Accuracy of Death Certificates in COPD: Analysis from the TORCH Trial

The Towards a Revolution in COPD Health (TORCH) trial was an international clinical trial of chronic obstructive pulmonary disease (COPD) patients where cause of death was assigned by an independent committee. Comparison of death certificate data and adjudicated cause of death allows a unique opportunity to determine death certificate accuracy and frequency of COPD listing on death certificates of COPD patients. In this analysis, the authors determine the concordance between adjudicated cause of death and primary and secondary cause of death from death certificates. In 317 (80%) of informative deaths, the primary or secondary cause of death from certificates agreed with adjudicated cause of death. Only 229 (58%) of death certificates in these COPD patients listed COPD on the certificate. COPD was not listed on the death certificate in 21% of deaths adjudicated to be caused by COPD exacerbation. Compared with pulmonary causes, the listing of COPD on certificates occurred with less frequency than cardiovascular, cancer and other categories of death. The combined primary and secondary listing on death certificates has good concordance with actual cause of death. COPD is under-reported on death certificates, and this under-reporting is more frequent when the primary cause of death is not pulmonary.

Effect of fruit and vegetable intake on oxidative stress and inflammation in COPD: a randomised controlled trial

Epidemiological evidence supports a positive relationship between fruit and vegetable (FV) intake, lung function and chronic obstructive pulmonary disease (COPD). Increasing FV intake may attenuate the oxidative stress and inflammation associated with COPD.

An exploratory randomised controlled trial to examine the effect of increased consumption of FV on oxidative stress and inflammation in moderate-to-severe COPD was conducted. 81 symptomatically stable patients with a habitually low FV intake (two or fewer portions of FV per day) were randomised to the intervention group (five or more portions of FV per day) or the control group (two or fewer portions of FV per day). Each participant received self-selected weekly home deliveries of FV for 12 weeks.

75 participants completed the intervention. There was a significant between-group change in self-reported FV intake and biomarkers of FV intake (zeaxanthin (p=0.034) and ß-cryptoxanthin (p=0.015)), indicating good compliance; post-intervention intakes in intervention and control groups were 6.1 and 1.9 portions of FV per day, respectively. There were no significant changes in biomarkers of airway inflammation (interleukin-8 and myeloperoxidase) and systemic inflammation (C-reactive protein) or airway and systemic oxidative stress (8-isoprostane).

This exploratory study demonstrated that patients with moderate-to-severe COPD were able to comply with an intervention to increase FV intake; however, this had no significant effect on airway or systemic oxidative stress and inflammation.

Comparison of nasal and bronchial epithelial cells obtained from patients with COPD

For in vitro studies of airway pathophysiology, primary epithelial cells have many advantages over immortalised cell lines. Nasal epithelial cells are easier to obtain than bronchial epithelial cells and can be used as an alternative for in vitro studies. Our objective was to compare nasal and bronchial epithelial cells from subjects with COPD to establish if these cells respond similarly to pro-inflammatory stimuli. Cell cultures from paired nasal and bronchial brushings (21 subjects) were incubated with cigarette smoke extract (CSE) prior to stimulation with Pseudomonas aeruginosa lipopolysaccharide. IL-6 and IL-8 were measured by ELISA and Toll-like receptor 4 (TLR-4) message and expression by RT-PCR and FACS respectively. IL-8 release correlated significantly between the two cell types. IL-6 secretion was significantly less from bronchial compared to nasal epithelial cells and secreted concentrations did not correlate. A 4 h CSE incubation was immunosuppressive for both nasal and bronchial cells, however prolonged incubation for 24 h was pro-inflammatory solely for the nasal cells. CSE reduced TLR-4 expression in bronchial cells only after 24 h, and was without effect on mRNA expression. In subjects with COPD, nasal epithelial cells cannot substitute for in vitro bronchial epithelial cells in airway inflammation studies. © 2012 Comer et al.

Airway epithelial cell apoptosis and inflammation in COPD, smokers and non-smokers

We hypothesised that primary bronchial epithelial cells (PBECs) from subjects with COPD respond differently to Pseudomonas aeruginosa lipopolysaccharide (PA LPS) after cigarette smoke extract (CSE) exposure than PBECs obtained from smokers without airflow obstruction (SWAO) and non-smokers (NS).PBECs from 16 COPD subjects, 10 SWAOand 9 NS were cultured at air-liquid interface. Cultures were incubated with CSE prior to stimulation with PA LPS. IL-6 and IL-8 were measured by ELISA and Toll-like receptor 4 expression by FACS. Activation of NF-?B was determined by western blotting and ELISA, and MAPK and caspase-3 activity by western blotting. Apoptosis was evaluated using Annexin-V staining and the terminal transferase-mediated dUTP nick end-labeling (TUNEL) methods.Constitutive release of IL-8 and IL-6 was greatest from the COPD cultures.However, CSE pre-treatment followed by PA LPS stimulation reduced IL-8 release from COPD PBECs, but increased it from cells of SWAOand NS. TLR-4 expression,MAPK and NF-?B activation in COPD cultures were reduced after CSE treatment, but not in the SWAOor NS groups, which was associated with increased apoptosis.CSE attenuates inflammatory responses to LPS in cells from people with COPD but not those from non-smoking individuals and those who smoke without airflow obstruction.

