Integrative Physiology of Pneumonia

Strategies for pneumococcal vaccination in older adults in the coming era

Pneumonia, predominantly caused by Streptococcus pneumoniae, remains a leading cause of global mortality. The 23-valent Pneumococcal polysaccharide vaccine (PPSV23) and conjugate vaccines (PCVs) are vital measures to fight against it. This paper discussed the changes in pneumococcal vaccination strategies, particularly for older adults, as vaccine effectiveness and epidemiological patterns shift. While PPSV23 maintains effectiveness against invasive pneumococcal disease (IPD), its effectiveness against pneumococcal pneumonia is declining. Conversely, PCV13 consistently demonstrates effectiveness against both IPD and pneumonia. Consequently, the US Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices recommends using PCVs, notably PCV20 and PCV15, over PPSV23. Japanese studies indicate a change in the efficacy/effectiveness of PPSV23 following PCV introduction in children, likely owing to serotype replacement and herd immunity. Additionally, recent data reveals a plateau in the reduction of PCV13 and PPSV23-covered serotypes, posing a challenge to current strategies. This paper indicates a paradigm shift in pneumonia management, acknowledging its chronic nature and potential to exacerbate other diseases. The future of pneumococcal vaccination lies in broader serotype coverage through PCVs, adapting to serotype changes driven by childhood vaccination programs. Furthermore, continuous research and vaccine development are crucial in this evolving field.

Novel Therapeutic Target for ALI/ARDS: Forkhead Box Transcription Factors

ALI/ARDS can be a pulmonary manifestation of a systemic inflammatory response or a result of overexpression of the body's normal inflammatory response involving various effector cells, cytokines, and inflammatory mediators, which regulate the body's immune response through different signalling pathways. Forkhead box transcription factors are evolutionarily conserved transcription factors that play a crucial role in various cellular processes, such as cell cycle progression, proliferation, differentiation, migration, metabolism, and DNA damage response. Transcription factors control protein synthesis by regulating gene transcription levels, resulting in diverse biological outcomes. The Fox family plays a role in activating or inhibiting the expression of various molecules related to ALI/ARDS through phosphorylation, acetylation/deacetylation, and control of multiple signalling pathways. An in-depth analysis of the integrated Fox family's role in ALI/ARDS can aid in the development of potential diagnostic and therapeutic targets for the condition.

Inflammatory and Immune Mechanisms in COPD: Current Status and Therapeutic Prospects

Background

Chronic obstructive pulmonary disease (COPD) currently ranks among the top three causes of mortality worldwide, presenting as a prevalent and complex respiratory ailment. Ongoing research has underscored the pivotal role of immune function in the onset and progression of COPD. The immune response in COPD patients exhibits abnormalities, characterized by diminished anti-infection capacity due to immune senescence, heightened activation of neutrophils and macrophages, T cell infiltration, and aberrant B cell activity, collectively contributing to airway inflammation and lung injury in COPD.

Objective

This review aimed to explore the pivotal role of the immune system in COPD and its therapeutic potential.

Methods

We conducted a review of immunity and COPD published within the past decade in the Web of Science and PubMed databases, sorting through and summarizing relevant literature.

Results

This article examines the pivotal roles of the immune system in COPD. Understanding the specific functions and interactions of these immune cells could facilitate the development of novel therapeutic strategies and interventions aimed at controlling inflammation, enhancing immune function, and mitigating the impact of respiratory infections in COPD patients.

Postinfectious Pulmonary Complications: Establishing Research Priorities to Advance the Field: An Official American Thoracic Society Workshop Report

Continued improvements in the treatment of pulmonary infections have paradoxically resulted in a growing challenge of individuals with postinfectious pulmonary complications (PIPCs). PIPCs have been long recognized after tuberculosis, but recent experiences such as the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic have underscored the importance of PIPCs following other lower respiratory tract infections. Independent of the causative pathogen, most available studies of pulmonary infections focus on short-term outcomes rather than long-term morbidity among survivors. In this document, we establish a conceptual scope for PIPCs with discussion of globally significant pulmonary pathogens and an examination of how these pathogens can damage different components of the lung, resulting in a spectrum of PIPCs. We also review potential mechanisms for the transition from acute infection to PIPC, including the interplay between pathogen-mediated injury and aberrant host responses, which together result in PIPCs. Finally, we identify cross-cutting research priorities for the field to facilitate future studies to establish the incidence of PIPCs, define common mechanisms, identify therapeutic strategies, and ultimately reduce the burden of morbidity in survivors of pulmonary infections.

Role of lifestyle factors on the development and long-term prognosis of pneumonia and cardiovascular disease in the Chinese population

BACKGROUND

Whether adherence to a healthy lifestyle is associated with a lower risk of developing pneumonia and a better long-term prognosis remains unclear. This study aimed to investigate associations of individual and combined lifestyle factors (LFs) with the incidence risk and long-term prognosis of pneumonia hospitalization.

METHODS

Using data from the China Kadoorie Biobank study, we used the multistate models to investigate the role of five high-risk LFs, including smoking, excessive alcohol drinking, unhealthy dietary habits, physical inactivity, and unhealthy body shape, alone or in combination in the transitions from a generally healthy state at baseline to pneumonia hospitalization or cardiovascular disease (CVD, regarded as a reference outcome), and subsequently to mortality.

RESULTS

Most of the five high-risk LFs were associated with increased risks of transitions from baseline to pneumonia and from pneumonia to death, but with different risk estimates. The greater the number of high-risk LFs, the higher the risk of developing pneumonia and long-term mortality risk after pneumonia, with the strength of associations comparable to that of LFs and CVD. Compared to participants with 0-1 high-risk LF, the adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for transitions from baseline to pneumonia and from pneumonia to death in those with five high-risk LFs were 1.43 (1.28-1.60) and 1.98 (1.61-2.42), respectively. Correspondingly, the respective HRs (95% CIs) for transitions from baseline to CVD and from CVD to death were 2.00 (1.89-2.11) and 1.44 (1.30-1.59), respectively. The risk estimates changed slightly when further adjusting for the presence of major chronic diseases.

CONCLUSION

In this Chinese population, unhealthy LFs were associated with an increased incidence and long-term mortality risk of pneumonia.

Mice fatal pneumonia model induced by less-virulent Streptococcus pneumoniae via intratracheal aerosolization

Aim: Animal models of fatal pneumonia caused by Streptococcus pneumoniae (Spn) have not been reliably generated using many strains of less virulent serotypes.Materials & methods: Pulmonary infection of a less virulent Spn serotype1 strain in the immunocompetent mice was established via the intratracheal aerosolization (ITA) route. The survival, local and systemic bacterial spread, pathological changes and inflammatory responses of this model were compared with those of mice challenged via the intratracheal instillation, intranasal instillation and intraperitoneal injection routes.Results: ITA and intratracheal instillation both induced fatal pneumonia; however, ITA resulted in better lung bacterial deposition and distribution, pathological homogeneity and delivery efficiency.Conclusion: ITA is an optimal route for developing animal models of severe pulmonary infections.

Active fractions from Jingfang Baidu Powder alleviate Klebsiella-induced Pneumonia by inhibiting TLR4/Myd88-ERK signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Jingfang Baidu Powder (JFBDP) is a classic traditional Chinese medicine prescription. Although Jingfang Baidu powder obtained a general consensus on clinical efficacy in treating pneumonia, there were many Chinese herbal drugs in formula, complex components, and large oral dosage, which brings certain obstacles to clinical application.

AIM OF THE STUDY

Therefore, screening of the active fraction that exerts anti-pneumonia helps improve the pharmaceutical preparation, improve the treatment compliance of patients, and further contribute to the clinical application, and the screening of the new active ingredients with anti-pneumonia. The histopathological observation, real-time quantitative PCR, western blotting, and immunofluorescence were applied to evaluate the anti-pneumonia efficacy of active fractions from JFBDP.

RESULTS

Three fractions from JFBDP inhibit the gene expression of IL-1β, IL-10, CCL3, CCL5, and CCL22 in lung tissue infected by Klebsiella at various degrees, and presented a good dose-response relationship. JF50 showed stronger anti-inflammatory effects among three fractions including JF30, JF50, and JF75. Besides, JF50 significantly reduced the protein expression of TLR4 and Myd88 in lung tissue infected with Klebsiella, and it also significantly inhibited p-ERK and p-NF-κB p65. JF50 significantly inhibits the protein expression of Caspase 3, Caspase 8, and Caspase 9 in lung tissue infected with Klebsiella at the dose of 25 mg/kg and 50 mg/kg.

CONCLUSION

JF50 improves lung pathological damage in Klebsiella pneumonia mice by inhibiting the TLR4/Myd88/NF-κB-ERK signaling pathway, and inhibiting apoptosis of lung tissue cells. These findings provide a reference for further exploring the active substance basis of Jingfang Baidu Powder in treating bacterial pneumonia.

A novel inherited CARD9 deficiency in an otherwise healthy woman with CNS candidiasis

Patients with caspase-associated recruitment domain-9 (CARD9) deficiency are more likely to develop invasive fungal disease that affect CNS. However, the understanding of how Candida invades and persists in CNS is still limited. We here reported a 24-year-old woman who were previously immunocompetent and diagnosed with CNS candidiasis. A novel autosomal recessive homozygous CARD9 mutation (c.184 + 5G > T) from this patient was identified using whole genomic sequencing. Furthermore, we extensively characterized the impact of this CARD9 mutation on the host immune response in monocytes, neutrophils and CD4 + T cells, using single cell sequencing and in vitro experiments. Decreased pro-inflammatory cytokine productions of CD14 + monocyte, impaired Th17 cell differentiation, and defective neutrophil accumulation in CNS were found in this patient. In conclusion, this study proposed a novel mechanism of CNS candidiasis development. Patients with CNS candidiasis in absence of known immunodeficiencies should be analyzed for CARD9 gene mutation as the cause of invasive fungal infection predisposition.

