Community-Acquired Pneumonia

Community-acquired pneumonia associated with influenza co-infection caused by fusobacterium necrophorum: a case report and literature review

BACKGROUND

Fusobacterium necrophorum is a rare pathogen associated with community-acquired pneumonia (CAP), particularly among healthy adults. This case report presents a rare documented case of CAP caused by F. necrophorum in a young individual, providing valuable insights for the diagnosis and treatment of similar cases.

CASE PRESENTATION

The patient was initially diagnosed with influenza, and subsequently developed CAP caused by F. necrophorum. Despite one week of outpatient treatment with moxifloxacin, the symptoms persisted, leading to hospitalisation. Treatment with piperacillin tazobactam/imipenem and doxycycline, which target atypical pathogens, did not result in improvement after admission. Conventional diagnostic methods failed to identify the causative pathogen; however, metagenomic next-generation sequencing of bronchoalveolar lavage fluid confirmed it to be F. necrophorum. The patient showed significant improvement after ten days of targeted treatment with ornidazole and imipenem/piperacillin tazobactam, and was discharged.

CONCLUSION

Uncommon pathogens, such as F. necrophorum, should be considered as potential culprits in young individuals with CAP when conventional cultures yield negative results but there is a strong suspicion of infection, especially if initial antibiotic therapy is ineffective.

Associations of serum MANF with severity and prognosis in community-acquired pneumonia patients

Mesencephalic astrocyte-derived neurotrophic factor (MANF), a novel endoplasmic reticulum stress-induced neurotrophic factor, exerts a protective role in both nervous and non-nervous systems. However, the relationship between serum MANF content and community-acquired pneumonia (CAP) patients remains unclear. A total of 319 adult patients diagnosed with CAP were enrolled. Serum MANF level was quantified using enzyme-linked immunosorbent assay (ELISA). A prospective cohort study was conducted to investigate the association of serum MANF levels with severity and prognosis. Compared with healthy volunteers, serum MANF content was evidently upregulated in CAP patients. The level of serum MANF was dramatically increased in parallel with the scores of CURB-65, PSI, APACHE II, and SMART-COP in CAP cases. Additionally, multivariate linear and logistic regression analyses revealed that serum MANF level was positively associated with scoring criteria among CAP patients. Besides, serum MANF level on admission was significantly elevated in CAP patients who required mechanical ventilation, ICU admission, and died within 30 days. Moreover, the higher serum MANF level on admission evidently increased the risk of poor prognosis during hospitalization. There was a better predictive power of serum MANF for poorly prognostic outcomes in CAP patients. The expression of serum MANF exhibits the positive correlations with the severity and poor prognosis among CAP patients. Serum MANF may have considerable clinical value and be regarded as a diagnostic and prognostic biomarker for CAP.

Systematic investigation of catechin/cyclodextrin encapsulated polymeric nanospheres for the treatment and nursing care of pediatric pneumonia-causing human pathogens

Pediatric pneumonia is a leading life-threatening condition affecting children worldwide, particularly those under the age of five, and is primarily caused by Streptococcus pneumoniae. The virulence factors of streptococcal species pose significant challenges to managing child health, often rendering current antibiotic treatments ineffective. This research highlights the anti-virulence potential of catechin and cyclodextrin combined with PLGA polymer against strains of S. pneumoniae and MRSA, with minimum inhibitory concentrations of 130 μg/mL and 128 μg/mL. The CA/CD@PLGA nanoparticles have demonstrated the ability to prevent these infectious pathogens from developing antibiotic resistance. Results from antibiofilm activity studies suggest that incorporating phytocompounds and polymers enhances the sustained release of targeted molecules onto bacterial cells, achieving an 83 % reduction in biofilm formation. Growth inhibition studies confirm that the CA/CD@PLGA nanospheres effectively suppress bacterial multiplication through a mechanism involving reactive oxygen species (ROS)-mediated cytotoxicity. The agar well diffusion assay concluded that CA/CD@PLGA significantly enhanced the release of catechin and cyclodextrin against both S. pneumoniae and MRSA. Furthermore, antifungal activity tests revealed that the interaction between catechin and cyclodextrin disrupts protein synthesis mechanisms in fungi such as Aspergillus fumigatus and Candida albicans. In vitro cytotoxicity results showed that 93 % of cells remained healthy, confirming that CA/CD@PLGA nanospheres are non-toxic to fibroblast cells. Overall, this research indicates that CA/CD@PLGA nanospheres could be an effective therapeutic option for controlling pediatric pneumonia. Looking ahead, this approach has the potential to become a promising and low-cost therapy for pneumonia management in nursing care applications.

Chlamydophila psittaci pneumonia followed by lower gastrointestinal ischemic necrosis: a case report

Background

Psittacosis, also known as parrot fever, is an uncommon infectious disease caused by Chlamydophila psittaci (C. psittaci). While C. psittaci infections are usually not life-threatening, the pathogenesis and associated complications are not yet fully understood.

Case description

A 54-year-old male was hospitalized due to a cough, accompanied by expectoration and dyspnea. After admission, the patient's breathing rapidly deteriorated, and despite the use of a ventilator, it was challenging to maintain respiratory function. While initiating extracorporeal membrane oxygenation (ECMO) and empirical anti-infection treatments, the alveolar lavage fluid was collected and examined by metagenomics next generation sequencing (mNGS). The mNGS result indicated C. psittaci. Subsequently, the anti-infection regimen was immediately adjusted. The respiratory function improved on the 13th day after admission, and ECMO was withdrawn. However, the patient developed abdominal distension and intestinal edema. After intravenous infusion therapy, intestinal ischemia and necrosis occurred and surgical resection was performed. The patient's condition improved after the operation and he was transferred to a local hospital for rehabilitation.

