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Background and Purpose: Toll‐like receptors 4 (TLR4) and TLR7/TLR8 play an important role in mediating the inflammatory effects of bacterial and viral pathogens. Interleukin‐1 receptor‐associated kinase 4 (IRAK4) is an important regulator of signalling by toll‐like receptor (TLR) and hence is a potential therapeutic target in diseases characterized by increased lung inflammatory signalling. Experimental Approach: We used an established murine model of acute lung inflammation, and studied human lung tissue ex vivo, to investigate the effects of inhibiting IRAK4 on lung inflammatory pathways. Key Results: We show that TLR4 stimulation produces an inflammatory response characterized by neutrophil influx and tumour necrosis factor‐α (TNF‐α) production in murine lungs and that these responses are markedly reduced in IRAK4 kinase‐dead mice. In addition, we characterize a novel selective IRAK4 inhibitor, BI1543673, and show that this compound can reduce lipopolysaccharide (LPS)‐induced airway inflammation in wild‐type mice. Additionally, BI1543673 reduced inflammatory responses to both TLR4 and TLR7/8 stimulation in human lung tissue studied ex vivo. Conclusion and Implications: These data demonstrate a key role for IRAK4 signalling in lung inflammation and suggest that IRAK4 inhibition has potential utility to treat lung diseases characterized by inflammatory responses driven through TLR4 and TLR7/8. [ABSTRACT FROM AUTHOR]

Background: Correctly diagnosing and accurately distinguishing mycoplasma pneumonia in children has consistently posed a challenge in clinical practice, as it can directly impact the prognosis of affected children. To address this issue, we analyzed chest X-rays (CXR) using various deep learning models to diagnose pediatric mycoplasma pneumonia. Methods: We collected 578 cases of children with mycoplasma infection and 191 cases of children with virus infection, with available CXR sets. Three deep convolutional neural networks (ResNet50, DenseNet121, and EfficientNetv2-S) were used to distinguish mycoplasma pneumonia from viral pneumonia based on CXR. Accuracy, area under the curve (AUC), sensitivity, and specificity were used to evaluate the performance of the model. Visualization was also achieved through the use of Class Activation Mapping (CAM), providing more transparent and interpretable classification results. Results: Of the three models evaluated, ResNet50 outperformed the others. Pretrained with the ZhangLabData dataset, the ResNet50 model achieved 80.00% accuracy in the validation set. The model also showed robustness in two test sets, with accuracy of 82.65 and 83.27%, and AUC values of 0.822 and 0.758. In the test results using ImageNet pre-training weights, the accuracy of the ResNet50 model in the validation set was 80.00%; the accuracy in the two test sets was 81.63 and 62.91%; and the corresponding AUC values were 0.851 and 0.776. The sensitivity values were 0.884 and 0.595, and the specificity values were 0.655 and 0.814. Conclusions: This study demonstrates that deep convolutional networks utilizing transfer learning are effective in detecting mycoplasma pneumonia based on chest X-rays (CXR). This suggests that, in the near future, such computer-aided detection approaches can be employed for the early screening of pneumonia pathogens. This has significant clinical implications for the rapid diagnosis and appropriate medical intervention of pneumonia, potentially enhancing the prognosis for affected children. [ABSTRACT FROM AUTHOR]

Despite the recognized clinical significance of vitamin D deficiency in other solid organ transplant recipients, its specific relevance in lung transplantation remains to be fully understood. In this study, we performed a retrospective observational study on the impact of vitamin D deficiency on clinical outcomes and prognosis in 125 lung transplant recipients (LTRs) from October 2014 to March 2020 at a university hospital in Seoul, South Korea. Among 125 LTRs, 51 patients (40.8%) were vitamin D deficient. LTRs in the vitamin D-deficient group exhibited a higher incidence of post-transplant pneumonia and overall mortality than those with normal vitamin D levels during the follow-up period. This trend persisted when subjects were stratified into vitamin D tertiles. Furthermore, post-transplant vitamin D levels and C-reactive protein (CRP) significantly impacted pneumonia incidence and survival outcomes. Prognosis also varied based on cumulative vitamin D supplementation after transplantation, with patients receiving higher cumulative supplementation demonstrating improved prognosis. Our findings underscore the importance of assessing and maintaining optimal vitamin D levels post-transplantation, suggesting a potential avenue for improving outcomes in lung transplant recipients, especially in mitigating infection risk and enhancing long-term survival. Further research into optimal vitamin D levels and supplementation strategies in this population is warranted. [ABSTRACT FROM AUTHOR]

Rhodococcus equi is a rare human opportunistic pathogen that has been increasingly reported in recent decades. It mainly affects immunosuppressed patients, and in particular human immunodeficiency virus (HIV)–infected patients, where it typically presents as cavitary pneumonia. Early treatment with combined and effective antimicrobials and antiretroviral therapy after prompt diagnosis is essential to ensure an optimal outcome. We present a case series of three human Rhodococcus equi infections in HIV‐infected patients with advanced immune suppression, treated at the University Hospital of Antwerp, Belgium. [ABSTRACT FROM AUTHOR]

Background: Sheep are a rarely raised livestock in Hainan Island, China, because of the unfavorable tropical marine climate. Here, this article reports a severe pneumonia in the sheep breeding and domestication facility caused acute mortality during the winter 2021–2022. Methods: Six sheep were clinically dissected and histopathologically observed. The bacteria were isolated and cultured by traditional methods and identified by 16S rRNA sequencing. The genotypes, serotypes, virulence genes and antimicrobial resistance genes were analyzed by PCR and whole genome sequencing. The pubMLST website was used for phylogenetic analysis of related strains. Kirby-Bauer disk diffusion method was used for antimicrobial susceptibility test. The antimicrobial susceptibility test standard was referred to the Clinical and Laboratory Standards Institute (CLSI). The virulence of bacteria was detected by mouse infection model. Results: Etiology and histopathology examination of the pneumonia reveled pulmonary abscess and alveolar neutrophilia and pulmonary fibrinous exudates. Escherichia coli was the only bacterial species isolated, primarily from the lungs and blood of the six dead or moribund sheep, a total of 29 E. coli strains were isolated. Antimicrobial resistance profiling shows that all the isolates were resistant to six agents (penicillin, ampicillin, cephalothin, neomycin, erythromycin, and vancomycin) belonging to five classes of antibiotics, classifying them as multi drug resistant (MDR). Furthermore, genotyping analysis revealed all strains were common with 11–17 virulence factors indicating high pathogenicity. The lab mice infection model shows that all strains severely affect the health status particularly weight loss, lethargy, pneumonia and shortly lead to death. The molecular epidemiological analysis indicated most strains share the same genotype as previously reported strains in humans and other farmed animals this suggests a high possibility of cross-species transmission (CST) of virulent and MDR isolates. This CST could be from sheep to humans and other farmed animals or from humans and other farmed animals to sheep. Conclusion: Therefore, this study indicates that E. coli is an emerging threat that causes sheep pneumonia in Hainan, and the quarantine of contacts is important to control the spread of virulent E. coli and the transmission of acquired resistance genes between humans and farmed animals such as sheep. [ABSTRACT FROM AUTHOR]

Caveolin-1 (Cav-1), a structural and functional component in the caveolae, plays a critical role in transcytosis, endocytosis, and signal transduction. Cav-1 has been implicated in the mediation of cellular processes by interacting with a variety of signaling molecules. Cav-1 is widely expressed in the endothelial cells, smooth muscle cells, and fibroblasts in the various organs, including the lungs. The Cav-1-mediated internalization and regulation of signaling molecules participate in the physiological and pathological processes. Particularly, the MAPK, NF-κB, TGFβ/Smad, and eNOS/NO signaling pathways have been involved in the regulatory effects of Cav-1 in lung diseases. The important effects of Cav-1 on the lungs indicate that Cav-1 can be a potential target for the treatment of lung diseases. A Cav-1 scaffolding domain peptide CSP7 targeting Cav-1 has been developed. In this article, we mainly discuss the structure of Cav-1 and its critical roles in lung diseases, such as pneumonia, acute lung injury (ALI), asthma, chronic obstructive pulmonary disease (COPD), pulmonary hypertension, pulmonary fibrosis, and lung cancer. [ABSTRACT FROM AUTHOR]

Background: Streptococcus salivarius is an opportunistic pathogen, and there have been no reported cases of Streptococcus salivarius pneumonia to date. Pneumomediastinum is usually secondary to tracheal or esophageal injury and is very rare as a complication of pneumonia. We report a case of Streptococcus salivarius pneumonia complicated by pneumomediastinum, aiming to enhance clinicians' awareness of rare pathogens and uncommon complications in pneumonia. Case presentation: The patient, a 36-year-old male, presented with a persistent cough and sputum production for one week, accompanied by a sore throat that had developed just one day prior. Chest computed tomography (CT) disclosed pneumomediastinum alongside obstructive atelectasis in the left lower lobe. Streptococcus salivarius infection was conclusively identified through bronchoalveolar lavage metagenomic next-generation sequencing (mNGS), as well as smear and culture analyses. The patient was administered intravenous amoxicillin-clavulanate potassium for a duration of seven days as part of the anti-infection regimen. Given the stability of the patient's respiratory and circulatory systems, a tube drainage procedure was deemed unnecessary. Post-treatment, the patient's clinical symptoms notably improved. A subsequent chest CT scan revealed the re-expansion of the left lower lung and near-complete resolution of pneumomediastinum. Conclusion: There are numerous pathogens that can cause pneumonia. While focusing on common pathogens, it is important not to overlook rare ones. When considering infections from rare pathogens, it is recommended to promptly perform a bronchoscopy and submit bronchoalveolar lavage fluid for mNGS to improve pathogen detection rates. During the diagnosis and treatment of pneumonia, it is crucial to be vigilant for rare complications. When a patient presents with symptoms such as dyspnea or subcutaneous emphysema, it is advisable to immediately perform a chest CT scan to rule out pneumomediastinum. [ABSTRACT FROM AUTHOR]