Local complement activation and modulation in mucosal immunity

The complement system is an evolutionarily conserved arm of innate immunity, which forms one of the first lines of host response to pathogens and assists in the clearance of debris. A deficiency in key activators/amplifiers of the cascade results in recurrent infection, whereas a deficiency in regulating the cascade predisposes to accelerated organ failure, as observed in colitis and transplant rejection. Given that there are over 60 proteins in this system, it has become an attractive target for immunotherapeutics, many of which are United States Food and Drug Administration-approved or in multiple phase 2/3 clinical trials. Moreover, there have been key advances in the last few years in the understanding of how the complement system operates locally in tissues, independent of its activities in circulation. In this review, we will put into perspective the abovementioned discoveries to optimally modulate the spatiotemporal nature of complement activation and regulation at mucosal surfaces.

Ventilator-associated pneumonia: pathobiological heterogeneity and diagnostic challenges

Ventilator-associated pneumonia (VAP) affects up to 20% of critically ill patients and induces significant antibiotic prescription pressure, accounting for half of all antibiotic use in the ICU. VAP significantly increases hospital length of stay and healthcare costs yet is also associated with long-term morbidity and mortality. The diagnosis of VAP continues to present challenges and pitfalls for the currently available clinical, radiological and microbiological diagnostic armamentarium. Biomarkers and artificial intelligence offer an innovative potential direction for ongoing future research. In this Review, we summarise the pathobiological heterogeneity and diagnostic challenges associated with VAP.

Clinical risk factors and blood protein biomarkers of 10-year pneumonia risk

BACKGROUND

Chronic inflammation may increase susceptibility to pneumonia.

RESEARCH QUESTION

To explore associations between clinical comorbidities, serum protein immunoassays, and long-term pneumonia risk.

METHODS

Framingham Heart Study Offspring Cohort participants ≥65 years were linked to their Centers for Medicare Services claims data. Clinical data and 88 serum protein immunoassays were evaluated for associations with 10-year incident pneumonia risk using Fine-Gray models for competing risks of death and least absolute shrinkage and selection operators for covariate selection.

RESULTS

We identified 1,370 participants with immunoassays and linkage to Medicare data. During 10 years of follow up, 428 (31%) participants had a pneumonia diagnosis. Chronic pulmonary disease [subdistribution hazard ratio (SHR) 1.87; 95% confidence interval (CI), 1.33-2.61], current smoking (SHR 1.79, CI 1.31-2.45), heart failure (SHR 1.74, CI 1.10-2.74), atrial fibrillation/flutter (SHR 1.43, CI 1.06-1.93), diabetes (SHR 1.36, CI 1.05-1.75), hospitalization within one year (SHR 1.34, CI 1.09-1.65), and age (SHR 1.06 per year, CI 1.04-1.08) were associated with pneumonia. Three baseline serum protein measurements were associated with pneumonia risk independent of measured clinical factors: growth differentiation factor 15 (SHR 1.32; CI 1.02-1.69), C-reactive protein (SHR 1.16, CI 1.06-1.27) and matrix metallopeptidase 8 (SHR 1.14, CI 1.01-1.30). Addition of C-reactive protein to the clinical model improved prediction (Akaike information criterion 4950 from 4960; C-statistic of 0.64 from 0.62).

CONCLUSIONS

Clinical comorbidities and serum immunoassays were predictive of pneumonia risk. C-reactive protein, a routinely-available measure of inflammation, modestly improved pneumonia risk prediction over clinical factors. Our findings support the hypothesis that prior inflammation may increase the risk of pneumonia.

Extra-pulmonary control of respiratory defense

Pneumonia persists as a public health crisis, representing the leading cause of death due to infection. Whether respiratory tract infections progress to pneumonia and its sequelae such as acute respiratory distress syndrome and sepsis depends on numerous underlying conditions related to both the causative agent and host. Regarding the former, pneumonia burden remains staggeringly high, despite the effectiveness of pathogen-targeting strategies such as vaccines and antibiotics. This demands a greater understanding of host features that collaborate to promote immune resistance and tissue resilience in the infected lung. Such features inside the pulmonary compartment have drawn much attention, where major advances have been made related to resident and recruited immune activity. By comparison, extra-pulmonary processes guiding pneumonia susceptibility are relatively elusive, constituting the focus of this review. Here we will highlight examples of when, how, and why tissues outside of the lungs dispatch signals that modulate local immunity in the airspaces. Topics include the liver, gut, bone marrow, brain and more, all of which contribute in direct and indirect ways to pneumonia outcome. When tuned appropriately, it has become clear that these responses can serve protective roles, and this will be considered distinctly from what would otherwise be aberrant responses characteristic of pneumonia-induced organ injury and sepsis. Further advances in this area may reveal novel targetable areas for clinical intervention that are not confined to the intra-pulmonary space.

Predictive significance of systemic immune-inflammation index combined with prealbumin for postoperative pneumonia following lung resection surgery

BACKGROUND

We aimed to determine whether systemic immune-inflammation index (SII) combined with prealbumin can provide better predictive power for postoperative pneumonia in patients undergoing lung resection surgery.

METHODS

We identified eligible patients undergoing lung resection surgery at the Affiliated Hospital of Nantong University from March 2021 to March 2022. Demographic characteristics, clinical data, and laboratory information were collected and reviewed from the electronic medical records of the patients. To test the effect of the combined detection of SII and prealbumin, we made an equation using logistic regression analysis. The receiver operating characteristic curve (ROC) was plotted to evaluate the predictive powers, sensitivity, and specificity of prealbumin, SII, and SII combined with prealbumin. Decision curve analysis (DCA) was used to determine the clinical validity and net benefit of different methods of detection.

RESULTS

Totally 386 eligible patients were included with a median age of 62.0 years (IQR: 55.0, 68.0), and 57 (14.8%) patients presented with postoperative pneumonia within 7 days after surgery. The multivariate regression analysis showed that preoperative SII as continuous variable was associated with an increased risk of postoperative pneumonia (OR: 1.38, 95% CI: 1.19-2.83, P = 0.011), whereas the prealbumin as continuous variable remained as an independent protective predictor of postoperative pneumonia in the adjusted analysis (OR: 0.80, 95% CI: 0.37-0.89, P = 0.023). Compared to SII or prealbumin, the combined detection of preoperative SII and prealbumin showed a higher predictive power with area under curve of 0.79 (95% CI: 0.71-0.86, P < 0.05 for all). Additionally, DCA indicated that the combined detection was superior over preoperative SII or prealbumin alone in clinical validity and net benefit.

CONCLUSION

Both preoperative SII and prealbumin are independent influencing factors for postoperative pneumonia after lung resection surgery. The combined detection of preoperative SII and prealbumin can significantly improve prediction capability to identify potential postoperative pneumonia-susceptible patients, facilitating early interventions to improve postoperative quality of life for surgical lung resection patients.

Investigating causal associations between pneumonia and lung cancer using a bidirectional mendelian randomization framework

BACKGROUND

Pneumonia and lung cancer are both major respiratory diseases, and observational studies have explored the association between their susceptibility. However, due to the presence of potential confounders and reverse causality, the comprehensive causal relationships between pneumonia and lung cancer require further exploration.

METHODS

Genome-wide association study (GWAS) summary-level data were obtained from the hitherto latest FinnGen database, COVID-19 Host Genetics Initiative resource, and International Lung Cancer Consortium. We implemented a bidirectional Mendelian randomization (MR) framework to evaluate the causal relationships between several specific types of pneumonia and lung cancer. The causal estimates were mainly calculated by inverse-variance weighted (IVW) approach. Additionally, sensitivity analyses were also conducted to validate the robustness of the causalty.

RESULTS

In the MR analyses, overall pneumonia demonstrated a suggestive but modest association with overall lung cancer risk (Odds ratio [OR]: 1.21, 95% confidence interval [CI]: 1.01 - 1.44, P = 0.037). The correlations between specific pneumonia types and overall lung cancer were not as significant, including bacterial pneumonia (OR: 1.07, 95% CI: 0.91 - 1.26, P = 0.386), viral pneumonia (OR: 1.00, 95% CI: 0.95 - 1.06, P = 0.891), asthma-related pneumonia (OR: 1.18, 95% CI: 0.92 - 1.52, P = 0.181), and COVID-19 (OR: 1.01, 95% CI: 0.78 - 1.30, P = 0.952). Reversely, with lung cancer as the exposure, we observed that overall lung cancer had statistically crucial associations with bacterial pneumonia (OR: 1.08, 95% CI: 1.03 - 1.13, P = 0.001) and viral pneumonia (OR: 1.09, 95% CI: 1.01 - 1.19, P = 0.037). Sensitivity analysis also confirmed the robustness of these findings.

CONCLUSION

This study has presented a systematic investigation into the causal relationships between pneumonia and lung cancer subtypes. Further prospective study is warranted to verify these findings.

