Viral epidemiology of acute exacerbations of chronic obstructive pulmonary disease

The Role of Viral Infections in the Development and Progression of COPD

Chronic obstructive pulmonary disease (COPD) is a common chronic disease seen in smokers associated with poor functional status, quality of life, and morbidity and mortality from acute worsening of chronic symptoms, also called exacerbations. As a disease, the risk factors for COPD are well defined; however, there is room for innovation in identifying underlying biological processes, or "endotypes," that lead to the emergence and/or progression of COPD. Identifying endotypes allows for more thorough understanding of the disease, may reveal the means of disease prevention, and may be leveraged in novel therapeutic approaches. In this review, we discuss the interface of viral infections with both cellular and epithelial immunity as a potential endotype of interest in COPD.

The use of antibiotics in the early stage of acute exacerbation of chronic obstructive pulmonary disease in patients without obvious signs of infection: a multicenter, randomized, parallel-controlled study

Introduction

Chronic obstructive pulmonary disease (COPD) is a chronic respiratory disease with high prevalence and mortality. In some acute exacerbations of COPD (AECOPD) in patients with no obvious signs of infection, early antibiotic treatment seems to clinically improve the disease, but more studies are needed to determine the prognostic impact of antibiotic treatment in AECOPD patients with no obvious signs of infection.

Purpose

To clarify the impact of antibiotic treatment on the short-term and long-term prognoses of AECOPD patients without obvious signs of infection.

Methods

The impact of the two treatment methods on the prognosis of patients was compared at 30, 90, 180, and 360 days after discharge. A multicenter, randomized, parallel-controlled clinical trial was conducted in a department of respiratory and critical care medicine in Central China. All patients met the inclusion criteria for AECOPD, and the patients were randomly assigned to the antibiotic group or the nonantibiotic group at a 1:1 ratio. Patients in the antibiotic group were given moxifloxacin 400 mg/day intravenously for 7 days. Patients in the nonantibiotic group were intravenously injected with the same amount of normal saline as the amount of moxifloxacin given to those in the antibiotic group for 7 days.

Results

There were 406 patients in the antibiotic group and 410 patients in the nonantibiotic group. During the short-term and long-term follow-ups, the acute exacerbation frequency, intensive care unit (ICU) treatment rate, mortality, and mMRC and CAT scores were not significantly different between the two groups (p > 0.05). At the 180- and 360-day follow-ups, the forced expiratory volume in 1 s (FEV1%) and peak expiratory flow (PEF) were not significantly different between the two groups (p > 0.05). The 30-day readmission rate was significantly lower in the antibiotic group than in the nonantibiotic group (p < 0.05). The time from discharge to the first acute exacerbation was not significantly different between the two groups (p > 0.05). The length of the first hospital stay after discharge was significantly lower in the antibiotic group (5.84 days) than in the nonantibiotic group (6.75 days) (p < 0.05). At the 30-day follow-up, the acute exacerbation frequency, age, C-reactive protein (CRP) level, and sputum viscosity were significantly greater in the nonantibiotic group than in the antibiotic group (p < 0.05). In addition, according to the receiver operating characteristic (ROC) analysis, the frequency of acute exacerbations at the 30-day follow-up was significantly greater in COPD patients aged >62.5 years, with a CRP level >12.56 mg/L or with a sputum viscosity >III, in the nonantibiotic group than in those in the antibiotic group, suggesting that the short-term prognosis was poor.

Conclusion

Patients who are >62.5 years of age, have a CRP concentration >12.56 mg/L, or have a sputum viscosity >III without obvious signs of infection should be treated with antibiotics to improve their short-term prognosis.

Clinical Trial Registration

(https://www.chictr.org.cn), (ChiCTR1800018921).

Mitogen-activated protein kinase-guided drug discovery for post-viral and related types of lung disease

Respiratory viral infections are a major public health problem, with much of their morbidity and mortality due to post-viral lung diseases that progress and persist after the active infection is cleared. This paradigm is implicated in the most common forms of chronic lung disease, such as asthma and COPD, as well as other virus-linked diseases including progressive and long-term coronavirus disease 2019. Despite the impact of these diseases, there is a lack of small-molecule drugs available that can precisely modify this type of disease process. Here we will review current progress in understanding the pathogenesis of post-viral and related lung disease with characteristic remodelling phenotypes. We will also develop how this data leads to mitogen-activated protein kinase (MAPK) in general and MAPK13 in particular as key druggable targets in this pathway. We will also explore recent advances and predict the future breakthroughs in structure-based drug design that will provide new MAPK inhibitors as drug candidates for clinical applications. Each of these developments point to a more effective approach to treating the distinct epithelial and immune cell based mechanisms, which better account for the morbidity and mortality of post-viral and related types of lung disease. This progress is vital given the growing prevalence of respiratory viruses and other inhaled agents that trigger stereotyped progression to acute illness and chronic disease.

Analyses of Factors Associated with Acute Exacerbations of Chronic Obstructive Pulmonary Disease: A Review

Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) is the exacerbation of a range of respiratory symptoms during the stable phase of chronic obstructive pulmonary disease (COPD). AECOPD is thus a dangerous stage and key event in the course of COPD, as its deterioration and frequency seriously affects the quality of life of patients and shortens their survival. Acute exacerbations occur and develop due to many factors such as infection, tobacco smoke inhalation, air pollution, comorbidities, airflow limitation, various biomarkers, history of previous deterioration, natural killer cell abnormalities, immunoglobulin G deficiency, genetics, abnormal muscle and nutritional status, negative psychology, and seasonal temperature changes. There is relatively limited research on the impact of the role of standardized management on the alleviation of AECOPD. However, with the establishment of relevant prevention and management systems and the promotion of artificial intelligence technology and Internet medical approaches, long-term effective and standardized management of COPD patients may help to achieve the quality of life and disease prognosis in COPD patients and reduce the risk of AE.

Impact of SARS-CoV-2 infective exacerbation of chronic obstructive pulmonary disease on clinical outcomes in a prospective cohort study of hospitalised adults

OBJECTIVES

To determine whether acute exacerbations of chronic obstructive pulmonary disease (AECOPD) triggered by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), have worse outcomes than AECOPD caused by other infectious agents or non-infective AECOPD (NI-COPD).

DESIGN

A two-hospital prospective cohort study of adults hospitalised with acute respiratory disease. We compared outcomes with AECOPD and a positive test for SARS-CoV-2 (n = 816), AECOPD triggered by other infections (n = 3038) and NI-COPD (n = 994). We used multivariable modelling to adjust for potential confounders and assessed variation by seasons associated with different SARS-CoV-2 variants.

SETTING

Bristol UK, August 2020-May 2022.

PARTICIPANTS

Adults (≥18 y) hospitalised with AECOPD.

MAIN OUTCOME MEASURES

We determined the risk of positive pressure support, longer hospital admission and mortality following hospitalisation with AECOPD due to non-SARS-CoV-2 infection compared with SARS-CoV-2 AECOPD and NI-COPD.

