Bronchial mucosal inflammation and illness severity in response to experimental rhinovirus infection in COPD

Neutrophil-to-Lymphocyte Ratio (NLR), Platelet-to-Lymphocyte Ratio (PLR) and Monocyte-to-Lymphocyte Ratio (MLR) as Biomarkers in Diagnosis Evaluation of Acute Exacerbation of Chronic Obstructive Pulmonary Disease: A Retrospective, Observational Study

Purpose

Hierarchical management is advocated in China to effectively manage chronic obstructive pulmonary disease (COPD) patients and reduce the incidence and mortality of acute exacerbation of COPD (AE-COPD). However, primary and community hospitals often have limited access to advanced equipment and technology. Complete blood count (CBC), which is commonly used in these hospitals, offers the advantages of being cost-effective and easily accessible. This study aims to evaluate the significance of routine blood indicators in aiding of diagnosing AE-COPD.

Patients and Methods

In this research, we enrolled a total of 112 patients diagnosed with AE-COPD, 92 patients with stable COPD, and a control group comprising 60 healthy individuals. Clinical characteristics, CBC parameters, and serum CRP levels were collected within two hours. To assess the associations between NLR/PLR/MLR and CRP by Spearman correlation test. The diagnostic accuracy of NLR, PLR and MLR in AE-COPD was assessed using Receiver Operating Characteristic Curve (ROC) and the area under the curve (AUC). Binary Logistic Regression analysis was conducted for the indicators of NLR, PLR and MLR.

Results

We found that patients with AE-COPD had significantly higher levels of NLR, PLR and MLR in contrast to patients with stable COPD. Additionally, the study revealed a noteworthy correlation between CRP and NLR (rs=0.5319, P<0.001), PLR (rs=0.4424, P<0.001), and MLR (rs=0.4628, P<0.001). By utilizing specific cut-off values, the amalgamation of NLR, PLR and MLR augmented diagnostic sensitivity. Binary logistic regression analysis demonstrated that heightened NLR and MLR act as risk factors for the progression of AE-COPD.

Conclusion

The increasing levels of NLR, PLR and MLR could function as biomarkers, akin to CRP, for diagnosis and assessment of acute exacerbations among COPD patients. Further research is required to validate this concept.

Causal role of immune cells in chronic obstructive pulmonary disease: Mendelian randomization study

OBJECTIVES

Innate and adaptive immunity play different roles in the pathogenesis of chronic obstructive pulmonary disease (COPD). However, previous studies on the relationship between immune cells and COPD reported inconsistent results.

METHODS

The causal connection between 731 immune cells and COPD was established using a two-sample Mendelian randomization (MR) analysis through publicly accessible genetic data. The heterogeneity and horizontal pleiotropism of the findings were confirmed using sensitivity analysis.

RESULTS

In the B-cell panel, B-cell activating factor receptor (BAFF-R) on CD20- and CD20 on IgD-CD38bright (OR (95% CI): 0.93 (0.88, 0.99) and 0.97 (0.95, 0.98), respectively) were discovered to be protective. In the cDC panel, CD62L- plasmacytoid DC AC, CD80 on monocytes and CD11c on myeloid DCs (OR (95% CI): 0.94 (0.92, 0.97), 0.97 (0.94, 0.99) and (0.97 (0.95, 0.98), respectively) exerted protective effects. However, unswitched memory AC (OR (95%CI): 1.08 (1.01,1.15)) and CD 19 on IgD- CD 27- (OR (95%CI): 1.06 (1.02,1.10)) were hazardous in the B-cell panel. However, among the 731 immune cell phenotypes, no causal relationship was found for COPD on immune cells.

CONCLUSION

This study found a potential causal relationship between immune cells in COPD, ruling out reverse causation. This study provides new avenues for studying the mechanisms of COPD.