Conclusion

This case report demonstrates the development of intestinal ischemic necrosis following severe C. psittaci pneumonia. This unique association has not been reported previously and highlights the importance of potential gastrointestinal complications in severe C. psittaci pneumonia, which are often underestimated. Timely diagnoses and treatments of such infections and complications are necessary to achieve favorable clinical outcomes.

A Machine Learning-Based Prediction Model for Acute Kidney Injury in Patients With Community-Acquired Pneumonia: Multicenter Validation Study

BACKGROUND

Acute kidney injury (AKI) is common in patients with community-acquired pneumonia (CAP) and is associated with increased morbidity and mortality.

OBJECTIVE

This study aimed to establish and validate predictive models for AKI in hospitalized patients with CAP based on machine learning algorithms.

METHODS

We trained and externally validated 5 machine learning algorithms, including logistic regression, support vector machine, random forest, extreme gradient boosting, and deep forest (DF). Feature selection was conducted using the sliding window forward feature selection technique. Shapley additive explanations and local interpretable model-agnostic explanation techniques were applied to the optimal model for visual interpretation.

RESULTS

A total of 6371 patients with CAP met the inclusion criteria. The development of CAP-associated AKI (CAP-AKI) was recognized in 1006 (15.8%) patients. The 11 selected indicators were sex, temperature, breathing rate, diastolic blood pressure, C-reactive protein, albumin, white blood cell, hemoglobin, platelet, blood urea nitrogen, and neutrophil count. The DF model achieved the best area under the receiver operating characteristic curve (AUC) and accuracy in the internal (AUC=0.89, accuracy=0.90) and external validation sets (AUC=0.87, accuracy=0.83). Furthermore, the DF model had the best calibration among all models. In addition, a web-based prediction platform was developed to predict CAP-AKI.

CONCLUSIONS

The model described in this study is the first multicenter-validated AKI prediction model that accurately predicts CAP-AKI during hospitalization. The web-based prediction platform embedded with the DF model serves as a user-friendly tool for early identification of high-risk patients.

Evaluation of omadacycline regimens for community-acquired bacterial pneumonia patients infected with Staphylococcus Aureus by pharmacokinetic/pharmacodynamic analysis

Omadacycline is an FDA-approved agent for community-acquired bacterial pneumonia (CABP). The purpose of this study is to evaluate the effectiveness of omadacycline for treating CABP patients infected with Staphylococcus aureus, including Methicillin-Resistant Staphylococcus aureus (MRSA) and Methicillin-Susceptible Staphylococcus aureus (MSSA), using pharmacokinetic/pharmacodynamic (PK/PD) analysis. Monte Carlo simulations (MCSs) were performed by utilizing omadacycline pharmacokinetic (PK) parameters, minimum inhibitory concentration (MIC) data, and in vivo PK/PD targets to calculate the probability of target attainment (PTA) and cumulative fraction of response (CFR) values for different dose regimens against MRSA and MSSA in CABP patients. A dosage regimen with a PTA or CFR expectation value greater than 90% was considered optimal. For all recommended dose regimens, PTA values for MRSA MIC ≤1 and MSSA MIC ≤4 on days 1, 4, and 7 were greater than 90%. Based on the MIC distribution of Staphylococcus aureus, all dose regimens had CFR values greater than 90% for both MRSA and MSSA. CFR values for different bacterial strains were still greater than 90% within the range of PK/PD target values less than 40, although they gradually decreased with increasing PK/PD target values. PK/PD modeling demonstrated that all recommended dose regimens of omadacycline are highly effective against CABP patients infected with MRSA and MSSA. The study provides theoretical support for the efficacy of omadacycline in different dose regimens.

Diagnosis and treatment experience of Chlamydia psittaci pneumonia: A multicenter retrospective study in China

BACKGROUND

In recent years, clinical cases of Chlamydia psittaci pneumonia have gradually increased. Chlamydia psittaci pneumonia can quickly progress to severe pneumonia, leading to respiratory failure. Chlamydia psittaci cannot be detected by commonly used detection methods, leading to difficulties in clinical diagnosis and treatment, which may eventually develop into severe Chlamydia psittaci pneumonia. Therefore, we should improve our diagnostic and treatment capabilities for this disease.

METHODS

This article retrospectively studied 61 cases of pneumonia from 12 different provinces in China, and classified them into severe pneumonia and non-severe pneumonia. Divided into two groups, with 23 cases of severe pneumonia and 38 cases of non-severe pneumonia. We compared the two groups in terms of imaging, laboratory testing, treatment, prognosis, etc., hoping to provide better explanations and help clinical physicians better diagnose the disease.

RESULTS

There is no difference in age, gender, contact history, smoking history, or basic disease between severe and non-severe Chlamydia psittaci pneumonia. The most prominent symptom is fever, with a median body temperature of 39.7 ℃, and other symptoms similar to common respiratory infections. White blood cells and neutrophils may not show significant elevation, but C-reactive protein (CRP) and procalcitonin (PCT) will both show significant elevation, often accompanied by a decrease in arterial oxygen pressure. Some patients may experience liver and kidney dysfunction, but there is no statistically significant difference between the two groups. Doxycycline remains the preferred drug for severe Chlamydia psittaci pneumonia. The imaging mainly shows consolidation and bronchial inflation sign, and may also present with pleural effusion.

