Pneumonia

The diagnostic efficacy of metagenomic next-generation sequencing (mNGS) in pathogen identification of pediatric pneumonia using bronchoalveolar lavage fluid (BALF): A systematic review and meta-analysis

OBJECTIVE

This meta-analysis evaluates and compares the diagnostic efficacy of metagenomic next-generation sequencing (mNGS) with conventional microbiological tests (CMTs) in diagnosing pediatric pneumonia using bronchoalveolar lavage fluid (BALF).

METHODS

Data were sourced from Embase, PubMed, Web of Science, and the Cochrane Library. The pooled positive detection rate (PDR) of pathogens was estimated using fixed-effects or random-effects models. Subgroup analyses explored factors influencing mNGS diagnostic performance. Data analysis was conducted using Review Manager (RevMan) 5.4 and Stata version 16.0.

RESULTS

The pooled PDR of mNGS was 85.83 %, which is higher than the pooled PDR of 49.97 % for CMTs. A random-effects model indicated that, compared to CMTs, mNGS has a significantly higher PDR in pediatric pneumonia (OR = 3.99, 95 %CI: 2.12-7.50, P < 0.0001, I2 = 81 %). Subgroup analysis indicated that mNGS exhibited greater advantages in the group using the QIAamp kit (OR = 5.55, 95 % CI: 3.03-10.16, P < 0.00001), the group using the Illumina Nextseq platform (OR = 4.87, 95 % CI: 2.97-7.99, P < 0.00001), the DNA-only mNGS group (OR = 4.54, 95 % CI: 2.73-7.54, P < 0.00001), and the non-severe pneumonia group (OR = 4.76, 95 % CI: 3.51-6.46, P < 0.00001). However, when the subgroups were categorized as mixed infections or single-pathogen infections, no statistically significant differences were observed (Mixed: OR = 1.77, 95 % CI: 0.30-10.56, P = 0.53; Single: OR = 3.97, 95 % CI: 0.42-37.87, P = 0.23) CONCLUSION: mNGS demonstrates high diagnostic efficacy in detecting pathogens in BALF from pediatric patients with pneumonia. The diagnostic stability of mNGS is influenced by sample extraction, sequencing platforms, positive interpretation criteria, and disease status. Standardized procedures and technologies can enhance mNGS diagnostic performance.

Decoding community-acquired pneumonia: a systematic review and analysis of diagnostic criteria and definitions used in clinical trials

BACKGROUND

Community-acquired pneumonia (CAP) is a frequent and potentially life-threatening condition. Even though the disease is common, evidence on CAP management is often of variable quality. This may be reinforced by the lack of a systematic and homogeneous way of defining the disease in randomized controlled trials (RCTs).

OBJECTIVES

This study aims to assess the diagnostic criteria and definitions of the term 'community-acquired' used in RCTs on CAP management.

DATA SOURCES

On the basis of the protocol (PROSPERO 2019 CRD42019147411), we conducted a systematic search of Medline/PubMed and the Cochrane Register of Controlled Trials for RCTs published or registered between 2010 and 2024.

STUDY ELIGIBILITY CRITERIA

Study eligibility criteria included completed and ongoing RCTs.

PARTICIPANTS

Participants included adults hospitalized with CAP.

METHODS OF DATA SYNTHESIS

Data were collected using a tested extraction sheet, as endorsed by the Cochrane Collaboration. After cross-checking, data were synthesized in a narrative and tabular form.

RESULTS

In total, 7173 records were identified through our searches. After removing records that did not fulfil the eligibility criteria, 170 studies were included. Diagnostic criteria were provided in 69.4% of studies, and the term 'community-acquired' was defined in 55.3% of studies. The most frequently included diagnostic criteria were pulmonary infiltrates (94.1%), cough (78.8%), fever (77.1%), dyspnoea (62.7%), sputum (57.6%), auscultation/percussion abnormalities (55.9%), and chest pain/discomfort (52.5%). The different criteria were used in 87 different sets across the studies. The term 'community-acquired' was defined in 57 different ways.

CONCLUSIONS

The diagnostic criteria and definitions of CAP in RCTs exhibit significant heterogeneity. Standardizing these criteria in clinical trials is crucial to ensure comparability across studies.

Comparing viral, bacterial, and coinfections in community-acquired pneumonia, a retrospective cohort study

OBJECTIVES

Despite the substantial rates of viral etiology in community-acquired pneumonia (CAP), empirical antibiotic therapy is regularly administered. This study compared the clinical presentation, antibiotic use, and outcomes of patients based on the identified causative pathogens.

METHODS

Patients that were immunocompetent and had CAP from the international, multicenter prospective cohort study on CAP (CAPNETZ) from 2007 to 2017 with available multiplex polymerase chain reaction testing for bacterial and viral pathogens from sputum were included. Patients were divided into four groups based on the detection of bacterial pathogens, viral pathogens, bacterial/viral coinfection, and no pathogen detected. Differences were analyzed using multivariate linear regression.

RESULTS

Patients with bacterial CAP were significantly younger (median age 60 years; adjusted odds ratio [aOR] 0.96 [0.94-0.98]) and reported less smoking (aOR 0.98 [0.97-1.0]). A higher CRB-65 score (confusion, respiratory rate, blood pressure, and age ≥65years) was associated with bacterial CAP (aOR 1.69 [1.1-2.58]). Bacterial CAP showed higher 180-day mortality (aOR 3.59 [1.09-11.8]) and viral CAP had higher 30-day mortality (aOR 15.79 [1.04-238.75]) than the other groups. Upon admission, the four groups could not be distinguished based on clinical presentation and showed no differences in CAP-related complications, length of hospital stay, or application/duration of antibiotic treatment (98.4% received antibiotics).

CONCLUSIONS

A pathogen-centered treatment algorithm for patients with CAP is required to avoid unnecessary antibiotic therapies, side effects and optimize patient outcomes and long-term morbidity.

Baicalin inhibits LPS-induced apoptosis and inflammation in WI- 38 cells by promoting FOXA2/TRIM27 Interaction: Implications for pediatric pneumonia mechanisms

BACKGROUND

Pediatric pneumonia is lung inflammation in newborns caused by many factors, which can impair the respiratory, circulatory and nervous systems and affect their growth and development. Baicalin, a flavonoid separated from Scutellaria baicalensis Georgi, possesses anti-inflammatory effects in lung diseases. The aim of this study was to explore the molecular mechanism of baicalin in exerting a protective effect in neonatal pneumonia.

METHODS

Effect of baicalin on viability of human fibroblast cells (WI-38 cell) was detected by CCK-8 assay. Then, the WI-38 cells were treated with lipopolysaccharide (LPS). Cell apoptosis and inflammatory cytokines were assessed by flow cytometry and ELISA. Additionally, the oxidative stress and endoplasmic reticulum stress (ERS) were evaluated using specific assays. The mRNA and protein levels were assessed by qRT-PCR and western blot. Finally, the binding between FOXA2 and TRIM27 was predicted and verified by employing the Jaspar database, ChIP and dual luciferase reporter assays.

RESULTS

1-40 µM baicalin had no impact on the viability in WI-38 cells, and 40 µM baicalin increased the viability of LPS-inhibited cells. Besides, baicalin mitigated the effects of LPS on apoptosis, inflammation, oxidative stress and ERS in WI-38 cells. Moreover, TRIM27 exhibited low expression levels in pediatric pneumonia and LPS-induced cells. Furthermore, baicalin promoted TRIM27 expression and inhibited the effects of LPS induction on cell production. Mechanically, FOXA2 was positively correlated with TRIM27 expression and baicalin inhibited the adverse effects of LPS induction on WI-38 cells via FOXA2/TRIM27.

CONCLUSION

These findings suggested that baicalin miaght exert protective effects against pediatric pneumonia by modulating FOXA2/TRIM27-dependent pathways.

A host-pathogen metabolic synchrony that facilitates disease tolerance

Disease tolerance mitigates organ damage from non-resolving inflammation during persistent infections, yet its underlying mechanisms remain unclear. Here we show, in a Pseudomonas aeruginosa pneumonia mouse model, that disease tolerance depends on the mitochondrial metabolite itaconate, which mediates cooperative host-pathogen interactions. In P. aeruginosa, itaconate modifies key cysteine residues in TCA cycle enzymes critical for succinate metabolism, inducing bioenergetic stress and promoting the formation biofilms that are less immunostimulatory and allow the bacteria to integrate into the local microbiome. Itaconate incorporates into the central metabolism of the biofilm, driving exopolysaccharide production-particularly alginate-which amplifies airway itaconate signaling. This itaconate-alginate interplay limits host immunopathology by enabling pulmonary glutamine assimilation, activating glutaminolysis, and thereby restrain detrimental inflammation caused by the inflammasome. Clinical sample analysis reveals that P. aeruginosa adapts to this metabolic environment through compensatory mutations in the anti-sigma-factor mucA, which restore the succinate-driven bioenergetics and disrupt the metabolic synchrony essential for sustaining disease tolerance.

