Feasibility and interpretation of FE(NO) measurements in asthma patients in general practice

BACKGROUND

Exhaled NO (FE(NO)) is a useful biomarker for the monitoring of asthma control and response to therapy. However, there is a lack of data on FE(NO) levels and their interpretation in Primary Care asthma population depending on their treatment and smoking habit. Besides, the majority of current FE(NO) tests have been done by stationary chemiluminescence analysers whose use is limited to research laboratories.

METHODS

FE(NO) measurements by the novel hand-held NO monitoring device (NIOX MINO) were made in 96 asthma patients (32 males, mean age 53+/-12) at five local General Practices during their scheduled 15-20 min visits for lung function assessment.

RESULTS

Success rate was 78% and the intra-subject coefficient of variation was 8.7%. Inhaled corticosteroid treatment had an overall reducing effect on the FE(NO) value (30.5 [19.8-49.8]) vs. patients not on the ICS (26.5 [19-94]) (p<0.044). FE(NO) levels in the ICS treated current or ex-smokers group of patients were still significantly above the normal values (p<0.0001). FE(NO) levels were similar in patients receiving ICS whether there were current, ex-smokers or non-smokers. The highest FE(NO) levels (94 [15.8-151]) were found in asthmatic current smokers and not receiving treatment with ICS. The most "normalised" FE(NO) levels (35.3 [13.5-35.3]) were seen in ex-smokers.

CONCLUSIONS

FE(NO) measurements performed with a new hand-held monitoring device are reproducible and feasible in General Practice in the majority of patients of different ages and asthma severities. A high percentage of patients with different severities of asthma and regardless of their treatment with ICS and current smoking habit (current and/or ex-smokers) had highly elevated FE(NO) values, suggesting that their current therapy was possibly insufficient to control the underlying degree of airway inflammation and asthma symptoms.

Global strategy for asthma management and prevention: GINA executive summary

Asthma is a serious health problem throughout the world. During the past two decades, many scientific advances have improved our understanding of asthma and ability to manage and control it effectively. However, recommendations for asthma care need to be adapted to local conditions, resources and services. Since it was formed in 1993, the Global Initiative for Asthma, a network of individuals, organisations and public health officials, has played a leading role in disseminating information about the care of patients with asthma based on a process of continuous review of published scientific investigations. A comprehensive workshop report entitled "A Global Strategy for Asthma Management and Prevention", first published in 1995, has been widely adopted, translated and reproduced, and forms the basis for many national guidelines. The 2006 report contains important new themes. First, it asserts that "it is reasonable to expect that in most patients with asthma, control of the disease can and should be achieved and maintained," and recommends a change in approach to asthma management, with asthma control, rather than asthma severity, being the focus of treatment decisions. The importance of the patient-care giver partnership and guided self-management, along with setting goals for treatment, are also emphasised.

Relative corticosteroid insensitivity of alveolar macrophages in severe asthma compared with non-severe asthma

BACKGROUND

About 5-10% of patients with asthma suffer from poorly controlled disease despite corticosteroid (CS) treatment, which may indicate the presence of CS insensitivity. A study was undertaken to determine whether relative CS insensitivity is present in alveolar macrophages from patients with severe asthma and its association with p38 mitogen-activated protein kinase (MAPK) activation and MAPK phosphatase-1 (MKP-1).

METHODS

Fibreoptic bronchoscopy and bronchoalveolar lavage (BAL) were performed in 20 patients with severe asthma and 19 with non-severe asthma and, for comparison, in 14 normal volunteers. Alveolar macrophages were exposed to lipopolysaccharide (LPS, 10 mug/ml) and dexamethasone (10(-8) and 10(-6) M). Supernatants were assayed for cytokines using an ELISA-based method. p38 MAPK activity and MKP-1 messenger RNA expression were assayed in cell extracts.

RESULTS

The inhibition of LPS-induced interleukin (IL)1beta, IL6, IL8, monocyte chemotactic protein (MCP)-1 and macrophage inflammatory protein (MIP)-1alpha release by dexamethasone (10(-6) M) was significantly less in macrophages from patients with severe asthma than in macrophages from patients with non-severe asthma. There was increased p38 MAPK activation in macrophages from patients with severe asthma. MKP-1 expression induced by dexamethasone and LPS, expressed as a ratio of LPS-induced expression, was reduced in severe asthma.

