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.

Targeted Literature Review of the Burden of Respiratory Syncytial Infection among High-Risk and Elderly Patients in Asia Pacific Region

INTRODUCTION

The burden of respiratory syncytial virus (RSV), which causes acute respiratory illness, is well recognized among the pediatric population but also imposes a significant risk to the elderly (age ≥ 60) and those with underlying comorbidities. The study aimed to review the most recent data on epidemiology and burden (clinical and economic) of RSV in the elderly/high-risk populations in China, Japan, South Korea, Taiwan, and Australia.

METHODS

A targeted review was conducted of English, Japanese, Korean, and Chinese language articles published from 1 January 2010 to 7 October 2020 relevant for the purpose.

RESULTS

A total of 881 studies were identified, and 41 were included. The median proportion of elderly patients with RSV in all adult patients with acute respiratory infection (ARI) or community acquired pneumonia was 79.78% (71.43-88.12%) in Japan, 48.00% (3.64-80.00%) in China, 41.67% (33.33-50.00%) in Taiwan, 38.61% in Australia, and 28.57% (22.76-33.33%) in South Korea. RSV was associated with a high clinical burden on those patients with comorbidities such as asthma and chronic obstructive pulmonary disease. In China, inpatients with ARI showed a significantly higher rate of RSV-related hospitalization than outpatients (13.22% versus 4.08%, p < 0.01). The median length of hospital stay among elderly patients with RSV was longest in Japan (30 days) and shortest in China (7 days). Mortality data varied by region with some studies reporting rates as high as 12.00% (9/75) in hospitalized elderly patients. Finally, data on the economic burden was only available for South Korea, with the median cost of a medical admission for an elderly patient with RSV being US dollar (USD) 2933.

CONCLUSION

RSV infection is a major source of disease burden among elderly patients, especially in regions with aging populations. It also complicates the management of those with underlying diseases. Appropriate prevention strategies are required to reduce the burden among the adult, especially the elderly, population. Data gaps regarding economic burden of RSV infection in the Asia Pacific region indicates the need for further research to increase our understanding on the burden of this disease in this region.

Association between lipid profiles and viral respiratory infections in human sputum samples

Background

Respiratory infections such as influenza account for significant global mortality each year. Generating lipid profiles is a novel and emerging research approach that may provide new insights regarding the development and progression of priority respiratory infections. We hypothesized that select clusters of lipids in human sputum would be associated with specific viral infections (Influenza (H1N1, H3N2) or Rhinovirus).

Methods

Lipid identification and semi-quantitation was determined with liquid chromatography and high-resolution mass spectrometry in induced sputum from individuals with confirmed respiratory infections (influenza (H1N1, H3N2) or rhinovirus). Clusters of lipid species and associations between lipid profiles and the type of respiratory viral agent was determined using Bayesian profile regression and multinomial logistic regression.

Results

More than 600 lipid compounds were identified across the sputum samples with the most abundant lipid classes identified as triglycerides (TG), phosphatidylethanolamines (PE), phosphatidylcholines (PC), Sphingomyelins (SM), ether-PC, and ether-PE. A total of 12 lipid species were significantly different when stratified by infection type and included acylcarnitine (AcCar) (10:1, 16:1, 18:2), diacylglycerols (DG) (16:0_18:0, 18:0_18:0), Lysophosphatidylcholine (LPC) (12:0, 20:5), PE (18:0_18:0), and TG (14:1_16:0_18:2, 15:0_17:0_19:0, 16:0_17:0_18:0, 19:0_19:0_19:0). Cluster analysis yielded three clusters of lipid profiles that were driven by just 10 lipid species (TGs and DGs). Cluster 1 had the highest levels of each lipid species and the highest prevalence of influenza A H3 infection (56%, n = 5) whereas cluster 3 had lower levels of each lipid species and the highest prevalence of rhinovirus (60%; n = 6). Using cluster 3 as the reference group, the crude odds of influenza A H3 infection compared to rhinovirus in cluster 1 was significantly (p = 0.047) higher (OR = 15.00 [95% CI: 1.03, 218.29]). After adjustment for confounders (smoking status and pulmonary comorbidities), the odds ratio (OR) became only marginally significant (p = 0.099), but the magnitude of the effect estimate was similar (OR = 16.00 [0.59, 433.03]).

Conclusions

In this study, human sputum lipid profiles were shown to be associated with distinct types of viral infection. Better understanding the relationship between respiratory infections of global importance and lipids contributes to advancing knowledge of pathogenesis of infections including identifying populations with increased susceptibility and developing effective therapeutics and biomarkers of health status.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-02091-w.