Postoperative pneumonia (POP) is a common complication after hip fracture surgery and is associated with increased mortality and other complications in elderly patients. This study aims to evaluate biomarkers, especially the glucose-albumin ratio (GAR), for predicting POP in elderly hip fracture patients. A total of 1279 elderly patients admitted to our hospital with hip fractures were included. We assessed 29 biomarkers and focused on GAR to determine its prognostic and predictive value for POP. Multivariable logistic regression and propensity score-matched analyses were conducted to calculate adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for POP, adjusting for potential confounders. Receiver operating characteristic (ROC) curves were utilized to determine the optimal cut-off of GAR for predicting POP. Among the biomarkers and combinations assessed, GAR demonstrated superior predictive capability for POP in elderly hip fracture patients. ROC analyses showed moderate predictive accuracy of GAR for POP, with an area under the curve of 0.750. Using the optimal cut-off of 0.175, the high GAR group was significantly associated with increased odds of POP (adjusted OR 2.14, 95%, CI 1.50–3.05). These associations remained significant after propensity score matching and subgroup analyses. Dose–response relationships between GAR and POP were observed. In conclusion, GAR may be a promising biomarker to predict POP risk in elderly hip fracture patients. Further studies are warranted to validate its clinical utility. However, this study has certain limitations, including its retrospective design, potential for selection bias due to the exclusion criteria, and the single-center nature of the study, which should be addressed in future prospective, multicenter studies. [ABSTRACT FROM AUTHOR]

Background Objectives Methods Results Conclusions Respiratory dysfunction is an important contributor to morbidity and mortality in advanced Parkinson's disease (PD), but it is unclear what parameters are sensitive to diagnose and monitor respiratory dysfunction across disease phases.We aimed to characterize respiratory dysfunction in mild to moderate PD.In 20 individuals without cardiopulmonary comorbidity, pulmonary and inspiratory muscle function testing were performed ON‐medication. Subsequently, the acute ventilatory response to hypoxia (HVR) was assessed by gradually decreasing FIO2 from 0.209 (room air) to 0.127, which was compared to eight age‐ and sex‐matched healthy controls under arterial blood gas monitoring. Lastly, on different days, the same 20 individuals with PD underwent six blinded exposures to 45‐min normobaric hypoxia at FiO2 0.163 and 0.127 or placebo OFF‐medication to assess breathing responses.At rest, individuals with greatest PD severity had a lower tidal volume (pairwise comparisons: 0.59 vs. 0.74, P = 0.038–0.050) and tended to have a higher breathing frequency (17.7 vs. 14.4, P = 0.076), despite normal pulmonary function. A 45‐min exposure to hypoxia induced a significantly lower acute HVR in individuals with PD compared to controls (−0.0489 vs. 0.133 L.min/%, P = 0.0038). Acute HVR was reduced regardless of disease severity. Subacute HVR in individuals with milder disease tended to be higher compared to those with more advanced disease (P = 0.079).Respiratory dysfunction is present in individuals with PD, including those with relatively mild disease severity, and is characterized by altered breathing patterns at rest, as well as a lower HVR, despite normal pulmonary and inspiratory muscle function testing. [ABSTRACT FROM AUTHOR]

AbstractThe purpose of this narrative review is to analyze the most recent studies about the role of C-reactive protein (CRP) and procalcitonin (PCT), two of the main biomarkers of infection, in distinguishing viral from bacterial etiology, in predicting the severity of infection and in guiding antibiotic stewardship in children with community-acquired pneumonia (CAP). The studies examined reveal that both CRP and PCT play a valuable role in diagnosing pediatric CAP, though each has limitations. CRP has moderate accuracy in distinguishing bacterial from viral infections, but its elevated levels are not exclusive to bacterial infections; PCT, however, shows higher specificity for bacterial CAP, with studies confirming its ability to differentiate bacterial causes, especially in severe cases. When integrated with clinical findings, CRP and PCT improve the sensitivity of pneumonia diagnoses and help in predicting severe outcomes such as sepsis and empyema; furthermore, both biomarkers prove useful in guiding antibiotic therapy, with PCT showing a more dynamic response to treatment. However, even though CRP and PCT offer valuable insights into the diagnosis and management of pediatric CAP, their application should be always integrated with clinical assessment rather than used in isolation. More studies are needed to define standardized thresholds and decision algorithms that incorporate these biomarkers. [ABSTRACT FROM AUTHOR]

Background: Streptococcus pneumoniae is the most frequent causative pathogen of bacterial pneumonia in children worldwide. Bangladesh introduced the 10-valent pneumococcal conjugate vaccine (PCV10) in their national immunization program for infants in 2015. We assessed its potential coverage in under-fives with community-acquired pneumonia (CAP) in the years before PCV10 was introduced. Methods: A total of 1502 childhood pneumonia cases (< 5 year olds living in the urban section Kamalapur, Dhaka) were enrolled between 2011 and 2013. Acute phase and late (convalescent) serum samples were collected from 1380 cases. Serotype-specific pneumococcal antibody concentrations were measured using a 25-plex immunoassay panel. Pneumococcal CAP was diagnosed based on a serotype-specific pneumococcal antibody response. Results: S. pneumoniae was serologically identified as causative pathogen in 406/1380 (29%) cases. The five most prevalent serotypes were (in descending order) 11A, 22F, 3, 2 and 19F. Based on the percentage of pneumonia cases associated with PCV10 vaccine types, the potential PCV10 coverage was 29% (116/406). Conclusions: In almost a third of the studied cases S. pneumoniae was identified as a causative pathogen. Because of the characteristics of the immunoassay, this might well be a gross underestimation. Nevertheless, the potential PCV10-coverage was low. Given the high serotype diversity, the region might benefit greatly from a higher-coverage PCV or recombinant protein vaccine. [ABSTRACT FROM AUTHOR]

Purpose: The present study explored the molecular characterization of human Adenovirus (HAdV) and its strains among hospitalized SARI cases in the pediatric unit of a tertiary care hospital in North-East India. Methods: Nasal and throat swabs were collected from 70 patients of Pediatric Unit, of a tertiary hospital in NE India from April 2023-October 2023. The samples were screened for the presence of HAdV using an adenovirus-specific Real-Time PCR Kit. For molecular characterization, Next Generation Sequencing (NGS) was performed by targeting the hexon gene of HAdV followed by post-sequencing analysis. Results: Overall, 18.57% (13/70) of samples were positive for HAdV. In context of the severity of illness, 3/13 adenovirus-positive patients (23.07%) died after hospitalization, had severe pneumonia among which two were of less than one year of age. Molecular characterization using NGS indicated that 4/13 individuals were infected with HAdV-B type 3 and 5/13 patients were infected with HAdV type 7. Notably, 4/7 cases of severe pneumonia were under five years of age and associated with HAdV type 7 infection. The ratio of non-synonymous to synonymous mutation (dN/dS) was comparatively low in HAdV type 7 positive samples (dN/dS=0.31). No non-synonymous mutation was observed in HAdV-B type 3 positive samples. The higher neutrophil percentage among the death cases suggested an acute immune response. Conclusion: The study demonstrated HAdV type 7 and HAdV-B type 3 as strains associated with pediatric SARI cases from April 2023-October 2023. Further, HAdV type 7 infection was primarily linked with lower respiratory tract infections mainly severe pneumonia. [ABSTRACT FROM AUTHOR]

Viral pneumonia is characterized by inflammation in the lungs triggered by respiratory viruses. Dayuan Yin (DYY), a traditional Chinese medicine formula known for treating infectious diseases, is hypothesized to offer therapeutic benefits in treating viral pneumonia, although its specific molecular impacts remain understudied. This study aimed to evaluate the therapeutic effects of DYY in mitigating HCoV-229E virus-induced pneumonia in mice. This study employed an HCoV-229E virus-infected mouse model to investigate the therapeutic potential and underlying molecular mechanisms of DYY on virus-induced pneumonia. The respiratory function and organ indices post-treatment were assessed. Lung tissue and tracheal lesions were evaluated via immunohistochemistry. Spleen immune cell composition was analyzed using flow cytometry. Inflammatory cytokines and viral loads were quantified using hypersensitive multiplex electrochemiluminescence method and PCR analysis, respectively. The expression levels of MAS1, Ras, Raf1, MEK1/2, and ERK1/2 in lung tissues were determined through western blot analysis. DYY significantly improved respiratory function, and reduced organ pathology in infected mice. It effectively decreased viral loads and inflammatory cytokines such as IL-6, IL-1β, and TNF-α in lung tissues. Enhancements in immune response were evidenced by increased CD4/CD8 ratios in the spleen. DYY also notably upregulated MAS1 protein levels and suppressed the activation of the Ras/Raf1/MEK/ERK signaling pathway. DYY enhanced respiratory function and exerted significant antiviral and immunomodulatory effects in mice infected with the HCoV-229E virus, primarily by modulating MAS1 expression and inhibiting the Ras/Raf1/MEK/ERK pathway. [ABSTRACT FROM AUTHOR]

