Molecular diagnosis of respiratory tract infection in acute exacerbations of chronic obstructive pulmonary disease

Direct activation of airway sensory C-fibers by SARS-CoV-2 S1 spike protein

Respiratory viral infection can lead to activation of sensory afferent nerves as indicated by the consequential sore throat, sneezing, coughing, and reflex secretions. In addition to causing troubling symptoms, sensory nerve activation likely accelerates viral spreading. The mechanism how viruses activate sensory nerve terminals during infection is unknown. In this study, we investigate whether coronavirus spike protein activates sensory nerves terminating in the airways. We used isolated vagally-innervated mouse trachea-lung preparation for two-photon microscopy and extracellular electrophysiological recordings. Using two-photon Ca2+ imaging, we evaluated a total number of 786 vagal bronchopulmonary nerves in six experiments. Approximately 49% of the sensory fibers were activated by S1 protein (4 μg/mL intratracheally). Extracellular nerve recording showed the S1 protein evoked action potential discharge in sensory C-fibers; of 39 airway C-fibers (one fiber per mouse), 17 were activated. Additionally, Fura-2 Ca2+ imaging was performed on neurons dissociated from vagal sensory ganglia (n = 254 from 22 mice). The result showed that 63% of neurons responded to S1 protein. SARS-CoV-2 S1 protein can lead to direct activation of sensory C-fiber nerve terminals in the bronchopulmonary tract. Direct activation of C-fibers may contribute to coronavirus symptoms, and amplify viral spreading in a population.

Tong Sai granules improves AECOPD via regulation of MAPK-SIRT1-NF-κB pathway and cellular senescence alleviation

ETHNOPHARMACOLOGICAL RELEVANCE

Tong Sai granules (TSG) a traditional Chinese medicine, are used to treat acute exacerbations of chronic obstructive pulmonary disease (AECOPD). Cellular senescence is considered the mechanism underlying AECOPD progression.

AIM OF THE STUDY

This study aimed to investigate the therapeutic mechanisms of TSG in an AECOPD rat model (established using cigarette smoke exposure and bacterial infection) and focused on the inhibition of cellular senescence in vivo and in vitro.

MATERIALS AND METHODS

Histological changes and levels of inflammatory cytokines, matrix metalloproteinases (MMPs), p53, and p21 were determined. A cellular senescence model was established by challenging airway epithelial cells with cigarette smoke extract (CSE) and lipopolysaccharide (LPS). Quantitative PCR, western blotting, and immunofluorescence were used to measure mRNA and protein levels. Additionally, UPLC-Q-Extractive-Orbitrap MS analysis, network analysis, and transcriptomics were used to analyze the potential compounds and molecular mechanisms of TSG.

RESULTS

The results showed that oral administration of TSG significantly reduced the severity of AECOPD in rats by ameliorating lung function decline and pathological injuries and increasing the levels of C-reactive protein and serum amyloid A, two well-known proinflammatory mediators of the acute phase response. Oral TSG administration also decreased the expression levels of proinflammatory cytokines (e.g., IL-6, IL-1β, and TNF-α), MMPs (e.g., MMP-2 and MMP-9), critical regulators of senescence such as p21 and p53, and the apoptotic marker γH2AX, all of which are factors in cellular senescence in lung tissue. TSG4 was isolated from TSGs using macroporous resin and found to significantly suppress cellular senescence in CSE/LPS-induced bronchial epithelial cells. Furthermore, 26 of 56 compounds identified in TSG4 were used to predict 882 potential targets. Additionally, 317 differentially expressed genes (DEGs) were detected in CSE/LPS-treated bronchial epithelial cells. Network analysis of the 882 targets and 317 DEGs revealed that TSG4 regulated multiple pathways, among which the mitogen-activated protein kinase-sirtuin 1-nuclear factor kappa B (MAPK-SIRT1-NF-κB) pathway is important in terms of antisenescent mechanisms. Moreover, in CSE/LPS-induced bronchial epithelial cells, p-p38, p-ERK1/2, p-JNK, and p-p65 levels were increased and SIRT1 levels were decreased after TSG4 treatment. Additionally, oral TSG administration decreased p-p38 and p-p65 levels and increased SIRT1 levels in the lung tissues of AECOPD model rats.

CONCLUSION

Collectively, these results indicate that TSGs ameliorate AECOPD by regulating the MAPK-SIRT1-NF-κB signaling pathway and subsequently suppressing cellular senescence.

How deep do you go? Clinical prediction of nasopharyngeal depth based on facial measurements

Nasopharyngeal depth (ND) prediction is clinically relevant in performing medical procedures, and in enhancing technique accuracy and patient safety. Nonetheless, clinical predictive variables and normative data in adults remain limited. This study aimed to determine normative data on ND and its correlation to external facial measurements. A multicenter cross-sectional study obtained data from adults presenting to otolaryngology clinics at five sites in Canada, Italy, and Spain. Investigators compared endoscopically measured depth from the nasal sill (soft tissue between the nasal ala and columella) to nasopharynx along the nasal floor to the "curved distance from the alar-facial groove along the face to the tragus" and "distance from the tragus to a plane perpendicular to the philtrum." When sinus computed tomography images were available, the distance from the nasopharynx to the nasal sill was also collected. 371 patients participated in the study (41% women; 51 years old, SD 18). Average ND was 9.4 cm (SD 0.86) and 10.1 cm (SD 0.9) for women and men, respectively (p < 0.001; 95% CI 0.46-0.86). Perpendicular distance was strongly correlated to ND (r = 0.775; p < 0.001), with an average underestimation of 0.1 cm (SD 0.65; 95% CI 0.06-0.2). The equation: ND (cm) = perpendicular distance*0.773 + 2.344, generated from 271 randomly selected participants, and validated on 100 participants, resulted in a 0.03 cm prediction error (SD 0.61; 95% CI -0.08-0.16). Nasopharyngeal depth can be approximated by the distance from the tragus to a plane perpendicular to the philtrum.