No evidence of harmful effects of steroids in severe exacerbations of COPD associated with influenza

Purpose

Methods

Results

Conclusion

Supplementary Information

Clinical significance of serum IgM and IgG levels in COVID-19 patients in Hubei Province, China

Background

There have been many studies about coronavirus disease 2019 (COVID-19), but the clinical significance of quantitative serum severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2)-specific IgM and IgG levels of COVID-19 patients have not been exhaustively analyzed. We aimed to investigate the time profiles of these IgM/IgG levels in COVID-19 patients and their correlations with clinical features.

Methods

A multicenter clinical study was conducted from February 20 to March 5 2020. It involved 179 COVID-19 patients (108 males and 71 females) from five hospitals in Huangshi in Hubei Province, China. To detect SARS-CoV-2-specific IgM/IgG, quantitative antibody assays (two-step indirect immunoassays with direct chemiluminescence technology) based on the nucleocapsid protein (NP) and spike protein 1 (S1) were used. For normally distributed data, means were compared using the t-test, χ ²-test, or exact probability method. For categorical data, medians were compared using Mann-Whitney U test.

Results

The median age was 57 (44-69) years (58 [38-69] for males and 57 [49-68] for females). The median duration of positive nucleic acid test was 22.32 (17.34-27.43) days. The mortality rate was relatively low (3/179, 1.68%). Serum SARS-CoV-2-specific IgG was detected around week 1 after illness onset, gradually increased until peaking in weeks 4 and 5, and then declined. Serum IgM peaked in weeks 2 and 3, then gradually declined and returned to its normal range by week 7 in all patients. Notably, children had milder respiratory symptoms with lower SARS-CoV-2-specific IgM/IgG levels. The duration of positive nucleic acid test in the chronic obstructive pulmonary disease (COPD) group was 30.36 (18.99-34.76) days, which was significantly longer than that in the non-COPD group (21.52 [16.75-26.51] days; P = 0.025). The peak serum SARS-CoV-2-specific IgG was significantly positively correlated with the duration of positive nucleic acid test. The incidence rate of severe and critical cases in the IgM^hi group (using the median IgM level of 29.95 AU/mL as the cutoff for grouping) was about 38.0% (19/50), which was twice as much as that in the IgM^lo group (18.4%; 9/49). The patients with positive chest imaging and lymphocytopenia (<1 × 10⁹/L) had a higher SARS-CoV-2-specific IgM level.

Conclusions

Quantitative SARS-CoV-2-specific IgM and IgG levels are helpful for the diagnosis, severity classification, and management of COVID-19 patients, and they should be monitored in each stage of this disease.

Detection of respiratory viruses and expression of inflammatory cytokines in patients with acute exacerbation chronic obstructive pulmonary disease in Mongolia China

Chronic obstructive pulmonary disease (COPD) was estimated to be the third cause of global mortality by 2020. Acute exacerbation COPD (AECOPD) is a sudden worsening of COPD symptoms and could be due to virus/bacterial infections and air pollution. Increased expression of inflammatory markers in patients with AECOPD is associated with viral infection. This study aimed to detect different viruses and analyze the expression of various inflammatory markers associated with AECOPD patients. Three hundred and forty-seven patients diagnosed with COPD according to GOLD criteria were included in this study. Swab samples and blood were collected for the detection of viruses by RT-PCR and expression of inflammatory markers, respectively. Of the swab samples, 113 (32.6%) of samples were positive for virus detection. Of these, HRV (39.8%) was the predominant virus detected followed by FluB (27.4%) and FluA (22.1%). The presence of HRV was significantly higher (p=0.044) among the other detected viruses. When compared to healthy controls the expression levels of TNF-α, IL-6 and IL-8 were significantly higher (p<0.05) in virus-positive patients. The IL-6 and IL-8 were the next predominantly expressed in markers among the samples. The higher expression rate of IL-8 was significantly (p<0.05) associated with patients having COPD GOLD III severity level and smoking history. Although HRV was the predominant virus detected the combined prevalence of Influenza A and B surpassing the rate of HRV. The high-level expression of well known inflammatory markers of AECOPD, TNF-α, IL-6 and IL-8 indicates a chronic severe illness. These markers play an important role and could be used as a marker for determining the severity of AECOPD.