CONCLUSIONS

The imaging of Chlamydia psittaci pneumonia usually shows consolidation with bronchial inflation sign, which can also be manifested as ground glass changes or solid masses. Atypical images are prone to misdiagnosis in the early stages. There are some differences in laboratory examination and imaging between severe pneumonia and non-severe pneumonia, which can help identify severe patients in the early stage. Metagenomic next-generation sequencing (mNGS) played an important role in the diagnosis of all cases in this article. Timely treatment has a good prognosis for the disease, and imaging lesions can be completely absorbed.

Reassessing Halm's clinical stability criteria in community-acquired pneumonia management

BACKGROUND

Halm's clinical stability criteria have long guided antibiotic treatment and hospital discharge decisions for patients hospitalised with community-acquired pneumonia (CAP). Originally introduced in 1998, these criteria were established based on a relatively small and select patient population. Consequently, our study aims to reassess their applicability in the management of CAP in a contemporary real-world setting.

METHODS

This cohort study included 2918 immunocompetent patients hospitalised with CAP from three hospitals in Denmark between 2017 and 2020. The primary outcome was time to achieve clinical stability as defined by Halm's criteria. Additionally, we examined recurrence of clinical instability and severe complications. Cumulative incidence function or Kaplan-Meier survival curves were used to analyse these outcomes, considering competing risks.

RESULTS

The study population primarily comprised elderly individuals (median age 75 years) with significant comorbidities. The median time to clinical stability according to Halm's criteria was 4 days, with one-fifth experiencing recurrence of instability after early clinical response (stability within 3 days). Severe complications within 30 days mainly comprised mortality, with rates of 5.1% (64/1257) overall in those with early clinical response, 1.7% (18/1045) in the subgroup without do-not-resuscitate orders and 17.3% (276/1595) among the rest.

CONCLUSION

Halm's clinical stability criteria effectively classify CAP patients with different disease courses, yet achieving stability required more time in this ageing population with substantial comorbidities and more severe disease. Early clinical response indicates reduced risk of complications, especially in those without do-not-resuscitate orders.

Physiologically Based Pharmacokinetic Model for Predicting Omadacycline Pharmacokinetics and Pharmacodynamics in Healthy and Hepatic Impairment Populations

PURPOSE

Omadacycline is a new broad-spectrum aminomethylcycline antibiotic. However, there have been limited pharmacokinetic and pharmacodynamic (PK/PD) studies of omadacycline in patients with hepatic impairment. The aim of this study was to explore the PK/PD of omadacycline intravenous administration in healthy and hepatically impaired populations.

METHODS

A physiologically based pharmacokinetic (PBPK) model of omadacycline was developed and validated based on published demographic data and the physiochemical properties of omadacycline. The PK processes in healthy adults were simulated and then extrapolated to a hepatically impaired population. Monte Carlo simulations were performed for PD evaluation by calculating the probability of target attainment (PTA) and the cumulative fraction of response (CFR) of the approved dosages.

FINDINGS

In the hepatically impaired population, there was no significant difference in the maximum concentration (Cmax) compared with the healthy population, while the area under the plasma concentration-time curve from the first data point extrapolated to infinity (AUC_inf) showed a slight increase. Monte Carlo simulations indicated that the dosage of 200 mg once daily or 100 mg twice daily intravenously (loading dose) and 100 mg once daily intravenously (maintenance dose) could cover the common pathogens of community-acquired bacterial pneumonia (CABP) and acute bacterial skin and skin structure infections (ABSSSI) : Streptococcus pneumoniae, Haemophilus influenzae, and Staphylococcus aureus.

IMPLICATIONS

Hepatic impairment exerts little impact on the PK properties of omadacycline, and no dosage adjustments are necessary for patients with mild and moderate hepatic impairment. Current dosing regimens are predicted to produce satisfactory therapeutic effects against non-drug-resistant strains of Staphylococcus aureus, Streptococcus pneumoniae, and Haemophilus influenzae but may not produce the desired AUC/MIC ratios in patients with Escherichia coli or Klebsiella pneumoniae.

An explainable machine learning-based model to predict intensive care unit admission among patients with community-acquired pneumonia and connective tissue disease

BACKGROUND

There is no individualized prediction model for intensive care unit (ICU) admission on patients with community-acquired pneumonia (CAP) and connective tissue disease (CTD) so far. In this study, we aimed to establish a machine learning-based model for predicting the need for ICU admission among those patients.

METHODS

This was a retrospective study on patients admitted into a University Hospital in China between November 2008 and November 2021. Patients were included if they were diagnosed with CAP and CTD during admission and hospitalization. Data related to demographics, CTD types, comorbidities, vital signs and laboratory results during the first 24 h of hospitalization were collected. The baseline variables were screened to identify potential predictors via three methods, including univariate analysis, least absolute shrinkage and selection operator (Lasso) regression and Boruta algorithm. Nine supervised machine learning algorithms were used to build prediction models. We evaluated the performances of differentiation, calibration, and clinical utility of all models to determine the optimal model. The Shapley Additive Explanations (SHAP) and Local Interpretable Model-Agnostic Explanations (LIME) techniques were performed to interpret the optimal model.