Diagnosing the cause of death can be challenging, particularly for patients with no prior history of visits to the treating hospital. We encountered a case involving a 76‐year‐old male who was discovered in a state of cardiopulmonary arrest at his home and subsequently declared deceased in our hospital due to severe pneumonia. He had exhibited symptoms of fever over 37°C and severe coughing for several days. Despite consulting a primary care physician one day prior, his symptoms worsened. Autopsy findings revealed an increase in lung weight and diffuse changes in parenchyma. Histological analysis showed numerous inflammatory cells and exudate within the alveoli. Gram and Periodic acid‐Schiff staining were negative, but slight staining was observed in the cytoplasm of macrophages by Warthin‐starry and Gimenez stains. Tests using a pan bacterial/viral detection kit and qualitative polymerase chain reaction (PCR) for Legionella pneumophila were negative. However, using deoxyribonucleic acid extracted from formalin‐fixed paraffin‐embedded lung tissue, PCR amplification of the ssrA gene of congeneric Legionella species yielded positive results. The results suggest that the cause of death was likely due to bacterial pneumonia caused by Legionella species. [ABSTRACT FROM AUTHOR]

Background: Pneumonia remains one of the most common causes of hospitalization and is leading cause of morbidity and mortality. Some studies have reported a relationship between serum levels of vitamin D and an increased incidence of pneumonia. The aim of this work was to assess vitamin D in infants, toddlers and preschool children suffering from pneumonia and correlate its level with severity, duration of hospital stay and outcome. Methods: This cross-sectional study wasconducted on 120 preschool children. They suffered frompneumonia and were admitted to the PICU and Pulmonology Unit, Children's Hospital Zagazig University from July 2021 to June 2022. A complete clinical examination was performed with special concern for anthropometric measurements, a history of sun exposure, a history of Ca and vitamin D supplementation, a previous history of LRTIS, a duration of hospital stay, a chest examination, signs of respiratory distress, CBC, CRP, blood pH and vitamin D. Results: The study included 51 (42.5%) infants, 53(44.2%) toddlers and 16 (13.3%) preschool children. Their ages ranged from 6 to 56 months. Regarding of severity, 49.2% of patients had severe pneumonia and 50.8% had very severe pneumonia. Vitamin D was insufficient in 14.2%, deficient in 73.3% and severely deficient in 12.5% of the patients. There was a significant relationship between vitamin D and the severity of pneumonia, duration of hospital stay, need for PICU and outcome. Conclusions: The role of vitamin D in the severity of pneumonia, duration of hospital stay and outcomes in children between 6 and 60 months could be assured. [ABSTRACT FROM AUTHOR]

Simple Summary: Our research explores the profile and risk factors for infections in multiple myeloma patients undergoing treatment with daratumumab, a key drug in chemotherapy regimens for this disease. The study seeks to identify which patients are at the highest risk of developing severe infections and the factors contributing to this risk, as infections are a major concern for these patients. Analysis of patient data from our facility showed that lower hemoglobin levels and poorer performance status significantly increase the risk of serious infections. Additionally, we developed predictive algorithms to identify individuals at elevated risk of developing pneumonia during treatment. The findings from our study may help healthcare providers identify high-risk patients and implement targeted strategies to prevent infections, ultimately improving patient care. Background: Daratumumab (Dara) is the first monoclonal antibody introduced into clinical practice to treat multiple myeloma (MM). It currently forms the backbone of therapy regimens in both newly diagnosed (ND) and relapsed/refractory (RR) patients. However, previous reports indicated an increased risk of infectious complications (ICs) during Dara-based treatment. In this study, we aimed to determine the profile of ICs in MM patients treated with Dara-based regimens and establish predictors of their occurrence. Methods: This retrospective, real-life study included MM patients treated with Dara-based regimens between July 2019 and March 2024 at our institution. Infectious events were evaluated using the Terminology Criteria for Adverse Events (CTCAE) version 5.0. Results: The study group consisted of a total of 139 patients, including 49 NDMM and 90 RRMM. In the RR setting, the majority (60.0%) of patients received the Dara, bortezomib, and dexamethasone (DVd) regimen, whereas ND patients were predominantly (98%) treated with the Dara, bortezomib, thalidomide, and dexamethasone (DVTd) regimen. Overall, 55 patients (39.6%) experienced ICs. The most common IC was pneumonia (37.5%), followed by upper respiratory tract infections (26.8%). Finally, twenty-five patients had severe ICs (grade ≥ 3) and required hospitalization, and eight patients died due to ICs. In the final multivariable model adjusted for setting (ND/RR) and age, hemoglobin level (OR 0.77, 95% CI: 0.61–0.96, p = 0.0037), and Eastern Cooperative Oncology Group (ECOG) >1 (OR 4.46, 95% CI: 1.63–12.26, p = 0.0037) were significant factors influencing severe IC occurrence. Additionally, we developed predictive models using the J48 decision tree, gradient boosting, and random forest algorithms. After conducting 10-fold cross-validation, these models demonstrated strong performance in predicting the occurrence of pneumonia during treatment with daratumumab-based regimens. Conclusions: Simple clinical and laboratory assessments, including hemoglobin level and ECOG scale, can be valuable in identifying patients vulnerable to infections during Dara-based regimens, facilitating personalized prophylactic strategies. [ABSTRACT FROM AUTHOR]

Bronchoalveolar lavage (BAL) is used by researchers to study molecular interactions within healthy and diseased human lungs. However, the utility of BAL fluid measurements may be limited by difficulties accounting for dilution of the epithelial lining fluid (ELF) sampled and inconsistent collection techniques. The use of endogenous markers to estimate ELF dilution has been proposed as a potential method to normalize acellular molecule measurements in BAL fluid, but these markers are also imperfect and prone to inaccuracy. The focus of this report is to review factors that affect the interpretation of acellular molecule measurements in lung ELF and present original data comparing the performance of several BAL dilution markers during health and in a human endobronchial endotoxin challenge model of acute inflammation. Our findings suggest that incomplete ELF and lavage fluid mixing, flux of markers across the alveolar barrier, and lung inflammation are all possible factors that can affect marker performance. Accounting for these factors, we show that commonly used markers including urea, total protein, albumin, and immunoglobulin M are likely unreliable BAL dilution markers. In contrast, surfactant protein D appears to be less affected by these factors and may be a more accurate and biologically plausible marker to improve the reproducibility of acellular BAL component measurements across individuals during health and inflammatory states. NEW & NOTEWORTHY: In this report, mathematical prediction models and real-world measurements are used to compare the performance of molecular markers of dilution in bronchoalveolar lavage fluid samples. Effects of acute inflammation within individual subjects are highlighted. These findings inform recommendations for normalizing measurements across bronchoalveolar lavage samples and highlight the need for additional markers to improve the rigor of translational studies utilizing bronchoalveolar lavage measurements. [ABSTRACT FROM AUTHOR]

Chronic obstructive pulmonary disease (COPD), comprised of chronic bronchitis and emphysema, is a leading cause of morbidity and mortality worldwide. Mitogen-activated protein 2 kinase (MAP2K) pathway activation is present in COPD lung tissue and a genetic polymorphism in Map2k1 associates with FEV1 decline in COPD, suggesting it may contribute to disease pathogenesis. To test the functional contribution of Map2k1 in cigarette smoke (CS)-induced lung inflammation, we used a short-term CS exposure model in mice deficient in myeloid Map2k1 (LysmCre+Mek1fl) and wild-type mice (Mek1fl). Mice deficient in myeloid Map2k1 had enhanced CS-induced lung inflammation characterized by increased neutrophil recruitment, vascular leak, augmented expression of elastolytic matrix metalloproteinases, and increased type I interferon-stimulated gene expression. The augmented neutrophilic inflammatory response could be abrogated by IFNAR1 blockade. These findings indicate that myeloid Map2k1 regulates the immune response to CS via inhibition of the type I interferon pathway. Overall, these results suggest that Map2k1 is a critical determinant in modulating the severity of CS-induced lung inflammation and its expression is protective. NEW & NOTEWORTHY: Activation of the mitogen-activated protein kinases (MAPK)-ERK1/2 pathway is present in COPD lung tissue compared with healthy lungs. Our study using mice deficient in myeloid Map2k1 reveals that Map2k1 is a critical determinant in modulating the severity of CS-induced lung inflammation via suppression of type I interferon responses, and its expression is protective. [ABSTRACT FROM AUTHOR]

The soluble receptor for advanced glycation end-products (sRAGE) is a marker of alveolar type I cell injury associated with outcomes in COVID-19 pneumonia. How plasma sRAGE changes over time and whether it remains associated with long-term clinical outcomes beyond a single measurement in COVID-19 have not been well studied. We studied two cohorts in randomized clinical trials of monoclonal antibody treatment for COVID-19 (bamlanivimab and tixagevimab/cilgavimab). We first studied the association between baseline plasma sRAGE and 90-day clinical outcomes, which had been previously demonstrated in the bamlanivimab cohort, among hospitalized patients with COVID-19 supported with high-flow nasal oxygen (HFNO) or noninvasive ventilation (NIV) in the tixagevimab/cilgavimab study. Next, we investigated the relationship between day 3 sRAGE and 90-day outcomes and how plasma sRAGE changes over the first 3 days of hospitalization in both clinical trial cohorts. We found that plasma sRAGE in the highest quartile in the HFNO/NIV participants in the tixagevimab/cilgavimab trial was associated with a significantly lower rate of 90-day sustained recovery [recovery rate ratio = 0.31, 95% confidence interval (CI) = 0.14–0.71, P = 0.005] and with a significantly higher rate of 90-day mortality (hazard ratio = 2.49, 95% CI = 1.15–5.43, P = 0.021) compared with the lower three quartiles. Day 3 plasma sRAGE in both clinical trial cohorts remained associated with 90-day clinical outcomes. The trajectory of sRAGE was not influenced by treatment assignment. Our results indicate that plasma sRAGE is a valuable prognostic marker in COVID-19 up to 3 days after initial hospital presentation. NEW & NOTEWORTHY: The soluble receptor for advanced glycation end-products (sRAGE) is a marker of alveolar type I epithelial cell injury associated with clinical outcomes in acute respiratory distress syndrome and, more recently, in hospitalized subjects with COVID-19. How plasma sRAGE changes over time and whether plasma sRAGE remains associated with long-term clinical outcomes beyond a single baseline measurement in patients with COVID-19 have not been well studied. [ABSTRACT FROM AUTHOR]