Activated platelet membrane vesicles for broad-spectrum bacterial pulmonary infections management

The development of new antibiotics has lagged behind the rapid evolution of bacterial resistance, prompting the exploration of alternative antimicrobial strategies. Host-directed therapy (HDT) has emerged as a promising approach by harnessing innate immune system's natural defense mechanisms, which reduces reliance on antibiotics, and mitigates the development of resistance. Building on the important role of platelets in host immunity, activated platelet membrane vesicles (PLTv) are developed here as a host-directed therapy for broad-spectrum antibacterial infection management, leveraging several key mechanisms of action. PLTv neutralizes bacterial toxins, thereby reducing cytotoxicity. The presence of platelet receptors on PLTv enables them to act as decoys, binding bacteria through receptor interactions and facilitating their phagocytosis by neutrophils and macrophages. Additionally, PLTv bound to bacteria promote the formation of neutrophil extracellular traps (NETs), enhancing the immune system's ability to trap and kill bacteria. In mouse models of pulmonary infections caused by the Methicillin-resistant Staphylococcus aureus, P. aeruginosa, and A. baumannii, administration of PLTv significantly reduces bacterial counts in the lungs and protects against mortality. Taken together, the present work highlights PLTv as a promising host-directed therapy for combating broad-spectrum pulmonary drug-resistant bacterial infections, leveraging their ability to neutralize toxins, act as decoys, promote phagocytosis, and facilitate NETs formation.

Willingness to engage in self-care impacts clinical outcomes at discharge in hospitalized pneumonia patients: a descriptive study

BACKGROUND

The objective of this study was to evaluate the association between willingness to engage in self-care and clinical outcomes in patients hospitalized with community-acquired pneumonia (CAP).

METHODS

An observational study in patients hospitalized with CAP was conducted. Patients were divided into two groups according to the willingness to engage in self-care, that was assessed with the Patient Activation Measure (PAM). Participants with scores ≤ 47.0 points were included in the unwillingness to engage in self-care group, and patients with PAM score > 47 points were included in the willingness to engage in self-care group. Main variables were assessed at hospital discharge and included clinical symptoms (cough, dyspnea, pain and fatigue), physical status, activity levels, psychological inflexibility and restrictions in daily life activities and social participation.

RESULTS

A total of 66 patients were included in the study (34 in the patients unwilling to engage and 32 in the patients willing to engage). Significant differences were found in clinical symptoms, psychological inflexibility, and restrictions in daily life activities and social participation in favor to patients' willingness to engage in self-care at hospital discharge.

CONCLUSIONS

Patients with CAP willing to engage in self-care showed improvements in clinical symptoms, psychological flexibility, and fewer limitations in daily activities and social participation at discharge.

Inhalable Polymeric Nanoparticle Containing Triphenylphosphanium Bromide-modified Sonosensitizer for Enhanced Therapy of Acute Bacterial Pneumonia

Sonodynamic therapy (SDT) has good feasibility to deeply seated infections, but SDT alone is insufficient being highly effective against multidrug-resistant (MDR) bacteria. SDT combined with triphenylphosphanium bromide (P+Ph3Br-) is expected to solve this problem. This work develops a pseudo-conjugated polymer PFCPS-P containing cationic P+Ph3Br--modified sonosensitizer FCPS (FCPS-P) and ROS-sensitive thioketal bonds. PFCPS-P is assembled with DSPE-mPEG2000 to generate nanoparticle NPFCPS-P. FCPS has SDT effect and generates ROS under ultrasound (US) stimulation. ROS triggers the degradation of NPFCPS-P and release of FCPS-P, endowing highly favored biosafety. FCPS-P targets to bacterial surface through electrostatic interaction and achieves bacterial killing under a synergistic action of SDT and P+Ph3Br-. In vitro, NPFCPS-P+US gives >90% inhibition rates against MDR ESKAPE pathogens, moreover, it causes bacterial metabolic disorders including inhibited nucleic acid synthesis, disordered energy metabolism, excessive oxidative stress, and suppressed biofilm formation and virulence. In mice, NPFCPS-P+US exhibits a 99.3% bactericidal rate in Pseudomonas aeruginosa-induced sublethal pneumonia and renders a 90% animal survival rate in lethal pneumonia, and additionally immunological staining and transcriptomics analyses reveal that NPFCPS-P+US induces inhibited inflammatory response and accelerated lung injury repair. Taken together, NPFCPS-P+US is a promising antibiotics-alternative strategy for treating deeply seated bacterial infections.

Ensemble of Deep Learning Architectures with Machine Learning for Pneumonia Classification Using Chest X-rays

Pneumonia is a severe health concern, particularly for vulnerable groups, needing early and correct classification for optimal treatment. This study addresses the use of deep learning combined with machine learning classifiers (DLxMLCs) for pneumonia classification from chest X-ray (CXR) images. We deployed modified VGG19, ResNet50V2, and DenseNet121 models for feature extraction, followed by five machine learning classifiers (logistic regression, support vector machine, decision tree, random forest, artificial neural network). The approach we suggested displayed remarkable accuracy, with VGG19 and DenseNet121 models obtaining 99.98% accuracy when combined with random forest or decision tree classifiers. ResNet50V2 achieved 99.25% accuracy with random forest. These results illustrate the advantages of merging deep learning models with machine learning classifiers in boosting the speedy and accurate identification of pneumonia. The study underlines the potential of DLxMLC systems in enhancing diagnostic accuracy and efficiency. By integrating these models into clinical practice, healthcare practitioners could greatly boost patient care and results. Future research should focus on refining these models and exploring their application to other medical imaging tasks, as well as including explainability methodologies to better understand their decision-making processes and build trust in their clinical use. This technique promises promising breakthroughs in medical imaging and patient management.

Diagnostic approach in acute hypoxemic respiratory failure

Acute hypoxemic respiratory failure (AHRF) is the leading cause of intensive care unit (ICU) admissions. Of patients with AHRF, 40 %-50 % will require invasive mechanical ventilation during their stay in the ICU, and 30 %-80 % will meet the Berlin Criteria for Acute Respiratory Distress Syndrome (ARDS). Rapid identification of the underlying cause of AHRF is necessary before initiating targeted treatment. Almost 10 % of patients with ARDS have no identified classic risk factors however, and the precise cause of AHRF may not be identified in up to 15 % of patients, particularly in cases of immunosuppression. In these patients, a multidisciplinary, comprehensive, and hierarchical diagnostic work-up is mandatory, including a detailed history and physical examination, chest computed tomography, extensive microbiological investigations, bronchoalveolar lavage fluid cytological analysis, immunological tests, and investigation of the possible involvement of pneumotoxic drugs.

Metabolomic studies of respiratory infections in early life: A narrative review

Respiratory infections are a leading cause of morbidity and mortality during the early life period, and experiencing recurrent infections may increase the risk of developing chronic respiratory diseases, such as asthma. Over the last several decades, metabolomics methods have been applied to inform upon the underlying biochemistry of pediatric respiratory infection response, to discriminate between respiratory infection types, and to identify biomarkers of severity and susceptibility. While these studies have demonstrated the power of applying metabolomics to the study of pediatric respiratory infection and contributed to an understanding of respiratory infections during the unique period of immune development, key differences in study design, infection type(s) of interest, biosamples, metabolomics measurement methods, and lack of external validation have limited the translation of these findings into the clinic. The purpose of this review is to summarize overlaps across existing studies of commonly reported metabolomics findings and emphasize areas of opportunity for future study. We highlight several metabolomics pathways-such as the citric acid cycle and sphingolipid metabolism-that have been reported consistently in respiratory infection response. We then discuss putatively identified metabolomic markers to discriminate between respiratory infection types and possible markers of infection severity and proneness. Finally, we close with a summary and perspective of future directions of the field.

Viral community-acquired pneumonia: what's new since COVID-19 emerged?

INTRODUCTION

All over the world, viral pneumonia has a significant impact on morbidity and mortality, especially among vulnerable populations. The most common respiratory viruses causing pneumonia include influenza virus, respiratory syncytial virus, adenoviruses and rhinovirus. The COVID-19 pandemic has changed the landscape of viral pneumonia and has reshaped our understanding of the role of viruses in this disease. We are now more aware of the importance of early diagnosis, the impact of co-infections, the effects of viral variants, and the long-term consequences of post-viral pneumonia.

AREAS COVERED

We discuss the latest scientific evidence regarding epidemiology, diagnosis, treatment, and prevention of viral pneumonia. This review summarizes findings from a PubMed search on respiratory viruses in community-acquired pneumonia.

EXPERT OPINION

Our experience during the COVID-19 pandemic has changed our perspective on respiratory viruses and their role in viral pneumonia. Diagnostic advances have been made, co-infections have received greater recognition, immune responses to viral infections are better understood, and approaches to treating viral pneumonia have expanded. Despite this progress, however, research on the impact of respiratory viruses on pneumonia must continue to pursue the development of new antivirals and vaccines, and investigate the long-term sequelae, especially in cases of severe viral pneumonia.

Short-course antibiotic strategies for ventilator-associated pneumonia

PURPOSE OF REVIEW

Evidence behind antibiotic duration while treating ventilator-associated pneumonia (VAP) remains unclear. There is a need to balance minimizing the development of antimicrobial resistance without compromising clinical outcomes given the high mortality.

RECENT FINDINGS

Recent studies have suggested that shorter antibiotic courses, when individualized to clinical response, may be adequate for treating VAP without increasing the incidence of mortality or recurrence, regardless of pathogens. Moreover, shortening duration may reduce the risk of adverse events, including acute kidney injury.

SUMMARY

Shortening the duration of antibiotic treatment for VAP, in the setting of appropriate clinical response, is a reasonable strategy to reduce costs and selective pressure driving antimicrobial resistance. This was demonstrated in the latest REGARD-VAP study, even among VAP patients with nonfermenting Gram-negative bacilli or carbapenem-resistant pathogens. Given the challenges in diagnosing VAP, such pragmatic approaches would be essential as part of overall antibiotic stewardship programmes. Further refinement to the criteria for antibiotic cessation may be possible.