RESULTS

The included patients were randomly divided into the training set (1070 patients) and the testing set (459 patients) at a ratio of 70:30. The intersection results of three feature selection approaches yielded 16 predictors. The eXtreme gradient boosting (XGBoost) model achieved the highest area under the receiver operating characteristic curve (AUC) (0.941) and accuracy (0.913) among various models. The calibration curve and decision curve analysis (DCA) both suggested that the XGBoost model outperformed other models. The SHAP summary plots illustrated the top 6 features with the greatest importance, including higher N-terminal pro-B-type natriuretic peptide (NT-proBNP) and C-reactive protein (CRP), lower level of CD4 + T cell, lymphocyte and serum sodium, and positive serum (1,3)-β-D-glucan test (G test).

CONCLUSION

We successfully developed, evaluated and explained a machine learning-based model for predicting ICU admission in patients with CAP and CTD. The XGBoost model could be clinical referenced after external validation and improvement.

Assessing the risk of concurrent mycoplasma pneumoniae pneumonia in children with tracheobronchial tuberculosis: retrospective study

Objective

This study aimed to create a predictive model based on machine learning to identify the risk for tracheobronchial tuberculosis (TBTB) occurring alongside Mycoplasma pneumoniae pneumonia in pediatric patients.

Methods

Clinical data from 212 pediatric patients were examined in this retrospective analysis. This cohort included 42 individuals diagnosed with TBTB and Mycoplasma pneumoniae pneumonia (combined group) and 170 patients diagnosed with lobar pneumonia alone (pneumonia group). Three predictive models, namely XGBoost, decision tree, and logistic regression, were constructed, and their performances were assessed using the receiver's operating characteristic (ROC) curve, precision-recall curve (PR), and decision curve analysis (DCA). The dataset was divided into a 7:3 ratio to test the first and second groups, utilizing them to validate the XGBoost model and to construct the nomogram model.

Results

The XGBoost highlighted eight significant signatures, while the decision tree and logistic regression models identified six and five signatures, respectively. The ROC analysis revealed an area under the curve (AUC) of 0.996 for XGBoost, significantly outperforming the other models (p < 0.05). Similarly, the PR curve demonstrated the superior predictive capability of XGBoost. DCA further confirmed that XGBoost offered the highest AIC (43.226), the highest average net benefit (0.764), and the best model fit. Validation efforts confirmed the robustness of the findings, with the validation groups 1 and 2 showing ROC and PR curves with AUC of 0.997, indicating a high net benefit. The nomogram model was shown to possess significant clinical value.

Conclusion

Compared to machine learning approaches, the XGBoost model demonstrated superior predictive efficacy in identifying pediatric patients at risk of concurrent TBTB and Mycoplasma pneumoniae pneumonia. The model's identification of critical signatures provides valuable insights into the pathogenesis of these conditions.

Clinical Characteristics and Microorganisms Isolated in Community-Acquired Pneumonia in the COVID-19 Period

Introduction

Community-acquired pneumonia is a leading cause of mortality and hospital admissions. The aetiology remains unknown in 30-65% of the cases. Molecular tests are available for multiple pathogen detection and are under research to improve the causal diagnosis.

Methods

We carried out a prospective study to describe the clinical characteristics and aetiology of community-acquired pneumonia during the COVID-19 pandemic and to assess the diagnostic effectivity of the microbiological tests, including a molecular test of respiratory pathogens (FilmArray™ bioMérieux).

Results

From the 1st of February 2021 until the 31st of March 2022, 225 patients were included. Failure in microorganism identification occurred in approximately 70% of patients. Streptococcus pneumoniae was the most common isolate. There were 5 cases of viral pneumonia. The tested FilmArray exhibited a low positivity rate of 7% and mainly aided in the diagnosis of viral coinfections.

Conclusions

Despite our extensive diagnostic protocol, there is still a low rate of microorganism identification. We have observed a reduction in influenza and other viral pneumoniae during the COVID-19 pandemic. Having a high NEWS2 score on arrival at the emergency department, an active oncohematological disease or chronic neurological conditions and a positive microbiological test result were related to worse outcomes. Further research is needed to determine the role of molecular tests in the microbiological diagnosis of pneumonia.

Identification and Clinical Characteristics of Community-Acquired Acinetobacter baumannii in Patients Hospitalized for Moderate or Severe COVID-19 in Peru

Acinetobacter baumannii has been described as a cause of serious community-acquired infections in tropical countries. Currently, its implications when simultaneously identified with other pathogens are not yet adequately understood. A descriptive study was conducted on hospitalized patients with a diagnosis of moderate/severe SARS-CoV-2-induced pneumonia confirmed via real-time RT-PCR. Patients aged > 18 years who were admitted to a specialized COVID-19 treatment center in Peru were selected for enrollment. A. baumannii was detected via the PCR amplification of the blaOXA-51 gene obtained from nasopharyngeal swabs within 48 h of hospitalization. A total of 295 patients with COVID-19 who met the study inclusion criteria were enrolled. A. baumannii was simultaneously identified in 40/295 (13.5%) of COVID-19-hospitalized patients. Demographic data and comorbidities were comparable in both Acinetobacter-positive and -negative subgroups. However, patients identified as being infected with Acinetobacter were more likely to have received outpatient antibiotics prior to hospitalization, had a higher requirement for high-flow nasal cannula and a higher subjective incidence of fatigue, and were more likely to develop Acinetobacter-induced pneumonia during hospitalization. Conclusions: The group in which SARS-CoV-2 and A. baumannii were simultaneously identified had a higher proportion of fatigue, a higher frequency of requiring a high-flow cannula, and a higher proportion of superinfection with the same microorganism during hospitalization.