Acute Exacerbation of Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality worldwide and results in an economic and social burden that is both substantial and increasing. The natural history of COPD is punctuated by exacerbations, which have major short- and long-term implications on the patient and health care system. Evidence-based guidelines stipulate that early detection and prompt treatment of exacerbations are essential to ensure optimal outcomes and to reduce the burden of COPD. In this review, we provide a concise overview of COPD exacerbations and their risk factors and etiology (infection vs noninfectious), outlining the initial evaluation, triaging, and current management including invasive and noninvasive ventilation, in addition to the prognosis and the preventive strategies.

Sputum colour as a marker for bacteria in acute exacerbations of COPD: protocol for a systematic review and meta-analysis

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a major cause of years of life lost globally. Acute exacerbations of COPD (AECOPD) drive disease progression, reduce quality of life and are a source of mortality in COPD. Approximately 50% of AECOPD are due to bacterial infections. Diagnosing bacterial infection as the aetiology of AECOPD however remains challenging as investigations are limited by practicality, accuracy and expense. Clinicians have traditionally used sputum colour as a marker of bacterial infection in AECOPD, despite the lack of high-quality evidence for this practice. The aim of this systematic review and meta-analysis is to determine the diagnostic accuracy of sputum colour in the diagnosis of bacterial causes of AECOPD.

METHODS

Articles will be searched for in electronic databases (MEDLINE, Google Scholar Scopus, Web of Science, Africa-Wide, CINAHL and Health Source Nursing Academy) and we will conduct a review of citation indexes and the grey literature. Two reviewers will independently conduct study selection, against pre-defined eligibility criteria, data extraction and quality assessment of included articles using the QUADAS-2 tool. We will perform a meta-analysis using a bivariate logistic regression model with random effects. We will explore heterogeneity through the visual examination of the forest plots of sensitivities and specificities and through the inclusion of possible sources of heterogeneity as covariates in a meta-regression model if sufficient studies are included in the analysis. We also perform a sensitivity analysis to explore the effect of study quality on our findings. The results of this review will be reported according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis statement and will be submitted for peer-review and publication.

DISCUSSION

The findings of this review will assist clinicians in diagnosing the aetiology of AECOPD and may have important implications for decision making in resource-limited settings, as well as for antimicrobial stewardship.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42019141498.

Pertussis in high-risk groups: an overview of the past quarter-century

Infectious diseases can impact chronic medical conditions. However, it is currently not clear how pertussis correlates with preexisting or underlying disorders. We reviewed literature from the last 25 years to describe the burden and impact of pertussis infection in specific risk groups in individuals aged ≥11 years.

Our literature search returned 543 hits, of which 18 were eligible for this review. Adolescents and adults with underlying conditions, such as asthma, chronic obstructive pulmonary disease (COPD), or obesity are potentially at increased risk of pertussis infection. Immunodeficiency and smoking have also been associated with worsened pertussis symptoms and an increased pertussis-related hospitalization rate. In patients with pertussis and preexisting asthma or COPD, symptoms were worsened, and health-care costs were consequently increased.

Further efforts are needed to close the knowledge gap and to understand the burden of pertussis in at-risk adolescent and adult populations to help inform vaccination strategies and recommendations.

Potential clinical utility of multiple target quantitative polymerase chain reaction (qPCR) array to detect microbial pathogens in patients with chronic obstructive pulmonary disease (COPD)

Background

Culture-independent methods such as quantitative polymerase chain reaction (qPCR) are more sensitive for detecting pathogens than conventional culture. This study aimed to test the clinical potential of a multiple target qPCR array in identifying sputum pathogens, compared to traditional culture.

Methods

Forty chronic obstructive pulmonary disease (COPD) patients provided spontaneous sputum and blood samples during an exacerbation event (n=25 patients) and in stable state (n=15 patients). Sputum was processed and analysed by microscopy, culture and sensitivity testing (MCS) to identify living microbial isolates, and multiple target qPCR (44 targets for bacterial and fungal pathogens and antibiotic resistance genes), and 16S rRNA gene sequencing.

Results

Six microbial isolates (5 bacterial, 1 fungal) were cultured from 20 exacerbation and 10 stable patient sputum samples. Four of these microbial isolates had their presence in patient sputum confirmed by qPCR. All bacterial targets detected by qPCR were further confirmed by 16S rRNA gene sequencing at a genus level. qPCR identified significantly more bacterial pathogens than culture (P<0.001). The most prevalent bacterial species identified by qPCR were Streptococcus pneumoniae (72% of patients), Pseudomonas aeruginosa (40%), Prevotella oris (32%) and Haemophilus influenzae (17%). Microbial species diversity and richness were not significantly different between samples obtained from exacerbating and clinically stable cases. 16S rRNA gene sequencing identified Pseudomonas 4408227 (P=0.022, FDR =0.043 AUC =0.72) as a significantly different bacterial OTU (operational taxonomic units) in exacerbation sputum samples compared to stable state samples.

Conclusions

Multiple target qPCR was more sensitive for detection of sputum pathogens in COPD patients than conventional culture. 16S rRNA gene sequencing confirmed the identity at a genus level of all bacterial targets detected by qPCR, as well as identifying bacterial OTUs that could potentially be used to distinguish between exacerbation and stable COPD disease states. Multiple target qPCR pathogen detection in the sputum of COPD patients warrants further investigation to determine how it may influence COPD clinical management.