RESULTS

Patients with SARS-CoV-2 AECOPD, in comparison to non-SARS-CoV-2 infective AECOPD or NI-COPD, more frequently required positive pressure support (18.5% and 7.5% vs. 11.7%, respectively), longer hospital stays (median [interquartile range, IQR]: 7 [3-15] and 5 [2-10] vs. 4 [2-9] days, respectively) and had higher 30-day mortality (16.9% and 11.1% vs. 5.9%, respectively) (all p < 0.001). In adjusted analyses, SARS-CoV-2 AECOPD was associated with a 55% (95% confidence interval [95% CI]: 24-93), 26% (95% CI: 15-37) and 35% (95% CI: 10-65) increase in the risk of positive pressure support, hospitalisation length and 30-day mortality, respectively, relative to non-SARS-CoV-2 infective AECOPD. The difference in risk remained similar during periods of wild-type, Alpha and Delta SARS-CoV-2 strain dominance, but diminished during Omicron dominance.

CONCLUSIONS

SARS-CoV-2-related AECOPD had worse patient outcomes compared with non-SARS-CoV-2 AECOPD or NI-AECOPD, although the difference in risks was less pronounced during Omicron dominance.

Incidence of Respiratory Syncytial Virus Infection in Older Adults: Limitations of Current Data

INTRODUCTION

Respiratory syncytial virus (RSV) is an important cause of severe respiratory illness in older adults and adults with respiratory or cardiovascular comorbidities. Published estimates of its incidence and prevalence in adult groups vary widely. This article reviews the potential limitations affecting RSV epidemiology studies and suggests points to consider when evaluating or designing them.

METHODS

Studies reporting the incidence or prevalence of RSV infection in adults in high-income Western countries from 2000 onwards were identified via a rapid literature review. Author-reported limitations were recorded, together with presence of other potential limitations. Data were synthesized narratively, with a focus on factors affecting incidence estimates for symptomatic infection in older adults.

RESULTS

A total of 71 studies met the inclusion criteria, most in populations with medically attended acute respiratory illness (ARI). Only a minority used case definitions and sampling periods tailored specifically to RSV; many used influenza-based or other criteria that are likely to result in RSV cases being missed. The great majority relied solely on polymerase chain reaction (PCR) testing of upper respiratory tract samples, which is likely to miss RSV cases compared with dual site sampling and/or addition of serology. Other common limitations were studying a single season, which has potential for bias due to seasonal variability; failure to stratify results by age, which underestimates the burden of severe disease in older adults; limited generalizability beyond a limited study setting; and absence of measures of uncertainty in the reporting of results.

CONCLUSIONS

A significant proportion of studies are likely to underestimate the incidence of RSV infection in older adults, although the effect size is unclear and there is also potential for overestimation. Well-designed studies, together with increased testing for RSV in patients with ARI in clinical practice, are required to accurately capture both the burden of RSV and the potential public health impact of vaccines.

Antiviral Responses of Tissue-resident CD49a+ Lung Natural Killer Cells Are Dysregulated in Chronic Obstructive Pulmonary Disease

Rationale: Tissue-resident natural killer (trNK) cells have been identified in numerous organs, but little is known about their functional contribution to respiratory immunity, in particular during chronic lung diseases such as chronic obstructive pulmonary disease (COPD). Objectives: To investigate the phenotype and antiviral responses of trNK cells in murine cigarette smoke-induced experimental COPD and in human lung parenchyma from COPD donors. Methods: Mice were exposed to cigarette smoke for 12 weeks to induce COPD-like lung disease. Lung trNK cell phenotypes and function were analyzed by flow cytometry in both murine and human disease with and without challenge with influenza A virus. Measurements and Main Results: In the mouse lung, CD49a+CD49b+EOMES+ and CD49a+CD49b-EOMESlo NK cell populations had a distinct phenotype compared with CD49a- circulating NK cells. CD49a+ NK cells were more extensively altered earlier in disease onset than circulating NK cells, and increased proportions of CD49a+ NK cells correlated with worsening disease in both murine and human COPD. Furthermore, the presence of lung disease delayed both circulating and trNK cell functional responses to influenza infection. CD49a+ NK cells markedly increased their NKG2D, CD103, and CD69 expression in experimental COPD after influenza infection, and human CD49a+ NK cells were hyperactive to ex vivo influenza infection in COPD donors. Conclusions: Collectively, these results demonstrate that trNK cell function is altered in cigarette smoke-induced disease and suggests that smoke exposure may aberrantly prime trNK cell responsiveness to viral infection. This may contribute to excess inflammation during viral exacerbations of COPD.

COPD Is Associated with Elevated IFN-β Production by Bronchial Epithelial Cells Infected with RSV or hMPV

IFN treatment may be a viable option for treating COPD exacerbations based on evidence of IFN deficiency in COPD. However, in vitro studies have used primarily influenza and rhinoviruses to investigate IFN responses. This study aims to investigate the susceptibility to infection and IFN response of primary bronchial epithelial cells (BECs) from COPD donors to infection with RSV and hMPV. BECs from five COPD and five healthy donors were used to establish both submerged monolayer and well-differentiated (WD) cultures. Two isolates of both RSV and hMPV were used to infect cells. COPD was not associated with elevated susceptibility to infection and there was no evidence of an intrinsic defect in IFN production in either cell model to either virus. Conversely, COPD was associated with significantly elevated IFN-β production in response to both viruses in both cell models. Only in WD-BECs infected with RSV was elevated IFN-β associated with reduced viral shedding. The role of elevated epithelial cell IFN-β production in the pathogenesis of COPD is not clear and warrants further investigation. Viruses vary in the responses that they induce in BECs, and so conclusions regarding antiviral responses associated with disease cannot be made based on single viral infections.

Bacterial and Viral Infection in Patients Hospitalized for Acute Exacerbation of Chronic Obstructive Pulmonary Disease: Implication for Antimicrobial Management and Clinical Outcome

Patients with chronic obstructive pulmonary disease (COPD) exhibit frequent acute exacerbations (AE). The objectives of this study were first to evaluate the prevalence of pathogens associated to these episodes by combining conventional bacteriology and multiplex viral and bacterial PCR assays in sputum specimens, and second to determine whether C-reactive protein (CRP) value and clinical outcome could be influenced by the type of microbial agent(s) recovered from these samples. A cohort of 84 Tunisian patients hospitalized at the emergency room for AECOPD was investigated prospectively for the semi-quantitative detection of bacteria by conventional culture (the threshold of positivity was of 10⁷ CFU/ml) and for the detection of viral genome and DNA of atypical bacteria by quantitative PCR using two commercial multiplex respiratory kits (Seegene and Fast-track). The two kits exhibited very similar performances although the Seegene assay was a bit more sensitive. A large number and variety of pathogens were recovered from the sputum samples of these 84 patients, including 15 conventional bacteria, one Chlamydia pneumoniae and 63 respiratory viruses, the most prevalent being rhinoviruses (n = 33) and influenza viruses (n = 13). From complete results available for 74 patients, the presence of bacteria was significantly associated with risk of recurrence at 6 and 12 months post-infection. The combination of these different markers appears useful for delineating correctly the antimicrobial treatment and for initiating a long-term surveillance in those patients with high risk of recurrent exacerbation episodes. A prospective study is required for confirming the benefits of this strategy aimed at improving the stewardship of antibiotics.

Human rhinovirus infection and COPD: role in exacerbations and potential for therapeutic targets

INTRODUCTION

Respiratory virus infections (predominantly rhinoviruses) are the commonly identified in COPD exacerbations but debate about their role as a trigger of exacerbations continues. Experimental infection studies have provided significant new evidence establishing a causal relationship between virus infection and COPD exacerbations and contributed to a better understanding of the mechanisms of virus-induced exacerbations. However as yet no anti-viral treatments have undergone clinical trials in COPD patients.