Severe asthma is a syndromic label assigned to patients based on clinical parameters, yet there are diverse underlying molecular endotypes in severe asthma pathobiology. Immunophenotyping of asthma biospecimens commonly includes a mixture of granulocytes and lymphocytes. Recently, a subset of patients with severe asthma was defined as non-type 2 with neutrophil-enriched inflammation associated with increased Th17 CD4+ T cells and IL-17 levels. Here, we used an allergen-driven mouse model of increased IL-17 and mixed granulocyte lung inflammation to determine the impact of upstream regulation by an Anticalin protein that specifically binds IL-23. Airway administration of the IL-23-binding Anticalin protein (AcIL-23) decreased lung neutrophils, eosinophils, macrophages, lymphocytes, IL-17+ CD4 T cells, mucous cell metaplasia, and methacholine-induced airway hyperresponsiveness. Selective targeting of IL-23 with a monoclonal antibody (IL-23p19; αIL-23) also decreased macrophages, IL-17+ CD4 T cells, and airway hyperresponsiveness. In contrast, a monoclonal antibody against IL-17A (αIL-17A) had no significant effect on airway hyperresponsiveness but did decrease lung neutrophils, macrophages, and IL-17+ CD4 T cells. Targeting the IL-23 pathway did not significantly change IL-5+ or IL-13+ CD4 T cells. Together, these data indicate that airway AcIL-23 mirrored the activity of systemic anti-IL-23 antibody to decrease airway hyperresponsiveness in addition to mixed granulocytic inflammation and that these protective actions were broader than blocking IL-17A or IL-5 alone, which selectively decreased airway neutrophils and eosinophils, respectively. NEW & NOTEWORTHY: This is the first report of an Anticalin protein engineered to neutralize IL-23 (AcIL-23). Airway administration of AcIL-23 in mice regulated allergen-driven airway inflammation, mucous cell metaplasia, and methacholine-induced airway hyperresponsiveness. In mixed granulocytic allergic lung inflammation, immune regulation of IL-23 was broader than neutralization of either IL-17 or IL-5. [ABSTRACT FROM AUTHOR]

Background: Calprotectin, a calcium-binding protein, plays a crucial role in inflammation and has been associated with various inflammatory diseases, including asthma. However, its regulation and impact on steroid hyporesponsiveness, especially in severe asthma, remain poorly understood. Methods: This study investigated the regulation of calprotectin proteins (S100A8 and S100A9) by IL-17 and its role in steroid hyporesponsiveness using in vitro and in vivo models. Calprotectin expression was assessed in primary bronchial fibroblasts from healthy controls and severe asthmatic patients, as well as in mouse models of steroid hyporesponsive lung inflammation induced by house dust mite (HDM) allergen and cyclic-di-GMP (cdiGMP) adjuvant. The effects of IL-17A stimulation on calprotectin expression and steroid response markers in bronchial epithelial and fibroblast cells were examined. Additionally, the therapeutic potential of paquinimod, a calprotectin inhibitor, in mitigating airway inflammation and restoring steroid response signatures in the mouse model was evaluated. Results: The results demonstrated upregulation of calprotectin expression in asthmatic bronchial fibroblasts compared to healthy controls, as well as in refractory asthma samples compared to non-refractory asthma. IL-17 stimulation induced calprotectin expression and dysregulated glucocorticoid response signatures in lung epithelial and fibroblast cells. Treatment with paquinimod reversed IL-17-induced dysregulation of steroid signatures, indicating the involvement of calprotectin in this process. In the HDM/cdiGMP mouse model, paquinimod significantly attenuated airway inflammation and hyperresponsiveness, and restored steroid response signatures, whereas dexamethasone showed limited efficacy. Mechanistically, paquinimod inhibited MAPK/ERK and NF-κB pathways downstream of calprotectin, leading to reduced lung inflammation. Conclusion: These findings highlight calprotectin as a potential therapeutic target regulated by IL-17 in steroid hyporesponsive asthma. Targeting calprotectin may offer a promising approach to alleviate airway inflammation and restore steroid responsiveness in severe asthma. Further investigations are warranted to explore its therapeutic potential in clinical settings and elucidate its broader implications in steroid mechanisms of action. [ABSTRACT FROM AUTHOR]

Introduction: Influenza A is a virus from the Orthomixoviridae family responsible for high lethality rates and morbidity, despite clinically proven vaccination strategies and some anti-viral therapies. The eicosanoid Lipoxin A4 (LXA4) promotes the resolution of inflammation by decreasing cell recruitment and pro-inflammatory cytokines release, but also for inducing activation of apoptosis, efferocytosis, and macrophage reprogramming. Objective: Here, we evaluated whether a synthetic lipoxin mimetic, designated AT-01-KG, would improve the course of influenza A infection in a murine model. Method: Mice were infected with influenza A/H1N1 and treated with AT-01-KG (1.7 μg/kg/day, i.p.) at day 3 post-infection. Results: AT-01-KG attenuated mortality, reducing leukocyte infiltration and lung damage at day 5 and day 7 post-infection. AT-01-KG is a Formyl Peptide Receptor 2 (designated FPR2/3 in mice) agonist, and the protective responses were not observed in fpr2/3 −/− animals. In mice treated with LXA4 (50 μg/kg/day, i.p., days 3–6 post-infection), at day 7, macrophage reprogramming was observed, as seen by a decrease in classically activated macrophages and an increase in alternatively activated macrophages in the lungs. Furthermore, the number of apoptotic cells and cells undergoing efferocytosis was increased in the lavage of treated mice. Treatment also modulated the adaptive immune response, increasing the number of T helper 2 cells (Th2) and regulatory T (Tregs) cells in the lungs of the treated mice. Conclusion: Therefore, treatment with a lipoxin A4 analog was beneficial in a model of influenza A infection in mice. The drug decreased inflammation and promoted resolution and beneficial immune responses, suggesting it may be useful in patients with severe influenza. [ABSTRACT FROM AUTHOR]

The aim of this meta-analysis was to evaluate the efficacy and safety of robotic pancreaticoduodenectomy (RPD) in improving perioperative aspects and postoperative complications in patients. Methods: We searched PubMed, Embase, Web of Science, and the Cochrane Library database systems for studies that compared RPD with laparoscopic pancreaticoduodenectomy (LPD). Meta-analysis was performed for 24 relevant outcomes, including perioperative outcomes and postoperative complications. Subsequently, a subgroup analysis based on geographical regions was conducted to investigate the impact of regional differences on the perioperative outcomes of the RPD group and the LPD group. Results: This review found 19 studies with 12,731 individuals (3539 RPD and 9192 LPD). In comparison to LPD, RPD had lower rates of Conversion (OR = 0.58, P < 0.00001), Blood Transfusion (OR = 0.59, P = 0.02), Length of Stay (MD = − 0.54, P = 0.01), postoperative complications [Pneumonia (OR = 0.31, P < 0.0001), and Wound Disruption (OR = 0.26, P = 0.0007)], and more thorough lymph node harvesting (MD = 1.25, P = 0.001). Subgroup analysis showed that Blood Transfusion (I2 = 55%, P = 0.02), Conversion (I2 = 30%, P < 0.00001), Length of Stay (I2 = 71%, P = 0.01), and Lymph Node Harvested (I2 = 87%, P = 0.001) were statistically significant. Interestingly, compared to China, other countries had lower rates of Conversion and more lymph nodes harvested for RPD surgery. Conclusion: The benefits of RPD surgery over LPD surgery in terms of therapy and an optimistic short-term prognosis are clearly supported by this study. Moreover, subgroup analysis based on regional differences revealed statistically significant results for Conversion, Length of Stay (days), Number of Lymph Nodes Harvested and the rate of Blood Transfusion, indicating significant variability across regions. This study provides a solid theoretical foundation and basis for the advancement of RPD in clinical practice. [ABSTRACT FROM AUTHOR]

Background Sepsis and pneumonia in the elderly comprise a significant portion of medical admissions. Chloramphenicol has been used in Israel for treatment of bacterial infections, without evidence regarding its efficacy and safety. Objectives We aimed to examine whether chloramphenicol was associated with similar outcomes to ceftriaxone, for treatment of sepsis and pneumonia in the elderly with dementia and functional disability. Methods Patients over 75, with dementia and functional disability, admitted to the internal medicine ward at Beilinson Hospital between 2011 and 2021, with community-acquired aspiration pneumonia or sepsis of undetermined source were included. Patients with mild dementia and independent in their activities of daily living were excluded. Primary outcome was 30- and 90-day all-cause mortality. A propensity-weighted multivariable model was constructed using inverse probability of treatment weighting. Results were expressed as OR with 95% CI. Results In total, 1558 patients were included: 512 treated with chloramphenicol and 1046 with ceftriaxone. The cohort consisted of elderly patients (mean age 87 ± 6.2 years) with comorbidities; 30- and 90-day all-cause mortality were similar [222/512 (43.3%) versus 439/1046 (41.9%) P  = 0.602, and 261/512 (50.9%) versus 556/1046 (53.1%) P  = 0.419, respectively]. Propensity-weighted, logistic multivariable analysis for 30- and 90-day all-cause mortality revealed similar mortality rates for chloramphenicol and ceftriaxone (OR 1.049 95% CI 0.217–1.158, OR 0.923 95% CI 0.734–1.112, respectively). Conclusion In this retrospective cohort of elderly debilitated patients hospitalized with pneumonia and sepsis, we found no difference in 30- and 90-day mortality between those treated with chloramphenicol or ceftriaxone. Further studies should determine the efficacy and safety of chloramphenicol in this population. [ABSTRACT FROM AUTHOR]