Quercetin attenuates inflammation in LPS-induced lung epithelial cells via the Nrf2 signaling pathway

BACKGROUND

Pneumonia is the leading cause of death among children under five, and kill almost two million children each year. Quercetin, a flavonoid polyphenolic compound, exerts many beneficial biological activities, including anti-inflammatory functions. Our study aimed to investigate the possibility of quercetin as a therapeutic agent for pneumonia and its role in the inflammatory response induced by lipopolysaccharide (LPS).

METHODS

LPS induced human alveolar epithelial cell A549 as a lung inflammation model in vitro. The effects of quercetin on the production of cytokines and the expression of related-proteins were detected by Enzyme-Linked ImmunoSorbent Assay and Western Blot, respectively. Cell Counting Kit-8 assay was used to detect cell viability. flow cytometry was used to measure cell apoptosis. NO levels were also analyzed through NO kit.

RESULTS

Our results found that quercetin attenuated the release of IL-1β, IL-6, PGE2, and nitrite in LPS-induced A549 cells. In addition, quercetin inhibits cell apoptosis and relieves ROS generation in LPS-induced A549 cells. Quercetin also inhibits LPS-induced NF-κB activation. They have upregulated the expression of nuclear factor erythroid 2 (Nrf2) and HO-1.

CONCLUSION

In conclusion, these results suggested that quercetin attenuates LPS-induced inflammation in A549 by activating the Nrf2 signaling pathway.

The mortality and years of life lost for community-acquired pneumonia before and during COVID-19 pandemic in China

Background

Community-acquired pneumonia (CAP) is a leading cause of mortality worldwide, but disease burden of CAP is not clear so far. We aim to explore the spatial and temporal trends of mortality and years of life lost (YLL) due to CAP during 2013-2021 in mainland China, especially the mortality changes before and during COVID-19 pandemic due to COVID-19 related non-pharmaceutical interventions (NPIs).

Methods

We used data from the National Mortality Surveillance System to estimate the age-standardized rates of death and YLL of CAP at national and provincial level in China during 2013-2021. Monthly and provincial NPIs data were obtained from Oxford COVID-19 Government Response Tracker. The Average annual percentage change (AAPC) and mortality reduction were estimated by log-linear regression and interrupted time series, respectively.

Findings

In China, most CAP that caused deaths had no clear etiology, and bacterial pneumonia and viral pneumonia were the leading 2 causes among CAP deaths with determined etiology before and during COVID-19 pandemic. The age-standardized CAP mortality rate decreased from 11.18 per 100,000 in 2013 to 8.76 per 100,000 in 2019, and to 5.74 per 100,000 in 2021 (AAPC -4.51% vs -7.89%). Trends were similar in age-standardized rate of YLL. Both rates declined more for viral pneumonia, compared with bacterial pneumonia. After adjusting for NPIs at provincial level after 2020, the NPIs for COVID-19 was associated with significant reductions in CAP mortality (-0.34 per 100,000, -0.41 to -0.27; p < 0.0001), and provinces that economically developed and conducted strict regular NPIs against COVID-19 contributed the most reduction.

Interpretation

We observed a decreasing trend of age-standardized CAP mortality from 2013 to 2019, and a dramatical reduction during COVID-19 pandemic, especially for viral pneumonia. Our study provided the evidence for the effectiveness of regular NPIs on the significant reductions in CAP mortality.

Funding

This work has been supported by Beijing Municipal Science and Technology Project Z191100006619101, Chinese Academy of Medical Sciences (CAMS) Innovation Fund for Medical Sciences (CIFMS 2021-I2M-1-048), CAMS Institute of Respiratory Medicine Grant for Young Scholars (2023-ZF-8) and the New Cornerstone Science Foundation.

Efficacy and Safety of Corticosteroid Therapy for Community-Acquired Pneumonia: A Meta-Analysis and Meta-Regression of Randomized, Controlled Trials

BACKGROUND

Community-acquired pneumonia (CAP) is associated with high morbidity and mortality. In the present study, we aimed to assess the effect of corticosteroids on all-cause mortality in patients hospitalized with CAP.

METHODS

For this meta-analysis and meta-regression, we conducted a systematic search of trials that evaluated the effect of corticosteroid therapy in patients hospitalized with CAP through March 2023. We included randomized, controlled trials, comparing adjunctive corticosteroid therapy with the standard of care alone for treatment of patients hospitalized with CAP and reporting all-cause mortality. We excluded retrospective analyses, observational data, and trial protocols. The primary outcome was all-cause mortality within 30 days after hospital admission. The safety analysis included the frequency of adverse events and steroid-associated adverse events.