Pseudomonas aeruginosa-derived flagellin stimulates IL-6 and IL-8 production in human bronchial epithelial cells: A potential mechanism for progression and exacerbation of COPD

Background and purpose of the study: Pseudomonas aeruginosa commonly colonizes the airway of patients with chronic obstructive pulmonary disease (COPD) and exacerbates their symptoms. P. aeruginosa carries flagellin that stimulates toll-like receptor (TLR)-5; however, the role of flagellin in the pathogenesis of COPD remains unclear. The aim of the study was to evaluate the mechanisms of the flagellin-induced innate immune response in bronchial epithelial cells, and to assess the effects of anti-inflammatory agents for treatment. Materials and methods: We stimulated BEAS-2B cells with P. aeruginosa-derived flagellin, and assessed mRNA expression and protein secretion of interleukin (IL)-6 and IL-8. We also used mitogen-activated protein kinases (MAPK) inhibitors to assess the signaling pathways involved in flagellin stimulation, and investigated the effect of clinically available anti-inflammatory agents against flagellin-induced inflammation. Results: Flagellin promoted protein and mRNA expression of IL-6 and IL-8 in BEAS-2B cells and induced phosphorylation of p38, ERK, and JNK; p38 phosphorylation-induced IL-6 production, while IL-8 production resulted from p38 and ERK phosphorylation. Fluticasone propionate (FP) and dexamethasone (DEX) suppressed IL-6 and IL-8 production in BEAS-2B cells, but clarithromycin (CAM) failed to do so. Conclusions: P. aeruginosa-derived flagellin-induced IL-6 and IL-8 production in bronchial epithelial cells, which partially explains the mechanisms of progression and exacerbation of COPD. Corticosteroids are the most effective treatment for the suppression of flagellin-induced IL-6 and IL-8 production in the bronchial epithelial cells.

Bronchial epithelial cells produce CXCL1 in response to LPS and TNFα: A potential role in the pathogenesis of COPD

RATIONALE

Neutrophilic airway inflammation plays a central role in chronic obstructive pulmonary disease (COPD). CXC chemokine ligand (CXCL)1 is a neutrophil chemokine involved in the pathogenesis of COPD. However, its clinical significance in COPD patients is poorly understood.

AIM OF THE STUDY

To assess the production of CXCL1 by bronchial epithelial cells in response to lipopolysaccharide (LPS) and tumor necrosis factor (TNF)α.

MATERIALS AND METHODS

We measured sputum CXCL1 and CXCL8 levels in patients with COPD, asthma, and asthma-COPD overlap (ACO), and compared them to those of patients with interstitial pneumonia (IP). Using primary human bronchial epithelial cells and BEAS-2B cells, CXCL1 protein release and mRNA expression were measured after LPS or TNFα stimulation. We evaluated signal transduction mechanisms for CXCL1 production using nuclear factor-κ B (NF-kB) and mitogen-activated protein kinase (MAPK) inhibitors, and examined the effects of anti-inflammatory agents on CXCL1 production in BEAS-2B cells.

RESULTS

Sputum CXCL1 levels in COPD and ACO patients were higher than in IP patients, whereas sputum CXCL8 levels were not. Sputum CXCL1 levels were not affected by inhaled corticosteroid usage, whereas sputum CXCL8 levels tended to be affected. LPS and TNFα stimulated CXCL1 production and mRNA expression in bronchial epithelial cells. NF-kB and MAPK p38 were involved in LPS-induced CXCL1 production. Therapeutic anti-inflammatory agents minimally attenuated CXCL1 production and considerably inhibited CXCL8 production in BEAS-2B cells.

CONCLUSIONS

Sputum CXCL1 levels is a potentially better diagnostic marker for COPD than sputum CXCL8 levels, which is explained by that CXCL1 production in bronchial epithelial cells is less affected by therapeutic anti-inflammatory agents than CXCL8 production.

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.

Chronic obstructive pulmonary disease subpopulations and phenotyping

The diagnosis and treatment of chronic obstructive pulmonary disease (COPD) has been based largely on a one-size-fits-all approach. Diagnosis of COPD is based on meeting the physiologic criteria of fixed obstruction in forced expiratory flows and treatment focus on symptomatic relief, with limited effect on overall prognosis. However, patients with COPD have distinct features that determine very different evolutions of the disease. In this review we highlight distinct subgroups of COPD characterized by unique pathophysiologic derangements, response to treatment, and disease progression. It is likely that identification of subgroups of COPD will lead to discovery of much needed disease-modifying therapeutic approaches. We argue that a precision approach that integrates multiple dimensions (clinical, physiologic, imaging, and endotyping) is needed to move the field forward in the treatment of this disease.

Critical regulation of inflammation via class A scavenger receptor

Background

Inflammation is an important cause of COPD. Alveolar macrophages are the major innate immune cells that have an important role in COPD pathology. Class A scavenger receptor (SR-A) is a pattern recognition receptor expressed on macrophages. This study investigates the role of SR-A in COPD progression via regulation of inflammation.

Patients and methods

SR-A expression in COPD patients and control subjects (smokers and nonsmokers without COPD) was measured by immunohistochemistry, immunofluorescence, and real-time PCR. The cytokine levels in BAL were measured by enzyme-linked immunosorbent assay. To further prove our hypothesis, we treated RAW264.7 cells that overexpress SR-A with lipopolysaccharides, poly(I:C), cigarette smoke extract, and H1N1 influenza separated from patients for 24 h and examined the levels of inflammatory cytokines.

Results

In both groups, COPD and smokers without COPD, SR-A expression level was upregulated in alveolar macrophages. SR-A mRNA level was positively correlated with inflammatory cytokines and negatively correlated with FEV₁% predicted in COPD patients. In RAW-SR-A cells, level of inflammatory cytokines was significantly higher when compared with control ones.

Conclusion

SR-A could increase inflammation stimulated by cigarette smoke extracts, bacteria, and virus, leading to long-term inflammation in COPD, and thus might be used as a new therapeutic target for COPD treatment.