Obesity dysregulates the pulmonary antiviral immune response

Obesity is a well-recognized risk factor for severe influenza infections but the mechanisms underlying susceptibility are poorly understood. Here, we identify that obese individuals have deficient pulmonary antiviral immune responses in bronchoalveolar lavage cells but not in bronchial epithelial cells or peripheral blood dendritic cells. We show that the obese human airway metabolome is perturbed with associated increases in the airway concentrations of the adipokine leptin which correlated negatively with the magnitude of ex vivo antiviral responses. Exogenous pulmonary leptin administration in mice directly impaired antiviral type I interferon responses in vivo and ex vivo in cultured airway macrophages. Obese individuals hospitalised with influenza showed dysregulated upper airway immune responses. These studies provide insight into mechanisms driving propensity to severe influenza infections in obesity and raise the potential for development of leptin manipulation or interferon administration as novel strategies for conferring protection from severe infections in obese higher risk individuals.

Eosinophil values in exacerbation and stable chronic obstructive pulmonary disease and its relationship to maintenance therapy in stable chronic obstructive pulmonary disease patients

Background

Chronic obstructive pulmonary disease (COPD) is characterised by persistent and progressive airflow limitations. The study aimed to determine the relationship between eosinophil values in patients with stable and exacerbated COPD, and the relationship of eosinophil values with two drug regimens used as maintenance therapy in stable COPD.

Materials and methods

This cross-sectional study and the variables used in this study were eosinophil counts in stable and exacerbated COPD patients.

Results

Eighty-three patients with stable and exacerbated COPD were included. Stable COPD (63.9%) was predominant, with the highest degree of symptoms in group A 18 patients (34%) and Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2; 35 patients (66%). The degree of COPD exacerbation was dominated by Type II COPD 15 patients (50%). Eosinophil counts in patients with stable COPD were less than 100 cells/mm3 37 patients (44.6%), while in patients with COPD exacerbation, it was greater than 100 cells/mm3 with a total of 30 patients (36.1%). Long acting muscarinic antagonist class of drugs was the most used treatment as maintenance therapy in stable COPD 34 patients (64.2%).

Conclusion

The eosinophil counts in patients with COPD exacerbation were significantly higher than those in patients with stable COPD. The provision of maintenance therapy in the long acting β-2 agonist + inhaled glucocorticosteroid group of stable COPD patients was generally provided to COPD patients with eosinophil values greater than 100 cells/mm3, and the provision of long-term maintenance therapy in stable COPD patients was generally given to COPD patients with eosinophil values less than 100 cells/mm3.

The emerging role of NOTCH3 receptor signalling in human lung diseases

The mammalian respiratory system or lung is a tree-like branching structure, and the main site of gas exchange with the external environment. Structurally, the lung is broadly classified into the proximal (or conducting) airways and the distal alveolar region, where the gas exchange occurs. In parallel with the respiratory tree, the pulmonary vasculature starts with large pulmonary arteries that subdivide rapidly ending in capillaries adjacent to alveolar structures to enable gas exchange. The NOTCH signalling pathway plays an important role in lung development, differentiation and regeneration post-injury. Signalling via the NOTCH pathway is mediated through activation of four NOTCH receptors (NOTCH1-4), with each receptor capable of regulating unique biological processes. Dysregulation of the NOTCH pathway has been associated with development and pathophysiology of multiple adult acute and chronic lung diseases. This includes accumulating evidence that alteration of NOTCH3 signalling plays an important role in the development and pathogenesis of chronic obstructive pulmonary disease, lung cancer, asthma, idiopathic pulmonary fibrosis and pulmonary arterial hypertension. Herein, we provide a comprehensive summary of the role of NOTCH3 signalling in regulating repair/regeneration of the adult lung, its association with development of lung disease and potential therapeutic strategies to target its signalling activity.

Application of a VP4/VP2-inferred transmission clusters in estimating the impact of interventions on rhinovirus transmission

BACKGROUND

Despite the clinical burden attributable to rhinovirus (RV) infections, the RV transmission dynamics and the impact of interventions on viral transmission remain elusive.