RESULTS

The literature search identified 35 713 citations, of which 15 studies and 3367 patients were eligible for the final analysis. The all-cause mortality at 30 days was significantly lower in the corticosteroid group (104 of 1690, 6.15%) than in the control group (152 of 1677, 9.06%; risk ratio [RR], 0.67; 95% confidence interval [CI], .53 to .85; P = .001; I2 = 0%). In 9 studies (2549 patients) that reported the occurrence of adverse events, corticosteroid therapy was not associated with an increased risk of developing any adverse event compared with standard care (RR, 0.90; 95% CI, .65 to 1.24; P = .5; I2 = 88%).

CONCLUSIONS

Adjunctive systemic corticosteroid therapy in patients hospitalized with CAP was associated with a reduction in all-cause mortality by day 30. The benefits were more pronounced in patients with severe pneumonia.

The diagnostic utility of microscopic quality assessment of sputum samples in the era of rapid syndromic PCR testing

This prospective study assessed the value of initial microscopy evaluation of sputum samples submitted for rapid syndromic PCR-based testing. Bacterial detections by the BioFire FilmArray Pneumonia Panel plus in 126 high- and 108 low-quality sputum samples, based on initial microscopy evaluation in samples from patients with lower respiratory tract infections were compared. We found that high-quality samples had a higher proportion of bacterial detections compared to low-quality samples (P = 0.013). This included a higher proportion of detections of bacteria deemed clinically relevant by predefined criteria (70% and 55%, P = 0.016), as well as a higher proportion of detections of Haemophilus influenzae (36% and 20%, P = 0.010). High-quality samples also had more detections of bacteria with high semi-quantitative values. The study found no significant difference between high- and low-quality samples in the proportions of samples with a single species of bacteria detected, samples with a bacteria treated by the clinician, samples with detection of a proven etiology of community-acquired pneumonia by predefined criteria, the number of bacterial species detected, or the detection of Streptococcus pneumoniae, Moraxella catarrhalis, or Staphylococcus aureus. The results showed that 40% (95% CI 35%-47%) of the bacterial detections would have been missed if only high-quality samples were analyzed. This included 41% (27%-56%) of detections of S. pneumoniae, 33% (23%-45%) of detections of H. influenzae, 42% (28%-58%) of detections of S. aureus, and 37% (23%-54%) of detections of M. catarrhalis. These findings suggest that all sputum samples submitted for rapid syndromic PCR testing should be analyzed, regardless of initial microscopy quality assessment. (This study has been registered at ClinicalTrials.gov under registration no. NCT04660084.) IMPORTANCE Microscopic quality assessment of sputum samples was originally designed for sputum culture, and its applicability in today's workflow, which includes syndromic PCR testing, may differ. Addressing this crucial gap, our study emphasizes the need to optimize the use and workflow of syndromic PCR panels, like the BioFire FilmArray Pneumonia plus (FAP plus), in microbiology laboratories. These advanced PCR-based tests offer rapid and comprehensive pathogen detection for respiratory infections, yet their full potential remains uncertain. By comparing bacterial detections in high- and low-quality sputum samples, we underscore the importance of including low-quality samples in testing. Our findings reveal a significant proportion of potentially clinically relevant bacterial detections that would have been missed if only high-quality samples were analyzed. These insights support the efficient implementation of syndromic PCR panels, ultimately enhancing patient care and outcomes.

Dynamic nomogram for predicting acute kidney injury in patients with community-acquired pneumonia

INTRODUCTION

Acute kidney injury (AKI) is a common complication in patients with community-acquired pneumonia (CAP) and negatively affects both short-term and long-term prognosis in patients with CAP. However, no study has been conducted on developing a clinical tool for predicting AKI in CAP patients. Therefore, this study aimed to develop a predictive tool based on a dynamic nomogram for AKI in CAP patients.

METHODS

This retrospective study was conducted from January 2014 to May 2017, and data from adult inpatients with CAP at Nanjing First Hospital were analysed. Demographic data and clinical data were obtained. The least absolute shrinkage and selection operator (LASSO) regression model was used to select important variables, which were entered into logistic regression to construct the predictive model for AKI. A dynamic nomogram was based on the results of the logistic regression model. Calibration and discrimination were used to assess the performance of the dynamic nomogram. A decision curve analysis was used to assess clinical efficacy.

RESULTS

A total of 2883 CAP patients were enrolled in this study. The median age was 76 years (IQR 63-84), and 61.3% were male. AKI developed in 827 (28.7%) patients. The LASSO regression analysis selected five important factors for AKI (albumin, acute respiratory failure, CURB-65 score, Cystatin C and white cell count), which were then entered into the logistic regression to construct the predictive model for AKI in CAP patients. The dynamic nomogram model showed good discrimination with an area under the receiver operating characteristics curve of 0.870 and good calibration with a Brier score of 0.129 and a calibration plot. The decision curve analysis showed that the dynamic nomogram prediction model had good clinical decision-making.

CONCLUSION

This easy-to-use dynamic nomogram may help physicians predict AKI in patients with CAP.

Prognostic significance of frailty in hospitalized elderly patients with community-acquired pneumonia: a retrospective cohort study

BACKGROUND

Frailty is associated with poor prognosis in a wide range of illnesses. However, its prognostic implications for older patients with community-acquired pneumonia (CAP) are not adequately addressed.

METHODS

In this study, patients were classified into 3 groups according to the frailty index based on standard laboratory tests (FI-Lab) score: robust (FI-Lab < 0.2), pre-frail (FI-Lab 0.2-0.35), and frail (FI-Lab ≥ 0.35). The relationships between frailty and all-cause mortality and short-term clinical outcomes (length of stay, duration of antibiotic therapy, in-hospital mortality) were examined.