Background Ceftolozane/tazobactam and ceftazidime/avibactam are commonly used in patients with MDR- Pseudomonas aeruginosa (PSA) pneumonia (PNA). This study compared outcomes between non-COVID-19 hospitalized patients with MDR-PSA PNA who received ceftolozane/tazobactam or ceftazidime/avibactam. Methods The study included non-COVID-19 adult hospitalized patients with MDR-PSA PNA in the PINC AI Healthcare Database (2016–22) who received ceftolozane/tazobactam or ceftazidime/avibactam within 3 days of index culture for ≥2 days. Outcomes were mortality, recurrent MDR-PSA PNA, discharge destination, post-index culture day length of stay (LOS) and costs (in US dollars, USD), and hospital readmission. Results The final sample included 197 patients (117 ceftolozane/tazobactam, 80 ceftazidime/avibactam). No significant differences were observed in mortality and post-index culture LOS and costs between groups. In the multivariable analyses, patients who received ceftolozane/tazobactam versus ceftazidime/avibactam had lower recurrent MDR-PSA PNA (7.9% versus 18.0%, P  = 0.03) and 60 day PNA-related readmissions (11.1% versus 28.5%, P  = 0.03) and were more likely to be discharged home (25.8% versus 9.8%, P  = 0.03). Compared with ceftazidime/avibactam patients, ceftolozane/tazobactam patients had lower adjusted median total antibiotic costs (5052 USD versus 8099 USD, P  = 0.003) and lower adjusted median comparator (ceftolozane/tazobactam or ceftazidime/avibactam) antibiotic costs (3938 USD versus 6441 USD, P  = 0.005). In the desirability of outcome ranking (DOOR) analysis, a ceftolozane/tazobactam-treated patient was more likely to have a more favourable outcome than a ceftazidime/avibactam-treated patient [DOOR probability: 59.6% (95% CI: 52.5%–66.8%)]. Conclusions Early treatment with ceftolozane/tazobactam may offer some clinical and cost benefits over ceftazidime/avibactam in patients with MDR-PSA PNA. Further large-scale studies are necessary to comprehensively understand the outcomes associated with these treatments for MDR-PSA PNA. [ABSTRACT FROM AUTHOR]

Background: For patients with pneumonia, the rapid detection of pathogens is still a major global problem in clinical practice because traditional diagnostic techniques for infection are time-consuming and insensitive. Metagenomic next-generation sequencing (mNGS) is a novel technique that has the potential to improve pathogen diagnosis. This study aimed to investigate the microbiological diagnostic ability of mNGS compared with conventional culture and to determine the optimal time to test patients for pneumonia. Methods: A prospective study using data from June 2020 to June 2021 was performed at a tertiary teaching hospital in China. We included 56 patients from all adult patients with a clinical diagnosis of pneumonia. Blood and bronchoalveolar lavage fluid (BALF) samples were taken for simultaneous mNGS and conventional culture testing. Results: All 56 patients underwent both conventional culture and mNGS. Of these patients, 37 were diagnosed with severe pneumonia and 17 were diagnosed with non-severe pneumonia. The top three pathogenic bacteria detected by mNGS were Acinetobacter baumannii, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Enterococcus faecium was detected more frequently in the non-severe pneumonia group (4 vs. 0, p < 0.05). The findings revealed that the detection rate of mNGS (84%) was superior to that of conventional culture methods (48%). Notably, the percentage of mNGS-positive BALF samples (46/56, 82.14%) was significantly greater than that of blood samples (27/56, 48.21%). The etiological comparison demonstrated that mNGS-positive samples, which received clinical approval, tended to be associated with a more normalized temperature, lower PCO2 levels, and a higher SOFA score than mNGS-negative samples (p = 0.022, p = 0.0.028, and p = 0.038, respectively). Conclusions: In this study, we discovered that the etiology of lung infections frequently involves multiple pathogens. The use of mNGS in BALF is instrumental for detecting nonviral pathogens associated with lung infections. Although the rate of positive blood NGS results is significantly influenced by various clinical factors, for patients suspected of having viral, Legionella, or tsutsugamushi infections, plasma mNGS could serve as a complementary diagnostic tool. [ABSTRACT FROM AUTHOR]

Respiratory syncytial virus (RSV) selectively targets ciliated cells in human bronchial epithelium and can cause bronchiolitis and pneumonia, mostly in infants. To identify molecular targets of intervention during RSV infection in infants, we investigated how age regulates RSV interaction with the bronchial epithelium barrier. Employing precision-cut lung slices and air-liquid interface cultures generated from infant and adult human donors, we found robust RSV virus spread and extensive apoptotic cell death only in infant bronchial epithelium. In contrast, adult bronchial epithelium showed no barrier damage and limited RSV infection. Single nuclear RNA-Seq revealed age-related insufficiency of an antiapoptotic STAT3 activation response to RSV infection in infant ciliated cells, which was exploited to facilitate virus spread via the extruded apoptotic ciliated cells carrying RSV. Activation of STAT3 and blockade of apoptosis rendered protection against severe RSV infection in infant bronchial epithelium. Lastly, apoptotic inhibitor treatment of a neonatal mouse model of RSV infection mitigated infection and inflammation in the lung. Taken together, our findings identify a STAT3-mediated antiapoptosis pathway as a target to battle severe RSV disease in infants. [ABSTRACT FROM AUTHOR]

A leading cause of mortality after influenza infection is the development of a secondary bacterial pneumonia. In the absence of a bacterial superinfection, prescribing antibacterial therapies is not indicated but has become a common clinical practice for those presenting with a respiratory viral illness. In a murine model, we found that antibiotic use during influenza infection impaired the lung innate immunologic defenses toward a secondary challenge with methicillin-resistant Staphylococcus aureus (MRSA). Antibiotics augment lung eosinophils, which have inhibitory effects on macrophage function through the release of major basic protein. Moreover, we demonstrated that antibiotic treatment during influenza infection caused a fungal dysbiosis that drove lung eosinophilia and impaired MRSA clearance. Finally, we evaluated 3 cohorts of hospitalized patients and found that eosinophils positively correlated with antibiotic use, systemic inflammation, and worsened outcomes. Altogether, our work demonstrates a detrimental effect of antibiotic treatment during influenza infection that has harmful immunologic consequences via recruitment of eosinophils to the lungs, thereby increasing the risk of developing a secondary bacterial infection. [ABSTRACT FROM AUTHOR]

Background: Hospital-acquired pneumonia (HAP) is the most common hospital-acquired infection (HAI). HAP is associated with a high burden of morbidity and mortality, but the diagnosis is difficult to establish and the incidence uncertain. Methods: Patients aged ≥ 18 years hospitalised with radiologically verified non-ventilator hospital acquired pneumonia (NV-HAP) during 2018 were retrospectively identified at Drammen Hospital, a Norwegian general hospital. Infectious Diseases Society of America and the American Thoracic Society's definition of HAP was used. Results: In total 119 cases of NV-HAP were identified among 27,701 admissions. The incidence was 4.3 per 1000 admissions and 1.2 per 1000 patient-days. The median age was 74 years, 63% were male and median Charlson comorbidity index was 5. Coronary heart disease (42%) was the most common comorbidity. Median length of stay was 17.2 days. A blood culture was obtained in 53.8% of patients, while samples from lower airways were seldom obtained (10.9%). In-hospital mortality was 21%, accumulated 30-day mortality was 27.7% and accumulated 1-year mortality was 39.5%. Thirty-day readmission rate among survivors was 39.4%. Conclusion: NV-HAP was present in approximately 1 in 250 hospitalisations, most had multiple comorbidities, and 1 in 5 died in hospital. Although thorough microbiological sampling is recommended when NV-HAP is suspected, our data indicate that airway sampling is infrequent in clinical practice. Our findings underscore the need to develop microbiological diagnostic strategies to achieve targeted antimicrobial treatment that may improve patient outcomes and reduce broad-spectrum antibiotic usage. [ABSTRACT FROM AUTHOR]

Background: Tracheostomy tube changes are a considerable part of the management of patients with tracheostomy and are necessary for preventing aspiration pneumonia, especially in patients with long‐term tracheostomy. The process of tracheostomy tube changes in many patients may not be timely, safe or efficient. Aim: The objectives were to implement a quality improvement intervention that reduces the incidence of aspiration pneumonia in patients with tracheostomy, improve staff knowledge about tracheostomy tube changes and improve staff adherence to documentation. Methods: A pre‐post intervention design was used in this quality improvement project. We created a change strategy bundle that included identification of the need for and observation determination of the timing of tube changes timing, change assessments, identification of the person and location, preparation, co‐operation and maintenance. A tracheostomy tube change workflow was also created. Then, the intervention was implemented in the clinic after staff training. The incidence of aspiration pneumonia, staff knowledge and staff adherence were compared before and after the intervention. Results: Two hundred and 20 patients were enrolled (105 in the preintervention group; 115 in the postintervention group) with 88 tracheostomy tube change episodes (23 in the preintervention group; 65 in the postintervention group). Thirty‐five staff members completed the training and surveys. The incidence of pneumonia decreased from 43.8% to 27.8% after the intervention (p =.013). The knowledge score of staff increased from 46.57 ± 11.10 to 88.14 ± 6.76, and the implementation rate of the audit increased to 67.32%–100%. Conclusions: This quality improvement project regarding tracheostomy changes reduced the incidence of pneumonia, increased staff knowledge about tracheostomy tube changes and improved staff adherence. Relevance to Clinical Practice: A standardized tracheostomy tube change bundle, education, interprofessional collaboration and culture changes were important to ensure the best outcomes in this quality improvement project. These factors improved the timeliness, efficiency and safety of tracheostomy tube changes. [ABSTRACT FROM AUTHOR]