AREAS COVERED

This review discusses the evidence for and against respiratory viruses being the main trigger of COPD exacerbations from both epidemiological studies and experimental infection studies. The host immune response to rhinovirus infection and how abnormalities in host immunity may underlie increased susceptibility to virus infection in COPD are discussed and the role of dual viral-bacterial infection in COPD exacerbations. Finally the current state of anti-viral therapy is discussed and how these may be used in the future treatment of COPD exacerbations.

EXPERT OPINION

Respiratory virus infections are the trigger of a substantial proportion of COPD exacerbations and rhinoviruses are the most common virus type. Clinical trials of anti-viral agents are needed in COPD patients to determine whether they are effective in virus-induced COPD exacerbations.

The burden of respiratory syncytial virus in adults: a systematic review and meta-analysis

Respiratory syncytial virus (RSV) is the most common pathogen associated with acute lower respiratory tract infections in young children. RSV is also a major viral pathogen causing severe lung disease in the adult population, particularly among the elderly. We conducted a review of adult RSV studies published from January 1970 to February 2017 to determine the burden of disease among adults worldwide. There were no restrictions on health care setting or definition of RSV infection. A total of 1530 published studies were identified, 95 of which were included in this review. The incidence rates of hospitalised RSV acute respiratory tract infection (ARI) in adults >65 years old ranged from 7.3 to 13.0/10⁵ population in Africa and Asia and from 190 to 254/10⁵ population in the USA. Higher incidence rates (195–1790/10⁵ population) were observed in adults ≥50 years old for outpatient or emergency visits in the USA. Of all ARI patients, RSV accounted for 1–10% in adults and 2–14% in patients with chronic diseases or transplantation. Given the limitations in the existing data, significant efforts should be made to generate evidence on the burden of RSV infections in adults and to estimate the potential impact of future preventive interventions.

The Discontinuation of Antibiotics in Patients with Chronic Obstructive Pulmonary Disease Exacerbation and a Positive Respiratory Viral Assay: A Single-center Retrospective Analysis

Background

The use of antibiotics in chronic obstructive pulmonary disorder (COPD) exacerbations attributed to viral infections is observed in this study. The aim of this analysis is to describe the rate of discontinuation of antibiotics in patients who have an acute exacerbation of COPD (AECOPD) caused by viral infections, in turn encouraging the use of the respiratory viral panel in an effort to improve antibiotic stewardship at our facility.

Methods

A retrospective chart review was performed. A total of 92 patients were analyzed who had a positive respiratory viral polymerase chain reaction (PCR) (RVP) admitted for COPD exacerbations, of which 20 patients had a bacterial co-infection by a sputum analysis. Patients with a positive infiltrate on chest X-ray (CXR) were excluded. The rate of discontinuation of antibiotics, excluding azithromycin and doxycycline, in patients with a positive RVP with and without a bacterial co-infection were analyzed.

Results

Of these 92 patients, we found that a bacterial co-infection was detected by sputum culture in 20 patients. The average number of days until discontinuation for patients with no bacterial coinfection was 1.67 days while for those with a bacterial co-infection was 3.20 days. The difference in the number of days was statistically significant (p<0.001).

Conclusion

In conclusion, patients with an identified viral etiology of COPD exacerbations had antibiotics discontinued significantly sooner than those patients with bacterial coinfections.

Influence of the Lung Microbiota Dysbiosis in Chronic Obstructive Pulmonary Disease Exacerbations: The Controversial Use of Corticosteroid and Antibiotic Treatments and the Role of Eosinophils as a Disease Marker

Chronic obstructive pulmonary disease (COPD) is a debilitating lung disease associated with loss of lung function, poorer quality of life, co-morbidities, significant mortality, and higher health care costs. Frequent acute exacerbations of COPD are sudden worsening of symptoms, the nature of which is associated with bacterial or viral infections. However, one-third of exacerbations remain of undetermined origin. Although it is largely discussed and controversial, current guidelines recommend treatment of exacerbations with bronchodilators, antibiotics, and systemic corticosteroids; this is despite being associated with limited benefits in term of reducing mortality, side effects and without paying attention to the heterogeneity of these exacerbations. Increasing evidence suggests that the lung microbiota plays an important role in COPD and numerous studies have reported differences in the microbiota between healthy and disease states, as well as between exacerbations and stable COPD, leading to the hypothesis that frequent acute exacerbation is more likely to experience significant changes in lung microbiota composition. These findings will need further examination to explain the causes of lung dysbiosis, namely microbial composition, the host response, including the recruitment of eosinophils, lifestyle, diet, cigarette smoking and the use of antibiotics and corticosteroids. It is now important to assess: 1) Whether alterations in the lung microbiota contribute to disease pathogenesis, especially in exacerbations of unknown origin; 2) The role of eosinophils; and 3) Whether the microbiota of the lung can be manipulated therapeutically to improve COPD exacerbation event and disease progression. In summary, we hypothesize that the alterations of the lung microbiota may explain the undetermined origins of exacerbations and that there is an urgent need to facilitate the design of intervention studies that aim at conserving the lung microbial flora.

The effect of respiratory viral assay panel on antibiotic prescription patterns at discharge in adults admitted with mild to moderate acute exacerbation of COPD: a retrospective before- after study

Background

Despite well-defined criteria for use of antibiotics in patients presenting with mild to moderate Acute Exacerbation of Chronic Obstructive Pulmonary Disease (AECOPD), their overuse is widespread. We hypothesized that following implementation of a molecular multiplex respiratory viral panel (RVP), AECOPD patients with viral infections would be more easily identified, limiting antibiotic use in this population. The primary objective of our study was to investigate if availability of the RVP decreased antibiotic prescription at discharge among patients with AECOPD.

Methods

This is a single center, retrospective, before (pre-RVP) - after (post-RVP) study of patients admitted to a tertiary medical center from January 2013 to March 2016. The primary outcome was antibiotic prescription at discharge. Groups were compared using univariable and multivariable logistic-regression.

Results

A total of 232 patient-episodes were identified, 133 following RVP introduction. Mean age was 68.1 (pre-RVP) and 68.3 (post-RVP) years respectively (p = 0.88). Patients in pre-RVP group were similar to the post-RVP group with respect to gender (p = 0.54), proportion of patients with BMI < 21(p = 0.23), positive smoking status (p = 0.19) and diagnoses of obstructive sleep apnea (OSA, p = 0.16). We found a significant reduction in antibiotic prescription rate at discharge in patients admitted with AECOPD after introduction of the respiratory viral assay (pre-RVP 77.8% vs. post-RVP 63.2%, p = 0.01). In adjusted analyses, patients in the pre-RVP group [OR 2.11 (CI: 1.13–3.96), p = 0.019] with positive gram stain in sputum [OR 4.02 (CI: 1.61–10.06), p = 0.003] had the highest odds of antibiotic prescription at discharge.

Conclusions

In patients presenting with mild to moderate Acute Exacerbation of Chronic Obstructive Pulmonary Disease (AECOPD), utilization of a comprehensive respiratory viral panel can significantly decrease the rate of antibiotic prescription at discharge.