CONCLUSION

Alveolar macrophages from patients with severe asthma demonstrate CS insensitivity associated with increased p38 MAPK activation that may result from impaired inducibility of MKP-1.

Outcomes for COPD pharmacological trials: from lung function to biomarkers

The American Thoracic Society/European Respiratory Society jointly created a Task Force on "Outcomes for COPD pharmacological trials: from lung function to biomarkers" to inform the chronic obstructive pulmonary disease research community about the possible use and limitations of current outcomes and markers when evaluating the impact of a pharmacological therapy. Based on their review of the published literature, the following document has been prepared with individual sections that address specific outcomes and markers, and a final section that summarises their recommendations.

Importance of inhaler devices in the management of airway disease

The delivery of drugs by inhalation is an integral component of asthma and chronic obstructive pulmonary disease (COPD) management. However, even with effective inhaled pharmacological therapies, asthma, particularly, remains poorly controlled around the world. The reasons for this are manifold, but limitations of treatment guidelines in terms of content, implementation and relevance to everyday clinical life, including insufficient patient education, access to health care and cost of medication as well as poor inhaler technique are likely to contribute. Considering that inhalation therapy is a cornerstone in asthma and COPD management, little advice is provided in the guidelines regarding inhaler selection. The pressurised metered dose inhaler (pMDI) is still the most frequently prescribed device worldwide, but even after repeated tuition many patients fail to use it correctly. In addition, the correct technique can be lost over time. Although several improvements in pMDIs such as a change in the propellant and actuation have resulted in improvements in lung deposition, many dry powder inhalers (DPIs) are easier to use. However, these devices also have limitations such as dependency of drug particle size on flow rate and loss of the metered dose if the patient exhales through the device before inhaling. Improvements in using inhalation devices more efficiently, in inhaler design for supporting patient compliance, and advances in inhaler technology to assure drug delivery to the lungs, have the potential to improve asthma and COPD management and control. New and advanced devices are considered being helpful to minimise the most important problems patients have with current DPIs.

Interval and non-compliant breast cancers diagnosed in women aged 50–69 in a Canadian breast cancer screening program: Clinical-pathologic correlations

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Background: Assessment of interval breast cancers and screening compliance are important parameters in the assessment of any comprehensive breast screening program. Clinical-pathologic examination of interval cancers may also be helpful in understanding differences between screen-detected and interval disease. The Nova Scotia Breast Screening Program (NSBSP) was founded in 1991 and, as of Jan 2007, 86,071 women aged 50–69 have entered the program, with 255,350 screening examinations completed. Methods: The Mammography Information System and Diagnostic Reporting System databases were used to identify all interval (diagnosed after a negative screen and before the recommended next screen) and non-compliant (diagnosed after a negative screen and after the recommended next screen) invasive breast cancer diagnoses. Unpaired t-tests were used to compare age at diagnosis, detection time and tumor size and the Chi- square test was used to compare the odds ratio of nodal involvement between interval and non-compliant cases. Results: A total of 1,189 screen-detected, 309 interval and 260 non-compliant invasive breast cancers were diagnosed amongst program participants aged 50–69 over this time period. Mean values (standard deviation, SD) for interval vs. non-compliant cases were; age at diagnosis 58.8 (SD=5.6) vs. 59.6 (SD=5.9) years (p=0.113); time to detection from last screen 363.9 (SD=187.6) vs. 1296 (SD=868.4) days (p<0.0001); tumor size 15.9 (SD=15.0) vs. 14.6 (SD=14.7) mms. (p=0.342). The incidence of nodal involvement in interval vs. non-compliant breast cancers was 32% and 23.5% respectively resulting in an odds ratio of 1.54, p=0.023. Conclusions: Interval and non-compliant breast cancers made up a significant proportion of all invasive cancers diagnosed amongst program participants. The finding of more cases having involved nodes at diagnosis despite no significant difference in mean age at diagnosis or tumor size suggests that interval disease may have a more aggressive phenotype. Data on tumor grade, lymphovascular invasion, hormone receptor status and HER2/neu over-expression are being collected.