RESULTS

Finally, 1164 patients were included, the median age was 75 years (interquartile range: 69, 82), and 438 patients (37.6%) were women. According to FI-Lab, 261(22.4%), 395(33.9%), and 508(43.6%) were robust, pre-frail, and frail. After adjustment for confounding variables, frailty was independently associated with prolonged antibiotic treatment (p = 0.037); pre-frailty and frailty were independently associated with longer inpatient days (p < 0.05 for both). The risk of in-hospital mortality was independently increased in frail patients (HR = 5.01, 95% CI = 1.51-16.57, p = 0.008) but not pre-frail patients (HR = 2.87, 95% CI = 0.86-9.63, p = 0.088) compared to robust patients. During a median follow-up of 33.9 months (interquartile range: 32.8 to 35.1 months), 408 (35.1%) patients died, of whom 29 (7.1%) were robust, 112 (27.5%) were pre-frail, and 267 (65.9%) were frail. Compared to robust patients, frail and pre-frail were significantly associated with increased risk for all-cause death (HR = 4.29, 95%CI: 1.78-10.35 and HR = 2.42 95%CI: 1.01-5.82, respectively).

CONCLUSIONS

Frailty is common among older patients with CAP and is strongly associated with increased mortality, longer length of stay, and duration of antibiotics. A routine frail assessment at the admission of elderly patients with CAP is necessary as the first step for appropriate multidisciplinary interventions.

Prevalence and Etiology of Community- and Hospital-Acquired Pneumonia in Saudi Arabia and Their Antimicrobial Susceptibility Patterns: A Systematic Review

(1) Background and Objectives: Pneumonia is a major cause of morbidity and mortality worldwide, including in Saudi Arabia, and the prevalence and etiology of the disease varies depending on the setting. The development of effective strategies can help reduce the adverse impact of this disease. Therefore, this systematic review was conducted to explore the prevalence and etiology of community-acquired and hospital-acquired pneumonia in Saudi Arabia, as well as their antimicrobial susceptibility. (2) Materials and Methods: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 recommendations were followed for this systematic review. Several databases were used to perform a thorough literature search, and papers were then assessed for eligibility by two independent reviewers. The Newcastle-Ottawa Scale (NOS) was used to extract the data from the relevant research and evaluate its quality. (3) Results: This systematic review included 28 studies that highlighted the fact that gram-negative bacteria, particularly Acinetobacter spp. and Pseudomonas aeruginosa, were the common cause of hospital-acquired pneumonia, while Staphylococcus aureus and Streptococcus spp. were responsible for community-acquired pneumonia in children. The study also found that bacterial isolates responsible for pneumonia showed high resistance rates against several antibiotics, including cephalosporins and carbapenems. (4) Conclusions: In conclusion, the study found that different bacteria are responsible for community- and hospital-acquired pneumonia in Saudi Arabia. Antibiotic resistance rates were high for several commonly used antibiotics, highlighting the need for rational antibiotic use to prevent further resistance. Moreover, there is a need to conduct more regular multicenter studies to assess etiology, resistance, and susceptibility patterns of pneumonia-causing pathogens in Saudi Arabia.

Blood heparin-binding protein and neutrophil-to-lymphocyte ratio as indicators of the severity and prognosis of community-acquired pneumonia

BACKGROUND

Community-acquired pneumonia (CAP) is particularly prevalent and has high mortality in severely ill patients, but the role of current biomarkers is limited. This study aimed to evaluate the importance of blood heparin-binding protein (HBP) and neutrophil-to-lymphocyte ratio (NLR) in assessing the severity and prognosis of CAP in adults.

METHODS

The clinical information of 206 CAP patients was retrospectively analyzed. Receiver operating characteristic (ROC) curves were created, and the accuracy of the diagnosis of severe pneumonia was evaluated by the area under the curve (AUC). Univariate and multivariate Cox regression analysis was used to examine independent factors affecting the 30-day prognosis. The Kruskal-Wallis test was utilized to contrast the variations among etiology.

RESULTS

Patients with severe pneumonia showed greater HBP and NLR compared to those with common pneumonia. The AUC of HBP was 0.723 (95% CI: 0.655-0.790) for the diagnosis of severe pneumonia, while NLR and HBP exhibited superior sensitivity (80.00%) and specificity (76.19%), respectively. Their combination boosted the diagnostic specificity (84.13%) while increasing the diagnostic sensitivity (86.25%) when combined with white blood cell (WBC) count. The 30-day mortality in CAP patients was independently predicted by HBP and NLR. However, there were no appreciable differences in HBP amongst patients with various etiologies.

CONCLUSION

HBP and NLR were also independent predictors of 30-day death in CAP patients and grew with increasing severity in these patients. Their combination opened up new possibilities. Furthermore, there is no connection between HBP and the etiology of CAP.

Cellular analysis and metagenomic next-generation sequencing of bronchoalveolar lavage fluid in the distinction between pulmonary non-infectious and infectious disease

Background

The aim of the current study was to investigate the clinical value of cellular analysis and metagenomic next-generation sequencing (mNGS) of bronchoalveolar lavage fluid (BALF) in differentiating pulmonary non-infectious and infectious diseases in immunocompetent patients.