Exacerbation induces a microbiota shift in sputa of COPD patients

Little is known about the microbiota shift induced by exacerbation in chronic obstructive pulmonary disease (COPD) patients. The sputa microbiota of COPD patients was evaluated when clinically stable and during acute exacerbations of the disease. Sputa microbiota was analyzed using 16S ribosomal RNA gene pyrosequencing and quantitative polymerase chain reaction-based pathogen detection. Nine COPD patients were enrolled. Pyrosequencing of 16S rRNA genes identified 2,267 unique bacterial operational taxonomic units. Principal microbiota shifts during exacerbation were in either Proteobacteria, Firmicutes or Bacteroidetes. Streptococcus and Moraxella levels were detected during exacerbation in severe (Global Initiative for Chronic Obstructive Lung Disease 3) COPD patients. Most of the clinically-important genera found in the sputum with the pyrosequencing of 16S rRNA gene correlated with specific quantitative polymerase chain reactions for bacteria while respiratory viruses were nearly absent. Sputum microbiotas of exacerbated COPD patients are complex. This pilot study shows a clear shift in the microbiota of patients during exacerbation. The nature of this shift varies from patient to patient in such a way that the treatment should be patient-specific. Further studies are needed to establish the impact of microbial exacerbations on the pulmonary microbiota.

Resveratrol therapeutics combines both antimicrobial and immunomodulatory properties against respiratory infection by nontypeable Haemophilus influenzae

The respiratory pathogen nontypeable Haemophilus influenzae (NTHi) is an important cause of acute exacerbation of chronic obstructive pulmonary disease (AECOPD) that requires efficient treatments. A previous screening for host genes differentially expressed upon NTHi infection identified sirtuin-1, which encodes a NAD-dependent deacetylase protective against emphysema and is activated by resveratrol. This polyphenol concomitantly reduces NTHi viability, therefore highlighting its therapeutic potential against NTHi infection at the COPD airway. In this study, resveratrol antimicrobial effect on NTHi was shown to be bacteriostatic and did not induce resistance development in vitro. Analysis of modulatory properties on the NTHi-host airway epithelial interplay showed that resveratrol modulates bacterial invasion but not subcellular location, reduces inflammation without targeting phosphodiesterase 4B gene expression, and dampens β defensin-2 gene expression in infected cells. Moreover, resveratrol therapeutics against NTHi was evaluated in vivo on mouse respiratory and zebrafish septicemia infection model systems, showing to decrease NTHi viability in a dose-dependent manner and reduce airway inflammation upon infection, and to have a significant bacterial clearing effect without signs of host toxicity, respectively. This study presents resveratrol as a therapeutic of particular translational significance due to the attractiveness of targeting both infection and overactive inflammation at the COPD airway.

Sputum bacteriology and clinical response to antibiotics in moderate exacerbation of chronic obstructive pulmonary disease

BACKGROUND

Presence of purulent sputum during an acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is considered sufficient indication for starting empirical antibiotics. We investigated the relationship between detection of potentially pathogenic bacteria (PPB) using sputum culture or polymerase chain reaction (PCR) and clinical response and sought the risk factors for PPB growth.

METHODS

In 342 outpatients with AECOPD, we compared detection rates of H. influenzae (HI) and S. pneumoniae (SP) using conventional sputum culture versus PCR. The utility of either technique to predict clinical cure or failure after effective antibiotics was assessed. The factors predicting positive sputum cultures were evaluated using logistic regression.

RESULTS

Using sputum culture, 132 PPB were detected. The predominant bacteria were HI (40.9%) and SP (19.7%). Detection of HI or SP in sputum was higher using PCR than culture growth (60.8% vs 18.6%; P < .001). Clinical response was not affected by the results of either technique. Independent risk factors for PPB isolation were Gram-negative bacteria on sputum smear (OR 15.78, 95% CI 6.38-39.06; P < .001), sputum purulence (OR 2.31, 95% CI, 1.05-5.11; P = .04), body temperature (OR 0.16, 95% CI 0.05-0.54; P = .003), albumin level (OR 0.29, 95% CI 0.09-0.88; P = .03) and dyspnea grade (OR 0.51, 95% CI 0.27-0.96; P = .04).

CONCLUSIONS

Neither culture growth nor PCR positivity for HI or SP in sputum predicted clinical response to antibiotics; therefore, these tests are not necessary for outpatients with AECOPD. Examining Gram-staining and purulence on sputum smear, however, was significant to predict PPB growth in sputum.

Serum inflammatory biomarkers and clinical outcomes of COPD exacerbation caused by different pathogens

BACKGROUND AND OBJECTIVE

COPD exacerbation is characterized by worsening of symptoms, warranting change in treatment. Systemic and airway inflammation play roles in the pathogenesis of COPD exacerbation. We hypothesized whether increased serum inflammatory biomarkers are associated with the clinical outcomes of COPD exacerbation caused by different infectious pathogens.

METHODS

COPD patients with exacerbation were recruited from a hospital emergency department during 2014-2015. Serum procalcitonin (PCT) and C-reactive protein (CRP) were measured. Dyspnea, eosinopenia, consolidation, acidemia, and atrial fibrillation (DECAF) score was calculated for predicting mortality. Multiplex polymerase chain reaction was carried out for respiratory viral assay from nasopharyngeal swabs, and sputum bacterial culture was also performed. Hospital mortality, invasive mechanical ventilation requirement, and length of hospital stay (LOS) were evaluated, and their associations with clinical characteristics, DECAF score, and serum biomarkers were examined.

RESULTS

A total of 62 COPD patients were enrolled. These patients were classified as Global Initiative for Obstructive Lung Disease (GOLD) stage 2, 3, and 4 in 12.9%, 6.4%, and 80.7% of cases, respectively. Isolated bacterial exacerbation was recovered in 30.6% of exacerbation episodes: Klebsiella pneumoniae was the most commonly identified bacteria. Viral pathogens and coinfections were noted in 9.6% and 16.1% of exacerbated patients, respectively. Influenza was the most commonly detected viral pathogen. Serum biomarkers and DECAF score for viruses, bacteria, coinfection, and noninfectious causes of exacerbations were similar. Neither DECAF score nor serum biomarkers were able to differentiate patients with and without mortality or requiring mechanical ventilation. Increased serum PCT was noted in patients with LOS ≥7 days when compared with those with LOS <7 days (0.38 ng/mL vs 0.1 ng/mL; P=0.035).