Neutrophils and galectin-3 defend mice from lethal bacterial infection and humans from acute respiratory failure

Respiratory infection by Pseudomonas aeruginosa, common in hospitalized immunocompromised and immunocompetent ventilated patients, can be life-threatening because of antibiotic resistance. This raises the question of whether the host's immune system can be educated to combat this bacterium. Here we show that prior exposure to a single low dose of lipopolysaccharide (LPS) protects mice from a lethal infection by P. aeruginosa. LPS exposure trained the innate immune system by promoting expansion of neutrophil and interstitial macrophage populations distinguishable from other immune cells with enrichment of gene sets for phagocytosis- and cell-killing-associated genes. The cell-killing gene set in the neutrophil population uniquely expressed Lgals3, which encodes the multifunctional antibacterial protein, galectin-3. Intravital imaging for bacterial phagocytosis, assessment of bacterial killing and neutrophil-associated galectin-3 protein levels together with use of galectin-3-deficient mice collectively highlight neutrophils and galectin-3 as central players in LPS-mediated protection. Patients with acute respiratory failure revealed significantly higher galectin-3 levels in endotracheal aspirates (ETAs) of survivors compared to non-survivors, galectin-3 levels strongly correlating with a neutrophil signature in the ETAs and a prognostically favorable hypoinflammatory plasma biomarker subphenotype. Taken together, our study provides impetus for harnessing the potential of galectin-3-expressing neutrophils to protect from lethal infections and respiratory failure.

Inflammatory and endothelial host responses in community-acquired pneumonia: exploring the relationships with HbA1c, admission plasma glucose, and glycaemic gap-a cross-sectional study

Introduction

Diabetes is associated with dysregulated immune function and impaired cytokine release, while transient acute hyperglycaemia has been shown to enhance inflammatory cytokine release in preclinical studies. Although diabetes and acute hyperglycaemia are common among patients with community-acquired pneumonia (CAP), the impact of chronic, acute, and acute-on-chronic hyperglycaemia on the host response within this population remains poorly understood. This study investigated whether chronic, acute, and acute-on- chronic hyperglycaemia are associated with distinct mediators of inflammatory, endothelial, and angiogenic host response pathways in patients with CAP.

Methods

In a cross-sectional study of 555 patients with CAP, HbA1c, admission plasma (p)-glucose, and the glycaemic gap (admission p-glucose minus HbA1c- derived average p-glucose) were employed as measures of chronic, acute, and acute-on-chronic hyperglycaemia, respectively. Linear regression was used to model the associations between the hyperglycaemia measures and 47 proteins involved in inflammation, endothelial activation, and angiogenesis measured at admission. The models were adjusted for age, sex, CAP severity, pathogen, immunosuppression, comorbidity, and body mass index. Adjustments for multiple testing were performed with a false discovery rate threshold of less than 0.05.

Results

The analyses showed that HbA1c levels were positively associated with IL-8, IL-15, IL-17A/F, IL-1RA, sFlt-1, and VEGF-C. Admission plasma glucose was also positively associated with these proteins and GM-CSF. The glycaemic gap was positively associated with IL-8, IL-15, IL-17A/F, IL-2, and VEGF-C.

Conclusion

In conclusion, chronic, acute, and acute-on-chronic hyperglycaemia were positively associated with similar host response mediators. Furthermore, acute and acute-on-chronic hyperglycaemia had unique associations with the inflammatory pathways involving GM-CSF and IL-2, respectively.

B cells in the pneumococcus-infected lung are heterogeneous and require CD4+ T cell help including CD40L to become resident memory B cells

Recovery from respiratory pneumococcal infections generates lung-localized protection against heterotypic bacteria, mediated by resident memory lymphocytes. Optimal protection in mice requires re-exposure to pneumococcus within days of initial infection. Serial surface marker phenotyping of B cell populations in a model of pneumococcal heterotypic immunity revealed that bacterial re-exposure stimulates the immediate accumulation of dynamic and heterogeneous populations of B cells in the lung, and is essential for the establishment of lung resident memory B (BRM) cells. The B cells in the early wave were activated, proliferating locally, and associated with both CD4+ T cells and CXCL13. Antagonist- and antibody-mediated interventions were implemented during this early timeframe to demonstrate that lymphocyte recirculation, CD4+ cells, and CD40 ligand (CD40L) signaling were all needed for lung BRM cell establishment, whereas CXCL13 signaling was not. While most prominent as aggregates in the loose connective tissue of bronchovascular bundles, morphometry and live lung imaging analyses showed that lung BRM cells were equally numerous as single cells dispersed throughout the alveolar septae. We propose that CD40L signaling from antigen-stimulated CD4+ T cells in the infected lung is critical to establishment of local BRM cells, which subsequently protect the airways and parenchyma against future potential infections.

Elucidating the anti-inflammatory activity of platycodins in lung inflammation through pulmonary distribution dynamics and grey relational analysis of cytokines

ETHNOPHARMACOLOGICAL RELEVANCE

Platycodonis Radix (PR) is a traditional herbal remedy used to prevent and treat lung inflammation, and platycodins are speculated to be the major active constituents. However, concrete experimental verification for this assertion remains absent thus far.

AIM OF THE STUDY

This study aims to compare the pulmonary distribution dynamics of five platycodins and analyze their effects on cytokines. Through the grey relational analysis (GRA) between pulmonary active components and cytokines, the study ascertains platycodins as the potential effective component against lung inflammation.

MATERIALS AND METHODS

A rat lung inflammation model was created using lipopolysaccharides (LPS). Pulmonary distribution dynamics were analyzed via LC-MS/MS. Cytokine changes and distribution patterns in lung tissues were studied by multi-factor reagent kit. GRA was applied to determine correlations between pulmonary components and cytokines. Finally, the anti-inflammatory properties of platycodins were further studied using LPS-induced BEAS-2B cells in vitro.

RESULTS

The results showed that five platycodins (Platycodin D, Platycodin D3, Deapio Platycodin D, 3-O-β-D-Glucopyranosyl Platycodigenin, and Platycodigenin) featured fast absorption rate, short time to peak, and slow metabolism rate. The pulmonary distribution dynamics were significantly affected within 2 h after LPS modeling. At the same time, PR altered the relationships among different cytokines induced by LPS stimulation, particularly inflammatory cytokines IL-6 and IFN-γ. The GRA results indicated good correlation between the pulmonary distribution dynamics of the five platycodins components and the changing patterns of cytokine levels, with Platycodin D3 contributing the most. Additionally, Platycodin D3 exhibited a protective role against LPS-induced inflammation by reducing the production of pro-inflammatory mediators such as IL-1β, IL-8, and ROS, as well as increasing the expression of the anti-inflammatory mediator IL-10.

CONCLUSIONS

Platycodins are the main anti-inflammatory agents in PR and there is a good correlation with cytokines. This contributes to the anti-pneumonia effect of PR.

Discovery of potential quality markers of Fritillariae thunbergii bulbus in pneumonia by combining UPLC-QTOF-MS, network pharmacology, and molecular docking

Fritillariae thunbergii bulbus (FTB) is a popular Chinese herbal medicine with various applications in respiratory diseases. The quality evaluation of FTB has been insufficient to date, as the active ingredients and mechanisms of action of FTB remain unclear. This study proposes a novel strategy for exploring the quality markers (Q-markers) of FTB based on UPLC-QTOF-MS analysis, network pharmacology, molecular docking, and molecular dynamics (MD) simulation. A total of 26 compounds in FTB were identified by UPLC-QTOF-MS. Ten of these compounds were screened as Q-markers based on network pharmacology for their anti-pneumonia effects, including imperialine, peimisine, peiminine, ebeiedinone, zhebeirine, puqiedine, 9-hydroxy-10,12-octadecadienoic acid, (9Z,12Z,15Z)-13-hydroxy-9,12,15-octadecatrienoic acid, 9,12,15-octadecatrienoic acid, and (2E,4Z,7Z,10Z,13Z,16Z,19Z)-2,4,7,10,13,16,19-docosaheptaenoic acid methyl ester (DAME). These Q-markers were predicted to act on multiple targets and pathways associated with pneumonia. Molecular docking results revealed that most of the Q-markers showed high affinity with at least one of the main targets of pneumonia, and the top ten complexes were confirmed with MD simulation. Network pharmacology indicated that FTB may act on the TNF signaling pathway, HIF-1 signaling pathway, JAK-STAT signaling pathway, etc. The results demonstrated that imperialine (P8), peimisine (P9), peiminine (P11), ebeiedine (P15), zhebeirine (P16), and puqiedine (P18) may be potential Q-markers of FTB, and AKT1, IL-6, VEGFA, TP53, EGFR, STAT3, PPARG, MMP9, and CASP3 may be promising therapeutic targets for pneumonia treatment that are worthy of further research.

Definition, Epidemiology, and Pathogenesis of Severe Community-Acquired Pneumonia

The clinical presentation of community-acquired pneumonia (CAP) can vary widely among patients. While many individuals with mild symptoms can be managed as outpatients with excellent outcomes, there is a distinct subgroup of patients who present with severe CAP. In these cases, the mortality rate can reach approximately 25% within 30 days and even up to 50% within a year. It is crucial to focus attention on these patients who are at higher risk. Among the various definitions of severe CAP found in the literature, one commonly used criterion is the requirement for admission to intensive care unit. Notable epidemiological characteristics of these patients include the impact of acute cardiovascular diseases on clinical outcomes and the enduring, independent effect of pneumonia on long-term outcomes. Factors such as pathogen virulence, the presence of comorbidities, and the host response are important contributors to the pathogenesis of severe CAP. In these patients, the host response may be dysregulated and compartmentalized. Gaining a better understanding of the epidemiology and pathogenesis of severe CAP will provide a foundation for the development of new therapies for this condition. This manuscript aims to review the definition, epidemiology, and pathogenesis of severe CAP, shedding light on important aspects that can aid in the improvement of patient care and outcomes.