In vivo experimental models of infection and disease

Human and animal models continue to play a crucial role in research to understand host immunity to rhinovirus (RV) and identify disease mechanisms. Human models have provided direct evidence that RV infection is capable of exacerbating chronic respiratory diseases and identified immunological processes that correlate with clinical disease outcomes. Mice are the most commonly used nonhuman experimental RV infection model. Although semipermissive, under defined experimental conditions sufficient replication occurs to induce host immune responses that recapitulate immunity and disease during human infection. The capacity to use genetically modified mouse strains and drug interventions has shown the mouse model to be an invaluable research tool defining causal relationships between host immunity and disease and supporting development of new treatments. Used in combination the insights achieved from human and animal experimental infection models provide complementary insights into RV biology and yield novel therapeutic options to reduce the burden of RV-induced disease.

Mixed viral infections of the respiratory tract; an epidemiological study during consecutive winter seasons

The current study aimed to describe the molecular epidemiology of mixed respiratory viral infections during consecutive winter seasons in a tertiary care hospital. Patients with symptoms of respiratory tract infection were evaluated during the 2009‐2011 and 2013‐15 winter seasons. A clinical microarray technique was used for viral detection. Clinical and epidemiological data were correlated with mixed viral detection and the need for hospitalization. In 332 out of 604 (54.4%) evaluated patients (17.6% children) a respiratory virus was identified. Mixed viral infections were diagnosed in 68/332 (20.5%) patients with virus detection (66.2% mixed Influenza‐RSV infections). Mixed viral infections were more commonly detected in children (OR 3.7; 95%CI 1.9‐5.6, P < 0.01) and patients with comorbidities. In logistic regression analyses, mixed viral infections were associated with younger age (mean age 30.4 years vs. 41.8 years, P ≤ 0.001) and increased rates of fever (OR: 2.7; 95%CI 1.04‐7.2, P < 0.05) but no adverse outcomes or increased rates of hospitalization. High rates of mixed viral infections were noted during all winter seasons (especially Influenza and RSV) and were more common in younger patients. The clinical significance of mixed respiratory viral infection needs further elucidation.

Interleukin-22 attenuates double-stranded RNA-induced upregulation of PD-L1 in airway epithelial cells via a STAT3-dependent mechanism

Double-stranded RNA derived from viruses induces host immune responses. PD-L1, also known as B7-H1, is an immune-checkpoint molecule associated with the escape of viruses from host immune systems, which plays a role in the persistence of viral infection, resulting in exacerbations of underlying diseases such as asthma and chronic obstructive pulmonary disease. Interleukin (IL)-22 is produced from various immune cells and has protective properties on mucosal tissue. The binding of IL-22 to IL-22 receptor induces STAT3 activation. We investigated the effect of IL-22 on the expression in airway epithelial cells in vitro and in mouse lungs in vivo after the stimulation with an analog of viral double-stranded RNA, polyinosinic-polycytidylic acid (poly I:C). Stimulation with poly I:C upregulated PD-L1 expression on BEAS-2B cells. This upregulation of PD-L1 was attenuated by IL-22 administration. STAT3 phosphorylation was induced by IL-22 and poly I:C. Treatment of cells with STAT3 siRNA abolished the effect of IL-22 on the poly I:C-induced upregulation of PD-L1. This upregulation of PD-L1 was also attenuated by IL-11, a cytokine inducing STAT3 phosphorylation, in BEAS-2B cells. In mouse lung cells in vivo, IL-22 suppressed poly I:C-induced upregulation of PD-L1. These results suggest that IL-22 attenuates virus-induced upregulation of PD-L1 in airway epithelial cells via a STAT3-dependent mechanism.

The epidemiology of medically attended respiratory syncytial virus in older adults in the United States: A systematic review

Objective

This review was undertaken to assess the historical evidence of the disease incidence and burden of laboratory-confirmed respiratory syncytial virus (RSV) in medically attended older adults.

Design

A qualitative systematic literature review was performed; no statistical synthesis of the data was planned, in anticipation of expected heterogeneity across studies in this population.

Methods

A literature search of PubMed, Embase, and the Cochrane Library was conducted for studies of medically attended RSV in older adults (≥ 50 years) published in the last 15 years. Two independent reviewers screened titles and abstracts based on predefined inclusion and exclusion criteria.

Results

From 10 studies reporting incidence proportions, RSV may be the causative agent in up to 12% of medically attended acute respiratory illness in older adults unselected for comorbidities, with variations in clinical setting and by year. In multiple studies, medically attended–RSV incidence among older adults not selected for having underlying health conditions increased with increasing age. Of prospectively followed lung transplant recipients, 16% tested positive for RSV. In hospitalized adults with chronic cardiopulmonary diseases, 8% to 13% were infected with RSV during winter seasons (8%-13%) or metapneumovirus season (8%). Hospitalizations for RSV in older adults typically lasted 3 to 6 days, with substantial proportions requiring intensive care unit admission and mechanical ventilation. Among older adults hospitalized with RSV, the mortality rate was 6% to 8%.

Conclusions

Protection of older adults against RSV could reduce respiratory-related burden, especially as age increases and the prevalence of comorbidities (especially cardiopulmonary comorbidities) grows.

Analysis of viral infection and biomarkers in patients with acute exacerbation of chronic obstructive pulmonary disease

OBJECTIVE

To investigate viral infection in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) in Shanghai, and to analyze the clinical characteristics and biomarkers in viral infection.

METHODS

This study included all consecutive patients who were admitted for a diagnosis of AECOPD during June 2013 to May 2015. Thirty-one stable COPD patients and 31 healthy controls were also recruited. Oropharyngeal samples were assessed, PCR for respiratory viruses were performed. Patients were divided into AECOPD virus-positive (+) group and AECOPD virus-negative (-) group according to viral detection. Luminex was used to detect the concentrations of inflammatory cytokines in the serum.

RESULTS

A total of 264 patients were included with a mean age of 75 ± 0.5 years. There were 72 patients (27.3%) identified with viral positive, of whom two patients were detected with double viral infections (FluA + FluB and RSVA + HRV, respectively). The rate of viral detection was associated with season, highest in winter. Comparisons of clinical characteristics showed no significant differences between AECOPD virus+ group and AECOPD virus- group. However, serum concentrations of interferon-inducible protein-10 (IP-10) and interferon-gamma (IFN-γ) in virus+ AECOPD patients were significantly higher than those in the virus- AECOPD, stable COPD and healthy control groups (P < .05).

CONCLUSION

Viral infection was an important pathogen in AECOPD patients; the most common viruses included FluA, HRV and FluB. It was very difficult to diagnose the viral infection according to clinical characteristics. The increased of serum IP-10 and IFN-γ levels might be value to indicate viral infection in AECOPD.

The recent advances of phenotypes in acute exacerbations of COPD

Exacerbations of COPD are clinically relevant events with therapeutic and prognostic implications. Yet, significant heterogeneity of clinical presentation and disease progression exists within acute exacerbations of COPD (AECOPD). Currently, different phenotypes have been widely used to describe the characteristics among patients with AECOPD. This has proved to be significant in the treatment and prediction of the outcomes of the disease. In this review of published literature, the phenotypes of AECOPD were classified according to etiology, inflammatory biomarkers, clinical manifestation, comorbidity, the frequency of exacerbations, and so on. This review concentrates on advancements in the use of phenotypes of AECOPD.