CONCLUSION

Increased serum PCT is associated with longer LOS in COPD exacerbation. However, CRP and DECAF score play limited roles in predicting clinical outcome and lack an association with causes of exacerbation.

The Expression of IL-6, TNF-α, and MCP-1 in Respiratory Viral Infection in Acute Exacerbations of Chronic Obstructive Pulmonary Disease

Viral infection is a common trigger for acute exacerbations of chronic obstructive pulmonary disease (AECOPD). The aim of this study is to investigate the expression of cytokines in AECOPD. Patients with AECOPD requiring hospitalization were recruited. Meanwhile healthy volunteers of similar age that accepted routine check-ups and showed no clinical symptoms of inflammatory diseases were also recruited. Induced sputum and serum were collected. Induced sputum of participants was processed and tested for thirteen viruses and bacteria. Forty cytokines were assayed in serum using the Quantibody Human Inflammation Array 3 (Ray Biotech, Inc.). The most common virus detected in virus positive AECOPD (VP) was influenza A (16%). No virus was found in controls. Circulating levels of IL-6, TNF-α, and MCP-1 were elevated in VP and coinfection subjects (p < 0.05), while the levels of 37 other cytokines showed no difference, compared with virus negative groups and controls (p > 0.05). Additionally, VP patients were less likely to have received influenza vaccination. VP patients had a systemic inflammation response involving IL-6, TNF-α, and MCP-1 which may be due to virus-induced activation of macrophages. There are important opportunities for further investigating AECOPD mechanisms and for the development of better strategies in the management and prevention of virus-related AECOPD.

Cigarette smoke alters the ability of human dendritic cells to promote anti-Streptococcus pneumoniae Th17 response

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is associated with chronic inflammation and impaired immune response to pathogens leading to bacteria-induced exacerbation of the disease. A defect in Th17 cytokines in response to Streptococcus pneumoniae, a bacteria associated with COPD exacerbations, has been recently reported. Dendritic cells (DC) are professional antigen presenting cells that drive T-cells differentiation and activation. In this study, we hypothesized that exposure to cigarette smoke, the main risk factor of COPD, might altered the pro-Th17 response to S. pneumoniae in COPD patients and human DC.

METHODS

Pro-Th1 and -Th17 cytokine production by peripheral blood mononuclear cells (PBMC) from COPD patients was analyzed and compared to those from smokers and non-smokers healthy subjects. The effect of cigarette smoke extract (CSE) was analyzed on human monocyte-derived DC (MDDC) from controls exposed or not to S. pneumoniae. Bacteria endocytosis, maturation of MDDC and secretion of cytokines were assessed by flow cytometry and ELISA, respectively. Implication of the oxidative stress was analyzed by addition of antioxidants and mitochondria inhibitors. In parallel, MDDC were cocultured with autologous T-cells to analyze the consequence on Th1 and Th17 cytokine production.

RESULTS

PBMC from COPD patients exhibited defective production of IL-1β, IL-6, IL-12 and IL-23 to S. pneumoniae compared to healthy subjects and smokers. CSE significantly reduced S. pneumoniae-induced MDDC maturation, secretion of pro-Th1 and -Th17 cytokines and activation of Th1 and Th17 T-cell responses. CSE exposure was also associated with sustained CXCL8 secretion, bacteria endocytosis and mitochondrial oxidative stress. Antioxidants did not reverse these effects. Inhibitors of mitochondrial electron transport chain partly reproduced inhibition of S. pneumoniae-induced MDDC maturation but had no effect on cytokine secretion and T cell activation.

CONCLUSIONS

We observed a defective pro-Th1 and -Th17 response to bacteria in COPD patients. CSE exposure was associated with an inhibition of DC capacity to activate antigen specific T-cell response, an effect that seems to be not only related to oxidative stress. These results suggest that new therapeutics boosting this response in DC may be helpful to improve treatment of COPD exacerbations.

Airway Vagal Neuroplasticity Associated with Respiratory Viral Infections

Respiratory virus infections leads to coughing, sneezing, and increases in reflex parasympathetic bronchoconstriction and secretions. These responses to viral infection are exclusively or largely secondary to changes in the function of the nervous system. For many with underlying airway pathologies such as asthma and COPD, this neuroplasticity can lead to disease exacerbations and hospitalization. Relatively little is understood about the cellular and molecular mechanisms that underlie the changes in neuronal control of the respiratory tract during viral infection, but the evidence supports the idea that changes occur in the physiology of both the sensory and autonomic innervation. Virus infection can lead to acute increases in the activity of sensory nerves as well as to genetic changes causing alterations in sensory nerve phenotype. In addition, respiratory viral infections are associated with changes in the control of neurotransmitter release from cholinergic nerve endings terminating at the level of the airway smooth muscle.

Bacterial flora in the sputum and comorbidity in patients with acute exacerbations of COPD

OBJECTIVE

To determine in patients admitted with an acute exacerbation of chronic obstructive pulmonary disease (AE-COPD) the association between the isolation of potential pathogens in a conventional sputum culture and comorbidities.

PATIENTS AND METHODS

The ESMI study is a multicenter observational study. Patients with AE-COPD admitted to the Internal Medicine departments of 70 hospitals were included. The clinical characteristics, treatments, and comorbidities were gathered. The results of conventional sputum cultures were recorded.

RESULTS

A total of 536 patients were included, of which 161 produced valid sputum and a potentially pathogenic microorganism was isolated from 88 subjects (16.4%). The isolation of Pseudomonas aeruginosa (30.7%) was associated with a greater severity of the lung disease (previous admissions [P= 0.026], dyspnea scale [P=0.047], post-broncodilator forced expiratory volume in 1 second (FEV1) [P=0.005], and the BODEx index [P=0.009]); also with higher prevalence of cor pulmonale (P=0.017), heart failure (P=0.048), and cerebrovascular disease (P=0.026). Streptococcus pneumoniae (26.1%) was associated with more comorbidity according to number of diseases (P=0.018); notably, peripheral artery disease (P=0.033), hypertension (P=0.029), dyslipidemia (P=0.039), osteoporosis (P=0.0001), and depression (P=0.005).