MSCs alleviate LPS-induced acute lung injury by inhibiting the proinflammatory function of macrophages in mouse lung organoid-macrophage model

Acute lung injury (ALI) is an inflammatory disease associated with alveolar injury, subsequent macrophage activation, inflammatory cell infiltration, and cytokine production. Mesenchymal stem cells (MSCs) are beneficial for application in the treatment of inflammatory diseases due to their immunomodulatory effects. However, the mechanisms of regulatory effects by MSCs on macrophages in ALI need more in-depth study. Lung tissues were collected from mice for mouse lung organoid construction. Alveolar macrophages (AMs) derived from bronchoalveolar lavage and interstitial macrophages (IMs) derived from lung tissue were co-cultured, with novel matrigel-spreading lung organoids to construct an in vitro model of lung organoids-immune cells. Mouse compact bone-derived MSCs were co-cultured with organoids-macrophages to confirm their therapeutic effect on acute lung injury. Changes in transcriptome expression profile were analyzed by RNA sequencing. Well-established lung organoids expressed various lung cell type-specific markers. Lung organoids grown on spreading matrigel had the property of functional cells growing outside the lumen. Lipopolysaccharide (LPS)-induced injury promoted macrophage chemotaxis toward lung organoids and enhanced the expression of inflammation-associated genes in inflammation-injured lung organoids-macrophages compared with controls. Treatment with MSCs inhibited the injury progress and reduced the levels of inflammatory components. Furthermore, through the nuclear factor-κB pathway, MSC treatment inhibited inflammatory and phenotypic transformation of AMs and modulated the antigen-presenting function of IMs, thereby affecting the inflammatory phenotype of lung organoids. Lung organoids grown by spreading matrigel facilitate the reception of external stimuli and the construction of in vitro models containing immune cells, which is a potential novel model for disease research. MSCs exert protective effects against lung injury by regulating different functions of AMs and IMs in the lung, indicating a potential mechanism for therapeutic intervention.

The shifting lipidomic landscape of blood monocytes and neutrophils during pneumonia

The lipidome of immune cells during infection has remained unexplored, although evidence of the importance of lipids in the context of immunity is mounting. In this study, we performed untargeted lipidomic analysis of blood monocytes and neutrophils from patients hospitalized for pneumonia and age- and sex-matched noninfectious control volunteers. We annotated 521 and 706 lipids in monocytes and neutrophils, respectively, which were normalized to an extensive set of internal standards per lipid class. The cellular lipidomes were profoundly altered in patients, with both common and distinct changes between the cell types. Changes involved every level of the cellular lipidome: differential lipid species, class-wide shifts, and altered saturation patterns. Overall, differential lipids were mainly less abundant in monocytes and more abundant in neutrophils from patients. One month after hospital admission, lipidomic changes were fully resolved in monocytes and partially in neutrophils. Integration of lipidomic and concurrently collected transcriptomic data highlighted altered sphingolipid metabolism in both cell types. Inhibition of ceramide and sphingosine-1-phosphate synthesis in healthy monocytes and neutrophils resulted in blunted cytokine responses upon stimulation with lipopolysaccharide. These data reveal major lipidomic remodeling in immune cells during infection, and link the cellular lipidome to immune functionality.

A living neutrophil Biorobot synergistically blocks multifaceted inflammatory pathways in macrophages to effectively neutralize cytokine storm

Cytokine storm is a potentially life-threatening immune response typically correlated with lung injury, particularly in people with underlying disease states, such as pneumonia. Therefore, the prompt treatment of cytokine storm is essential for successful recovery from a potentially fatal condition. Herein, a living anti-inflammatory Biorobot (firefighter), composed of neutrophils encapsulating mannose-decorated liposomes of the NF-κB inhibitor TPCA-1 and STING inhibitor H-151 (M-Lip@TH, inflammatory retardant), is developed for alleviating hyperinflammatory cytokine storm through targeting multiple inflammatory pathways in macrophages. Biorobot fully inherits the chemotaxis characteristics of neutrophils, and efficiently delivers and releases therapeutic M-Lip@TH at the inflammatory site. Subsequently, M-Lip@TH selectively targets macrophages and simultaneously blocks the transcription factor NF-κB pathway and STING pathway, thereby preventing the overproduction of cytokines. Animal studies show that Biorobot selectively targets LPS-induced acute lung injury, and not only inhibits the NF-κB pathway to suppress the release of various pro-inflammatory cytokines and chemokines, but also blocks the STING pathway to prevent an overactive immune response, which helps to neutralize cytokine storms. Particularly, Biorobot reduces lung inflammation and injury, improves lung function, and increases the survival rates of pneumonia mice. Therefore, Biorobot represents a rational combination therapy against cytokine storm, and may provide insights into the treatment of diseases involving overactive immune responses.

A methodical exploration of imaging modalities from dataset to detection through machine learning paradigms in prominent lung disease diagnosis: a review

BACKGROUND

Lung diseases, both infectious and non-infectious, are the most prevalent cause of mortality overall in the world. Medical research has identified pneumonia, lung cancer, and Corona Virus Disease 2019 (COVID-19) as prominent lung diseases prioritized over others. Imaging modalities, including X-rays, computer tomography (CT) scans, magnetic resonance imaging (MRIs), positron emission tomography (PET) scans, and others, are primarily employed in medical assessments because they provide computed data that can be utilized as input datasets for computer-assisted diagnostic systems. Imaging datasets are used to develop and evaluate machine learning (ML) methods to analyze and predict prominent lung diseases.

OBJECTIVE

This review analyzes ML paradigms, imaging modalities' utilization, and recent developments for prominent lung diseases. Furthermore, the research also explores various datasets available publically that are being used for prominent lung diseases.

METHODS

The well-known databases of academic studies that have been subjected to peer review, namely ScienceDirect, arXiv, IEEE Xplore, MDPI, and many more, were used for the search of relevant articles. Applied keywords and combinations used to search procedures with primary considerations for review, such as pneumonia, lung cancer, COVID-19, various imaging modalities, ML, convolutional neural networks (CNNs), transfer learning, and ensemble learning.

RESULTS

This research finding indicates that X-ray datasets are preferred for detecting pneumonia, while CT scan datasets are predominantly favored for detecting lung cancer. Furthermore, in COVID-19 detection, X-ray datasets are prioritized over CT scan datasets. The analysis reveals that X-rays and CT scans have surpassed all other imaging techniques. It has been observed that using CNNs yields a high degree of accuracy and practicability in identifying prominent lung diseases. Transfer learning and ensemble learning are complementary techniques to CNNs to facilitate analysis. Furthermore, accuracy is the most favored metric for assessment.

Inter-alpha-trypsin inhibitor (IαI) and hyaluronan modifications enhance the innate immune response to influenza virus in the lung

The inter-alpha-trypsin inhibitor (IαI) complex is composed of the bikunin core protein with a single chondroitin sulfate (CS) attached and one or two heavy chains (HCs) covalently linked to the CS chain. The HCs from IαI can be transferred to hyaluronan (HA) through a TNFα-stimulated gene-6 (TSG-6) dependent process to form an HC•HA matrix. Previous studies reported increased IαI, HA, and HC•HA complexes in mouse bronchoalveolar lavage fluid (BALF) post-influenza infection. However, the expression and incorporation of HCs into the HA matrix of the lungs during the clinical course of influenza A virus (IAV) infection and the biological significance of the HC•HA matrix are poorly understood. The present study aimed to better understand the composition of HC•HA matrices in mice infected with IAV and how these matrices regulate the host pulmonary immune response. In IAV infected mice bikunin, HC1-3, TSG-6, and HAS1-3 all show increased gene expression at various times during a 12-day clinical course. The increased accumulation of IαI and HA was confirmed in the lungs of infected mice using immunohistochemistry and quantitative digital pathology. Western blots confirmed increases in the IαI components in BALF and lung tissue at 6 days post-infection (dpi). Interestingly, HCs and bikunin recovered from BALF and plasma from mice 6 dpi with IAV, displayed differences in the HC composition by Western blot analysis and differences in bikunin's CS chain sulfation patterns by mass spectrometry analysis. This strongly suggests that the IαI components were synthesized in the lungs rather than translocated from the vascular compartment. HA was significantly increased in BALF at 6 dpi, and the HA recovered in BALF and lung tissues were modified with HCs indicating the presence of an HC•HA matrix. In vitro experiments using polyinosinic-polycytidylic acid (poly(I:C)) treated mouse lung fibroblasts (MLF) showed that modification of HA with HCs increased cell-associated HA, and that this increase was due to the retention of HA in the MLF glycocalyx. In vitro studies of leukocyte adhesion showed differential binding of lymphoid (Hut78), monocyte (U937), and neutrophil (dHL60) cell lines to HA and HC•HA matrices. Hut78 cells adhered to immobilized HA in a size and concentration-dependent manner. In contrast, the binding of dHL60 and U937 cells depended on generating a HC•HA matrix by MLF. Our in vivo findings, using multiple bronchoalveolar lavages, correlated with our in vitro findings in that lymphoid cells bound more tightly to the HA-glycocalyx in the lungs of influenza-infected mice than neutrophils and mononuclear phagocytes (MNPs). The neutrophils and MNPs were associated with a HC•HA matrix and were more readily lavaged from the lungs. In conclusion, this work shows increased IαI and HA accumulation and the formation of a HC•HA matrix in mouse lungs post-IAV infection. The formation of HA and HC•HA matrices could potentially create specific microenvironments in the lungs for immune cell recruitment and activation during IAV infection.

A decreased impact of air pollution on hospital pneumonia visits during COVID-19 outbreak in northeastern Thailand

Background

The coronavirus disease 2019 (COVID-19) pandemic had effects on changes in people, society, and pollutant sources. This was a unique research opportunity to assess the effects on the risk of pneumonia resulted from the changes in air pollution and personal hygiene regarding city lockdown.