The risk of stroke-related pneumonia: a systematic review of peripheral immunodepression markers

INTRODUCTION

Ischemic stroke (IS)-associated pneumonia is a leading cause of mortality after stroke, driven by peripheral immune imbalance. This systematic review evaluates immunosuppression markers associated with pneumonia following IS in clinical studies.

METHODS

Following PRISMA guidelines, we searched PubMed/MEDLINE, EMBASE, and LILACS databases until March 2024. Inclusion criteria comprised clinical studies assessing IS-related immunosuppression and pneumonia, excluding in vitro and animal studies. Study quality was assessed using the Newcastle-Ottawa Scale.

RESULTS

A total of 32 studies met the inclusion criteria, analyzing 1,833 post-stroke patients. Findings indicate that increased interleukin-6 (IL-6), interleukin-10 (IL-10), and C-reactive protein (CRP) levels, alongside decreased repulsive guidance molecule A (RGM-A), are early indicators of post-stroke pneumonia. Meta-analysis was not conducted due to heterogeneity in study methodologies and populations.

CONCLUSIONS

Elevated IL-6, IL-10, and CRP levels, along with reduced RGM-A, are associated with post-stroke pneumonia, emphasizing the role of immune dysregulation in its pathophysiology. Despite promising findings, further studies with standardized detection techniques are needed to enhance diagnostic accuracy and improve patient prognosis. The variability in study methodologies presents a limitation to drawing definitive conclusions.Registration: PROSPERO CRD42024543108.

Sphaeropsidin A covalently binds to Cys 151 of Keap1 to attenuate LPS-induced acute pneumonia in mice

INTRODUCTION

Kelch ECH-associating protein 1 (Keap1)-Nuclear factor erythroid 2-related factor 2 (Nrf2) axis is crucial for regulating oxidative stress and inflammatory responses in acute pneumonia. Sphaeropsidin A (SA) is a antioxidant diterpenoid isolated from Sphaeropsis sapinea f. sp. cupressi, discovered as a novel Nrf2 agonist by our research group previously. However, the accurate function and mechanism of SA in treating acute pneumonia are still unknown.

METHODS

The therapeutic effect of SA was evaluated in LPS-induced acute pneumonia in mice. The underlying mechanism of action was then analyzed by transcriptomics. The direct target of SA was identified through the synthesis of SA-biotin probe, and the binding amino acid residues were found and verified by LC-MS/MS analysis and site-specific mutation. Finally, knockout mice were employed to verify the mechanism of SA.

RESULTS

Our data indicated that SA significantly inhibited LPS-induced acute pneumonia in mice via up-regulating Nrf2, inhibiting NLRP3 inflammasome and NF-κB activation, and identified Keap1 as the direct target of SA. Specifically, the effective dose of SA in mice was only 2 mg/kg. SA selectively covalent bound to Keap1 in cysteine 151 residue (Cys151). SA mediated the activation of Nrf2 and reduced the level of ROS, thereby inhibiting the NF-κB and NLRP3 inflammasome. Besides, SA formed hydrogen bond with ASP48 of ASC, blocking its oligomerization and inhibiting the activation of NLRP3 inflammasome.

CONCLUSION

This study indicates that SA might be a new covalent molecule of Keap1 to activate Nrf2, and is a promising drug candidate or lead molecule for the therapy of acute pneumonia through regulating Nrf2/NF-κB/NLRP3 inflammasome axis.

Modulating oxidative stress: a reliable strategy for coping with community-acquired pneumonia in older adults

Community-acquired pneumonia (CAP) remains one of the leading respiratory diseases worldwide. With the aging of the global population, the morbidity, criticality and mortality rates of CAP in older adults remain high every year. Modulating the signaling pathways that cause the inflammatory response and improve the immune function of patients has become the focus of reducing inflammatory damage in the lungs, especially CAP in older adults. As an important factor that causes the inflammatory response of CAP and affects the immune status of the body, oxidative stress plays an important role in the occurrence, development and treatment of CAP. Furthermore, in older adults with CAP, oxidative stress is closely associated with immune senescence, sarcopenia, frailty, aging, multimorbidity, and polypharmacy. Therefore, multiple perspectives combined with the disease characteristics of older adults with CAP were reviewed to clarify the research progress and application value of modulating oxidative stress in older adults with CAP. Clearly, there is no doubt that targeted modulation of oxidative stress benefits CAP in older adults. However, many challenges and unknowns concerning how to modulate oxidative stress for further practical clinical applications exist, and more targeted research is needed. Moreover, the limitations and challenges of modulating oxidative stress are analyzed with the aim of providing references and ideas for future clinical treatment or further research in older adults with CAP.

Rapid Bacterial/Viral Infections Typing Strategy Using a Portable Dual-Channel Electrochemical Biosensor Based on One-Step Assembly of Immunomagnetic Beads

Amidst multiple epidemics, a rapid, sensitive, economical, and portable infection diagnosis strategy is crucial for primary medical care, particularly through the analysis of pathogen sources to determine appropriate antibiotic use. C-reactive protein (CRP) and serum amyloid A (SAA) are host-related biomarkers, and their combined detection can effectively distinguish between bacterial and viral infections, which holds great significance for the diagnosis of unknown pathogens. In this work, a portable dual-channel electrochemical biosensor based on a one-step assembly of immunomagnetic beads was proposed for the on-site combined detection of plasma CRP and SAA, which streamlined the operation and shortened the minimum detection time to less than 3 min. The biosensor exhibited excellent linearity in the detection of 3.125-1250 ng/mL CRP and 31.25-1250 ng/mL SAA, with detection limits of 0.91 and 12 ng/mL, respectively, falling within the clinically relevant reference range. Through simulated sample tests, the biosensor effectively distinguished between bacterial infection, viral infection, and healthy plasma samples. The actual sample tests demonstrated a high correlation and comparable medical value to enzyme-linked immunosorbent assay. Overall, this proposed strategy showed potential to aid in infection diagnosis and enable rapid combined detection of multiple biomarkers.

FEN1-assisted LAMP for specific and multiplex detection of pathogens associated with community-acquired pneumonia

Lower respiratory tract infections (LRITs), including community-acquired pneumonia (CAP), are the fifth leading cause of death worldwide over the last ten years, posing a serious threat to global healthcare. Conventional laboratory assays for detecting pathogens are hindered by complicated procedures, a long turnaround time and a lack of multiplex detection capabilities. In this study, a flap-endonuclease 1 (FEN1)-assisted loop-mediated isothermal amplification (LAMP) method was designed, and an assay based on this method was developed to identify three leading pathogens for CAP, namely, Streptococcus pneumoniae, Mycoplasma pneumoniae and Haemophilus influenzae. FEN1-assisted LAMP utilized a sequence-specific probe with a flap structure to generate an amplified signal, demonstrating high specificity and sensitivity with a low limit of detection (100 copies per μL). Based on the cleavage of flap probes by FEN1, our assay was able to detect three pathogens in a single reaction. This method is highly consistent with the polymerase chain reaction (PCR) in clinical sample testing. This simple, specific and multiple detection method has the potential to identify CAP and could be applied to detect other pathogen infections.

Application of metagenomic next-generation sequencing in the diagnosis of pathogens in patients with diabetes complicated by community-acquired pneumonia

To explore the clinical utility and optimal timing of metagenomic next-generation sequencing (mNGS) in diagnosing pathogens in patients with diabetes complicated by community-acquired pneumonia (CAP). The study included 50 hospitalized patients diagnosed with diabetes complicated by CAP who underwent conventional microbiological testing (CMT) and mNGS using bronchoalveolar lavage fluid. Among the 50 cases, 16% presented no respiratory symptoms. There were significant increases in inflammatory markers such as C-reactive protein, erythrocyte sedimentation rate, and interleukin-6, with patchy imaging changes being the most prevalent. The positive rates for pathogen detection by mNGS and CMTs were 78 and 21% (P < 0.05). The mNGS was significantly better than the CMTs in the detection of rare pathogens such as Anaerobes, Chlamydia psittaci, Legionella pneumophila, Mycobacterium bovis, Aspergillus fumigatus, and Pneumocystis japonicus (P < 0.05). After clinical interpretation, 85% (22/26) of viruses, 24% (9/37) of bacteria, and 25% (2/8) of fungi were non-pathogen organisms by mNGS. There was a significant difference in the rates of adjustment in anti-infection treatment strategies based on the pathogen detection results from CMTs and mNGS, which were 2 and 46%, respectively (P < 0.05). We found that mNGS was superior to CMTs in terms of the positive rate of pathogen detection, detecting mixed infection incidence, rare pathogen detection rates, and the adjustment of treatment strategies. However, mNGS results need to be interpreted in the context of the clinic.