Machine learning (ML) tools for acute respiratory distress syndrome (ARDS) detection and prediction are increasingly used. Therefore, understanding risks and benefits of such algorithms is relevant at the bedside. ARDS is a complex and severe lung condition that can be challenging to define precisely due to its multifactorial nature. It often arises as a response to various underlying medical conditions, such as pneumonia, sepsis, or trauma, leading to widespread inflammation in the lungs. ML has shown promising potential in supporting the recognition of ARDS in ICU patients. By analyzing a variety of clinical data, including vital signs, laboratory results, and imaging findings, ML models can identify patterns and risk factors associated with the development of ARDS. This detection and prediction could be crucial for timely interventions, diagnosis and treatment. In summary, leveraging ML for the early prediction and detection of ARDS in ICU patients holds great potential to enhance patient care, improve outcomes, and contribute to the evolving landscape of precision medicine in critical care settings. This article is a concise definitive review on artificial intelligence and ML tools for the prediction and detection of ARDS in critically ill patients. [ABSTRACT FROM AUTHOR]

Background: Early initiation of targeted antibiotic therapy is important to achieve the best patient outcomes in intubated patients with pneumonia in the intensive care unit (ICU). This study aimed to investigate the applicability of multiplex polymerase chain reaction (PCR) in an ICU by comparing the test results to the results of conventional microbiological methods to assess the possible impact on antibiotic therapy. Method: This retrospective study investigated adult patients with pneumonia on mechanical ventilation in the ICU. Tracheal aspirates were collected within 24h after intubation and the initiation of mechanical ventilation. Samples were initially tested by conventional microbiological methods and subsequently re‐evaluated with rapid multiplex PCR on stored samples. Concordance between the two methods was assessed. An intensivist and a microbiologist retrospectively reviewed the patients' electronic health records for relevant clinical details to evaluate the potential impact of multiplex PCR results on antibiotic therapy. Results: In this study, 76 patients were enrolled and 55 (72.4%) tested positive for 95 pathogens using multiplex PCR, while conventional microbiological methods identified 40 pathogens in 32 (42.2%) patients. Concordance between the two methods was observed in 42 (55.3%) patients. Multiplex PCR detected 39 additional pathogens in 31 (40.7%) patients. Retrospective analysis indicated potential antibiotic de‐escalation in 35 (46.1%) patients and escalation in 4 (5.3%) patients. Multiplex PCR significantly reduced the turnaround time for test results. Conclusion: In ICU patients with suspected pneumonia, multiplex PCR identified a higher number of pathogens compared to CMM. A retrospective assessment indicates that the use of multiplex PCR could potentially have prompted the de‐escalation of antibiotic therapy in nearly half of the patients. Therefore, multiplex PCR may serve as a supplement to CMM in guiding antibiotic stewardship. [ABSTRACT FROM AUTHOR]

Although most countries recommend amoxicillin for paediatric pneumonia, there is a long tradition of treatment with penicillin V (PcV) in Sweden, thus not empirically covering Haemophilus influenzae. There are, however, large regional differences in treatment practice. The aim was to compare clinical outcomes (treatment failure and severe complications), in children aged 1–59 months treated with PcV vs. amoxicillin for pneumonia. This population-based emulated target trial included all children born in Sweden between 2001 and 2021, using national health, sociodemographic, and population registers. All pneumonia cases from hospitals and paediatric outpatient clinics in children aged 1–59 months treated as outpatients with PcV or amoxicillin between July 2005 and December 2021, were identified. Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) for treatment failure (newly dispensed antibiotic prescription or pneumonia-associated hospitalization day 1–14) and severe complications (lung complications, an invasive bacterial disease, admission to intensive care unit or death day 1–28) were calculated with logistic regression analysis. PcV was prescribed in 14 766 cases and amoxicillin in 10 566. Treatment failure occurred in 7.7% with PcV vs. 4.7% with amoxicillin, aOR 1.76 (95% CI: 1.54–2.00). Severe complications were rare, with no significant difference between PcV and amoxicillin (0.3% vs. 0.2%, aOR 0.96, 95% CI: 0.53–1.73). Sensitivity and interaction analyses showed consistent results. PcV treatment compared with amoxicillin, was associated with an increased risk for treatment failure but not for severe complications. The absolute risks for adverse outcomes were low in both groups suggesting a minor role of H. influenzae in paediatric pneumonia. [ABSTRACT FROM AUTHOR]

To evaluate the relative effectiveness of high-dose quadrivalent influenza vaccine (QIV-HD) versus standard-dose quadrivalent influenza vaccine (QIV-SD) against recurrent hospitalizations and its potential variation in relation to influenza circulation. We did a post-hoc analysis of a pragmatic, open-label, randomized trial of QIV-HD versus QIV-SD performed during the 2021–2022 influenza season among adults aged 65–79 years. Participants were enrolled in October 2021–November, 2021 and followed for outcomes from 14 days postvaccination until 31 May, 2022. We investigated the following outcomes: Hospitalizations for pneumonia or influenza, respiratory hospitalizations, cardio-respiratory hospitalizations, cardiovascular hospitalizations, all-cause hospitalizations, and all-cause death. Outcomes were analysed as recurrent events. Cumulative numbers of events were assessed weekly. Cumulative relative effectiveness estimates were calculated and descriptively compared with influenza circulation. The trial is registered at Clinicaltrials.gov: NCT05048589. Among 12,477 randomly assigned participants, receiving QIV-HD was associated with lower incidence rates of hospitalizations for pneumonia or influenza (10 vs. 33 events, incidence rate ratio [IRR] 0.30 [95% CI, 0.14–0.64]; p 0.002) and all-cause hospitalizations (647 vs. 742 events, IRR 0.87 [95% CI, 0.76–0.99]; p 0.032) compared with QIV-SD. Trends favouring QIV-HD were consistently observed over time including in the period before active influenza transmission; i.e. while the first week with a ≥10% influenza test positivity rate was calendar week 10, 2022, the first statistically significant reduction in hospitalizations for pneumonia or influenza was already observed by calendar week 3, 2022 (5 vs. 15 events, IRR 0.33 [95% CI, 0.11–0.94]; p 0.037). In a post-hoc analysis, QIV-HD was associated with lower incidence rates of hospitalizations for pneumonia or influenza and all-cause hospitalizations compared with QIV-SD, with trends evident independent of influenza circulation levels. Our exploratory results correspond to a number needed to treat of 65 (95% CI 35–840) persons vaccinated with QIV-HD compared with QIV-SD to prevent one additional all-cause hospitalization per season. Further research is needed to confirm these hypothesis-generating findings. [ABSTRACT FROM AUTHOR]

Interleukin (IL)‐33 released from airway epithelial cells plays a vital role in shaping type 2 immune responses by binding to the ST2 receptor present in many immune cells, including mast cells (MCs). Intranasal administration of IL‐33 in mice induces type 2 lung inflammation, an increase in lung MC progenitors, and transepithelial migration of leukocytes to the bronchoalveolar space. The aim of this study was to determine the contribution of MCs in IL‐33‐induced lung pathology. Four daily intranasal administrations of IL‐33 reduced spirometry‐like lung function parameters, induced airway hyperresponsiveness, and increased leukocytes in bronchoalveolar lavage fluid (BAL) in an ST2‐dependent manner. MC‐deficient (Cpa3cre/+) mice, which lack MCs, had intact spirometry‐like lung function but slightly reduced airway hyperresponsiveness, possibly related to reduced IL‐33 or serotonin. Strikingly, Cpa3cre/+ mice exposed to IL‐33 had 50% reduction in BAL T‐cells, and CXCL1 and IL‐33 were reduced in the lung. Intranasal IL‐33 induced CXCR2 expression in T‐cells in a MC‐independent fashion. Furthermore, IL‐33‐induced lung MCs were immunopositive for CXCL1 and localized in the epithelium of wild‐type mice. These results suggest that MCs are required to sustain intact lung IL‐33 and CXCL1 levels in mice with IL‐33‐induced airway inflammation, thereby facilitating T‐cell accumulation in the bronchoalveolar space. [ABSTRACT FROM AUTHOR]

To look for the spectrum of infections and the factors predisposing to infection in patients with systemic sclerosis (SSc). In this retrospective study, demographic, clinical features, details of infections, immunosuppressive therapy, and outcomes of patients with SSc attending clinics at department of Clinical Immunology and Rheumatology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India from 1990 to 2022 were captured. Multivariable-adjusted logistic regression was applied to identify independent predictors of infection. Data of 880 patients, mean age 35.5 ± 12 years, and female: male ratio 7.7:1, were analyzed. One hundred and fifty-three patients had at least 1 infection with a total of 233 infectious episodes. Infections were most common in lung followed by skin and soft tissue. Tuberculosis was diagnosed in 45 patients (29.4%). Klebsiella was the commonest non-tubercular organism in lung and Escherichia coli in urinary tract infections. In comparison to matched control group, patients with infection had a greater number of admissions due to active disease, odds ratio (OR) 6.27 (CI 3.23–12.18), were receiving immunosuppressive medication OR, 5.05 (CI 2.55–10.00), and had more digital ulcers OR, 2.53 (CI 1.17–5.45). Patients who had infection had more likelihood for death OR, 13.63 (CI 4.75 -39.18). Tuberculosis is the commonest infection and lung remains the major site of infection in patients with SSc. Number of hospital admissions, digital ulcers and immunosuppressive therapy are predictors of serious infection in patients with SSc. Patients with infections had more likelihood of death. [ABSTRACT FROM AUTHOR]