Methods

This study, we estimated time-series relative risks (RRs) of pneumonia (n=94,288) associated with PM10, PM2.5, NO2, and O3 in Khon Kaen province and its vicinity, using Poison regression with generalized additive model and compared air pollutant-associated risk of pneumonia before vs. during the COVID-19 outbreak [2018-2021].

Results

During the COVID-19 period, pneumonia cases, PM2.5, PM10, and NO2 levels were lower than those before the COVID-19 but the O3 level was significantly higher. The single-pollutant analyses showed that the increase in PM10, PM2.5, and NO2 were significantly associated with pneumonia risks at single-day lag 0 in the earlier two years (2018-2019). For multi-pollutant analyses, there were higher RRs in PM2.5 at lag 0 [RR =1.078, 95% confidence interval (CI): 1.004 to 1.157], lag 4 (RR =1.054, 95% CI: 1.011 to 1.098) and lag 5 (RR =1.090, 95% CI: 1.021 to 1.165) and for all cumulative-day lags, greatest was at lag 0-5 (RR =1.314, 95% CI: 1.200 to 1.439) before the COVID-19 period while there were lower pneumonia RRs of a 10-µg/m3 increase in PM2.5 at single-day lag 1 (RR =1.064, 95% CI: 1.002 to 1.130) and for all cumulative-day lags, greatest was at lag 0-5 (RR =1.201, 95% CI: 1.073 to 1.344) during the COVID-19 outbreak. Multi-pollutant of NO2 significantly increased pneumonia risk in cumulative day exposure before the COVID-19 outbreak at lag 0-3 (RR =1.050, 95% CI: 1.001 to 1.100). It was significantly greater than that risk during the outbreak.

Conclusions

This study revealed that the lockdown measures to control COVID-19 were effective in improving air quality and lowering associated pneumonia risk. These findings would help raise awareness about measures and policies to preserve the air quality to increase respiratory health benefits.

Signaling pathways and potential therapeutic targets in acute respiratory distress syndrome (ARDS)

Acute respiratory distress syndrome (ARDS) is a common condition associated with critically ill patients, characterized by bilateral chest radiographical opacities with refractory hypoxemia due to noncardiogenic pulmonary edema. Despite significant advances, the mortality of ARDS remains unacceptably high, and there are still no effective targeted pharmacotherapeutic agents. With the outbreak of coronavirus disease 19 worldwide, the mortality of ARDS has increased correspondingly. Comprehending the pathophysiology and the underlying molecular mechanisms of ARDS may thus be essential to developing effective therapeutic strategies and reducing mortality. To facilitate further understanding of its pathogenesis and exploring novel therapeutics, this review provides comprehensive information of ARDS from pathophysiology to molecular mechanisms and presents targeted therapeutics. We first describe the pathogenesis and pathophysiology of ARDS that involve dysregulated inflammation, alveolar-capillary barrier dysfunction, impaired alveolar fluid clearance and oxidative stress. Next, we summarize the molecular mechanisms and signaling pathways related to the above four aspects of ARDS pathophysiology, along with the latest research progress. Finally, we discuss the emerging therapeutic strategies that show exciting promise in ARDS, including several pharmacologic therapies, microRNA-based therapies and mesenchymal stromal cell therapies, highlighting the pathophysiological basis and the influences on signal transduction pathways for their use.

'Pterocephalodes hookeri-Onosma hookeri' decoction protects against LPS-induced pulmonary inflammation via inhibiting TLR4/ NF-κB signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

As the second-largest traditional medical system in China, Tibetan medicine has a long history and abundant resources. To promote the development of the Tibetan medicine industry, it is essential to study the pharmacological activities of Tibetan medicine based on its traditional usage methods.

AIM OF THE STUDY

Pneumonia has been a worldwide health problem with high morbidity and mortality rates, especially in the context of the COVID-19 epidemic. Given the unique advantages of traditional Tibetan medicine in treating pulmonary diseases, further research is warranted to develop potential anti-pneumonia drugs.

MATERIALS AND METHODS

In our study, the potential combined decoction from traditional Tibetan medicine was determined by the data mining method. The antioxidant activity in vitro, anti-inflammatory effects on the macrophage cell model, as well as the anti-pulmonary inflammation effects on the LPS-induced mice model, have been explored to investigate the potential anti-pneumonia role of the decoction. Additionally, we conducted network pharmacology analysis to identify the potential targets against pneumonia, which were further confirmed by western blot assays.

RESULTS

Following the combination therapy of Pterocephalodes hookeri (C.B.Clarke) V.Mayer & Ehrend. and Onosma hookeri var. longiflora (Duthie) A.V.Duthie ex Stapf ('P-O'), the clearance of DPPH radical and the total reducing power were all improved, as well as alleviated the toxicity. On the in vitro level, 'P-O' pre-treatment reduced the secretion of NO, TNF-α, IL-6, and IL-1β in LPS-stimulated RAW264.7 cells, while promoting the concentration of IL-10. Meanwhile, on the in vivo level, the 'P-O' pre-treating also could alleviate LPS-induced pulmonary inflammation by reducing the pulmonary edema and leakage of the lung microvascular, improving the pathological change of lung tissue and regulating the cytokines content in bronchoalveolar lavage fluid (BALF). Furthermore, network pharmacology analysis revealed that the mechanism of 'P-O' in treating pneumonia in a multi-component, multi-target, and multi-pathway network, with the TLR4/NF-κB signaling pathway playing a crucial role, as demonstrated by the western blot assay results.

CONCLUSION

In summary, the combination therapy of 'P-O' exhibited good antioxidant activity and anti-inflammatory activity in vitro, as well as a therapeutic effect against pulmonary inflammation in vivo. These findings provide evidence for the clinical application of 'P-O' and offer new approaches for treating pneumonia.

Network pharmacology and transcriptomics to determine Danggui Yifei Decoction mechanism of action for the treatment of chronic lung injury

ETHNOPHARMACOLOGICAL RELEVANCE

Several children with pneumonia (especially severe cases) have symptoms of cough and expectoration during the recovery stage after standard symptomatic treatment, which eventually results in chronic lung injury. Danggui yifei Decoction (DGYFD), a traditional Chinese formula, has shown clinical promise for the treatment of chronic lung injury during the recovery stage of pneumonia, however, its mechanism of action is yet to be deciphered.

AIM OF THIS STUDY

To investigate the therapeutic mechanism of DGYFD for the treatment of chronic lung injury by integrating network pharmacology and transcriptomics.

MATERIALS AND METHODS

BALB/c mice were used to establish the chronic lung injury mouse model by intratracheal instillation of lipopolysaccharide (LPS). Pathological analysis of lung tissue, lung injury histological score, lung index, protein levels in bronchoalveolar lavage fluid (BALF), immunohistochemical staining, blood rheology, inflammatory cytokines, and oxidative stress levels were used to evaluate the pharmacological effects of DGYFD. Chemical components of DGYFD were identified using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Integrated network pharmacology together with transcriptomics was used to predict potential biological targets. Western blot analysis was used to verify the results.

RESULTS

In this study, we demonstrated that DGYFD could improve lung injury pathological changes, decreases lung index, down-regulate NO and IL-6 levels, and regulate blood rheology. In addition, DGYFD was able to reduce the protein levels in BALF, up-regulate the expression levels of occludin and ZO-1, improve the ultrastructure of lung tissues, and reverse the imbalance of AT I and AT II cells to repair the alveolar-capillary permeability barrier. Twenty-nine active ingredients of DGYFD and 389 potential targets were identified by UPLC-MS/MS and network pharmacology, and 64 differentially expressed genes (DEGs) were identified using transcriptomics. GO and KEGG analysis revealed that the MAPK pathway may be the molecular target. Further, we found that DGYFD inhibits phosphorylation levels of p38 MAPK and JNK in chronic lung injury mouse models.

CONCLUSIONS

DGYFD could regulate the imbalance between the excessive release of inflammatory cytokines and oxidative stress, repair the alveolar-capillary permeability barrier and improve the pathological changes during chronic lung injury by regulating the MAPK signaling pathway.

Neutrophil responsiveness to IL-10 impairs clearance of Streptococcus pneumoniae from the lungs

The early immune response to bacterial pneumonia requires a careful balance between pathogen clearance and tissue damage. The anti-inflammatory cytokine interleukin (IL)-10 is critical for restraining otherwise lethal pulmonary inflammation. However, pathogen-induced IL-10 is associated with bacterial persistence in the lungs. In this study, we used mice with myeloid cell specific deletion of IL-10R to investigate the cellular targets of IL-10 immune suppression during infection with Streptococcus pneumoniae, the most common bacterial cause of pneumonia. Our findings suggest that IL-10 restricts the neutrophil response to S. pneumoniae, as neutrophil recruitment to the lungs was elevated in myeloid IL-10 receptor (IL-10R)-deficient mice and neutrophils in the lungs of these mice were more effective at killing S. pneumoniae. Improved killing of S. pneumoniae was associated with increased production of reactive oxygen species and serine protease activity in IL-10R-deficient neutrophils. Similarly, IL-10 suppressed the ability of human neutrophils to kill S. pneumoniae. Burdens of S. pneumoniae were lower in myeloid IL-10R-deficient mice compared with wild-type mice, and adoptive transfer of IL-10R-deficient neutrophils into wild-type mice significantly improved pathogen clearance. Despite the potential for neutrophils to contribute to tissue damage, lung pathology scores were similar between genotypes. This contrasts with total IL-10 deficiency, which is associated with increased immunopathology during S. pneumoniae infection. Together, these findings identify neutrophils as a critical target of S. pneumoniae-induced immune suppression and highlight myeloid IL-10R abrogation as a mechanism to selectively reduce pathogen burdens without exacerbating pulmonary damage.