CD209d/e are required for macrophage-mediated phagocytosis and activation during methicillin-resistant Staphylococcus aureus pulmonary host defense

Staphylococcus aureus is a commensal and opportunist pathogen of the upper respiratory tract. The recognition of pathogen-associated molecular patterns through pattern-recognition receptors is crucial for eliminating microorganisms such as S. aureus. DC-SIGN (CD209) is a pattern-recognition receptor that binds to a broad range of pathogens, promoting phagocytosis. Here we aimed to study the role of mouse homologues of DC-SIGN, CD209d/e, in a methicillin-resistant S. aureus (MRSA) pulmonary infection model. CD209d/e-/- and wild-type C57BL/6 mice were infected with MRSA and inflammatory parameters were evaluated. CD209d/e-/- mice had delayed bacterial burden and mortality together with increased frequency of neutrophils and decreased dendritic cells in the lung compared with control mice. iNOS+ macrophages, and regulatory T cell frequency were decreased in the lungs of CD209d/e-/- mice. CD209d/e-/- mice had increased levels of inflammatory cytokines in the lungs, but levels of IL-12p40 were decreased. MRSA reduced expression of interferon-γ and pattern-recognition receptors in CD209d/e-/- mice. MRSA uptake by phagocytes was decreased in the lungs of CD209d/e-/- versus control mice. CD209d/e-/- bone marrow derived macrophages showed impaired MRSA uptake and killing. These data suggest that CD209d/e are essential receptors to control inflammation by activating macrophages leading to MRSA uptake and killing.

Development and validation of a clinical prediction model for pneumonia - associated bloodstream infections

Purpose

The aim of this study was to develop a valuable clinical prediction model for pneumonia-associated bloodstream infections (PABSIs).

Patients and methods

The study retrospectively collected clinical data of pneumonia patients at the First Medical Centre of the Chinese People's Liberation Army General Hospital from 2019 to 2024. Patients who met the definition of pneumonia-associated bloodstream infections (PABSIs) were selected as the main research subjects. A prediction model for the probability of bloodstream infections (BSIs) in pneumonia patients was constructed using a combination of LASSO regression and logistic regression. The performance of the model was verified using several indicators, including receiver operating characteristic (ROC) curve, calibration curve, decision curve analysis (DCA) and cross validation.

Results

A total of 423 patients with confirmed pneumonia were included in the study, in accordance with the Inclusion Criteria and Exclusion Criteria. Of the patients included in the study, 73 developed a related bloodstream infection (BSI). A prediction model was constructed based on six predictors: long-term antibiotic use, invasive mechanical ventilation, glucocorticoids, urinary catheterization, vasoactive drugs, and central venous catheter placement. The areas under the curve (AUC) of the training set and validation set were 0.83 and 0.80, respectively, and the calibration curve demonstrated satisfactory agreement between the two.

Conclusion

This study has successfully constructed a prediction model for bloodstream infections associated with pneumonia cases, which has good stability and predictability and can help guide clinical work.

A multi-modal deep learning solution for precise pneumonia diagnosis: the PneumoFusion-Net model

Background

Pneumonia is considered one of the most important causes of morbidity and mortality in the world. Bacterial and viral pneumonia share many similar clinical features, thus making diagnosis a challenging task. Traditional diagnostic method developments mainly rely on radiological imaging and require a certain degree of consulting clinical experience, which can be inefficient and inconsistent. Deep learning for the classification of pneumonia in multiple modalities, especially integrating multiple data, has not been well explored.

Methods

The study introduce the PneumoFusion-Net, a deep learning-based multimodal framework that incorporates CT images, clinical text, numerical lab test results, and radiology reports for improved diagnosis. In the experiments, a dataset of 10,095 pneumonia CT images was used-including associated clinical data-most of which was used for training and validation while keeping part of it for validation on a held-out test set. Five-fold cross-validation was considered in order to evaluate this model, calculating different metrics including accuracy and F1-Score.

Results

PneumoFusion-Net, which achieved 98.96% classification accuracy with a 98% F1-score on the held-out test set, is highly effective in distinguishing bacterial from viral types of pneumonia. This has been highly beneficial for diagnosis, reducing misdiagnosis and further improving homogeneity across various data sets from multiple patients.

Conclusion

PneumoFusion-Net offers an effective and efficient approach to pneumonia classification by integrating diverse data sources, resulting in high diagnostic accuracy. Its potential for clinical integration could significantly reduce the burden of pneumonia diagnosis by providing radiologists and clinicians with a robust, automated diagnostic tool.

Effectiveness of Yinhua Pinggan granules in community-acquired pneumonia: a randomized, double-blind clinical trial

Ethnopharmacological relevance

Community-acquired pneumonia (CAP) is an acute inflammation of the alveoli and distal bronchi caused by bacterial, viral, or other pathogenic microbial infections. Yinhua Pinggan (YHPG) granules have demonstrated anti-inflammatory, antibacterial, and antiviral effects, suggesting their potential as a treatment option for CAP.

Aim

To assess the efficacy and safety of traditional Chinese medicine (TCM), YHPG granules, in combination with conventional pneumonia treatments.

Materials and methods

This randomized, double-blind, placebo-controlled clinical trial was conducted at a medical center in Hangzhou and involved 240 eligible participants. In addition to conventional pneumonia treatment, participants were randomly assigned in a 1:1 ratio to receive either YHPG granules or placebo for 10 days. The primary outcome measure was the difference in pneumonia cure rates at the end of treatment. Secondary outcomes included chest CT absorption rate, criticality score (SMART-COP score), Acute Physiology and Chronic Health Evaluation II (APACHE II) score, C-reactive protein (CRP) level, lactate (LC) level, procalcitonin (PCT) level, time for symptom recovery, length of hospital stay, and TCM syndrome scores.

Results

In total, 229 participants were included in the analysis. The pneumonia cure rate in the YHPG granule group was higher than that in the placebo group (37.2% vs. 22.4%, mean difference: 14.75%, 95% CI: 3.05-26.46, p < 0.05), indicating the superiority of YHPG granules. The granules significantly improved the chest CT absorption rate, pneumonia severity, and CRP and LC levels (p < 0.05). Additionally, YHPG granules resulted in a shorter recovery time from fever and lung rales, reduced hospital stay, and lowered the TCM syndrome scores than the placebo (p < 0.05). No significant differences were observed in other outcomes between the two groups (p > 0.05). Notably, the use of YHPG granules was associated with fewer adverse reactions.

Conclusion

YHPG granules are a promising adjunct therapeutic agent for CAP.

Clinical Trial Registration

https://www.chictr.org.cn/showproj.html?proj=127908, identifier ChiCTR2100047501.

Lianhua Qingke Tablet in severe pneumonia: Clinical efficacy and immunoregulatory mechanisms

ETHNOPHARMACOLOGICAL RELEVANCE

Lianhua Qingke (LHQK), a traditional Chinese medicine, has shown efficacy in treating acute and chronic bronchitis and bronchiolitis. However, the specific mechanism underlying the therapeutic effects of LHQK on severe pneumonia is not clear.

AIM OF THE STUDY

Severe pneumonia remains a critical health challenge, particularly in cases progressing to sepsis and septic shock, where host immune responses become dysregulated or dysfunctional. This study aims to evaluate the immunomodulatory effects of LHQK in severe pneumonia.

MATERIALS AND METHODS

This research examined LHQK's therapeutic and immunomodulatory mechanisms in patients with severe pneumonia and a lipopolysaccharide (LPS)-induced mouse model of severe pneumonia. Patients with severe pneumonia were randomized into three groups: basal treatment, LHQK-Low dose (12 tablets/day), and LHQK-High dose (24 tablets/day). BALB/c mice were categorized into four groups: control, model, LHQK-Low dose (3.7 mg/kg), and LHQK-High dose (7.4 mg/kg). Clinical efficacy was evaluated by assessing parameters including the value and rate of change in APACHE II score, improvement in chest X-ray or CT, partial pressure of oxygen (PO2), oxygen saturation in arterial blood (SaO2), oxygenation index (OI), and the length of hospitalization after 7 days of treatment. The viscosity of sputum was measured by viscosimeter. Moreover, lung histopathology, airway barrier integrity, and immune cells in BALF, were assessed using hematoxylin and eosin staining, immunostaining, and Wright-Giemsa staining. Cytokine levels were measured using Luminex assay and Olink, while pulmonary immune cell patterns were analyzed using multiplex fluorescence and Cytometry by Time-Of-Flight (CyTOF).

RESULTS

In comparison to the basal treatment group of patients, LHQK treatment exhibited a reduction in the severity of severe pneumonia and inflammatory status, as evidenced by observations on Chest X-ray or CT scans. Additionally, LHQK treatment led to an elevation in OI, PO2, and SaO2 levels, and notably, a decreased duration of hospitalization. Further analysis revealed that LHQK enhanced the integrity of the airway epithelial barrier, reduced the viscosity of sputum, and significantly decreased inflammatory cells infiltration. The application of Luminex and Olink assay further confirmed the inhibitory impact of LHQK on the cytokine storm in mice. Moreover, multiplex fluorescence and CyTOF analysis demonstrated that LHQK effectively suppressed the activation of monocyte derived macrophages, neutrophils, and Treg cells, while preserved the levels of alveolar macrophages, B cells, and CD4+ and CD8+ T lymphocytes, therefore restoring immune homeostasis within the lung of severe pneumonia. These findings significantly substantiate the potential clinical application of LHQK in severe pneumonia treatment.

CONCLUSION

LHQK demonstrates therapeutic efficacy in severe pneumonia by maintaining structural integrity, suppressing cytokine storms, enhancing intrinsic immunity, reversing T cell exhaustion, and correcting lung immune disorders. These findings significantly substantiate LHQK's potential clinical application in severe pneumonia treatment.

Unfractionated heparin may improve near-term survival in patients admitted to the ICU with sepsis attributed to pneumonia: an observational study using the MIMIC-IV database

Introduction

Limited data are available on the use, duration, and dosage of anticoagulant therapy in patients with pneumonia-induced sepsis, and the survival benefits of heparin remain uncertain. This study aimed to assess whether heparin administration improves near-term survival in critically ill patients with pneumonia-induced sepsis and identify the optimal dosage and treatment duration.