Respiratory viruses in acute exacerbations of chronic obstructive pulmonary disease

Objective:

Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) cause significant morbidity, mortality, and an inexorable decline of lung function. Data from developed countries have shown viruses to be important causes of AECOPD, but data from developing countries like India are scant. We set out to determine the contribution of viruses in the causation of hospitalized patients with AECOPD.

Methods:

Twin nasopharyngeal/oropharyngeal swabs collected from 233 patients admitted with an acute AECOPD and tested for respiratory viruses including respiratory syncytial virus A and B, parainfluenza were (PIV) 1, 2, 3, and 4, human metapneumovirus (hMPV) A and B, influenza A and B, enterovirus, corona NL65, OC43, and 229E viruses, adenovirus 2 and 4, rhinovirus, and bocavirus, by duplex real time reverse-transcription polymerase chain reaction (qRT-PCR) using CDC approved primers and probes. Samples positive for influenza A were subtyped for A/H1N1pdm09 and A/H3N2 whereas influenza B samples were subtyped into B/Yamagata and B/Victoria subtypes, using primers and probes recommended by CDC, USA.

Results:

Respiratory viruses were detected in 46 (19.7%) cases, influenza A/H3N2 and rhinoviruses being the most common viruses detected. More than one virus was isolated in four cases consisting of hMPV-B + adeno-2 + Inf-B; rhino + H3N2, PIV-1 + rhino; and PIV-1+ hMPV-B in one case each. Ancillary supportive therapeutic measures included bronchodilators, antibiotics, steroids, and ventilation (noninvasive in 42 and invasive in 4). Antiviral therapy was instituted in influenza-positive patients. Three patients with A/H3N2 infection died during hospitalization.

Conclusions:

We conclude that respiratory viruses are important contributors to AECOPD in India. Our data calls for prompt investigation during an exacerbation for viruses to obviate inappropriate antibiotic use and institute antiviral therapy in viral disease amenable to antiviral therapy. Appropriate preventive strategies like influenza vaccination also need to be employed routinely.

Pathogenesis of Viral Infection in Exacerbations of Airway Disease

Chronic airway diseases are a significant cause of morbidity and mortality worldwide, and their prevalence is predicted to increase in the future. Respiratory viruses are the most common cause of acute pulmonary infection, and there is clear evidence of their role in acute exacerbations of inflammatory airway diseases such as asthma and chronic obstructive pulmonary disease. Studies have reported impaired host responses to virus infection in these diseases, and a better understanding of the mechanisms of these abnormal immune responses has the potential to lead to the development of novel therapeutic targets for virus-induced exacerbations. The aim of this article is to review the current knowledge regarding the role of viruses and immune modulation in acute exacerbations of chronic pulmonary diseases and to discuss exciting areas for future research and novel treatments.

Parainfluenza Virus Infection

Human parainfluenza viruses (HPIVs) are single-stranded, enveloped RNA viruses of the Paramyoviridaie family. There are four serotypes which cause respiratory illnesses in children and adults. HPIVs bind and replicate in the ciliated epithelial cells of the upper and lower respiratory tract and the extent of the infection correlates with the location involved. Seasonal HPIV epidemics result in a significant burden of disease in children and account for 40% of pediatric hospitalizations for lower respiratory tract illnesses (LRTIs) and 75% of croup cases. Parainfluenza viruses are associated with a wide spectrum of illnesses which include otitis media, pharyngitis, conjunctivitis, croup, tracheobronchitis, and pneumonia. Uncommon respiratory manifestations include apnea, bradycardia, parotitis, and respiratory distress syndrome and rarely disseminated infection. Immunity resulting from disease in childhood is incomplete and reinfection with HPIV accounts for 15% of respiratory illnesses in adults. Severe disease and fatal pneumonia may occur in elderly and immunocompromised adults. HPIV pneumonia in recipients of hematopoietic stem cell transplant (HSCT) is associated with 50% acute mortality and 75% mortality at 6 months. Though sensitive molecular diagnostics are available to rapidly diagnose HPIV infection, effective antiviral therapies are not available. Currently, treatment for HPIV infection is supportive with the exception of croup where the use of corticosteroids has been found to be beneficial. Several novel drugs including DAS181 appear promising in efforts to treat severe disease in immunocompromised patients, and vaccines to decrease the burden of disease in young children are in development.

Different pattern of viral infections and clinical outcomes in patient with acute exacerbation of chronic obstructive pulmonary disease and chronic obstructive pulmonary disease with pneumonia

Respiratory viruses are well‐known causes of acute exacerbation of chronic obstructive pulmonary disease (AE‐COPD) and also important pathogens for concomitant pneumonia in COPD (CP‐COPD). However, the differences in a viral infection pattern and clinical impacts of respiratory viruses between the two groups have not been well investigated. The clinical and microbiological data from COPD patients admitted with AE‐COPD (n = 281) or CP‐COPD (n = 284) between January 2010 and December 2012 were reviewed. After excluding 88 patients (40 with AE‐COPD and 48 with CP‐COPD) who did not undergo a multiplex RT‐PCR test for respiratory viruses, the demographic characteristics, identified viruses, and clinical outcomes of the AE‐COPD and CP‐COPD groups were compared. Respiratory viruses were identified in 41.9% of AE‐COPD group and 33.5% of the CP‐COPD groups. The most common virus was influenza virus in the AE‐COPD group (33.7%) versus human coronavirus (24.1%) in the CP‐COPD group. Influenza virus was significantly more common in the AE‐ACOPD group than in the CP‐COPD group (P < 0.01). In‐hospital mortality of AE‐COPD and CP‐COPD were 1.2% and 12.3%, respectively (P < 0.01). Among CP‐COPD patients, in‐hospital mortality of patients with only viral infection group, only bacterial infection group, and viral‐bacterial co‐infection were 2.6%, 25.8%, and 17.5%, respectively (P = 0.01). Respiratory viruses were commonly identified in both AE‐COPD and CP‐COPD, influenza virus and human coronavirus were the most common viruses identified in AE‐COPD and CP‐COPD patients, respectively. The mortality rates of only viral infection group was significantly lower than only bacterial infection or viral‐bacterial co‐infection group in CP‐COPD patients. J. Med. Virol. 88:2092–2099, 2016. © 2016 Wiley Periodicals, Inc.

The role of viral infections in exacerbations of chronic obstructive pulmonary disease and asthma

Asthma and chronic obstructive pulmonary disease (COPD) are major causes of global morbidity and mortality worldwide. The clinical course of both asthma and COPD are punctuated by the occurrence of exacerbations, acute events characterized by increased symptoms and airflow obstruction. Exacerbations contribute most of the morbidity, mortality and excess healthcare costs associated with both asthma and COPD. COPD and asthma exacerbations are frequently associated with respiratory virus infections and this has led to an intense research focus into the mechanisms of virus-induced exacerbations over the past decade. Current therapies are effective in reducing chronic symptoms but are less effective in preventing exacerbations, particularly in COPD. Understanding the mechanisms of virus-induced exacerbation will lead to the development of new targeted therapies that can reduce the burden of virus-induced exacerbations. In this review we discuss current knowledge of virus-induced exacerbations of asthma and COPD with a particular focus on mechanisms, human studies, virus-bacteria interactions and therapeutic advances.