Interaction between long noncoding RNA and microRNA in lung inflammatory diseases

BACKGROUND

Non-coding RNAs (ncRNAs) are a group of RNAs that cannot synthesize proteins, but are critical in gene expression regulation. Long non-coding RNAs (lncRNAs) and microRNAs (miRNAs), the two major family members, are intimately involved in controlling immune response, cell proliferation, apoptosis, differentiation and polarization, and cytokine secretion. Their interactions significantly influence lung inflammatory diseases and could be potential therapeutic targets.

OBJECTIVES

The review aims to elucidate the role of ncRNAs, especially the interactions between lncRNA and miRNA in lung diseases, including acute and chronic lung inflammatory diseases, as well as lung cancer. And provide novel insights into disease mechanisms and potential therapeutic methods.

METHODS

We conducted a comprehensive review of the latest studies on lncRNA and miRNA in lung inflammatory diseases. Our research involved searching through electronic databases like PubMed, Web of Science, and Scopus.

RESULTS

We explain the fundamental characteristics and functions of miRNA and lncRNA, their potential interaction mechanisms, and summarize the newly explorations on the role of lncRNA and miRNA interactions in lung inflammatory diseases.

CONCLUSIONS

Numerous lncRNAs and miRNAs have been found to partipicate in all stages of lung inflammatory diseases. While ncRNA-based therapies have been validated and developed, there remain challenges in developing more stable and effective drugs for clinical use.

Inhalation of panaxadiol alleviates lung inflammation via inhibiting TNFA/TNFAR and IL7/IL7R signaling between macrophages and epithelial cells

Background

Lung inflammation occurs in many lung diseases, but has limited effective therapeutics. Ginseng and its derivatives have anti-inflammatory effects, but their unstable physicochemical and metabolic properties hinder their application in the treatment. Panaxadiol (PD) is a stable saponin among ginsenosides. Inhalation administration may solve these issues, and the specific mechanism of action needs to be studied.

Methods

A mouse model of lung inflammation induced by lipopolysaccharide (LPS), an in vitro macrophage inflammation model, and a coculture model of epithelial cells and macrophages were used to study the effects and mechanisms of inhalation delivery of PD. Pathology and molecular assessments were used to evaluate efficacy. Transcriptome sequencing was used to screen the mechanism and target. Finally, the efficacy and mechanism were verified in a human BALF cell model.

Results

Inhaled PD reduced LPS-induced lung inflammation in mice in a dose-dependent manner, including inflammatory cell infiltration, lung tissue pathology, and inflammatory factor expression. Meanwhile, the dose of inhalation was much lower than that of intragastric administration under the same therapeutic effect, which may be related to its higher bioavailability and superior pharmacokinetic parameters. Using transcriptome analysis and verification by a coculture model of macrophage and epithelial cells, we found that PD may act by inhibiting TNFA/TNFAR and IL7/IL7R signaling to reduce macrophage inflammatory factor-induced epithelial apoptosis and promote proliferation.

Conclusion

PD inhalation alleviates lung inflammation and pathology by inhibiting TNFA/TNFAR and IL7/IL7R signaling between macrophages and epithelial cells. PD may be a novel drug for the clinical treatment of lung inflammation.

C/EBPβ: The structure, regulation, and its roles in inflammation-related diseases

Inflammation, a mechanism of the human body, has been implicated in many diseases. Inflammatory responses include the release of inflammatory mediators by activating various signaling pathways. CCAAT/enhancer binding protein β (C/EBPβ), a transcription factor in the C/EBP family, contains the leucine zipper (bZIP) domain. The expression of C/EBPβ is mediated at the transcriptional and post-translational levels, such as phosphorylation, acetylation, methylation, and SUMOylation. C/EBPβ has been involved in inflammatory responses by mediating several signaling pathways, such as MAPK/NF-κB and IL-6/JAK/STAT3 pathways. C/EBPβ plays an important role in the pathological development of inflammation-related diseases, such as osteoarthritis, pneumonia, hepatitis, inflammatory bowel diseases, and rheumatoid arthritis. Here, we comprehensively discuss the structure and biological effects of C/EBPβ and its role in inflammatory diseases.

Clinical risk factors and blood protein biomarkers of 10-year pneumonia risk

Background

Chronic inflammation may increase susceptibility to pneumonia.

Research Question

To explore associations between clinical comorbidities, serum protein immunoassays, and long-term pneumonia risk.

Methods

Framingham Heart Study Offspring Cohort participants ≥65 years were linked to their Centers for Medicare Services claims data. Clinical data and 88 serum protein immunoassays were evaluated for associations with 10-year incident pneumonia risk using Fine-Gray models for competing risks of death and least absolute shrinkage and selection operators for covariate selection.

Results

We identified 1,370 participants with immunoassays and linkage to Medicare data. During 10 years of follow up, 428 (31%) participants had a pneumonia diagnosis. Chronic pulmonary disease [subdistribution hazard ratio (SHR) 1.87; 95% confidence interval (CI), 1.33-2.61], current smoking (SHR 1.79, CI 1.31-2.45), heart failure (SHR 1.74, CI 1.10-2.74), atrial fibrillation/flutter (SHR 1.43, CI 1.06-1.93), diabetes (SHR 1.36, CI 1.05-1.75), hospitalization within one year (SHR 1.34, CI 1.09-1.65), and age (SHR 1.06 per year, CI 1.04-1.08) were associated with pneumonia. Three baseline serum protein measurements were associated with pneumonia risk independent of measured clinical factors: growth differentiation factor 15 (SHR 1.32; CI 1.02-1.69), C-reactive protein (SHR 1.16, CI 1.06-1.27) and matrix metallopeptidase 8 (SHR 1.14, CI 1.01-1.30). Addition of C-reactive protein to the clinical model improved prediction (Akaike information criterion 4950 from 4960; C-statistic of 0.64 from 0.62).

Conclusions

Clinical comorbidities and serum immunoassays were predictive of pneumonia risk. C-reactive protein, a routinely-available measure of inflammation, modestly improved pneumonia risk prediction over clinical factors. Our findings support the hypothesis that prior inflammation may increase the risk of pneumonia.

High throughput sequencing technology reveals alteration of lower respiratory tract microbiome in severe aspiration pneumonia and its association with inflammation

BACKGROUND

Aspiration pneumonia is a common and severe clinical condition. The microbiome present in the lower respiratory tract plays a crucial role in regulating human inflammatory response. However, the relationship between the altered lower respiratory tract microbiome and inflammation in aspiration pneumonia remains inadequately explored.

PURPOSE

To investigate the alteration of the lower respiratory tract microbiome in severe aspiration pneumonia patients and explore the potential correlation between microbiome components and inflammatory response.

METHOD

Patients in the severe aspiration pneumonia group and control group were enrolled from the intensive care unit of Jinshan Hospital, Fudan University between December 31, 2020 and August 19, 2021. Sputum specimens were collected from all participants and subsequently subjected to 16S rDNA high throughput sequencing technology. The concentration of inflammatory cytokines in serum was measured using enzyme-linked immunosorbent assay (ELISA) kits, and collected data including patients' demographic information, clinical data, and laboratory examination results were recorded for further analysis.

RESULTS

Alteration in the lower respiratory tract microbiome was observed in severe aspiration pneumonia. Compared to the control group, a significant decrease in the relative abundance of Firmicutes was found at the phylum level (P < 0.01). At the family level, the relative abundance of Corynebacteriaceae, Enterobacteriaceae and Enterococcaceae increased significantly (P < 0.001, P < 0.05, P < 0.01). There were no significant differences in community diversity of the lower respiratory tract between the two groups. Patients in the severe aspiration pneumonia group exhibited significantly higher levels of inflammation compared to those in the control group. Correlation analysis showed that the relative abundance of Corynebacteriaceae was positively correlated with the expression level of IL-1β and IL-18 (P = 0.002, P = 0.02); the relative abundance of Enterobacteriaceae was negatively correlated with IL-4 (P = 0.011); no other significant correlations have been identified between microbiome and inflammatory indicators thus far (P > 0.05).

CONCLUSIONS

Alteration of the lower respiratory tract microbiome is critically involved in inflammation and disease progression in severe cases of aspiration pneumonia. The potential inflammation regulation properties of the microbiome hold promising value for developing novel therapeutic approaches aimed at mitigating the severity of the disease.

Circ_0026579 knockdown ameliorates lipopolysaccharide-induced human lung fibroblast cell injury by regulating CXCR1 via miR-370-3p

Pneumonia is an inflammatory disease in lower respiratory tracts and its development involves the regulation of RNAs. Circular RNAs are a class of RNA subgroups that can mediate the progression of pneumonia. However, the molecular mechanism of circ_0026579 in regulating pneumonia occurrence remains unclear. The study is designed to reveal the role of circ_0026579 in lipopolysaccharide (LPS)-induced human lung fibroblast cell injury and the underlying mechanism. The expression levels of circ_0026579, miR-370-3p and C-X-C motif chemokine receptor 1 (CXCR1) were detected by quantitative real-time polymerase chain reaction or by western blotting. The production of tumour necrosis factor-α, interleukin (IL)-1β and IL-6 was assessed by enzyme-linked immunosorbent assays. Malondialdehyde and superoxide dismutase levels were analysed using commercial kits. Cell viability, proliferation and apoptosis were analysed by cell counting kit-8 assay, 5-Ethynyl-2'-deoxyuridine assay and flow cytometry analysis, respectively. The binding relationship between miR-370-3p and circ_0026579 or CXCR1 was identified by dual-luciferase reporter assay, RNA immunoprecipitation assay and RNA pull-down assay. Circ_0026579 and CXCR1 expression were significantly upregulated, whereas miR-370-3p was downregulated in the serum of pneumonia patients. LPS treatment induced inflammatory response, oxidative stress and cell apoptosis and inhibited cell proliferation in MRC-5 cells; however, these effects were reversed after circ_0026579 depletion. In terms of the mechanism, circ_0026579 acted as a miR-370-3p sponge, and miR-370-3p combined with CXCR1. Additionally, circ_0026579 depletion ameliorated LPS-induced MRC-5 cell disorder by increasing miR-370-3p expression. CXCR1 overexpression also relieved the miR-370-3p-mediated effects in LPS-treated MRC-5 cells. Further, circ_0026579 induced CXCR1 expression by interacting with miR-370-3p. Circ_0026579 absence ameliorated MRC-5 cell dysfunction induced by LPS through the regulation of the miR-370-3p/CXCR1 axis.