Methods

This study utilized the Medical Information Mart for Intensive Care-IV (MIMIC-IV) database. The variance inflation factor was employed to exclude highly collinear variables. Propensity score matching (PSM), the Cox proportional hazards model, and Cox regression subgroup analysis were used to evaluate the outcomes of subcutaneous heparin prophylactic anticoagulation after intensive care unit (ICU) admission. The primary outcomes were 30-, 45-, and 60-d mortality rates. Secondary outcomes included ICU length of stay (LOS_ICU), hospital length of stay (LOS_Hospital), in-hospital mortality, and the incidence of gastrointestinal bleeding.

Results

We enrolled 1,586 adult patients with pneumonia-induced sepsis. After PSM, 1,176 patients remained (588 in the heparin group and 588 in the non-heparin group). The 45-d survival rate was significantly higher in the heparin-treated group than that in the non-heparin group (84.4% vs. 79.4%; HR: 0.75; 95% CI: 0.572-0.83; adjusted HR: 0.73, 95% CI: 0.563-0.964; P < 0.05). LOS_ICU and LOS_Hospital were significantly shorter in the heparin group (P < 0.001), with no significant difference in gastrointestinal bleeding incidence between the two groups. Cox proportional hazards models demonstrated that heparin dose and duration were strongly associated with 45-d survival. Subgroup analysis indicated a significant survival advantage in patients aged 18-60 years, without diabetes, chronic obstructive pulmonary disease, or stage 1 acute kidney injury, who received a daily heparin dose of 3 mL for more than 7 d.

Conclusion

Our study found that early administration of heparin, particularly in sufficient doses (Heparin Sodium 5,000 units/mL, 1 mL per dose, three times daily (TID)) for more than 7 d, was associated with reduced near-term mortality in critically ill patients with pneumonia-induced sepsis. These findings underscore the potential benefits of anticoagulant therapy in this high-risk patient population.

Clinical Characteristics and Predicting Disease Severity in Chlamydia psittaci Infection Based on Metagenomic Next-Generation Sequencing

Introduction

Psittacosis pneumonia, as a zoonotic infection, is induced by the pathogen Chlamydia psittaci. In the present study, we sought to characterize the clinical manifestations and prognosticate the severity of psittacosis pneumonia.

Methods

We retrospectively verified instances of psittacosis pneumonia in Zhejiang province, China, from January 2021 to April 2024. Relevant data pertaining to epidemiological, clinical, and laboratory aspects were compiled and evaluated.

Results

Among a total of 110 individuals enrolled who were diagnosed with psittacosis pneumonia, the median age being 62.0 years (IQR, 53-69 years). The most common comorbidities were hypertension (36.4%) and diabetes mellitus (17.3%). Patients categorized as having severe disease (n=68) were significantly older than those with mild disease (n=42). Most patients had notable elevations in aspartate aminotransferase (AST), creatine kinase (CK), creatine kinase-MB (CK-MB), lactate dehydrogenase (LDH), D-dimer, C-reactive protein (CRP), procalcitonin, total bilirubin (TBil), and interleukin-6, as along with significant reductions in lymphocytes, monocytes, albumin, and interleukin-4. Chest CT scans showed bilateral lung involvement in 70 cases. In the cohort of patients having received empirical antibiotic therapy, 57.3% had their antibacterial medication adjusted in light of the mNGS findings. mNGS results indicated that 31.8% (35/110) had suspected coinfections. The random forest classifiers based upon the clinical and laboratory characteristics attained AUC values of 0.822.

Discussion

The study underscores the efficacy of mNGS as a robust diagnostic tool for detecting Chlamydia psittaci, which can simultaneously detect other pathogens and guide clinical treatment. Severe patients exhibit significant inflammatory imbalances and lymphocyte depletion. A predictive model based on clinical and laboratory data at admission can effectively guide early clinical intervention.

A 5-transcript signature for discriminating viral and bacterial etiology in pediatric pneumonia

Pneumonia stands as the primary cause of death among children under five, yet current diagnosis methods often result in inadequate or unnecessary treatments. Our research seeks to address this gap by identifying host transcriptomic biomarkers in the blood of children with definitive viral and bacterial pneumonia. We performed RNA sequencing on 192 prospectively collected whole blood samples, including 38 controls and 154 pneumonia cases, uncovering a 5-transcript signature (genes FAM20A, BAG3, TDRD9, MXRA7, and KLF14) that effectively distinguishes bacterial from viral pneumonia (area under the curve (AUC): 0.95 [0.88-1.00]). Initial validation using combined definitive and probable cases yielded an AUC of 0.87 [0.77-0.97], while full validation in a new prospective cohort of 32 patients achieved an AUC of 0.92 [0.83-1.00]. This robust signature holds significant potential to enhance diagnostics accuracy for pediatric pneumonia, reducing diagnostic delays and unnecessary treatments and potentially transforming clinical practice.

Detecting Respiratory Pathogens for Diagnosing Lower Respiratory Tract Infections at the Point of Care: Challenges and Opportunities

Lower respiratory tract infections (LRTIs) are a leading cause of mortality worldwide, claiming millions of lives each year and imposing significant healthcare costs. Accurate detection of respiratory pathogens is essential for the effective management of LRTIs. However, this process often relies on sputum analysis, which requires extensive pretreatment steps. The viscous nature and complex composition of sputum present additional challenges, especially in settings where a rapid diagnosis at the point of care is essential. In this review, we describe the main types of LRTI, highlighting different patient care pathway and points of care. We review current methods for liquefying sputum samples and provide an overview of current commercially available diagnostic tools used in hospitals for LRTI detection. Furthermore, we critically review recent advancements in the literature focused on detecting respiratory pathogens and mechanisms of antimicrobial resistance in sputum, including nucleic acid amplification tests, immunoassays and other innovative approaches. Throughout the paper, we highlight challenges and opportunities associated with developing new biosensor technologies tailored for detecting respiratory pathogens in lower respiratory specimens. By shedding light on these pressing issues, we aim to inspire scientific community to create innovative diagnostic tools to address the urgent healthcare burden of lung diseases.

Case report: Clinical characteristics of anthrax meningoencephalitis: two cases diagnosed using metagenomic next-generation sequencing and literature review

Purpose

To explore the clinical features, diagnosis, treatment, and prognosis of anthrax meningoencephalitis.

Methods

The clinical data of two cases of anthrax meningoencephalitis were summarized and the relevant literature was reviewed.

Results

Both patients, who were farmers, had cutaneous lesions prior to the onset of meningoencephalitis. The clinical manifestations included fever (2/2), headache (2/2), stupor (2/2), meningeal signs (2/2), and lymph node enlargement (2/2). The CSF analysis showed erythrocytes, increased neutrophils, low glucose levels and high protein levels. CSF cytology revealed rod-shaped bacilli. Metagenomic next-generation sequencing of the CSF from both patients detected Bacillus anthracis. Additionally, cultures confirmed the presence of endogenous spores of macrobacteria. Brain imaging revealed subarachnoid hemorrhages and minimal cerebral edema. Despite aggressive antibiotic treatment, both patients died. Fifty-seven articles of the past 70 years were reviewed. There were 59 patients of anthrax meningoencephalitis in total, including 46 patients died. Stupor (42/46, 91.3% vs. 3/13, 46.2%, p = 0.001), agitation (15/46, 32.6% vs. 0/13, 0.0%, p = 0.043) and intracranial hemorrhage (37/46, 80.4% vs. 4/13, 30.8%, p = 0.002) were more common in the deceased group. Two types of bactericidal drugs or intrathecal injection drugs presented more often in the surviving group (10/13, 76.9% vs. 13/46, 28.3%, p = 0.001), whereas penicillin monotherapy presented more often in the deceased group (23/46, 50.0% vs. 2/13, 15.4%, p = 0.026).

Conclusion

Anthrax meningoencephalitis typically presents as a rapidly progressive bacterial meningoencephalitis. The occurrence of stupor, agitation and intracranial hemorrhage is possibly correlated with poor outcome. Two types of bactericidal drugs or intrathecal injection drugs are associated with better prognosis. Metagenomic next-generation sequencing can quickly and accurately detect B. anthracis in CSF.

Characteristics of plastic bronchitis in children with infectious pneumonia

BACKGROUND

Multiple studies have reported that infectious pneumonia can induce the production of plastic casts, which threatens children's health. We explored the characteristics of plastic bronchitis (PB) in clinical practice by analysing clinical medical records.

METHODS

A retrospective study was conducted. Children with pneumonia and large chest shadows were included in this study. The differences in characteristics between patients with plastic bronchitis and those without plastic bronchitis were analysed. The distribution of pathogens was statistically analysed. Grouping analysis based on PB and pathogen conditions was also conducted.

RESULTS

A total of 185 patients were included in this study. The patients were divided into two groups: the PB group (n = 48) and the non-PB group (n = 137). The duration of illness before hospitalization in the PB group was mostly longer than that in the non-PB group. The frequency distribution of the inspiratory three concave signs in the PB group was significantly greater than that in the non-PB group. Compared with those in the non-PB group, the number of patients with abnormally elevated of D-D dimer, LDH, ALT, and AST in the PB group was significantly greater. Mycoplasma pneumoniae (MP) was the main pathogen observed in both the PB and non-PB groups. In cases of MP infection without plastic bronchitis, treatment with macrolide antibiotics occurred significantly earlier. Most cases of pleural effusion in the PB-MP group were discovered more than 7 days after onset. However, in the PB-nonMP group, most cases of pleural effusion were detected within 7 days of onset. There was a difference observed in the distribution of pulmonary necrosis between the PB group and the non-PB group.