CONCLUSION

Patients with AE-COPD and P. aeruginosa present higher severity of COPD, while those with S. pneumoniae present greater comorbidity. The potentially pathogenic microorganism obtained in the sputum culture depends on the associated comorbidities.

Determinants of bacteriological outcomes in exacerbations of chronic obstructive pulmonary disease

Purpose

Changes in sputum microbiology following antibiotic treatment of acute exacerbations of chronic obstructive pulmonary disease (AECOPD), including patterns of bacteriological relapse and superinfection are not well understood. Sputum microbiology at exacerbation is not routinely performed, but pathogen presence and species are determinants of outcomes. Therefore, we determined whether baseline clinical factors could predict the presence of bacterial pathogens at exacerbation. Bacterial eradication at end of treatment (EOT) is associated with clinical resolution of exacerbation. We determined the clinical, microbiological and therapeutic factors that were associated with bacteriological eradication in AECOPD at EOT and in the following 8 weeks.

Methods

Sputum bacteriological outcomes (i.e., eradication, persistence, superinfection, reinfection) from AECOPD patients (N = 1352) who were randomized to receive moxifloxacin or amoxicillin/clavulanate in the MAESTRAL study were compared. Independent predictors of bacterial presence in sputum at exacerbation and determinants for bacteriological eradication were analyzed by logistic regression and receiver operating characteristic (ROC) analyses.

Results

Significantly greater bacteriological eradication with moxifloxacin was mainly driven by superior Haemophilus influenzae eradication (P = 0.002, EOT). Baseline clinical factors were a weak predictor of the presence of pathogens in sputum (AUC_ROC = 0.593). On multivariate analysis, poorer bacterial eradication was associated with antibiotic resistance (P = 0.0001), systemic steroid use (P = 0.0024) and presence of P. aeruginosa (P = 0.0282).

Conclusions

Since clinical prediction of bacterial presence in sputum at AECOPD is poor, sputum microbiological analysis should be considered for guiding antibiotic therapy in moderate-to-severe AECOPD, particularly in those who received concomitant systemic corticosteroids or are at risk for infection with antibiotic-resistant bacteria.

Electronic supplementary material

The online version of this article (doi:10.1007/s15010-015-0833-3) contains supplementary material, which is available to authorized users.

Antibiotic Resistant and Virulence Determinants of Staphylococcus haemolyticus C10A as Revealed by Whole Genome Sequencing

Staphylococcus haemolyticus is one of the pathogens that harbor a high level of antibiotic resistance. Here, we highlighted the potential determinants for multidrug resistance and virulence from the draft genome of Staphylococcus haemolyticus strain C10A, isolated from a patient with chronic obstructive pulmonary disease exacerbation.

Transmission and effect of multiple clusters of seasonal influenza in a Swiss geriatric hospital

Objectives

To investigate a nosocomial outbreak of influenza.

Design

Prospective outbreak investigation with active case finding and molecular typing.

Setting

A large academic geriatric hospital in Switzerland.

Participants

Elderly hospitalized adults.

Measurements

Based on syndromic surveillance, a nosocomial influenza outbreak was suspected in February 2012. All suspected cases were screened for respiratory viruses using real‐time reverse transcription polymerase chain reaction of nasopharyngeal swabs. Infection control procedures (droplet precautions with single room isolation whenever possible) were implemented for all suspected or confirmed cases. Specimens positive for influenza viruses were processed and sequenced whenever possible to track transmission dynamics.

Results

Respiratory samples from 155 suspected cases were analyzed during the outbreak period, of which 69 (44%) were positive for influenza virus, 26 (17%) were positive for other respiratory viruses, and 60 (39%) were negative. Three other cases fulfilled clinical criteria for influenza infection but were not sampled, and one individual was admitted with an already positive test, resulting in a total of 73 influenza cases, of which 62 (85%) were classified as nosocomial. Five distinct clusters of nosocomial transmission were identified using viral sequencing, with epidemiologically unexpected in‐hospital transmission dynamics. Seven of 23 patients who experienced influenza complications died. Sixteen healthcare workers experienced an influenza‐like illness (overall vaccination rate, 36%).

Conclusion

Nosocomial influenza transmission caused more secondary cases than repeated community importation during this polyclonal outbreak. Molecular tools revealed complex transmission dynamics. Low healthcare worker vaccination rates and gaps in recommended infection control procedures are likely to have contributed to nosocomial spread of influenza, which remains a potentially life‐threatening disease in elderly adults.

Relationship between azithromycin susceptibility and administration efficacy for nontypeable Haemophilus influenzae respiratory infection

Nontypeable Haemophilus influenzae (NTHI) is an opportunistic pathogen that is an important cause of acute exacerbations of chronic obstructive pulmonary disease (AECOPD). COPD is an inflammatory disease of the airways, and exacerbations are acute inflammatory events superimposed on this background of chronic inflammation. Azithromycin (AZM) is a macrolide antibiotic with antibacterial and anti-inflammatory properties and a clinically proven potential for AECOPD prevention and management. Relationships between AZM efficacy and resistance by NTHI and between bactericidal and immunomodulatory effects on NTHI respiratory infection have not been addressed. In this study, we employed two pathogenic NTHI strains with different AZM susceptibilities (NTHI 375 [AZM susceptible] and NTHI 353 [AZM resistant]) to evaluate the prophylactic and therapeutic effects of AZM on the NTHI-host interplay. At the cellular level, AZM was bactericidal toward intracellular NTHI inside alveolar and bronchial epithelia and alveolar macrophages, and it enhanced NTHI phagocytosis by the latter cell type. These effects correlated with the strain MIC of AZM and the antibiotic dose. Additionally, the effect of AZM on NTHI infection was assessed in a mouse model of pulmonary infection. AZM showed both preventive and therapeutic efficacies by lowering NTHI 375 bacterial counts in lungs and bronchoalveolar lavage fluid (BALF) and by reducing histopathological inflammatory lesions in the upper and lower airways of mice. Conversely, AZM did not reduce bacterial loads in animals infected with NTHI 353, in which case a milder anti-inflammatory effect was also observed. Together, the results of this work link the bactericidal and anti-inflammatory effects of AZM and frame the efficacy of this antibiotic against NTHI respiratory infection.