Cause-specific mortality adjudication in the UPLIFT® COPD trial:findings and recommendations

Mortality is an important endpoint in chronic obstructive pulmonary disease (COPD) trials, although accurately determining cause of death is difficult. In the Understanding the Potential Long-term Impacts on Function with Tiotropium (UPLIFT®) trial, a mortality adjudication committee (MAC) provided systematic, independent and blinded assessment of cause-specific mortality of all 981 reported deaths. Here we describe this process of mortality adjudication and methodological revisions introduced to help standardise the adjudication of two areas recognised to pose particular difficulty; firstly, the classification of fatal COPD exacerbations that occur in the setting of pneumonia and secondly, the categorisation of sudden death. In addition MAC determined cause of death was compared with that reported by site investigators (SIs). MAC-assigned causes of death were: respiratory, 35%; cancer, 25%; cardiovascular, 11%; sudden cardiac death, 4.4%; sudden death, 3.4%; other, 8.8%; unknown, 12.4%. Cancer/cardiac deaths were more common in Global Initiative for Chronic Obstructive Lung Disease stage II, respiratory deaths in stages III and IV. Agreement between MAC and SI regarding cause of death was complete (50.2%), incomplete (18.5%) or none (31.3%). The SI classified deaths as cardiac three-fold more frequently than MAC (incidence rate [IR]/100 patient-years 0.797 vs. 0.257), although IR ratios for cardiac deaths for tiotropium vs. control were similar between SI and MAC. Discrepancies between MAC- and SI-adjudicated causes of death are common, especially increased reporting of cardiac deaths by the SI. Future multicentre COPD trials should plan appropriate infrastructure before study initiation to ensure collection and interpretation of fatal events data.

Professionals delivering palliative care to people with COPD: qualitative study

This article describes health and social care professionals' perceptions of palliative care and facilitators and barriers to the delivery of such care for patients with advanced chronic obstructive pulmonary disease. Health professionals participated in semi structured interviews and focus groups which were analysed using content analysis. According to participants, care of patients with chronic obstructive pulmonary disease is focused upon the management of symptoms, with emphasis focused predominately on an acute model of care. Key barriers towards the delivery of palliative care included the reluctance to negotiatie end-of-life decisions and a perceived lack of understanding among patients and carers regarding the illness trajectory. Consequently the delivery of palliative care was viewed as a specialist role rather than an integral component of care. There is a need for education and training for health and social care professions to plan and provide high quality end-of-life care.

Respiratory syncytial virus infections enhance cigarette smoke induced COPD in mice

Respiratory syncytial viral (RSV) infections are a frequent cause of chronic obstructive pulmonary disease (COPD) exacerbations, which are a major factor in disease progression and mortality. RSV is able to evade antiviral defenses to persist in the lungs of COPD patients. Though RSV infection has been identified in COPD, its contribution to cigarette smoke-induced airway inflammation and lung tissue destruction has not been established. Here we examine the long-term effects of cigarette smoke exposure, in combination with monthly RSV infections, on pulmonary inflammation, protease production and remodeling in mice. RSV exposures enhanced the influx of macrophages, neutrophils and lymphocytes to the airways of cigarette smoke exposed C57BL/6J mice. This infiltration of cells was most pronounced around the vasculature and bronchial airways. By itself, RSV caused significant airspace enlargement and fibrosis in mice and these effects were accentuated with concomitant smoke exposure. Combined stimulation with both smoke and RSV synergistically induced cytokine (IL-1a, IL-17, IFN-c, KC, IL-13, CXCL9, RANTES, MIF and GM-CSF) and protease (MMP-2, -8, -12, -13, -16 and cathepsins E, S, W and Z) expression. In addition, RSV exposure caused marked apoptosis within the airways of infected mice, which was augmented by cigarette smoke exposure. RSV and smoke exposure also reduced protein phosphatase 2A (PP2A) and protein tyrosine phosphates (PTP1B) expression and activity. This is significant as these phosphatases counter smoke-induced inflammation and protease expression. Together, these findings show for the first time that recurrent RSV infection markedly enhances inflammation, apoptosis and tissue destruction in smoke-exposed mice. Indeed, these results indicate that preventing RSV transmission and infection has the potential to significantly impact on COPD severity and progression.

Respiratory Infections Cause the Release of Extracellular Vesicles: Implications in Exacerbation of Asthma/COPD

Background: Infection-related exacerbations of respiratory diseases are a major health concern; thus understanding the mechanisms driving them is of paramount importance. Despite distinct inflammatory profiles and pathological differences, asthma and COPD share a common clinical facet: raised airway ATP levels. Furthermore, evidence is growing to suggest that infective agents can cause the release of extracellular vesicle (EVs) in vitro and in bodily fluids. ATP can evoke the P2X7/caspase 1 dependent release of IL-1β/IL-18 from EVs; these cytokines are associated with neutrophilia and are increased during exacerbations. Thus we hypothesized that respiratory infections causes the release of EVs in the airway and that the raised ATP levels, present in respiratory disease, triggers the release of IL-1β/IL-18, neutrophilia and subsequent disease exacerbations.

Methods: To begin to test this hypothesis we utilised human cell-based assays, ex vivo murine BALF, in vivo pre-clinical models and human samples to test this hypothesis.

Results: Data showed that in a murine model of COPD, known to have increased airway ATP levels, infective challenge causes exacerbated inflammation. Using cell-based systems, murine models and samples collected from challenged healthy subjects, we showed that infection can trigger the release of EVs. When exposed to ATP the EVs release IL-1b/IL-18 via a P2X₇/caspase-dependent mechanism. Furthermore ATP challenge can cause a P2X₇ dependent increase in LPS-driven neutrophilia.

Conclusions: This preliminary data suggests a possible mechanism for how infections could exacerbate respiratory diseases and may highlight a possible signalling pathway for drug discovery efforts in this area.