CONCLUSIONS

MP is a common pathogen observed in PB cases caused by single-pathogen infections and multiple-pathogen infections. PB may be a potential cause of pulmonary necrosis. Furthermore, PB exhibits diverse clinical manifestations due to host and pathogen factors.

The use of machine learning based models to predict the severity of community acquired pneumonia in hospitalised patients: A systematic review

Background

Community acquired pneumonia (CAP) is a common cause of hospital admission. CAP carries significant risk of adverse outcomes including organ dysfunction, intensive care unit (ICU) admission and death. Earlier admission to ICU for those with severe CAP is associated with better outcomes. Traditional prediction models are used in clinical practice to predict the severity of CAP. However, accuracy of predicting severity may be improved by using machine learning (ML) based models with added advantages of automation and speed. This systematic review evaluates the evidence base of ML-prediction tools in predicting CAP severity.

Methods

MEDLINE, EMBASE and PubMed were systematically searched for studies that used ML-based models to predict mortality and/or ICU admission in CAP patients, where a performance metric was reported.

Results

11 papers including a total of 351,365 CAP patients were included. All papers predicted severity and four predicted ICU admission. Most papers applied multiple ML algorithms to datasets and derived area under the receiver operator characteristic curve (AUROC) of 0.98 at best performance and 0.57 at worst, with a mixed performance against traditional prediction tools.

Conclusion

Although ML models showed good performance at predicting CAP severity, the variables selected for inclusion in each model varied significantly which limited comparisons between models and there was a lack of reproducible data, limiting validity. Future research should focus on validating ML predication models in multiple cohorts to derive robust, reproducible performance measures, and to demonstrate a benefit in terms of patient outcomes and resource use.

Impact of variations in airborne microbiota on pneumonia infection: An exploratory study

BACKGROUND

Previous studies showed airborne bacteria affect pneumonia incidence, but specific impacts of bacterial communities on Klebsiella pneumoniae infection were unknown.

METHODS

Five different ratios of bacterial community structures were randomly generated. Mice were divided into control, artificial bacterial community exposure, and corresponding Klebsiella pneumoniae challenge groups. Changes in body weight, blood parameters, pulmonary pathology, inflammatory factors, metabolomics, and fecal microbiota were analyzed.

RESULTS

Different bacterial community exposures had varying degrees of influence on body weight, complete blood count, inflammatory factors, alveolar lavage fluid and plasma metabolome, as well as intestinal microbiota at baseline and after infection. Metabolomic analysis showed that microbial exposure affected both bronchoalveolar lavage fluid and plasma metabolomes, suggesting systemic effects of microbial exposure on the organism. Differences in the structure of artificial microbiota had inconsistent effects on both the baseline state and the post-infection state, hinting at crosstalk between microbial exposure and Klebsiella pneumoniae infection. KEGG pathway analysis unveiled possible molecular mechanisms underlying the overall impact of microbial exposure on the lungs and the body as a whole. In the intestinal microbiota, differences were found in composition at the phylum and genus levels. Spearman correlation analysis established potential correlations between intestinal microbiota and differential metabolites, suggesting a potential link within the lung-gut axis.

CONCLUSION

This study demonstrated the significant and systemic impact of air microbiota structure differences on health. Future research should explore the underlying mechanisms to enhance our understanding of the air-environment-health relationship and identify interventions for improving public health strategies.

Pulmonary embolism in children with mycoplasma pneumonia: can it be predicted?

PURPOSE

To investigate the clinical characteristics of Mycoplasma pneumoniae (MP) pneumonia (MPP) combined with pulmonary embolism (PE) in children.

METHODS

291 hospitalized pediatric cases with MPP were enrolled from January 2018 to May 2024 and divided into the PE group (141 cases) and non-PE control group (150 cases). Clinical data of both groups were analyzed and compared.

RESULTS

C-reactive protein (CRP), D-dimer, lactate dehydrogenase (LDH), and interleukin 6 (IL-6) were significantly higher in the PE group than in the non-PE control group. There were 85 males and 56 females in the PE group. The PE group has male-to-female ratio of 3: 2,and hemoptysis was observed in 11 children (7.08%), chest pain in 29 children (20.60%), and pulmonary necrosis in 89 children (63.12%). In the receiver operator curve(ROC), the areas under the curve(AUC) for D-dimer, CRP, IL-6, and LDH were 0.964, 0.690, 0.632, and 0.765, respectively. In the ROC curve, the cutoff values for D-dimer, CRP, IL-6, and LDH were 0.8 µg/ml, 24.2 mg/L, 37.8 pg/ml, and 461 U/L, respectively.

CONCLUSION

A proportion of children with MP infection combined with PE show atypical clinical symptoms. Children with MPP and elevated D-dimer levels, IL-6, CRP, erythrocyte sedimentation rate (ESR), and LDH may be prone to develop PE.

Adult vaccinations against respiratory infections

INTRODUCTION

Lower respiratory infections have a huge impact on global health, especially in older individuals, immunocompromised people, and those with chronic comorbidities. The COVID-19 pandemic highlights the importance of vaccination. However, there are lower rates of vaccination in the adult population that are commonly due to a missed opportunity to vaccinate. Vaccination offers the best strategy to prevent hospitalization, complications, and death caused by lower respiratory infections.

AREAS COVERED

In this review, the authors provide an overview of the vaccines for lower respiratory infections in the adult population. The review highlights the available data about the impact of vaccines on preventing respiratory infections, focusing on the pneumococcal vaccine, influenza vaccine, COVID-19 vaccines, and respiratory syncytial virus (RSV) vaccines. The authors discuss the currently available scientific evidence on the role of vaccines against respiratory infections. Finally, the authors review the current recommendations for vaccines in the adult population.

EXPERT OPINION

Scientific evidence on the effectiveness of vaccines against respiratory infections is important. An efficient implementation of adult immunization strategies will provide an opportunity to decrease the global burden of lower respiratory infections. Recognizing the existing vaccines and their recommendations for the adult population is essential to achieve a high vaccination rate in the population.

CFTR as a therapeutic target for severe lung infection

Lung infection is one of the leading causes of morbidity and mortality worldwide. Even with appropriate antibiotic and antiviral treatment, mortality in hospitalized patients often exceeds 10%, highlighting the need for the development of new therapeutic strategies. Of late, cystic fibrosis transmembrane conductance regulator (CFTR) is-in addition to its well-established roles in the lung airway and extrapulmonary organs-increasingly recognized as a key regulator of alveolar homeostasis and defense. In the alveolar epithelium, CFTR mediates alveolar fluid secretion and liquid homeostasis; in the microvascular endothelium, CFTR maintains vascular barrier function. CFTR also contributes to alveolar immunity. Yet, in lung infection, diverse molecular mechanisms reduce CFTR abundance and otherwise impair its function, promoting alveolar inflammation, edema, and cell death. Preservation or restoration of CFTR function by CFTR modulator drugs thus presents a promising avenue to combat lung infection in a pathogen-independent manner.

Investigating mechanisms of Sophora davidii (Franch.) skeels flower extract in treating LPS-induced acute pneumonia based on network pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

In TCM opinion, most of pneumonia is related to "lung heat". Sophora davidii (Franch.) Skeels flower was first documented in "Guizhou Herbal Medicine", and was recorded as having functions of clearing heat, detoxifying, and cooling blood. It can be used to treat lung heat cough.

AIM OF THE STUDY

To investigate main mechanisms of Sophora davidii flower extract (SDFE) in Treating LPS-induced acute Pneumonia.

MATERIALS AND METHODS

Acute pneumonia models on BEAS-2B cells and rats were established using LPS. The rat model was used to verified the protective effects of SDFE through HE staining, lung tissue W/D ratio assay, white blood cell count analysis, and ammonia-induced coughing test. Network pharmacology was applied to predict the active compounds, core targets and main pathways of SDFE in treating acute pneumonia. Western Blot and ELISA kits were employed to validate representative proteins in selected pathway in vivo and in vitro.

RESULTS

HE staining, lung tissue W/D ratio assay, white blood cell count analysis, and ammonia-induced coughing test showed SDFE could improve pathological features (leukocyte infiltration, pulmonary edema, lung injury and cough). Network pharmacology indicated MAPK/NF-κB pathway was the most relevant pathway. SDFE could significantly inhibit the expression of Fos and Jun, and the phosphorylation levels of p38, ERK, JNK, NF-κB and IκB. It also down-regulated the expression of pro-inflammatory factors (TNF-α, IL-6 and IL-1β).

CONCLUSIONS

SDFE can exert protective effects against acute pneumonia through the MAPK/NF-κB signaling pathway.