Methods

The present retrospective study was conducted from December 2017 to March 2020, and included immunocompetent patients with suspected pulmonary infection. High-resolution computed tomography, total cell counts and classification of BALF, conventional microbiological tests (CMTs), laboratory tests and mNGS of BALF were performed. Patients were assigned to pulmonary non-infectious disease (PNID) and pulmonary infectious disease (PID) groups based on final diagnoses. PNID-predictive values were analyzed via areas under receiver operating characteristic curves (AUCs). Optimal cutoffs were determined by maximizing the sum of sensitivity and specificity.

Results

A total of 102 patients suspected of pulmonary infection were enrolled in the study, 23 (22.5%) with PNID and 79 (77.5%) with PID. The diagnostic efficiency of BALF mNGS for differentiating PID from PNID was better than that of CMTs. Neutrophil percentage (N%) and the ratio of neutrophils to lymphocytes (N/L) in BALF were significantly lower in the PNID group than in the PID group. The AUCs for distinguishing PNID and PID were 0.739 (95% confidence interval [CI] 0.636-0.825) for BALF N%, 0.727 (95% CI 0.624-0.815) for BALF N/L, and 0.799 (95% CI 0.702-0.876) for BALF mNGS, with respective cutoff values of 6.7%, 0.255, and negative. Joint models of BALF mNGS combined with BALF N/L or BALF N% increased the respective AUCs to 0.872 (95% CI 0.786-0.933) and 0.871 (95% CI 0.784-0.932), which were significantly higher than those for BALF mNGS, BALF N%, and BALF N/L alone.

Conclusions

BALF N% ≤ 6.7% or BALF N/L ≤ 0.255 combined with a negative BALF mNGS result can effectively distinguish PNID from PID in immunocompetent patients with suspected pulmonary infection. BALF mNGS outperforms CMTs for identifying pathogens in immunocompetent patients, and the combination of mNGS and CMTs may be a better diagnostic strategy.

Diagnostic des pneumonies aiguës communautaires aux urgences et distinction entre étiologie virale ou bactérienne

La pandémie actuelle liée à l’émergence du SARSCoV-2 en 2019 a considérablement modifié la perception des médecins de l’impact des virus respiratoires et de leur rôle dans les pneumonies aiguës communautaires (PAC). Alors que plus de 25 % des tableaux de PAC chez l’adulte étaient d’origine virale, les virus respiratoires étaient souvent perçus comme des agents pathogènes peu graves. Devant le défi que représente encore à nos jours la documentation microbiologique d’une PAC, l’instauration d’un traitement empirique par antibiotiques est souvent réalisée aux urgences. La pandémie de COVID-19 a surtout mis en exergue le rôle déterminant de la biologie moléculaire et du scanner thoracique dans l’algorithme diagnostique de la PAC. En effet, un diagnostic rapide et fiable est la clé pour améliorer les mesures de précaution et réduire la prescription inutile d’antibiotiques. Du fait de prises en charges très différentes, il est nécessaire de distinguer l’étiologie virale de la bactérienne d’une PAC.

Post-chemotherapy pneumonia in Chinese patients with diffuse large B-cell lymphoma: Outcomes and predictive model

Pulmonary infections account for a large proportion of life-threatening adverse events that occur after chemotherapy in patients with diffuse large B-cell lymphoma (DLBCL); however, data on their influencing risk factors and the effects of infection are relatively limited. A total of 605 patients with DLBCL were newly diagnosed at our institution between March 2009 and April 2017, and 132 of these patients developed pneumonia after treatment (21.8%). There was a significant difference in overall survival (OS) between the pneumonia and non-pneumonia groups (hazard ratio 4.819, 95% confidence interval: 3.109–7.470, p < 0.0001), with 5-year OS of 41% and 82%, respectively. Pulmonary involvement, Eastern Cooperative Oncology Group score > 1, and hypoalbuminemia were identified as independent risk factors for the development of pneumonia. We constructed a prediction model based on these three factors, and the area under the curve was 0.7083, indicating good discrimination. This model may help clinicians develop individualized strategies for preventing and treating post-chemotherapy pneumonia in patients with DLBCL.

Lefamulin: a New Hope in the Field of Community-Acquired Bacterial Pneumonia

Purpose of Review

Community-acquired bacterial pneumonia (CABP) continues to be a worldwide health concern since it is the major cause of mortality and hospitalisation worldwide. Increased macrolide resistance among Streptococcus pneumoniae and other infections has resulted in a significantly larger illness burden, which has been exacerbated by evolving demography and a higher prevalence of comorbid disorders. Owing to such circumstances, the creation of new antibiotic classes is critical.

Recent Findings

Lefamulin, also referred to as BC-3781, is the primary pleuromutilin antibiotic which has been permitted for both intravenous and oral use in humans for the remedy of bacterial infections. It has shown activity against gram-positive bacteria including methicillin-resistant strains as well as atypical organisms which as often implicated in CABP. It has a completely unique mechanism of action that inhibits protein synthesis via way of means of stopping the binding of tRNA for peptide transfer. The C(14) side chain is responsible for its pharmacodynamic and antimicrobial properties, together with supporting in overcoming bacterial ribosomal resistance and mutations improvement amplifying the number of hydrogen bonds to the target site.

Summary

This review aims to highlight the pre-existing treatment options and specific purposes to shed some light upon the development of a new drug lefamulin and its specifications and explore this novel drug's superior efficacy to already existing treatment strategies.