Assessment of the Association of COPD and Asthma with In-Hospital Mortality in Patients with COVID-19. A Systematic Review, Meta-Analysis, and Meta-Regression Analysis

Together, chronic obstructive pulmonary disease (COPD) and asthma account for the most common non-infectious respiratory pathologies. Conflicting preliminary studies have shown varied effect for COPD and asthma as prognostic factors for mortality in coronavirus disease 2019 (COVID-19). The aim of this study was to explore the association of COPD and asthma with in-hospital mortality in patients with COVID-19 by systematically reviewing and synthesizing with a meta-analysis the available observational studies. MEDLINE, Scopus, and medRxiv databases were reviewed. A random-effects model meta-analysis was used, and I-square was utilized to assess for heterogeneity. In-hospital mortality was defined as the primary endpoint. Sensitivity and meta-regression analyses were performed. Thirty studies with 21,309 patients were included in this meta-analysis (1465 with COPD and 633 with asthma). Hospitalized COVID-19 patients with COPD had higher risk of death compared to those without COPD (OR: 2.29; 95% CI: 1.79–2.93; I² 59.6%). No significant difference in in-hospital mortality was seen in patients with and without asthma (OR: 0.87; 95% CI: 0.68–1.10; I² 0.0%). The likelihood of death was significantly higher in patients with COPD that were hospitalized with COVID-19 compared to patients without COPD. Further studies are needed to assess whether this association is independent or not. No significant difference was demonstrated in COVID-19-related mortality between patients with and without asthma.

Incidence and Prognostic Factors of Respiratory Viral Infections in Severe Acute Exacerbation of Chronic Obstructive Pulmonary Disease

Purpose

Severe acute exacerbations of chronic obstructive pulmonary disease (AECOPD) that require hospitalization and emergency department visits are associated with considerable morbidity and mortality. Respiratory viral infection is an important cause of severe AECOPD. We evaluated the incidence and prognostic factors of viral infection in severe AECOPD.

Patients and Methods

We performed a retrospective study of 262 cases of severe AECOPD in 192 patients who required hospitalization and emergency department visits at a tertiary teaching hospital in Daegu, Korea. A multiplex polymerase chain reaction panel using a nasopharyngeal swab sample was performed to detect viral infection.

Results

Viral infection was detected in 108 events (41.2%) from 96 patients. The most common virus was rhinovirus/enterovirus (27.5%), followed by influenza virus (22.5%), respiratory syncytial virus (13.3%), parainfluenza virus (12.5%), coronavirus (12.5%), metapneumovirus (7.5%), and adenovirus (4.2%). Virus-positive exacerbations, compared to virus-negative exacerbations, had a higher frequency of symptoms of rhinopharyngitis, higher neutrophil count and C-reactive protein (CRP) level, and lower eosinophil count. Multivariate analysis demonstrated that elevated CRP levels (odds ratio [OR], 2.76; 95% confidence interval [CI], 1.24–6.15), symptoms of rhinopharyngitis (OR, 1.98; 95% CI, 1.03–3.78), low eosinophil count (OR, 1.74; 95% CI, 1.03–2.92), and inhaled corticosteroid (ICS) use (OR, 1.70; 95% CI 1.04–2.80) were associated with viral infection in severe AECOPD.

Conclusion

The incidence of viral infection in severe AECOPD was 41.2%, and the most commonly detected virus was rhinovirus/enterovirus. Increased CRP level, symptoms of rhinopharyngitis, low eosinophil count, and use of ICS were associated with viral infection in severe AECOPD.

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.

Complicating Infections Associated with Common Endemic Human Respiratory Coronaviruses

Coronaviruses OC43, 229E, NL63, and HKU1 are endemic human respiratory coronaviruses that typically cause mild to moderate upper respiratory infections, similar to the common cold. They also may cause simple and complicated lower respiratory infections, otitis media, asthma exacerbations, gastroenteritis, and a few systemic complications. These viruses are usually seasonal (with winter dominance) and affect nearly all age groups. The seasonal and annual variation in virus prevalence has implications for understanding the concept of acquired immunity and its persistence or diminution. Coronaviruses generally have outbreak potential in susceptible populations of any age, particularly in patients with comorbidities, who tend to have increased clinical disease. These 4 coronaviruses are often found in the context of what appears to be coinfection with other pathogens, but especially other viruses. If coronaviruses are not specifically tested for, the sole detection of a viral copathogen would suggest the pathogen is the causative agent, when a coronavirus may be culpable, or both. The detection of these viruses in circumstances where respiratory viruses are generally sought in clinical samples is, therefore, justified. These pathogens can be chronically shed from the respiratory tract, which is more likely to occur among immunocompromised and complicated patients. These viruses share the potential for genetic drift. The genome is among the largest of RNA viruses, and the capability of these viruses to further change is likely underestimated. Given the potential disease among humans, it is justified to search for effective antiviral chemotherapy for these viruses and to consider uses in niche situations should effective therapy be defined. Whereas SARS-CoV-2 may follow the epidemiological pattern of SARS-CoV and extinguish slowly over time, there is yet concern that SARS-CoV-2 may establish itself as an endemic human respiratory coronavirus similar to OC43, 2299E, NL63, and HKU1. Until sufficient data are acquired to better understand the potential of SARS-CoV-2, continued work on antiviral therapy and vaccination is imperative.