Transforming Microbiological Diagnostics in Nosocomial Lower Respiratory Tract Infections: Innovations Shaping the Future

Introduction: Nosocomial lower respiratory tract infections (nLRTIs), including hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP), remain significant challenges due to high mortality, morbidity, and healthcare costs. Implementing accurate and timely diagnostic strategies is pivotal for guiding optimized antimicrobial therapy and addressing the growing threat of antimicrobial resistance. Areas Covered: This review examines emerging microbiological diagnostic methods for nLRTIs. Although widely utilized, traditional culture-based techniques are hindered by prolonged processing times, limiting their clinical utility in timely decision-making. Advanced molecular tools, such as real-time PCR and multiplex PCR, allow rapid pathogen identification but are constrained by predefined panels. Metagenomic next-generation sequencing (mNGS) provides comprehensive pathogen detection and resistance profiling yet faces cost, complexity, and interpretation challenges. Non-invasive methods, including exhaled breath analysis using electronic nose (e-nose) technology, gene expression profiling, and biomarker detection, hold promise for rapid and bedside diagnostics but require further validation to establish clinical applicability. Expert Opinion: Integrating molecular, metagenomic, biomarker-associated, and traditional diagnostics is essential for overcoming limitations. Continued technological refinements and cost reductions will enable broader clinical implementation. These innovations promise to enhance diagnostic accuracy, facilitate targeted therapy, and improve patient outcomes while contributing to global efforts to mitigate antimicrobial resistance.

The effect of immunosuppression on outcomes in elderly patients with community-acquired pneumonia

BACKGROUND

The effect of immunosuppression on clinical manifestations and outcomes was unclear in elderly patients with CAP.

METHODS

Elderly hospitalised patients with CAP were consecutively enrolled and were divided into immunocompromised hosts (ICHs) or non-ICHs groups. Clinical manifestations, severity, and outcomes were compared. The logistic regression model was used to determine the association between immunosuppression and outcomes. The primary outcome was 30-day mortality.

RESULTS

A total of 822 patients were enrolled, of whom 133 (16.2%) were immunocompromised. There were no differences between the two groups in vital signs, oxygenation, admission laboratory tests, need for mechanical ventilation and intensive care unit admission, except for a lower lymphocyte count in the ICH group (0.9*10^9/L, IQR 0.6-1.3*10^9/L [ICH group] vs. 1.2*10^9/L, IQR 0.8-1.7*10^9/L [non-ICH group]; p < 0.001). The 30-day mortality in ICHs was 15.8%, significantly higher than the 5.1% in non-ICHs (p < 0.001). The risk distribution of severity was similar between the two groups when assessed by CURB-65 on admission; however, the significant difference was found when assessed by PSI. Notably, in the CURB-65 low-risk group, the 30-day mortality was significantly higher in ICHs than in non-ICHs (9.7% vs. 1.1%, p < 0.001); but there was no difference between ICHs and non-ICHs in PSI low-risk group (3.7% vs. 0.6%; p > 0.05). After adjusting for age, sex, and comorbidities, immunosuppression was significantly associated with a higher risk of 30-day mortality (odds ratio 5.004, 95% CI [2.618-9.530]).

CONCLUSIONS

Immunosuppression was independently associated with an increased risk of 30-day mortality. CURB-65 may underestimate the mortality risk of ICHs.

Wavelength-Resolved Magnetic Multiplex Biosensor for Simultaneous and Ultrasensitive Detection of Pneumonia Pathogens via Catalytic Hairpin Assembly Strategy with Luminescent Iridium Complexes

Pneumonia is a prevalent acute respiratory infection and a major cause of mortality and hospitalization, and the urgent demand for a rapid, direct, and highly accurate diagnostic method capable of detecting both Streptococcus pneumoniae (S. pneumoniae) and Klebsiella pneumoniae (K. pneumoniae) arises from their prominent roles as the primary pathogens responsible for pneumonia. Herein, two luminescent iridium complexes with nonoverlapping photoluminescence spectra, iridium(III)-bis [4,6-(difluorophenyl)-pyridinato-N,C2'] picolinate (abbreviated as Ir-B) and bis (2-(3,5- dimethylphenyl) quinoline-C2,N') (acetylacetonato) iridium(III)) (abbreviated as Ir-R), were unprecedently proposed to construct a novel wavelength-resolved magnetic multiplex biosensor for simultaneous detection of S. pneumoniae and K. pneumoniae based on catalytic hairpin assembly (CHA) signal amplification strategy combined with dye-doped silica nanoparticles. Notably, the proposed wavelength-resolved multiplex biosensor not only exhibits a broad linear range from 50 pM to 10 nM but also demonstrates excellent recovery rates for S. pneumoniae (96.1-99.3%) and K. pneumoniae (94.8-101.5%) in real clinical samples, with corresponding relative standard deviation (RSD) values ranging from 2.57 to 3.15% for S. pneumoniae and 1.45 to 3.17% for K. pneumoniae. These favorable experimental outcomes undoubtedly offer a promising approach for the simultaneous detection of multiple pathogens in the future.

Comparative analysis of compartment-specific immunothrombotic biomarker profiles in bronchoalveolar lavage fluid and serum of patients with pneumonia-related acute respiratory distress syndrome: A preliminary cross-sectional study

Immunothrombosis has emerged as a potential mechanistic link underlying the development and progression of acute respiratory distress syndrome (ARDS), but understanding its specific profile in patients, both locally and systemically, is limited. The objective of this study was to characterize and compare the immunothrombotic signatures in patients diagnosed with pneumonia-related ARDS (p-ARDS) at both the pulmonary and systemic levels and to evaluate their clinical relevance. The study included 23 consecutive patients diagnosed with p-ARDS admitted to the intensive care unit at a tertiary university hospital from July 2022 to May 2023, alongside 40 concurrently hospitalized patients with common pneumonia as controls. Paired bronchoalveolar lavage fluid (BALF) and serum samples were collected from the participants for the analysis of 15 biomarkers to assess and quantify the pulmonary and systemic immunothrombotic signatures. The study results revealed significant pulmonary inflammation and systemic endothelial injury in p-ARDS patients compared to pneumonia controls. These observations were maintained after adjustment for severity of illness (Acute Physiology and Chronic Health Evaluation II scores). In terms of clinical relevance, inflammatory biomarkers (interleukin [IL]-6, IL-8) in BALF were found to correlate with PaO2/FiO2 ratio, while serum levels of a disintegrin and metalloproteinase with thrombospondin type 1 motif 13 (ADAMTS-13) and thrombomodulin showed associations with Sequential Organ Failure Assessment and Disseminated Intravascular Coagulation scores. In conclusion, this preliminary investigation identified compartment-specific variations in the immunothrombotic signature between patients with p-ARDS and those with pneumonia alone, with inflammatory responses predominantly localized in the alveolar compartments and coagulation/endothelial injury biomarkers more pronounced in peripheral blood.

Zwitterionic Polymer Lipid Nanoparticles Enabling Selective Organ Targeting Delivery of Small Interfering RNA for the Treatment of Hepatic and Pulmonary Inflammation

Lipid nanoparticles (LNPs) are clinically advanced small interfering RNA (siRNA) carriers, which can prevent the breakdown of siRNA during delivery and deliver siRNA into the cytoplasm to down-regulate the target gene. However, clinical LNPs are limited to the liver, and enhancing extrahepatic targeting is vital to expand the application of LNPs in vivo. Here, zwitterionic polymer LNPs (ZP-LNPs) are assembled with the zwitterionic polymer polycarboxybetaine (PCB) modified 1,2-dimyristoylglycerol (DMG) lipid DMG-PCBn can selectively deliver siRNA to liver and lung, respectively. Three libraries with 90 ZP-LNPs are established by adjusting the degree of polymerization of DMG-PCBn, the molar ratio of lipids, and the mass ratio between lipids and siRNA. Physicochemical and in vivo biodistribution results show that B4-3@siRNA and B5-1@siRNA with high siRNA encapsulation efficiency (>85%) achieve targeted siRNA delivery to the liver and lung, respectively. The mechanism findings indicate that pKa and protein corona are essential to determine the in vivo fate of ZP-LNPs and tendency for specific organs. Importantly, these two ZP-LNPs with siTNF-α can effectively reduce the levels of tumor necrosis factor α (TNF-α) in mice with hepatic inflammation and pulmonary inflammation, respectively, indicating their promising application for the treatment of diseases associated with liver and lung.

Clinical Application of Metagenomic Next-Generation Sequencing (mNGS) in Patients with Early Pulmonary Infection After Liver Transplantation

Purpose

To examine the clinical utility of metagenomic next-generation sequencing (mNGS) in individuals with early pulmonary infection following liver transplantation.

Patients and Methods

mNGS and traditional detection results were retrospectively collected from 99 patients with pulmonary infection within one week following liver transplantation. These patients were admitted to the Department of Critical Liver Diseases at Beijing Friendship Hospital from February 2022 to February 2024, along with their general clinical data.

Results

mNGS exhibited a significantly higher detection rate than traditional methods (92.93% vs 54.55%, P < 0.05) and was more effective in identifying mixed infections (67.68% vs 14.81%, P < 0.05). mNGS identified 303 pathogens in 92 patients, with Enterococcus faecium, Pneumocystis jirovecii, and human herpesvirus types 5 and 7 being the most prevalent bacteria, fungi, and viruses. A total of 26 positive cases were identified through traditional culture methods (sputum and bronchoalveolar lavage fluid), with 18 cases consistent with mNGS detection results, representing 69.23% consistency. Among the three drug-resistant bacteria that showed positivity in mNGS and traditional culture, the presence of drug-resistance genes-mecA in Staphylococcus aureus; KPC-2, KPC-9, KPC-18, KPC-26, OXA27, OXA423 in Klebsiella pneumoniae; and OXA488 and NDM6 in Pseudomonas aeruginosa-reliably predicted drug-resistance phenotype. The treatment regimen for 76 of the 92 patients with positive mNGS relied on these results; 74 exhibited significant symptom improvement, yielding a 97.37% recovery rate. The overall prognosis was favorable.