Association between Psychological Flexibility and Health Beliefs in the Uptake of Influenza Vaccination among People with Chronic Respiratory Diseases in Hong Kong

It is common for elderly people and those with such chronic disorders as respiratory diseases to suffer severe complications from influenza, a viral infection. The voluntary uptake of vaccination is vital to the effectiveness of influenza prevention efforts. The Health Belief Model (HBM) is the most commonly used framework in the field of vaccination behavior to explain the decision that people make to accept or refuse vaccination. In addition, psychological flexibility is considered helpful in causing people to be open to adopting new practices that are consistent with their values. This study examined the role of psychological flexibility and health beliefs in predicting the uptake of influenza vaccination among people in Hong Kong. Eligible participants were Hong Kong permanent residents aged 18 years or above with a history of chronic respiratory diseases (CRD). A convenience sample of 255 patients was recruited to participate in a cross-sectional survey in which HBM components and factors of psychological flexibility were assessed. The following variables were found to be significant predictors of vaccination: age, smoking status, comorbidity, previous hospitalization, perceived susceptibility, perceived severity, and psychological flexibility. Enhancing psychological flexibility might be a potential new direction for motivating people to accept influenza vaccination.

Toward antiviral therapy/prophylaxis for rhinovirus-induced exacerbations of chronic obstructive pulmonary disease: challenges, opportunities, and strategies

Chronic obstructive pulmonary disease (COPD) is a life-threatening lung illness characterized by persistent and progressive airflow limitation. Exacerbations of COPD contribute to the severity of this pathology and accelerate disease progression. To date, pharmacological treatment of both stable COPD patients and patients experiencing exacerbations is mainly symptomatic with bronchodilators and steroids as the mainstay of therapy. Bacteria trigger such exacerbations in a number of cases; hence, antibiotics might be included in the treatment as well. Several respiratory viruses are frequently detected in sputum from patients during COPD exacerbations. These include influenza viruses, respiratory syncytial virus, and, most often, rhinoviruses. In this review, we discuss the potential use of an anti-rhinovirus drug for the treatment and prophylaxis of rhinovirus-induced COPD exacerbations and the path forward toward the development and use of such a drug. Copyright © 2015 John Wiley & Sons, Ltd.

Analytical performance of the automated multianalyte point-of-care mariPOC® for the detection of respiratory viruses

The analytical performance of mariPOC® respi test (ArcDia® Laboratories, Turku, Finland) was evaluated using nucleic acid amplification techniques (NAATs) as the gold standard. The mariPOC assay allows automated detection of antigens from 8 respiratory viruses: influenza A and B viruses, respiratory syncytial virus, adenovirus, human metapneumovirus, and parainfluenza viruses 1-3. Positive results from samples with high viral load are available in 20min. Nasopharyngeal aspirates (n=192) from patients with acute respiratory infection and from previously positive samples were analyzed by mariPOC and NAATs (Simplexa(TM) FluA/FluB & RSV kit [n=118] and Luminex® Respiratory virus panel xTAG® RVP FAST [n=74]). Sensitivity, specificity, positive predictive value, and negative predictive value of mariPOC were 85.4%, 99.2%, 95.9%, and 97%, respectively, and 84.6% of positive results were reported in 20min. The good analytical performance and extended portfolio of mariPOC show this rapid assay as a good alternative for the etiological diagnosis of acute respiratory infection in laboratories that are not equipped with molecular assays.

Linking acute infection to chronic lung disease. The role of IL-33-expressing epithelial progenitor cells

Respiratory infection is a common feature of the major human airway diseases, such as asthma and chronic obstructive pulmonary disease, but the precise link between acute infection and chronic lung disease is still undefined. In a mouse model of this process, parainfluenza virus infection is followed by long-term induction of IL-33 expression and release and in turn innate immune cell generation of IL-13 and consequent airway disease signified by excess mucus formation. IL-33 induction was traceable to a subset of secretoglobin-positive airway epithelial cells linked to progenitor/stem cell function. In corresponding studies of humans with chronic obstructive pulmonary disease, an increase in IL-33 production was also detected in concert with up-regulation of IL-13 and airway mucus formation. In this case, increased IL-33 production was localized to a subset of airway basal cells that maintain an endogenous capacity for increased pluripotency and ATP-regulated release of IL-33 even ex vivo. The results provide evidence of a sustainable epithelial cell population that may be activated by environmental danger signals to release IL-33 and thereby lead to IL-13-dependent disease. The progenitor nature of this IL-33-expressing ATP-responsive cell population could explain an acquired susceptibility to chronic airway disease. The findings may therefore provide a new paradigm to explain the role of viral infection and the innate immune system in chronic lung disease based on the influence of long-term epithelial progenitor cells programmed for excess IL-33 production. Further studies are needed to address the basis for this type of postviral reprogramming and the means to correct it and thereby restore airway mucosal immune function to normal.

Replication and Inhibitors of Enteroviruses and Parechoviruses

The Enterovirus (EV) and Parechovirus genera of the picornavirus family include many important human pathogens, including poliovirus, rhinovirus, EV-A71, EV-D68, and human parechoviruses (HPeV). They cause a wide variety of diseases, ranging from a simple common cold to life-threatening diseases such as encephalitis and myocarditis. At the moment, no antiviral therapy is available against these viruses and it is not feasible to develop vaccines against all EVs and HPeVs due to the great number of serotypes. Therefore, a lot of effort is being invested in the development of antiviral drugs. Both viral proteins and host proteins essential for virus replication can be used as targets for virus inhibitors. As such, a good understanding of the complex process of virus replication is pivotal in the design of antiviral strategies goes hand in hand with a good understanding of the complex process of virus replication. In this review, we will give an overview of the current state of knowledge of EV and HPeV replication and how this can be inhibited by small-molecule inhibitors.

Influenza A virus-dependent remodeling of pulmonary clock function in a mouse model of COPD

Daily oscillations of pulmonary function depend on the rhythmic activity of the circadian timing system. Environmental tobacco/cigarette smoke (CS) disrupts circadian clock leading to enhanced inflammatory responses. Infection with influenza A virus (IAV) increases hospitalization rates and death in susceptible individuals, including patients with Chronic Obstructive Pulmonary Disease (COPD). We hypothesized that molecular clock disruption is enhanced by IAV infection, altering cellular and lung function, leading to severity in airway disease phenotypes. C57BL/6J mice exposed to chronic CS, BMAL1 knockout (KO) mice and wild-type littermates were infected with IAV. Following infection, we measured diurnal rhythms of clock gene expression in the lung, locomotor activity, pulmonary function, inflammatory, pro-fibrotic and emphysematous responses. Chronic CS exposure combined with IAV infection altered the timing of clock gene expression and reduced locomotor activity in parallel with increased lung inflammation, disrupted rhythms of pulmonary function, and emphysema. BMAL1 KO mice infected with IAV showed pronounced detriments in behavior and survival, and increased lung inflammatory and pro-fibrotic responses. This suggests that remodeling of lung clock function following IAV infection alters clock-dependent gene expression and normal rhythms of lung function, enhanced emphysematous and injurious responses. This may have implications for the pathobiology of respiratory virus-induced airway disease severity and exacerbations.

Viral Profile of COPD Exacerbations According to Patients

Background :

To compare the differences between elderly and non-elderly patients with acute exacerbations of chronic obstructive pulmonary disease (AECOPD) due to viral infections.

Methods :

Patients with chronic obstructive pulmonary disease (COPD) exacerbation were recruited and classified as elderly (>65 years) and non-elderly (≤ 65 years). Sputum and oropharyngeal samples were assessed, PCR for respiratory viruses and cultures for common pathogens were performed.