High-dimensional phenotyping of the peripheral immune response in community-acquired pneumonia

Background

Community-acquired pneumonia (CAP) represents a major health burden worldwide. Dysregulation of the immune response plays an important role in adverse outcomes in patients with CAP.

Methods

We analyzed peripheral blood mononuclear cells by 36-color spectral flow cytometry in adult patients hospitalized for CAP (n=40), matched control subjects (n=31), and patients hospitalized for COVID-19 (n=35).

Results

We identified 86 immune cell metaclusters, 19 of which (22.1%) were differentially abundant in patients with CAP versus matched controls. The most notable differences involved classical monocyte metaclusters, which were more abundant in CAP and displayed phenotypic alterations reminiscent of immunosuppression, increased susceptibility to apoptosis, and enhanced expression of chemokine receptors. Expression profiles on classical monocytes, driven by CCR7 and CXCR5, divided patients with CAP into two clusters with a distinct inflammatory response and disease course. The peripheral immune response in patients with CAP was highly similar to that in patients with COVID-19, but increased CCR7 expression on classical monocytes was only present in CAP.

Conclusion

CAP is associated with profound cellular changes in blood that mainly relate to classical monocytes and largely overlap with the immune response detected in COVID-19.

Lung inflammation is associated with lipid deposition

Lung inflammation, pneumonia, is an acute respiratory disease of varying etiology that has recently drawn much attention during the COVID-19 pandemic as lungs are among the main targets for SARS-CoV-2. Multiple other etiological agents are associated with pneumonias. Here, we describe a newly-recognized pathology, namely abnormal lipid depositions in the lungs of patients who died from COVID-19 as well as from non-COVID-19 pneumonias. Our analysis of both semi-thin and Sudan III-stained lung specimens revealed extracellular and intracellular lipid depositions irrespective of the pneumonia etiology. Most notably, lipid depositions were located within vessels adjacent to inflamed regions, where they apparently interfere with the blood flow. Structurally, the lipid droplets in the inflamed lung tissue were homogeneous and lacked outer membranes as assessed by electron microscopy. Morphometric analysis of lipid droplet deposition area allowed us to distinguish the non-pneumonia control lung specimens from the macroscopically intact area of the pneumonia lung and from the inflamed area of the pneumonia lung. Our measurements revealed a gradient of lipid deposition towards the inflamed region. The pattern of lipid distribution proved universal for all pneumonias. Finally, lipid metabolism in the lung tissue was assessed by the fatty acid analysis and by expression of genes involved in lipid turnover. Chromato-mass spectrometry revealed that unsaturated fatty acid content was elevated at inflammation sites compared to that in control non-inflamed lung tissue from the same individual. The expression of genes involved in lipid metabolism was altered in pneumonia, as shown by qPCR and in silico RNA-seq analysis. Thus, pneumonias of various etiologies are associated with specific lipid abnormalities; therefore, lipid metabolism can be considered to be a target for new therapeutic strategies.

Crystal ribcage: a platform for probing real-time lung function at cellular resolution

Understanding the dynamic pathogenesis and treatment response in pulmonary diseases requires probing the lung at cellular resolution in real time. Despite advances in intravital imaging, optical imaging of the lung during active respiration and circulation has remained challenging. Here, we introduce the crystal ribcage: a transparent ribcage that allows multiscale optical imaging of the functioning lung from whole-organ to single-cell level. It enables the modulation of lung biophysics and immunity through intravascular, intrapulmonary, intraparenchymal and optogenetic interventions, and it preserves the three-dimensional architecture, air-liquid interface, cellular diversity and respiratory-circulatory functions of the lung. Utilizing these capabilities on murine models of pulmonary pathologies we probed remodeling of respiratory-circulatory functions at the single-alveolus and capillary levels during disease progression. The crystal ribcage and its broad applications presented here will facilitate further studies of nearly any pulmonary disease as well as lead to the identification of new targets for treatment strategies.

GL7 ligand expression defines a novel subset of CD4+ TRM cells in lungs recovered from pneumococcus

Streptococcus pneumoniae is the most common etiology of bacterial pneumonia, one of the leading causes of death in children and the elderly worldwide. During non-lethal infections with S. pneumoniae, lymphocytes accumulate in the lungs and protect against reinfection with serotype-mismatched strains. Cluster of differentiation CD4+ resident memory T (TRM) cells are known to be crucial for this protection, but the diversity of lung CD4+ TRM cells has yet to be fully delineated. We aimed to identify unique subsets and their contributions to lung immunity. After recovery from pneumococcal infections, we identified a distinct subset of CD4+ T cells defined by the phenotype CD11ahiCD69+GL7+ in mouse lungs. Phenotypic analyses for markers of lymphocyte memory and residence demonstrated that GL7+ T cells are a subset of CD4+ TRM cells. Functional studies revealed that unlike GL7- TRM subsets that were mostly (RAR-related Orphan Receptor gamma T) RORγT+, GL7+ TRM cells exhibited higher levels of (T-box expressed in T cells) T-bet and Gata-3, corresponding with increased synthesis of interferon-γ, interleukin-13, and interleukin-5, inherent to both T helper 1 (TH1) and TH2 functions. Thus, we propose that these cells provide novel contributions during pneumococcal pneumonia, serving as important determinants of lung immunity.

Single-Cell RNA Sequencing and Transcriptome Analysis Revealed the Immune Microenvironment and Gene Markers of Acute Respiratory Distress Syndrome

Background

Acute respiratory distress syndrome (ARDS) is caused by severe pulmonary inflammation and the leading cause of death in the intensive care unit.

Methods

We used single-cell RNA sequencing to compare peripheral blood mononuclear cells from sepsis-induced ARDS (SEP-ARDS) and pneumonic ARDS (PNE-ARDS) patient. Then, we used the GSE152978 and GSE152979 datasets to identify molecular dysregulation mechanisms at the transcriptional level in ARDS.

Results

Markedly increased CD14 cells were the predominant immune cell type observed in SEP-ARDS and PNE-ARDS patients. Cytotoxic cells and natural killer (NK) T cells were exclusively identified in patients with PNE-ARDS. An enrichment analysis of differentially expressed genes (DEGs) suggested that Th1 cell differentiation and Th2 cell differentiation were enriched in cytotoxic cells, and that the IL-17 signaling pathway, NOD receptor signaling pathway, and complement and coagulation cascades were enriched in CD14 cells. Furthermore, according to GSE152978 and GSE152979, 1939 DEGs were identified in patients with ARDS and controls; they were mainly enriched in the Kyoto Encyclopedia of Genes and Genomes pathways. RBP7 had the highest area under the curve values among the 12 hub genes and was mainly expressed in CD14 cells. Additionally, hub genes were negatively correlated with NK cells and positively correlated with neutrophils, cytotoxic cells, B cells, and macrophages.

Conclusion

A severe imbalance in the proportion of immune cells and immune dysfunction were observed in SEP-ARDS and PNE-ARDS patients. RBP7 may be immunologically associated with CD14 cells and serve as a potential marker of ARDS.

Severe pneumonia induces immunosenescence of T cells in the lung of mice

Severe pneumonia may induce sequelae and accelerated aging process even after the person has recovered. However, the underline mechanism is not very clear. More research is needed to fully understand the long-term effects of severe pneumonia. In this study, we found that mice recovered from severe pneumonia showed lung immunosenescence, which was characterized by a bias naive-memory balance of T lymphocytes in the lung. The reduction of naïve T cells is associated with the diminished immune response to cancer or external new antigens, which is one of the key changes that occurs with age. Our results also indicate the link between severe pneumonia and aging process, which is mediated by the disrupted T cells homeostasis in the lungs after pneumonia.

Inflammatory and glycolytic programs underpin a primed blood neutrophil state in patients with pneumonia

Neutrophils are potent immune cells with key antimicrobial functions. Previous in vitro work has shown that neutrophil effector functions are mainly fueled by intracellular glycolysis. Little is known about the state of neutrophils still in the circulation in patients during infection. Here, we combined flow cytometry, stimulation assays, transcriptomics, and metabolomics to investigate the link between inflammatory and metabolic pathways in blood neutrophils of patients with community-acquired pneumonia. Patients' neutrophils, relative to neutrophils from age- and sex- matched controls, showed increased degranulation upon ex vivo stimulation, and portrayed distinct upregulation of inflammatory transcriptional programs. This neutrophil phenotype was accompanied by a high-energy state with increased intracellular ATP content, and transcriptomic and metabolic upregulation of glycolysis and glycogenolysis. One month after hospital admission, these metabolic and transcriptomic changes were largely normalized. These data elucidate the molecular programs that underpin a balanced, yet primed state of blood neutrophils during pneumonia.