Microbiome in Chronic Obstructive Pulmonary Disease: Role of Natural Products Against Microbial Pathogens

The "microbiome" is the operative term to refer to a collection of all taxa constituting microbial communities, such as bacteria, archaea, fungi and protists (originally microbiota). The microbiome consists of the indigenous microbial communities and of the host environment that they inhabit. Actually, it has been shown that there is a close relationship between the microbiome and human health and disease condition. Although, initially, the lung was considered sterile, actually, the existence of a healthy lung microbiome is usually accepted. Lung microbiome changes are reported in Chronic Obstructive Pulmonary Disease (COPD) and in its exacerbation. Viral and bacterial infections of the respiratory system are a major cause of COPD exacerbations (AECOPD) leading to increased local and systemic inflammation. Detection rates of virus in AECOPD are variable between 25-62% according to the detection method. The study of human airway and lung disease virome is quite recent and still very limited. The purpose of this review is to summarize recent findings on the lung microbiome composition with a special emphasis on virome in COPD and in AECOPD. Some drugs of natural origins active against resistant bacteria and virus are described.

Risk factors of chronic obstructive pulmonary disease exacerbations

Chronic Obstructive Pulmonary Disease (COPD) is a chronic respiratory disease characterised by persistent respiratory symptoms and airflow limitation. COPD has a major impact on public health, mainly because of its increasing prevalence, morbidity and mortality. The natural course of COPD is aggravated by episodes of respiratory symptom worsening termed exacerbations that contribute to disease progression. Acute Exacerbations of COPD (AECOPD) can be triggered by a multitude of different factors, including respiratory tract infections, various exposures, prior exacerbations, non-adherence to treatment and associated comorbidities. AECOPD are associated with an inexorable decline of lung function and a significantly worse survival outcome. This review will summarise the most important aspects regarding the impact of different factors that contribute to COPD exacerbations.

Diminished stimulator of interferon genes production with cigarette smoke-exposure contributes to weakened anti-adenovirus vectors response and destruction of lung in chronic obstructive pulmonary disease model

Cigarette smoke (CS) is the primary risk factor for chronic obstructive pulmonary disease (COPD) and dampens antiviral response, which increases viral infections and leads to COPD acute exacerbation (AECOPD). Adenovirus, a nonenveloped DNA virus, is linked with AECOPD, whose DNAs trigger innate immune response via interacting with pattern recognition receptors (PRRs). Stimulator of interferon genes (STING), as a cytosolic DNA sensor, participates in adenovirus-induced interferon β (IFNβ)-dependent antiviral response. STING is involved in various pulmonary diseases, but role of STING in pathogenesis of AECOPD is not well documented. In the present study, we explored relationship between STING and AECOPD induced by recombinant adenovirus vectors (rAdVs) and CS in wild type (WT) and STING-/- mice; and also characterized the inhibition of STING- IFNβ pathway in pulmonary epithelium exposed to cigarette smoke extract (CSE). We found that CS or CSE exposure alone dramatically inhibited STING expression, but not significantly effected IFNβ production. Moreover, CS or CSE-exposed significantly suppressed activation of STING-IFNβ pathway induced by rAdVs and suppressed clearance of rAdVs DNA. Inflammation, fibrosis and emphysema of lung tissues were exaggerated when treated with CS plus rAdVs, which further deteriorate in absences of STING. In A549 cells with knockdown of STING, we also observed enhancing apoptosis related to emphysema, especially CSE and adenovirus vectors in combination. Therefore, STING may play a protective role in preventing the progress of COPD.

Bacterial and Viral Identification Rate in Acute Exacerbation of Chronic Obstructive Pulmonary Disease in Korea

PURPOSE

The most common cause of acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is respiratory infection. Most studies of bacterial or viral cause in AECOPD have been conducted in Western countries. We investigated bacterial and viral identification rates in AECOPD in Korea.