Results :

247 patients (median age: 69.3±9.5 years) were recruited and categorized into group A: non-elderly patients [n=81 (32.8%), median age 58±5.99] and group B: elderly patients [n=166 (67.2%), median age 74.8±4.8] years. In 133 (53.8%) patients a viral infection was identified and in 34 (13.8%) a bacterial pathogen was isolated from cultures. In 18 (7.3%) patients a double infection (bacterial+viral) was identified. In group B, the presence of cardiac failure (46.6% vs 28.3%, p<0.001), renal failure (10.5% vs 4%, p=0.03), bacterial co-infection (13.8% vs 7.4%, p=0.04), influenza vaccination rates (45.5% vs 215, p<0.001), and longer hospital stay (8.4±4.4 vs 7.5±3.2 days, p=0.02) were higher than group A. The overall rate of viral infections did not differ according to age. A trend to higher rates of infection with parainfluenza 3 [19 (20%) patients in group B vs3 (7.5%) patients in group A, p=0.04] was observed in older patients.

Conclusion :

No differences on the rate and type of viral infections were noted for elderly vs non elderly patients. However, they tended to have more bacterial co-infections that led to AECOPD and longer hospitalization stays compared to non-elderly patients.

Respiratory syncytial virus infection-associated hospitalization in adults: a retrospective cohort study

BACKGROUND

Once considered primarily a pediatric concern, respiratory syncytial virus (RSV) infection is gaining recognition as a cause of significant morbidity and mortality in adults. A better understanding of RSV epidemiology and disease in adults is needed to guide patient management and to assess the need for prophylaxis, vaccines, and treatments.

METHODS

We conducted a retrospective cohort study of adults admitted to four hospitals in Toronto, Canada, between September 2012 and June 2013 with RSV identified by a qualitative real-time reverse-transcriptase polymerase chain reaction assay in nasopharyngeal swab or bronchoscopy specimens. Main outcomes were hospital length of stay, need for intensive care unit (ICU) or mechanical ventilation, and all-cause mortality.

RESULTS

Eighty-six patients were identified as requiring hospitalization for RSV infection (56% female). Median age was 74 (range 19-102) years; 29 (34%) were < 65 years. Eighty-three (97%) had underlying chronic medical conditions; 27 (31%) were immunosuppressed, and 10 (12%) known smokers. The most common symptoms and signs were cough in 73 (85%), shortness of breath in 68 (79%), sputum production in 54 (63%), weakness in 43 (50%), fever in 41 (48%), and wheezing in 33 (38%). Lower respiratory tract complications occurred in 45 (52%), cardiovascular complications occurred in 19 (22%), and possible co-pathogens were identified in 11 (13%). Sixty-seven (78%) were treated with antibiotics and 31 (36%) with anti-influenza therapy. Thirteen (15%) required ICU care and 8 (9%) required mechanical ventilation. Five (6%) died during hospitalization. Need for ICU and mechanical ventilation were associated with mortality (P ≤ 0.02). Median hospital length of stay was 6 days (mean 10.8 days).

CONCLUSIONS

RSV infection is associated with the need for extended hospital stay, ICU care and mortality in adults of all ages with chronic underlying conditions. Presenting signs and symptoms are nonspecific, co-infections occur, and patients often receive antibiotics and anti-influenza therapy. There is need for ongoing research and development of RSV prophylaxis, vaccines and treatments for adults.

The presence of Torque teno virus in chronic obstructive pulmonary disease

Torque Teno Virus (TTV) has been identified as transfusion-transmitted virus in humans, initially. Although TTV viremia is extremely common in the general population worldwide, there is no direct causal evidence linking TTV infection to specific clinical manifestations. Our hypothesis was that TTV might play a role in Chronic obstructive pulmonary disease (COPD) by inducing inflammatory mechanisms previously identified. The study was conducted on 57 COPD patients and 39 healthy control groups. COPD patient groups included: the patients (n:20) with exacerbation needed noninvasive ventilation, the patients (n:19) who received only medical treatment, and the invited patients (n:18) for outpatient control. Serum samples were collected from patients and voluntary blood donors. TTV DNA quantification was carried out with a real time PCR by the hybridization probe system and viral load was interpreted through the crossing point value. TTV DNA was detected in the majority of both patients and healthy control groups. The prevalence was 94.4% (17/18) in patients for outpatient control, 94.7% (18/19) in patients who received only medical treatment, 100% (20/20) in patients with exacerbation needed noninvasive ventilation and 84.6% (33/39) in healthy controls. This difference was not statistically significant. However, CP values was statistically different in all the patient groups from the control group. TTV DNA prevalence was higher in patients than healthy individuals. More interesting thing, viral load was highest in the patients with exacerbation needed noninvasive ventilation. As a result, TTV may be associated with COPD and the severity of it.

The relevance of respiratory viral infections in the exacerbations of chronic obstructive pulmonary disease—a systematic review

BACKGROUND

Despite the increasing knowledge on the role of viruses in exacerbations of COPD (AECOPD), it is less clear which viruses are involved and to what extent they contribute to exacerbations. This review aims to systematically combine and evaluate the available literature of the prevalence of respiratory viruses in patients with AECOPD, detected by PCR.

METHODS

An electronic search strategy was performed on PubMed and Embase and reference lists were screened for eligible studies. Cross-sectional, prospective studies and case-control studies were included. The primary outcome measure was the prevalence of respiratory viruses (adenovirus, bocavirus, coronavirus, EBV, hMPV, influenza, parainfluenza, rhino-/enterovirus, RSV) in respiratory secretions of patients during an AECOPD. Secondary outcomes were the odds of the presence of the viruses in different respiratory secretions and the odds of the presence of viruses in upper and lower respiratory tract (URT/LRT) samples.

RESULTS

Nineteen studies with 1728 patients were included. Rhino-/enteroviruses (16.39%), RSV (9.90%) and influenza (7.83%) were the most prevalent viruses detected with lower detection rates of coronaviruses (4.08%) and parainfluenza (3.35%). Adenovirus (2.07%), hMPV (2.78%) and bocaviruses (0.56%) appear to be rare causative agents of AECOPD. Definitive conclusions regarding the role of EBV cannot be made. Seven of the eight analyzed viruses had a higher prevalence in LRT samples. Coronaviruses were detected more frequently in the URT.

CONCLUSIONS

Respiratory viruses are frequently detected in both URT and LRT samples in AECOPD with rhino-/enteroviruses, RSV and influenza viruses the most prevalent viruses. Detection rates vary between the two sites for different viruses.

Epidemiology of virus-induced asthma exacerbations: with special reference to the role of human rhinovirus

Viral respiratory infections may be associated with the virus-induced asthma in adults as well as children. Particularly, human rhinovirus is strongly suggested a major candidate for the associations of the virus-induced asthma. Thus, in this review, we reviewed and focused on the epidemiology, pathophysiology, and treatment of virus-induced asthma with special reference on human rhinovirus. Furthermore, we added our preliminary data regarding the clinical and virological findings in the present review.