Lung microbiome and origins of the respiratory diseases

The studies on the composition of the human microbiomes in healthy individuals, its variability in the course of inflammation, infection, antibiotic therapy, diets and different pathological conditions have revealed their intra and inter-kingdom relationships. The lung microbiome comprises of major species members of the phylum Bacteroidetes, Firmicutes, Actinobacteria, Fusobacteria and Proteobacteria, which are distributed in ecological niches along nasal cavity, nasopharynx, oropharynx, trachea and in the lungs. Commensal and pathogenic species are maintained in equilibrium as they have strong relationships. Bacterial overgrowth after dysbiosis and/or imbalanced of CD4⁺ helper T cells, CD8⁺ cytotoxic T cells and regulatory T cells (Treg) populations can promote lung inflammatory reactions and distress, and consequently acute and chronic respiratory diseases. This review is aimed to summarize the latest advances in resident lung microbiome and its participation in most common pulmonary infections and pneumonia, community-acquired pneumonia (CAP), ventilator-associated pneumonia (VAP), immunodeficiency associated pneumonia, SARS-CoV-2-associated pneumonia, acute respiratory distress syndrome (ARDS) and chronic obstructive pulmonary disease (COPD). We briefly describe physiological and immunological mechanisms that selectively create advantages or disadvantages for relative growth of pathogenic bacterial species in the respiratory tract. At the end, we propose some directions and analytical methods that may facilitate the identification of key genera and species of resident and transient microbes involved in the respiratory diseases' initiation and progression.

Challenges and recommendations for addressing under-five pneumonia morbidity and mortality in Nigeria

Background

Pneumonia is a severe infection and one of the most common causes of mortality among children under five years of age, when not appropriately managed. Infection of the lungs by bacteria, viruses, or fungi and consequent inflammation may lead to cough and difficult breathing. Some of the key predisposing factors are malnutrition and air pollution. WHO reports that Africa has the highest burden of global child mortality, and 16% of all deaths in pneumonia, were children under five years of age in 2016.

Objectives

This study aimed to explore how health providers perceive pneumonia as a cause of under-five mortality in Nigeria.

Methods

A qualitative study design with in-depth interviews and focus group discussions was used to explore and understand nurses and pediatricians' views regarding the pneumonia situation, vaccinations, and preventive suggestions to reduce under five pneumonia deaths in Nigeria.

Results

Two themes and four categories emerged: participant's anxiety over the situation, their views on impediments, current policies and strategies, and suggestions on addressing severe pneumonia.

Conclusions

The results from this study highlight contextual issues playing major roles in pneumonia mortality among children in Nigeria, which will need approaches on several levels to address them.

Immunosuppressive dead cell as lung-targeting vehicle and cytokine absorption material for cytokine storm attenuation of pneumonia

Effectively controlling cytokine storm is important to reduce the mortality of severe pneumonia. In this work a bio-functional dead cell was engineered by one-time quick shock of live immune cells in liquid nitrogen, and the obtained immunosuppressive dead cell could server as both lung-targeting vehicle and cytokine absorption material. After loading the anti-inflammatory drugs of dexamethasone (DEX) and baicalin (BAI), the drug-loaded dead cell (DEX&BAI/Dead cell) could first passively target to the lung after intravenous administration and quickly release the drugs under high shearing stress of pulmonary capillaries, realizing drug enrichment in the lung. Then, the immunosuppressive dead cell acted as the camouflage of normal immune cells with various cytokine receptors exposing on their surface, to "capture" the cytokines and further reduce the state of inflammation. With above formulation design, a synergic anti-inflammatory effect between drugs and carrier could be achieved. In a lipopolysaccharide-induced pneumonia mice model, this system could calm down the cytokine storm with high efficacy and elongate the survival of mice.

Advances in immune response to pulmonary infection: Nonspecificity, specificity and memory

The lung immune response consists of various cells involved in both innate and adaptive immune processes. Innate immunity participates in immune resistance in a nonspecific manner, whereas adaptive immunity effectively eliminates pathogens through specific recognition. It was previously believed that adaptive immune memory plays a leading role during secondary infections; however, innate immunity is also involved in immune memory. Trained immunity refers to the long-term functional reprogramming of innate immune cells caused by the first infection, which alters the immune response during the second challenge. Tissue resilience limits the tissue damage caused by infection by controlling excessive inflammation and promoting tissue repair. In this review, we summarize the impact of host immunity on the pathophysiological processes of pulmonary infections and discuss the latest progress in this regard. In addition to the factors influencing pathogenic microorganisms, we emphasize the importance of the host response.

Qi-Dong-Huo-Xue-Yin balances the immune microenvironment to protect against LPS induced acute lung injury

COVID-19 induces acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) and leads to severe immunological changes that threatens the lives of COVID-19 victims. Studies have shown that both the regulatory T cells and macrophages were deranged in COVID-19-induced ALI. Herbal drugs have long been utilized to adjust the immune microenvironment in ALI. However, the underlying mechanisms of herbal drug mediated ALI protection are largely unknown. This study aims to understand the cellular mechanism of a traditional Chinese medicine, Qi-Dong-Huo-Xue-Yin (QD), in protecting against LPS induced acute lung injury in mouse models. Our data showed that QD intrinsically promotes Foxp3 transcription via promoting acetylation of the Foxp3 promoter in CD4⁺ T cells and consequently facilitates CD4⁺CD25⁺Foxp3⁺ Tregs development. Extrinsically, QD stabilized β-catenin in macrophages to expedite CD4⁺CD25⁺Foxp3⁺ Tregs development and modulated peripheral blood cytokines. Taken together, our results illustrate that QD promotes CD4⁺CD25⁺Foxp3⁺ Tregs development via intrinsic and extrinsic pathways and balanced cytokines within the lungs to protect against LPS induced ALI. This study suggests a potential application of QD in ALI related diseases.

CIRC_0012535 CONTRIBUTES TO LIPOPOLYSACCHARIDE-INDUCED FETAL LUNG FIBROBLAST APOPTOSIS AND INFLAMMATION TO REGULATE INFANTILE PNEUMONIA DEVELOPMENT BY MODULATING THE MIR-338-3P/IL6R SIGNALING

ABSTRACT

Background: Infantile pneumonia is a respiratory infection disease, seriously threatening the life of neonatal patients. Circular RNA (circRNA) dysregulation is reported to be involved in pneumonia pathogenesis. Circ_0012535 was previously displayed to be upregulated in blood samples of patients with community-acquired pneumonia. However, circ_0012535's role in this disorder remains unclear. We thus aim to unveil the functions of circ_0012535 in infantile pneumonia. Methods: Fetal lung fibroblasts (WI38) treated with LPS were used as pneumonia cell models. Expression analysis for circ_0012535, miR-338-3p and IL6R was performed using quantitative real-time polymerase chain reaction. Cell counting kit 88), 5-ethynyl-2'-deoxyuridine, and flow cytometry assays were implemented for cell function detection. The release of inflammatory factors, and superoxide dismutase activity and malonaldehyde content were ascertained using commercial kits. The putative binding between miR-338-3p and circ_0012535 or IL6R was validated by dual-luciferase analysis, RIP analysis, and pull-down analysis. Results: Circ_0012535 was highly expressed in LPS-treated WI38 cells. Knockdown of circ_0012535 recovered LPS-inhibited cell viability and proliferation and attenuated LPS-induced cell apoptosis, cell cycle arrest, inflammation, and oxidative stress. Circ_0012535 bound to miR-338-3p and negatively regulated miR-338-3p expression. Inhibition of miR-338-3p reversed the role of circ_0012535 knockdown, thereby recovering LPS-induced WI38 cell apoptosis and inflammation. MiR-338-3p bound to IL6R 3'UTR, and circ_0012535 shared miR-338-3p binding site with IL6R. IL6R overexpression reversed the role of miR-338-3p, thereby recovering LPS-induced WI38 cell apoptosis and inflammation. Conclusion: Circ_0012535 supported LPS-induced WI38 cell apoptosis and inflammation to promote the progression of infantile pneumonia, and circ_0012535 functioned partly by targeting the miR-338-3p/IL6R signaling.

Tidal breathing lung function analysis of wheezing and non-wheezing infants with pneumonia: A retrospective observational study

To compare lung function in wheezing and non-wheezing infants with pneumonia through tidal breathing analysis and explore the correlation between tidal breathing lung function and clinical characteristics. This retrospective observational study included infants with pneumonia hospitalized in the Affiliated Hospital of Guizhou Medical University between January 2018 and December 2018. Medical records were used to obtain the demographic characteristics, clinical characteristics, tidal breathing lung function results before and after a bronchodilator test, and positive remission rates after the bronchodilator test for each patient. Eighty-six wheezing infants (64 males, aged 6.5 [4.8, 9] months) and 27 non-wheezing infants (18 males, aged 7 [5, 12] months) were included. Non-wheezing infants were more likely to have normal airway function compared to wheezing infants (44.4% vs 23.3%, P = .033). Peak tidal expiration flow/tidal expiratory flow (TEF)25 in wheezing infants was significantly higher than that in non-wheezing infants (162.4 [141.2, 200.7] vs 143.3 [131, 178.8], P = .037). The positive remission rate of tidal inspiratory flow (TIF50)/TEF50 (53.5% vs 29.6%, P = .03) and TEF50 (58.1% vs 33.3%, P = .024) were significantly higher in the wheezing infants compared to non-wheezing infants (P = .03 and P = .024, respectively). Furthermore, respiratory rate, tidal volume, peak expiration flow, TEF25, TEF50, and TEF75 were significantly correlated to the age, height, weight, and platelet counts of infants in both the wheezing and non-wheezing infants (all P < .05). Wheezing infants with pneumonia were more likely to have worse tidal breathing lung function compared to non-wheezing infants with pneumonia. The tidal breathing lung function parameter (respiratory rate, tidal volume, peak expiration flow, TEF25, TEF50, and TEF75) were correlated to the age, height, weight, and platelet counts of both wheezing and non-wheezing infants.