Molecular detection of respiratory viruses

Over the past several years a wide variety of molecular assays for the detection of respiratory viruses has reached the market. The tests described herein range from kits containing primers and probes detecting specific groups of viruses, to self-contained systems requiring specialized instruments that extract nucleic acids and perform the polymerase chain reaction with little operator input. Some of the tests target just the viruses involved in large yearly epidemics such as influenza, or specific groups of viruses such as the adenoviruses or parainfluenza viruses; others can detect most of the known respiratory viruses and some bacterial agents.

Foxa3 induces goblet cell metaplasia and inhibits innate antiviral immunity

RATIONALE

Goblet cell metaplasia accompanies common pulmonary disorders that are prone to recurrent viral infections. Mechanisms regulating both goblet cell metaplasia and susceptibility to viral infection associated with chronic lung diseases are incompletely understood.

OBJECTIVES

We sought to identify the role of the transcription factor FOXA3 in regulation of goblet cell metaplasia and pulmonary innate immunity.

METHODS

FOXA3 was identified in airways from patients with asthma and chronic obstructive pulmonary disease. We produced transgenic mice conditionally expressing Foxa3 in airway epithelial cells and developed human bronchial epithelial cells expressing Foxa3. Foxa3-regulated genes were identified by immunostaining, Western blotting, and RNA analysis. Direct binding of FOXA3 to target genes was identified by chromatin immunoprecipitation sequencing correlated with RNA sequencing.

MEASUREMENTS AND MAIN RESULTS

FOXA3 was highly expressed in airway goblet cells from patients with asthma and chronic obstructive pulmonary disease. FOXA3 was induced by either IL-13 or rhinovirus. Foxa3 induced goblet cell metaplasia and enhanced expression of a network of genes mediating mucus production. Paradoxically, FOXA3 inhibited rhinovirus-induced IFN production, IRF-3 phosphorylation, and IKKε expression and inhibited viral clearance and expression of genes required for antiviral defenses, including MDA5, RIG-I, TLR3, IRF7/9, and nuclear factor-κB.

CONCLUSIONS

FOXA3 induces goblet cell metaplasia in response to infection or Th2 stimulation. Suppression of IFN signaling by FOXA3 provides a plausible mechanism that may serve to limit ongoing Th1 inflammation during the resolution of acute viral infection; however, inhibition of innate immunity by FOXA3 may contribute to susceptibility to viral infections associated with chronic lung disorders accompanied by chronic goblet cell metaplasia.

Experimental rhinovirus infection in COPD: implications for antiviral therapies

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

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

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

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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.

Burden of respiratory viruses in patients with acute respiratory failure

Respiratory viruses (RVs) are ubiquitous pathogens that represent a major cause of community-acquired pneumonia and chronic pulmonary diseases exacerbations. However, their contribution to acute respiratory failure events requiring intensive care unit admission in the era of rapid multiplex molecular assay deserves further evaluation. This study investigated the burden of viral infections in non immunocompromised patients admitted to the intensive care unit for acute respiratory failure using a multiplex molecular assay. Patients were investigated for RVs using immunofluoresence testing and a commercial multiplex molecular assay, and for bacteria using conventional culture. Half the patients (34/70, 49%) had a documented RVs infection. No other pathogen was found in 24 (71%) patients. Viral infection was detected more frequently in patients with obstructive respiratory diseases (64% vs. 29%; P = 0.0075). Multiplex molecular assay should be considered as an usefull diagnostic tool in patients admitted to the intensive care unit with acute respiratory failure, especially those with acute exacerbations of chronic obstructive pulmonary disease and asthma.

The host immune response contributes to Haemophilus influenzae virulence

BACKGROUND

There is compelling evidence that infections with non-typeable Haemophilus influenzae (NTHi) are associated with exacerbations in COPD patients. However, NTHi has also been isolated frequently during clinically stable disease. In this study we tested the hypothesis that genetically distinct NTHi isolates obtained from COPD patients differ in virulence which could account for dissimilarities in the final outcome of an infection (stable vs. exacerbation).

RESULTS

NTHi isolates (n = 32) were obtained from stable COPD patients, or during exacerbations. Genetically divergent NTHi isolates were selected and induction of inflammation was assessed as an indicator of virulence using different in vitro models. Despite marked genomic differences among NTHi isolates, in vitro studies could not distinguish between NTHi isolates based on their inflammatory capacities. Alternatively, when using a whole blood assay results demonstrated marked inter-, but not intra-individual differences in cytokine release between healthy volunteers irrespective of the origin of the NTHi isolate used.

CONCLUSION

Results suggest that the individual immune reactivity might be an important predictor for the clinical outcome (exacerbation vs. no exacerbation) following NTHi infection.

Long-term antifungal treatment improves health status in patients with chronic pulmonary aspergillosis: a longitudinal analysis

BACKGROUND

 Chronic pulmonary aspergillosis (CPA) is an infectious disease that progressively destroys lung tissue. To date, no longitudinal data on the efficacy of antifungal treatment on health status in CPA patients exist.

METHODS

 Using the standardized St George's Respiratory Questionnaire, the health status of 122 patients with was assessed at baseline and quarterly over 12 months. The score range was 0-100, where higher score indicates worse heath status, and a change of ≥4 was deemed the minimal clinically important difference. Lung function, body mass index, Medical Research Council dyspnea scale, disease severity, and demographic data were reported.