Conclusion

mNGS offers rapid detection, a high positivity rate, insensitivity to antibiotics, and a superior ability to detect mixed infections in patients with early post-transplant pulmonary infections. Additionally, mNGS shows good consistency with traditional culture and can predict drug-resistant phenotypes to guide targeted antibiotic therapy for early-stage post-transplant pulmonary infection after liver transplantation. Patients whose antibiotic therapy is based on mNGS results have experienced decreased mortality rates and overall improved prognosis.

Inflammatory Effects and Regulatory Mechanisms of Chitinase-3-like-1 in Multiple Human Body Systems: A Comprehensive Review

Chitinase-3-like-1 (Chi3l1), also known as YKL-40 or BRP-39, is a highly conserved mammalian chitinase with a chitin-binding ability but no chitinase enzymatic activity. Chi3l1 is secreted by various cell types and induced by several inflammatory cytokines. It can mediate a series of cell biological processes, such as proliferation, apoptosis, migration, differentiation, and polarization. Accumulating evidence has verified that Chi3l1 is involved in diverse inflammatory conditions; however, a systematic and comprehensive understanding of the roles and mechanisms of Chi3l1 in almost all human body system-related inflammatory diseases is still lacking. The human body consists of ten organ systems, which are combinations of multiple organs that perform one or more physiological functions. Abnormalities in these human systems can trigger a series of inflammatory environments, posing serious threats to the quality of life and lifespan of humans. Therefore, exploring novel and reliable biomarkers for these diseases is highly important, with Chi3l1 being one such parameter because of its physiological and pathophysiological roles in the development of multiple inflammatory diseases. Reportedly, Chi3l1 plays an important role in diagnosing and determining disease activity/severity/prognosis related to multiple human body system inflammation disorders. Additionally, many studies have revealed the influencing factors and regulatory mechanisms (e.g., the ERK and MAPK pathways) of Chi3l1 in these inflammatory conditions, identifying potential novel therapeutic targets for these diseases. In this review, we comprehensively summarize the potential roles and underlying mechanisms of Chi3l1 in inflammatory disorders of the respiratory, digestive, circulatory, nervous, urinary, endocrine, skeletal, muscular, and reproductive systems, which provides a more systematic understanding of Chi3l1 in multiple human body system-related inflammatory diseases. Moreover, this article summarizes potential therapeutic strategies for inflammatory diseases in these systems on the basis of the revealed roles and mechanisms mediated by Chi3l1.

Potential Use of GLP-1 and GIP/GLP-1 Receptor Agonists for Respiratory Disorders: Where Are We at?

Chronic respiratory disorders are the third leading cause of mortality globally. Consequently, there is a continuous pursuit of effective therapies beyond those currently available. The therapeutic potential of the glucagon-like peptide-1 (GLP-1) and the glucose-dependent insulinotropic polypeptide/GLP-1 (GIP/GLP-1) receptor agonists extends beyond the regulation of glycemia, including glucometabolic, cardiovascular, and renal effects, rendering them viable candidates, due to their mechanisms of action, for the possible treatment of respiratory disorders. This manuscript aims to provide a comprehensive evaluation of the evidence on potential direct (cellular) and indirect (metabolic) actions of GLP-1 and GIP/GLP-1 receptor agonists within the pulmonary systems. In addition, it examines their efficacy in addressing prevalent respiratory disorders, specifically chronic obstructive pulmonary disease (COPD), asthma, pneumonia, obstructive sleep apnea, pulmonary hypertension, lung cancer, and lung transplantation. Finally, the manuscript seeks to identify potential avenues for further focused research in this field.

Pneumococcal pneumonia is driven by increased bacterial turnover due to bacteriocin-mediated intra-strain competition

Using chromosomal barcoding, we observed that >97% of the Streptococcus pneumoniae (Spn) population turns over in the lung within 2 days post-inoculation in a murine model. This marked collapse of diversity and bacterial turnover was associated with acute inflammation (severe pneumococcal pneumonia), high bacterial numbers in the lungs, bacteremia, and mortality. Intra-strain competition mediated by the blp locus, which expresses bacteriocins in a quorum-sensing-dependent manner, was required for each of these effects. Bacterial turnover from the activity of Blp-bacteriocins increased the release of the pneumococcal toxin, pneumolysin (Ply), which was sufficient to account for the lung pathology. The ability of Ply to evade complement, rather than its pore-forming activity, prevented opsonophagocytic clearance of Spn enabling its multiplication in the lung, facilitating the inflammatory response and subsequent invasion into the bloodstream. Thus, our study demonstrates how an appreciation for bacterial population dynamics during infection provides new insight into pathogenesis.

Anti-inflammatory Effect of Symplocos prunifolia Extract in an In Vitro Model of Acute Pneumonia

Acute pneumonia is a respiratory disease characterized by inflammation within the lung tissue, exhibiting higher morbidity rates and mortality rates among immunocompromised children and older adults. Symplocos species have been traditionally used as herbal remedies for conditions like dysentery, skin ulcers, diarrhea, and dyspepsia. Contemporary research has employed various Symplocos species in the study of diverse diseases. However, the exact efficacy and mechanisms of action of Symplocos Prunifolia remain unknown. Therefore, this study investigated the anti-inflammatory mechanism of S. prunifolia extract (SPE) in A549 and RAW264.7 cells stimulated by lipopolysaccharide (LPS). SPE significantly reduced nitric oxide (NO) production and the protein expression levels of like inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in LPS-stimulated RAW 264.7 cells. Furthermore, it reduced the protein expression levels of iNOS, COX-2 and the levels of pro-inflammatory cytokines in LPS-stimulated A549 cells. The mechanism underlying the anti-inflammatory effect of SPE was associated with the inhibition of LPS stimulated the phosphoinositide-3-kinase/protein kinase B (PI3K/Akt) and Mitogen-activated protein kinase (MAPK) phosphorylation. Moreover, we confirmed that SPE decreased the nuclear translocation of nuclear factor-κB (NF-κB)/p65 stimulated by LPS. In conclusion, these results demonstrate that SPE alleviates inflammatory responses by deactivating the PI3K/Akt, MAPK, and NF-κB signaling pathways. Our findings suggest that SPE is a potential candidate for acute pneumonia prevention.

Serum Albumin-to-Creatinine Ratio: A Novel Predictor of Pulmonary Infection in Patients with ST-Segment Elevation Myocardial Infarction Undergoing Percutaneous Coronary Intervention

AIM

In patients with ST-segment elevation myocardial infarction (STEMI) undergoing percutaneous coronary intervention (PCI), a low serum albumin-to-creatinine ratio (sACR) is associated with elevated risk of poor short- and long-term outcomes. However, the relationship between sACR and pulmonary infection during hospitalization in patients with STEMI undergoing PCI remains unclear.

METHODS

A total of 4,507 patients with STEMI undergoing PCI were enrolled and divided into three groups according to sACR tertile. The primary outcome was pulmonary infection during hospitalization, and the secondary outcome was in-hospital major adverse cardiovascular events (MACE) including stroke, in-hospital mortality, target vessel revascularization, recurrent myocardial infarction, and all-cause mortality during follow-up.

RESULTS

Overall, 522 (11.6%) patients developed pulmonary infections, and 223 (4.9%) patients developed in-hospital MACE. Cubic spline models indicated a non-linear, L-shaped relationship between sACR and pulmonary infection (P=0.039). Receiver operating characteristic curve analysis indicated that sACR had good predictive value for both pulmonary infection (area under the ROC curve [AUC]=0.73, 95% CI=0.70-0.75, P＜0.001) and in-hospital MACE (AUC=0.72, 95% CI=0.69-0.76, P＜0.001). Kaplan-Meier survival analysis indicated that higher sACR tertiles were associated with a greater cumulative survival rate (P＜0.001). Cox regression analysis identified lower sACR as an independent predictor of long-term all-cause mortality (hazard ratio [HR]=0.96, 95% CI=0.95-0.98, P＜0.001).

CONCLUSIONS

A low sACR was significantly associated with elevated risk of pulmonary infection and MACE during hospitalization, as well as all-cause mortality during follow-up among patients with STEMI undergoing PCI. These findings highlighted sACR as an important prognostic marker in this patient population.

Demonstration of Resolution of Community-Acquired Pneumonia Over a Short Course of Antibiotics on [ 18 F]FDG-PET/CT Undertaken for Suspected Perimyocarditis Evaluation

A 28-year-old male presenting with left-sided pleuritic chest pain, cough, palpitation, and fever with mild ST depression in II, III, and aVF, raised troponin I, troponin T, creatine phosphokinase-MB, and erythrocyte sedimentation rate was referred for F-18 2-fluoro 2-deoxyglucose positron emission tomography with noncontrast computed tomography ([ 18 F]FDG-PET/CT) to rule out perimyocarditis. The first scan revealed incidental finding of [ 18 F]FDG avid left lobar pneumonia and inadequate myocardial suppression, thus perimyocarditis could not be ruled out. The clinician was informed and after counseling, patient consented for a repeat study post-high fat-low carbohydrate diet. A regional [ 18 F]FDG-PET/CT on the 5th day revealed adequate myocardial suppression, ruling out perimyocarditis. However, the metabolic and anatomical resolution of previously noted left lobar pneumonia was also observed in such a span of time with the administered antibiotics.