Effect of lianhuaqingwen capsules on airway inflammation in patients with acute exacerbation of chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is characterized by a chronic inflammatory response that is worsened by acute exacerbations. Lianhuaqingwen (LHQW) has anti-inflammatory and immune regulatory functions and may inhibit the airway inflammation that occurs during an acute exacerbation of COPD. In this study, 100 participants were recruited and randomly assigned, 1 : 1, to the LHQW and the conventional groups, which were treated, respectively, with LHQW capsules and conventional Western medicine or only conventional Western medicine. The scores of the CAT scale and levels of inflammatory cytokines in blood and sputum were measured during treatment. In addition, subjects were subdivided into high-risk and low-risk subgroups. The CAT scores in the LHQW group and high-risk subgroup were clearly improved from the 5th day, but the other groups improved only after treatment was completed. Expression levels of IL-8, TNF- α , IL-17, and IL-23 in the sputum and of IL-8 and IL-17 in the blood were significantly decreased after treatment, and similar results were found in subgroups. These data suggested that LHQW capsules can accelerate the improvement of AECOPD patients, especially for the high-risk subgroup, and the mechanism of action may be related to the decreased release of inflammatory mediators.

Respiratory viral infections among hospitalized adults: experience of a single tertiary healthcare hospital

Background

Following the 2009 H1N1 pandemic, there have been a large number of studies focusing on the epidemiology and outcomes of influenza A infection; however, there have been fewer studies focused on other respiratory viral infections.

Objectives

To define the epidemiology and outcomes of non-influenza respiratory viral infections in hospitalized adults.

Patients/Methods

Data on all patients ≥18 years of age with a positive molecular respiratory viral assay who were hospitalized at a single tertiary healthcare system in Chicago, IL, from retrospectively collected and analyzed.

Results

Over the study period, 503 of 46 024 (1·1%) admitted patients had a positive RVP result. Human rhinovirus was the most commonly detected virus followed by influenza A, human metapneumovirus, respiratory syncytial virus, and parainfluenza virus, adenovirus, and influenza B, respectively. Infection in immunocompromised patients was associated with a higher rate of progression to pneumonia and death.

Conclusions

Non-influenza respiratory viral infections are commonly detected among adults admitted to the hospital and can cause serious illness. The data can inform the prioritization of research into novel antiviral therapies for these infections.

Experimental rhinovirus infection in COPD: implications for antiviral therapies

•

COPD exacerbations are a major cause of morbidity and mortality; new treatments are urgently needed.

•

Respiratory viruses, particularly rhinoviruses, are a major cause of exacerbations.

•

Experimental rhinovirus infection is a valid model of virus-induced COPD exacerbations.

•

This model could be used to evaluate new antiviral treatments in COPD.

Chronic obstructive pulmonary disease (COPD) is a major public health problem and will be one of the leading global causes of mortality over the coming decades. Much of the morbidity, mortality and health care costs of COPD are attributable to acute exacerbations, the commonest causes of which are respiratory infections. Respiratory viruses are frequently detected in COPD exacerbations but direct proof of a causative relationship has been lacking. We have developed a model of COPD exacerbation using experimental rhinovirus infection in COPD patients and this has established a causative relationship between virus infection and exacerbations. In addition it has determined some of the molecular mechanisms linking virus infections to COPD exacerbations and identified potential new therapeutic targets. This new data should stimulate research into the role of antiviral agents as potential treatments for COPD exacerbations. Testing of antiviral agents has been hampered by the lack of a small animal model for rhinovirus infection and experimental rhinovirus infection in healthy volunteers has been used to test treatments for the common cold. Experimental rhinovirus infection in COPD subjects offers the prospect of a model that can be used to evaluate the effects of new treatments for virus-induced COPD exacerbations, and provide essential data that can be used in making decisions regarding large scale clinical trials.

Virus-induced exacerbations in asthma and COPD

Chronic obstructive pulmonary disease (COPD) is characterized by chronic airway inflammation and/or airflow limitation due to pulmonary emphysema. Chronic bronchitis, pulmonary emphysema, and bronchial asthma may all be associated with airflow limitation; therefore, exacerbation of asthma may be associated with the pathophysiology of COPD. Furthermore, recent studies have suggested that the exacerbation of asthma, namely virus-induced asthma, may be associated with a wide variety of respiratory viruses. COPD and asthma have different underlying pathophysiological processes and thus require individual therapies. Exacerbation of both COPD and asthma, which are basically defined and diagnosed by clinical symptoms, is associated with a rapid decline in lung function and increased mortality. Similar pathogens, including human rhinovirus, respiratory syncytial virus, influenza virus, parainfluenza virus, and coronavirus, are also frequently detected during exacerbation of asthma and/or COPD. Immune response to respiratory viral infections, which may be related to the severity of exacerbation in each disease, varies in patients with both COPD and asthma. In this regard, it is crucial to recognize and understand both the similarities and differences of clinical features in patients with COPD and/or asthma associated with respiratory viral infections, especially in the exacerbative stage. In relation to definition, epidemiology, and pathophysiology, this review aims to summarize current knowledge concerning exacerbation of both COPD and asthma by focusing on the clinical significance of associated respiratory virus infections.

Virus-induced exacerbations in asthma and COPD

Chronic obstructive pulmonary disease (COPD) is characterized by chronic airway inflammation and/or airflow limitation due to pulmonary emphysema. Chronic bronchitis, pulmonary emphysema, and bronchial asthma may all be associated with airflow limitation; therefore, exacerbation of asthma may be associated with the pathophysiology of COPD. Furthermore, recent studies have suggested that the exacerbation of asthma, namely virus-induced asthma, may be associated with a wide variety of respiratory viruses. COPD and asthma have different underlying pathophysiological processes and thus require individual therapies. Exacerbation of both COPD and asthma, which are basically defined and diagnosed by clinical symptoms, is associated with a rapid decline in lung function and increased mortality. Similar pathogens, including human rhinovirus, respiratory syncytial virus, influenza virus, parainfluenza virus, and coronavirus, are also frequently detected during exacerbation of asthma and/or COPD. Immune response to respiratory viral infections, which may be related to the severity of exacerbation in each disease, varies in patients with both COPD and asthma. In this regard, it is crucial to recognize and understand both the similarities and differences of clinical features in patients with COPD and/or asthma associated with respiratory viral infections, especially in the exacerbative stage. In relation to definition, epidemiology, and pathophysiology, this review aims to summarize current knowledge concerning exacerbation of both COPD and asthma by focusing on the clinical significance of associated respiratory virus infections.

Long-term IL-33-producing epithelial progenitor cells in chronic obstructive lung disease

Chronic obstructive lung disease is characterized by persistent abnormalities in epithelial and immune cell function that are driven, at least in part, by infection. Analysis of parainfluenza virus infection in mice revealed an unexpected role for innate immune cells in IL-13-dependent chronic lung disease, but the upstream driver for the immune axis in this model and in humans with similar disease was undefined. We demonstrate here that lung levels of IL-33 are selectively increased in postviral mice with chronic obstructive lung disease and in humans with very severe chronic obstructive pulmonary disease (COPD). In the mouse model, IL-33/IL-33 receptor signaling was required for Il13 and mucin gene expression, and Il33 gene expression was localized to a virus-induced subset of airway serous cells and a constitutive subset of alveolar type 2 cells that are both linked conventionally to progenitor function. In humans with COPD, IL33 gene expression was also associated with IL13 and mucin gene expression, and IL33 induction was traceable to a subset of airway basal cells with increased capacities for pluripotency and ATP-regulated release of IL-33. Together, these findings provide a paradigm for the role of the innate immune system in chronic disease based on the influence of long-term epithelial progenitor cells programmed for excess IL-33 production.