RESULTS

 Mean age of patients was 59 years, and 45% were female. Overall, patients with CPA had substantial health status impairment at baseline. After treatment, 47%-50% gained substantial health improvement with a mean reduction of score of 14 at both 6 and 12 months, whereas 32% deteriorated with a mean rise of score of 11 and 14 after 6 and 12 months of treatment and observation, respectively, and 21% were not much different (stable). Patients gained therapeutic benefit irrespective of their illness severity where >50% of those who had "poor" and "very poor" status at baseline improved with score reduction of ≥4 after 6 months of treatment. Replicating this analysis using a health status category, we found that at least 50% of patients with a "poor/very poor" health status category at baseline improved significantly to "fair" or "good/very good" categories. Side effects burdened health status considerably. In multivariate analysis, dyspnea and disease severity significantly defined health status impairment.

CONCLUSIONS

Antifungal therapy improved health status and prevented CPA progression in most patients.

Comprehensive molecular oncogenomic profiling and miRNA analysis of prostate cancer

This study was focused on molecular profiling of prostate cancer (PCa) using scant amounts of both frozen and formalin-fixed paraffin-embedded (FFPE) PCa tissue specimens. DNA and RNA were extracted and interrogated for: (1) whole-genome gene expression profiling, (2) miRNA expression analysis, (3) SNP analysis, and (4) mutation analysis. Data was statistically analyzed and correlated with clinical and pathologic variables. Expression profiling of 47,224 genes revealed 74 genes that were significant in predicting high tumor grade in PCa (p<0.0001). These were involved in many cellular processes as analyzed by Ingenuity Pathway Analysis (IPA). Using novel high throughput technologies, we identified a specific oncogenomic and miRNA signatures showing loss of miR-34 expression. Interestingly, p53 was at the center hub of the signaling pathways, and the loss of miR-34a expression was consistent with the central role of p53 in PCa. Analysis of 731,442 SNP's, revealed 638 SNP's that were significant in predicting high tumor grade (p<0.0001; logistic regression analysis). We also found, for the first time, a novel hot spot mutation in MET oncogene, variant T992I, suggesting that our findings would be useful in further defining the role of specific regulatory genes and miRNAs in the pathological evolution of PCa, and could also have potential clinical utility in improving diagnostic accuracy, refining prognostic and predictive capabilities and may serve as therapeutic targets.

Viral infection is associated with an increased proinflammatory response in chronic obstructive pulmonary disease

The development of new diagnostic methods based on molecular biology has led to evidence of the important role of respiratory viruses in chronic obstructive pulmonary disease (COPD) exacerbations. Cytokines and chemokines are recognized as key actors in the pathogenesis of COPD. The objective of this study was to evaluate the association between viral infection and host cytokine responses in 57 COPD patients hospitalized with an acute exacerbation. Seventeen cytokines were profiled using a Luminex-Biorad multiplex assay in plasma samples collected in the first 24 h following hospital admission. Stepwise linear regression analysis was performed, taking into account the influence of seven potential confounding factors in the results. Twenty-four out of 57 showed radiological signs of community-acquired pneumonia (CAP) at hospital admission, 25 patients required admission to the intensive care unit (ICU), 20 had a bacterial infection, and 20 showed a detectable respiratory virus in pharyngeal swabs. Regression analysis showed that viral infection correlated with higher levels of interleukin-6 (IL-6) (log value of the coefficient of regression B, p=0.47, 0.044), and monocyte chemoattractant protein-1 (MCP-1) (p=0.43, 0.019), and increased admission to the ICU. Viral infection also correlated with higher levels of interferon-γ (IFN-γ) (p=0.70, 0.026), which, in turn, was inversely associated with the severity of illness. Finally, viral infection was independently associated with higher levels of tumor necrosis factor-α (TNF-α) (p=0.40, 0.002). Thus our study demonstrates that in patients with COPD exacerbations, viral infection is directly associated with higher systemic levels of cytokines central to the development of the antiviral response, which are also known to contribute to inflammation-mediated tissue damage. These results reveal a potential specific role of viral infection in the pathogenesis of COPD exacerbations.

Moxifloxacin versus amoxicillin/clavulanic acid in outpatient acute exacerbations of COPD: MAESTRAL results

Bacterial infections causing acute exacerbations of chronic obstructive pulmonary disease (AECOPD) frequently require antibacterial treatment. More evidence is needed to guide antibiotic choice.

The Moxifloxacin in Acute Exacerbations of Chronic Bronchitis TriaL (MAESTRAL) was a multiregional, randomised, double-blind non-inferiority outpatient study. Patients were aged ≥60 yrs, with an Anthonisen type I exacerbation, a forced expiratory volume in 1 s <60% predicted and two or more exacerbations in the last year. Following stratification by steroid use patients received moxifloxacin 400 mg p.o. q.d. (5 days) or amoxicillin/clavulanic acid 875/125 mg p.o. b.i.d. (7 days). The primary end-point was clinical failure 8 weeks post-therapy in the per protocol population.

Moxifloxacin was noninferior to amoxicillin/clavulanic acid at the primary end-point (111 (20.6%) out of 538, versus 114 (22.0%) out of 518, respectively; 95% CI -5.89–3.83%). In patients with confirmed bacterial AECOPD, moxifloxacin led to significantly lower clinical failure rates than amoxicillin/clavulanic acid (in the intent-to-treat with pathogens, 62 (19.0%) out of 327 versus 85 (25.4%) out of 335, respectively; p=0.016). Confirmed bacterial eradication at end of therapy was associated with higher clinical cure rates at 8 weeks post-therapy overall (p=0.0014) and for moxifloxacin (p=0.003). Patients treated with oral corticosteroids had more severe disease and higher failure rates.

The MAESTRAL study showed that moxifloxacin was as effective as amoxicillin/clavulanic acid in the treatment of outpatients with AECOPD. Both therapies were well tolerated.