Long-term care facility (LTCF) residents are twice as likely to receive antibiotics compared with elderly living in the community, and studies have reported up to half of prescriptions in LTCFs as inappropriate. To identify factors contributing to general and inappropriate antibiotic prescription among LTCF residents with lower respiratory tract infections (LRTIs). In this prospective, multicentric, observational study, residents with LRTIs were recruited among 32 LTCFs in Western Switzerland during winter 2022–2023. Residents underwent lung ultrasound (LUS) within three days of LRTI onset, serving as the pneumonia diagnosis reference standard. Multivariate logistic regression and backward selection were used with P < 0.1 cut-off to identify factors among demographics, vital signs, diagnostic tests, and LTCF characteristics associated with (i) antibiotic prescription and (ii) inappropriate prescription. A total of 114 residents were included, 63% female, median age 87 years. Fifty-nine (52%) residents underwent diagnostic tests: 50 (44%) polymerase chain reaction (PCR) for respiratory viruses and 16 (14%) blood test with C-reactive protein and/or blood count. Sixty-three (55%) residents received antibiotics. Factors associated with antibiotic prescriptions were Rockwood Clinical Frailty Scale score ≥7, oxygen saturation <92%, performing a blood test, rural LTCFs, and female physician. Among residents receiving antibiotics, 48 (74%) had inappropriate prescriptions, with performance of respiratory virus PCR test as the only protective factor. Whereas half of LRTI residents received antibiotics, falling within lower ranges of European LTCFs prescription rates (53–80%), most antibiotic prescriptions were inappropriate. Utilization of diagnostic tests correlates with lower overall and inappropriate prescription, advocating for their use to optimize prescription practices in LTCFs. [ABSTRACT FROM AUTHOR]

BACKGROUND: Opioids are known to cause respiratory depression, aspiration, and to suppress the immune system. This study aimed to investigate the relationship between short- and long-term opioid use and the occurrence and clinical outcomes of pneumonia in South Korea. METHODS: The data for this population-based retrospective cohort analysis were obtained from the South Korean National Health Insurance Service. The opioid user group consisted of those prescribed opioids in 2016, while the non-user group, who did not receive opioid prescriptions that year, was selected using a 1:1 stratified random sampling method. The opioid users were categorized into short-term (1-89 d) and long-term (≥90 d) users. The primary end point was pneumonia incidence from January 1, 2017-December 31, 2021, with secondary end points including pneumonia-related hospitalizations and mortality rates during the study period. RESULTS: In total, 4,556,606 adults were enrolled (opioid group, 2,070,039). Opioid users had a 3% higher risk of pneumonia and an 11% higher risk of pneumonia requiring hospitalization compared to non-users. Short-term users had a 3% higher risk of pneumonia, and long-term users had a 4% higher risk compared to non-users (P < .001). Additionally, short-term users had an 8% higher risk of hospital-treated pneumonia, and long-term users had a 17% higher risk compared to non-users (P < .001). CONCLUSIONS: Both short- and long-term opioid prescriptions were associated with higher incidences of pneumonia and hospital-treated pneumonia. In addition, long-term opioid prescriptions were linked to higher mortality rates due to pneumonia. [ABSTRACT FROM AUTHOR]

Farmed cervids are of growing economic importance in the midwestern United States. Although diseases of wild and captive cervids have been examined in more northerly climates, little information exists on the health challenges of deer in the Midwest. We characterized and summarized the causes of mortality in farmed white-tailed deer (Odocoileus virginianus) submitted to the University of Missouri Veterinary Medical Diagnostic Laboratory (Columbia, MO, USA) over a 19-y period (2004–2023). Of 388 cases examined, 253 (65%) were carcasses submitted for autopsy, and 135 (35%) cases were tissue samples harvested by field veterinarians. Infectious disease was the most common cause of mortality (n = 335; 86.3%). Of infectious causes, primary pneumonia was most common (n = 140; 41.7%), followed by septicemia (n = 68; 20.1%), and primary enteritis (n = 64; 19.1%). Viruses were detected in 18% of pneumonia cases. The most common non-infectious diagnoses were emaciation and trauma (both 4 each; 1%). Thirteen animals (3.4%) died of unknown causes. Forty-nine percent of cases were juvenile deer <1-y-old. Most cases were received in the summer (212; 54.6%). Infectious diseases, particularly bacteria and viruses, pose a significant health challenge to farmed deer in the midwestern United States. [ABSTRACT FROM AUTHOR]

Secondary pneumonia has a significant clinical impact on critically ill patients with COVID-19. Considering potential geographic variations, this study explores the clinical implications of secondary pneumonia within East Asian populations. This multicenter, retrospective cohort study enrolled critical COVID-19 patients requiring intensive care units (ICUs) admission in Taiwan from December 31, 2020, to June 1, 2022. Among the 187 critical COVID-19 patients, 80 (42.8%) developed secondary pneumonia. The primary causative pathogens were gram-negative bacilli (GNB) (76.8%). Gram-positive cocci and fungi were mainly observed during the initial two weeks of ICU stay. Notably, the incidence of pulmonary aspergillosis was 9.2% during the first week of ICU stay and all Staphylococcus aureus were susceptible to methicillin. Multi-drug resistant organisms (MDROs) were responsible for 28.3% of the cases, exhibiting significantly longer ICU stays compared to the non-MDRO group (median, 27 vs. 14 days, P < 0.001). In the multivariate analysis, Acute Physiology and Chronic Health Evaluation II (APACHE II) and Sequential Organ Failure Assessment (SOFA) scores were associated with a significantly increased risk of secondary pneumonia. In-hospital mortality was significantly higher in patients with secondary pneumonia than in those without (37.7% vs. 16.7%, P = 0.02) and survival analysis demonstrated gram-negative bacilli-related secondary pneumonia contributed to a worse prognosis. Secondary pneumonia in critical COVID-19 patients significantly raised in-hospital mortality and extended hospital and ICU stays. Moreover, the presence of GNB notably predicted an unfavorable prognosis. [ABSTRACT FROM AUTHOR]

Metal oxide sensor‐based electronic nose (E‐Nose) technology provides an easy to use method for breath analysis by detection of volatile organic compound (VOC)‐induced changes of electrical conductivity. Resulting signal patterns are then analyzed by machine learning (ML) algorithms. This study aimed to establish breath analysis by E‐Nose technology as a diagnostic tool for severe acute respiratory syndrome coronavirus type 2 (SARS‐CoV‐2) pneumonia within a multi‐analyst experiment. Breath samples of 126 subjects with (n = 63) or without SARS‐CoV‐2 pneumonia (n = 63) were collected using the ReCIVA® Breath Sampler, enriched and stored on Tenax sorption tubes, and analyzed using an E‐Nose unit with 10 sensors. ML approaches were applied by three independent data analyst teams and included a wide range of classifiers, hyperparameters, training modes, and subsets of training data. Within the multi‐analyst experiment, all teams successfully classified individuals as infected or uninfected with an averaged area under the curve (AUC) larger than 90% and misclassification error lower than 19%, and identified the same sensor as most relevant to classification success. This new method using VOC enrichment and E‐Nose analysis combined with ML can yield results similar to polymerase chain reaction (PCR) detection and superior to point‐of‐care (POC) antigen testing. Reducing the sensor set to the most relevant sensor may prove interesting for developing targeted POC testing. [ABSTRACT FROM AUTHOR]

Background Immune checkpoint inhibitors (ICI) are associated with a distinct spectrum of toxicities. Data on irAE hospitalization rates and clinical course of patients with thoracic malignancies are lacking. Methods Patients with advanced thoracic malignancy treated with ICI (2/2016 to 6/2021) were retrospectively identified. Demographic and clinical data of confirmed irAE hospitalizations were extracted from the medical record and a descriptive analysis was performed. Results From February 2016 to June 2021, 1312 patients with thoracic malignancy received ICI (monotherapy, combination with 2nd ICI or other agents) with 102 patients (7.7%) hospitalized for irAEs. Treatment intent was first-line therapy in most patients (N  = 50, 49%) with 9% (n = 9) receiving adjuvant ICI (N  = 9). Sixty patients (59%) received ICI alone, 32% (N  = 33) chemo plus immunotherapy, and 7% (N  = 7) dual ICI. The median age on admission was 68 years. The median time between ICI initiation and admission was 64 days (1-935 days). Pneumonitis (32.3%; 33/102) was the most frequent indication for admission followed by gastroenterocolitis (19.6%; 20/102), hepatitis (12.7%; 13/102), myo/pericarditis (9.8%; 10/102), and endocrinopathies (9.8%; 10/102). Multi-organ toxicity occurred in 36% (N  = 37) of patients. Overall, 85.2% (87/102) of patients received systemic corticosteroids and 17.6% (18/102) required additional lines of immunosuppression. The median length of hospitalization stay was 7 days (2-28 days) with a 25.5% (n  = 26) readmission rate within 60 days and an 11.8% (n  = 12) in house mortality rate. Conclusions Severe irAE requiring inpatient admission, although infrequent, results in considerable morbidity, mortality, and healthcare utilization. Pneumonitis was the most common irAE requiring inpatient management in our patient population with a significant risk of mortality despite the use of guideline-directed systemic immunosuppression. This study highlights the continued need for collaborative efforts amongst medical specialties for improving the diagnostic and therapeutic management of patients with irAEs. [ABSTRACT FROM AUTHOR]