METHODS

A total of 3,935 nasopharyngeal specimens were examined, from which the VP4/VP2 gene was sequenced and genotyped. RV transmission clusters were reconstructed using the genetic threshold of 0.005 substitutions/site, estimated from the global VP4/VP2 sequences. A transmission cluster is characterized by the presence of at least two individuals (represent by nodes), whose viral sequences are genetically linked (represent by undirected edges) at the estimated genetic distance threshold supported by bootstrap value of ≥ 90%. To assess the impact of facemask, pleconaril and social distancing on RV transmission clusters, trials were simulated for interventions with varying efficacy and were evaluated based on the reduction in the number of infected patients (nodes) and the reduction in the number of nodes-connecting edges. The putative impact of intervention strategies on RV transmission clusters was evaluated through 10,000 simulations.

RESULTS

A substantial clustering of 168 RV transmission clusters of varying sizes were observed. This suggests that RV disease burden observed in the population was largely due to multiple sub-epidemics, predominantly driven by RV-A, followed by RV-C and -B. No misclassification of RV species and types were observed, suggesting the specificity and sensitivity of the analysis. Through 10,000 simulations, it was shown that social distancing may be effective in decelerating RV transmission, by removing more than 95% of nodes and edges within the RV transmission clusters. However, facemask removed less than 8% and 66% of nodes and edges, respectively, conferring moderate advantage in limiting RV transmission.

CONCLUSION

Here, we presented a network-based approach of which the degree of RV spread that fuel disease transmission in the region was mapped for the first time. The utilization of RV transmission clusters in assessing the putative impact of interventions on disease transmission at the population level was demonstrated.

The Molecular Epidemiology and Clinical Phylogenetics of Rhinoviruses Among Paediatric Cases in Sydney, Australia

OBJECTIVES

Rhinoviruses (RV) represent the most common aetiological agent of all acute respiratory tract infections across all age groups and a significant burden of disease among children. Recent studies have shown that RV-A and RV-C species are associated with increased disease severity. In order to better understand the potential associations between RV species and clinical features among paediatric cases, this study aimed to integrate genetic and epidemiological data using Bayesian phylogenetic methods.

METHODS

Potential associations between RV species and subtypes, and clinical disease severity using a matched dataset of 52 RV isolates sampled from children (< 18 years) in Sydney, Australia, between 2006 and 2009 were uncovered using epidemiological and phylogenetic methods.

RESULTS

It was found that RV-C was significantly more likely to be isolated from paediatric cases aged < 2 years compared with RV-A, although no significant differences in recorded symptoms were observed. Significant phylogenetic-trait associations between age and the VP4/VP2 capsid protein phylogeny suggest that age-specific variations in infectivity among subtypes may may be possible.

CONCLUSION

This study adds to the growing body of epidemiological evidence concerning RV. Improving surveillance and testing for RV, including routine whole genome sequencing, may improve understanding of the varied disease outcomes of RV species and subtypes. Future studies could aim to identify specific genetic markers associated with age-specific infectivity of RV, which could inform treatment practices and public health surveillance of RV.

Genome sequencing and phylogenetic reconstruction reveal a potential fourth rhinovirus species and its worldwide distribution

Genome sequences of members of a potential fourth rhinovirus (RV) species, provisionally denoted as rhinovirus A clade D, from patients with acute respiratory infection were determined. Bayesian coalescent analysis estimated that clade D emerged around the 1940s and diverged further around 2006-2007 into two distinctive sublineages (RV-A8-like and RV-A45-like) that harbored unique "clade-defining" substitutions. Similarity plots and bootscan mapping revealed a recombination breakpoint located in the 5'-UTR region of members of the RV-A8-like sublineage. Phylogenetic reconstruction revealed the distribution of clade D viruses in the Asia Pacific region and in Europe, underlining its worldwide distribution.