MATERIALS AND METHODS

We reviewed and analyzed medical records of 736 cases of AECOPD at the Korea University Guro Hospital. We analyzed bacterial and viral identification rates and classified infections according to epidemiological factors, such as Global Initiative for Chronic Obstructive Lung Disease stage, mortality, and seasonal variation.

RESULTS

The numbers of AECOPD events involving only bacterial identification, only viral identification, bacterial-viral co-identification, and no identification were 200 (27.2%), 159 (21.6%), 107 (14.5%), and 270 (36.7%), respectively. The most common infectious bacteria identified were Pseudomonas aeruginosa (13.0%), Streptococcus pneumoniae (11.4%), and Haemophilus influenzae (5.3%); the most common viruses identified were influenza virus (12.4%), rhinovirus (9.4%), parainfluenza virus (5.2%), and metapneumovirus (4.9%). The bacterial identification rate tended to be higher at more advanced stages of chronic obstructive pulmonary disease (p=0.020 overall, p=0.011 for P. aeruginosa, p=0.048 for S. pneumoniae). Staphylococcus aureus and Klebsiella pneumoniae were identified more in mortality group (p=0.003 for S. aureus, p=0.009 for K. pneumoniae). All viruses were seasonal (i.e., greater prevalence in a particular season; p<0.050). Influenza virus and rhinovirus were mainly identified in the winter, parainfluenza virus in the summer, and metapneumovirus in the spring.

CONCLUSION

This information on the epidemiology of respiratory infections in AECOPD will improve the management of AECOPD using antibiotics and other treatments in Korea.

Phenotyping and outcomes of hospitalized COPD patients using rapid molecular diagnostics on sputum samples

Background

Etiologies of acute exacerbations of chronic obstructive pulmonary disease (AECOPD) are heterogeneous. We phenotyped severe AECOPD based on molecular pathogen detection of sputum samples collected at hospitalization of COPD patients and determined their outcomes.

Methods

We phenotyped 72 sputum samples of COPD patients who were hospitalized with a primary diagnosis of AECOPD using a molecular array that detected common bacterial and viral respiratory pathogens. Based on these results, the patients were classified into positive or negative pathogen groups. The pathogen-positive group was further divided into virus or bacteria subgroups. Admission day 1 blood samples were assayed for N-terminal prohormone brain natriuretic peptide, CRP, and complete blood counts.

Results

A total of 52 patients had a positive result on the array, while 20 patients had no pathogens detected. The most common bacterial pathogen detected was Haemophilus influenzae and the most common virus was rhinovirus. The pathogen-negative group had the worse outcomes with longer hospital stays (median 6.5 vs 5 days for bacteria-positive group, P=0.02) and a trend toward increased 1-year mortality (P=0.052). The bacteria-positive group had the best prognosis, whereas the virus-positive group had outcomes somewhere in between the bacteria-positive and pathogen-negative groups.

Conclusion

Molecular diagnostics on sputum can rapidly phenotype serious AECOPD into bacteria-, virus-, or pathogen-negative groups. The bacteria-positive group appears to have the best prognosis, while pathogen-negative group has the worst. These data suggest that AECOPD is a heterogeneous event and that accurate phenotyping of AECOPD may lead to novel management strategies that are personalized and more precise.

Factors Influencing Influenza Vaccination Among Patients With Chronic Obstructive Pulmonary Disease: A Population-Based Cross-sectional Study

This study aimed to investigate the factors associated with vaccination coverage among chronic obstructive pulmonary disease (COPD) patients in Korea using the fourth to the sixth Korean National Health and Nutrition Examination Surveys (KNHANES IV, V, VI). A total of 16 812 subjects aged 40 years and older who underwent spirometry and had an "influenza vaccination history" were analyzed. The vaccination rate of middle-aged (40-64 years) COPD patients was only 31.9%; whereas, the vaccination rate of elderly (65 years and older) COPD patients was 80.0%. The results of a multiple regression analysis indicated that older age (odds ratio [OR], 1.12; 95% confidence interval [95% CI], 1.09-1.14), poor self-rated health status (OR, 1.45; 95% CI, 1.14-1.95), regular health check-up (OR, 2.61; 95% CI, 1.93-3.51), married marital status (OR, 0.64; 95% CI, 0.42-0.96), and household income below average (OR, 0.72; 95% CI, 0.53-0.98) were associated with influenza vaccination. More attention and targeted interventions are required to improve the influenza vaccination rate of COPD patients.

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.