Background Immune checkpoint inhibitors (ICIs) have revolutionized cancer care with incredible reductions in mortality. One of the most devastating complications of treatment is ICI-related pneumonitis (ICI-p). Despite this, little is known regarding risk factors for severe pneumonitis and treatment effectiveness of various therapeutic options for steroid-refractory disease. To address this, we conducted a retrospective study on patients with cancer who developed ICI-p. Methods We examined consecutive patients who received ICIs and developed ICI-p. Risk factors of interest for severe disease and steroid-refractory ICI-p, including pre-treatment pulmonary function tests (PFTs) and chest imaging, were compared between patients with severe (grades 3-5) and mild (grades 1-2) pneumonitis. The clinical and treatment courses for patients with steroid-refractory ICI-p were recorded. Results A total of 132 patients developed ICI-p, with 60 patients having mild and 72 with severe disease. We found that lower forced vital capacity percent predicted (66.24 vs 85.05, P  = .05), lower total lung capacity percent predicted (85.23 vs 99.71, P  = .13), and specific radiographic patterns on pre-treatment chest imaging were predictors of severe disease. Initial corticosteroid dose of less than 1 milligram per kilogram prednisone equivalent (P  = .14) was correlated with partially steroid-responsive or steroid-refractory ICI-p. Ten patients had steroid refractory ICI-p, and those who received IVIG alone as the immune suppressant beyond corticosteroids had improved survival (P  = 05). Conclusions We are the first to identify pre-treatment PFTs and chest imaging abnormalities as risk factors for severe ICI-p. We also found that lower corticosteroid doses were associated with partially steroid-responsive and steroid-refractory ICI-p. Larger, prospective studies are needed to validate our results. [ABSTRACT FROM AUTHOR]

Infections are one of the most significant healthcare and economic burdens across the world as underscored by the recent coronavirus pandemic. Moreover, with the increasing incidence of antimicrobial resistance, there is an urgent need to better understand host–pathogen interactions to design effective treatment strategies. The complement system is a key arsenal of the host defense response to pathogens and bridges both innate and adaptive immunity. However, in the contest between pathogens and host defense mechanisms, the host is not always victorious. Pathogens have evolved several approaches, including co‐opting the host complement regulators to evade complement‐mediated killing. Furthermore, deficiencies in the complement proteins, both genetic and therapeutic, can lead to an inefficient complement‐mediated pathogen eradication, rendering the host more susceptible to certain infections. On the other hand, overwhelming infection can provoke fulminant complement activation with uncontrolled inflammation and potentially fatal tissue and organ damage. This review presents an overview of critical aspects of the complement‐pathogen interactions during infection and discusses perspectives on designing therapies to mitigate complement dysfunction and limit tissue injury. [ABSTRACT FROM AUTHOR]

Objective: Despite being a less-invasive procedure, esophagectomy can cause severe infectious complications, such as pneumonia and anastomotic leakage. Herein, we aimed to clarify the inflammatory characteristics of pneumonia/anastomotic leakage after esophagectomy by assessing the difference between the postoperative trends of serum C-reactive protein (CRP) and procalcitonin (PCT) levels in patients with pneumonia/anastomotic leakage using the values on the consecutive postoperative day (POD). Methods: This study included 439 patients who underwent minimally invasive esophagectomy. Serum CRP and PCT levels were measured on PODs 1–7, 10, and 14. Pneumonia and anastomotic leakage were defined as Clavien–Dindo grades ≥ 2. Results: Pneumonia and anastomotic leakage occurred in 96 and 51 patients, respectively. The CRP and PCT levels peaked on POD 3 (11.6 ± 6.8 mg/dL) and POD 2 (0.69 ± 2.9 ng/mL), respectively. Between PODs 3 and 14, CRP levels were significantly higher in patients with pneumonia and anastomotic leakage than in those without complications (P < 0.001). Between PODs 3 and 14, PCT levels were significantly higher in patients with pneumonia; however, on most PODs, there were no significant differences in PCT levels between patients with and without anastomotic leakage. Conclusion: Inflammatory reactions caused by pneumonia may be more intense than those caused by anastomotic leakage after esophagectomy. Postoperative trends in serum CRP and PCT levels may vary depending on the complication type. Pneumonia and anastomotic leakage after esophagectomy can be potentially distinguished by the postoperative trend of PCT values before detailed examinations, such as computed tomography and endoscopy. [ABSTRACT FROM AUTHOR]

Aim: Methods of predicting severe postoperative complications after anatomical resection for hepatocellular carcinoma are yet to be established. We aimed to clarify the relationship between inflammation‐based prognostic scores and liver fibrosis markers and the incidence of postoperative complications after anatomical resection for hepatocellular carcinoma as well as the usefulness of these markers in surgical procedure selection. Methods: We included 374 patients with hepatocellular carcinoma who had undergone initial hepatectomy between January 2007 and December 2021. The association between inflammation‐based prognostic scores or liver fibrosis markers and postoperative complications was evaluated, and severe postoperative complication rates in the high‐risk group defined by these markers were compared in terms of surgical procedure. Results: The advanced lung cancer inflammation index and nonalcoholic fatty liver disease fibrosis score correlated significantly with severe postoperative complications after anatomical resection, with areas under the curve of 0.67 and 0.61, respectively. The combined advanced lung cancer inflammation index and nonalcoholic fatty liver disease fibrosis score resulted in a larger area under the curve (0.69). Furthermore, in the high‐risk group determined by the combined score, the anatomical resection group had a significantly higher incidence of severe complications than the partial resection group (P < 0.01). There were no significant differences in prognosis among the surgical procedures in the high‐risk group. Conclusion: The combined advanced lung cancer inflammation index and nonalcoholic fatty liver disease fibrosis score serves as a predictive marker for severe postoperative complications after anatomical resection. This combined marker may contribute to appropriate surgical procedure selection. [ABSTRACT FROM AUTHOR]

The Cd40l –/– mouse is a well-established model of X-linked hyper-immunoglobulin M (IgM) syndrome, an immunodeficiency disorder of human beings characterized by the lack of expression of the CD40 ligand (CD40L) on activated T-cells, predisposing to infections with opportunistic pathogens like Pneumocystis jirovecii. The aim of our study was to describe the pulmonary lesions in Cd40l –/– mice experimentally infected with Pneumocystis murina, in comparison with naturally infected severe combined immunodeficient (SCID) mice. Formalin-fixed paraffin-embedded lungs from 26 Cd40l –/–, 11 SCID, and 5 uninfected Cd40l –/– mice were examined by histology and immunohistochemistry for the presence of the pathogen and for leukocyte populations (CD3, CD4, CD45R/B220, CD8a, Iba-1, Ly-6G, CD206, MHC II, and NKp46/NCR1). Infection was confirmed by immunohistochemistry in 18/26 (69%) Cd40l –/– mice and in 11/11 (100%) SCID mice. Fourteen out of 26 (54%) Cd40l –/– mice had interstitial pneumonia. Twenty-three out of 26 (88%) Cd40l –/– mice had peribronchiolar/perivascular lymphoplasmacytic infiltrates, rich in B-cells and Mott cells. Acidophilic macrophage pneumonia was additionally found in 20/26 (77%) Cd40l –/– mice. Only 4/11 (36%) SCID mice had interstitial pneumonia, but no peribronchiolar/perivascular infiltrates or acidophilic macrophage pneumonia were observed in this strain. This study represents the first description of pulmonary histopathological lesions in Cd40l –/– mice infected with P. murina. We speculate that the singular characteristics of the inflammatory infiltrates observed in Cd40l –/– mice could be explained by the specific immune phenotype of the model. [ABSTRACT FROM AUTHOR]

Introduction: Neutrophils play a dichotomous role in community-acquired pneumonia (CAP), providing protection and potentially causing damage. Existing research on neutrophil function in CAP relies on animal studies, leaving a gap in patient-centered investigations. Methods: We used mass spectrometry to characterize the neutrophil proteome of moderately ill CAP patients at general ward admission and related the proteome to controls and clinical outcomes. Results: We prospectively included 57 CAP patients and 26 controls and quantified 3482 proteins in neutrophil lysates and 386 proteins in concurrently collected plasma. The extensively studied granule-related proteins in animal models did not drive the neutrophil proteome changes associated with human CAP. Proteome alterations were primarily characterized by an increased abundance of proteins related to (aerobic) metabolic activity and (m)RNA translation/processing, concurrent with a diminished presence of cytoskeletal organization-related proteins (all pathways p<0.001). Higher and lower abundances of specific proteins, primarily constituents of these pathways, were associated with prolonged time to clinical stability in CAP. Moreover, we identified a pronounced presence of platelet-related proteins in neutrophil lysates of particularly viral CAP patients, suggesting the existence of neutrophil-platelet complexes in non-critically ill CAP patients. Of the proteins measured in neutrophils, 4.3% were detected in plasma. Discussion: Our study presents new perspectives on the neutrophil proteome associated with CAP, laying the groundwork for forthcoming patient-centred investigations. Our results could pave the way for targeted strategies to fine-tune neutrophil responses, potentially improving CAP outcomes. [ABSTRACT FROM AUTHOR]