunosuppressed patients who are at risk of severe courses of diseases with higher morbidity and mortality from infections with viruses and facultative pathogens, such as nontuberculous mycobacteria (NTM). Based on the fundamental knowledge on the spectrum of pathogens of community-acquired and nosocomial lung infections, novel approaches in pathogen diagnostics and lung microbiome analytics are discussed and the applicability with respect to the current clinical routine is questioned.

Vitamin D Status in Neonatal Pulmonary Infections: Relationship to Inflammatory Indicators

AIM

The study aimed to evaluate serum vitamin D concentrations among neonates with pneumonia.

METHODS

This case-control study enrolled 33 neonates with pneumonia in addition to 30 healthy controls. CBC, CRP, Serum vitamin D and Pentraxin 3 levels were measured for all participants.

RESULTS

There was significant difference between patients and controls regarding Hemoglobin levels, TLC and CRP (p value < 0.01, = 0.002, < 0.01 respectively). Patients with pneumonia showed significant lower levels of Vit. D (9 ± 2.1) compared to controls (14.1 ± 2.8), P value < 0.01. However, patient group had significant higher levels of Pentraxin 3 (29.1 ± 4.8) compared with controls (12.6 ± 3), P value < 0.01. Moreover, mechanically ventilated patients revealed significant lower vit D (7.7 ± 1.8) and higher pentraxin 3 (32.2 ± 2.6) compared to patients on free oxygen (9.1 ± 2.1, 26.4 ± 3.7 respectively), P value = 0.05, 0.02 respectively. Regarding hospital stay, it had significant positive correlation with serum pentraxin 3 (r = 0.6, P value < 0.01) and significant negative correlation with serum vit D (r = -0.4, P value = 0.04). Finally a significant negative correlation between serum levels of vitamin D and Pentraxin 3 was found (r = -0.4, P value = 0.01).

CONCLUSION

Lower concentration of serum vitamin D may be significantly associated with neonatal pneumonia. It also can predict the need for mechanical ventilation and duration of hospital stay in neonatal pneumonia. Similarly, higher levels of Pentraxin 3 may be used as an indicator for mechanical ventilation need and a longer hospital stay in neonates with pneumonia.