No significant financial relationships to disclose.

Scientific rationale for using a single inhaler for asthma control

Clinical trials have recently demonstrated that using a budesonide/formoterol combination inhaler as regular maintenance treatment twice daily but also as a rescue therapy for breakthrough symptoms can provide more effective control of asthma, particularly in reducing exacerbations, than using a short-acting beta2-agonist or formoterol as rescue therapy. This suggests that the corticosteroid component of the combination therapy plays an important role in rescue therapy. Formoterol as a rescue therapy is effective in relieving symptoms by relaxing airway smooth muscle but is also likely to have important inhibitory effects on mast cells, plasma exudation and neutrophilic inflammation. Inhaled corticosteroids have much more rapid suppressing effects on airway inflammation than previously recognised and the increased dose used as rescue therapy may prevent the increase in airway inflammation that occurs during the evolution of an exacerbation, thus preventing its development. It is likely that the molecular interactions between beta2-agonists and corticosteroids also enhance the effect of the combination therapy as rescue therapy. There is now a strong scientific rationale for single inhaler therapy in asthma, but more research is now needed to better understand the mechanisms involved.

Exacerbations of chronic obstructive pulmonary disease

Exacerbations of chronic obstructive pulmonary disease are of major importance in terms of their prolonged detrimental effects on patients, the acceleration in disease progression and high healthcare costs. There is still debate about how exacerbations should be defined and graded, and their mechanisms are poorly understood. The major causal agents are either bacteria or viral infections, or a combination of the two. Noninfective causes include air pollution and pulmonary embolus but, in some patients, no cause is identified. Exacerbations represent an increase in the inflammation that is present in the stable state, with increased numbers of inflammatory cells (particularly neutrophils), cytokines, chemokines and proteases in the airways, and increased concentrations of certain cytokines and C-reactive protein in the blood. There are presently no reliable biomarkers with which to predict exacerbations. Exacerbations have a long-lasting adverse influence on health status. High doses of bronchodilators are the mainstay of treatment and systemic corticosteroids have some benefit. The routine use of antibiotics remains controversial but they are of benefit with exacerbations of a bacterial origin. Noninvasive ventilation is beneficial in preventing the need for intubation and its important complications but it is not certain whether its use in stable patients prevents exacerbations. Although important advances have been made, more effective treatments are needed in the future for prevention and treatment of exacerbations.

Inhibitory effect of p38 mitogen-activated protein kinase inhibitors on cytokine release from human macrophages

BACKGROUND AND PURPOSE

Macrophages release cytokines that may contribute to pulmonary inflammation in conditions such as chronic obstructive pulmonary disease. Thus, inhibition of macrophage cytokine production may have therapeutic benefit. p38 MAPK may regulate cytokine production, therefore, the effect of two p38 MAPK inhibitors, SB239063 and SD-282, on the release of TNF-alpha, GM-CSF and IL-8 from human macrophages was investigated.

EXPERIMENTAL APPROACH

Cytokine release was measured by ELISA. Immunoblots and mRNA expression studies were performed to confirm p38 MAPK isoform expression and activity. Macrophages were isolated from lung tissue of current smokers, ex-smokers and emphysema patients and exposed to lipopolysaccharide. These cells then released cytokines in a concentration-dependent manner.

KEY RESULTS

SB239063 only inhibited TNF-alpha release (EC50 0.3 +/- 0.1 microM). Disease status had no effect on the efficacy of SB239063. SD-282 inhibited both TNF-alpha and GM-CSF release from macrophages (EC50 6.1 +/- 1.4 nM and 1.8 +/- 0.6 microM respectively) but had no effect on IL-8 release. In contrast, both inhibitors suppressed cytokine production in monocytes.

CONCLUSIONS AND IMPLICATIONS

The differential effects of p38 MAPK inhibitors between macrophages and monocytes could not be explained by differences in p38 MAPK isoform expression or activity. However, the stability of TNF-alpha mRNA was significantly increased in macrophages compared to monocytes. These data suggest a differential involvement for p38 MAPK in macrophage cytokine production compared with monocytes. These effects are not due to lack of p38 activation or p38alpha expression in macrophages but may reflect differential effects on the stability of cytokine mRNA.

Pharmacology of airways and vessels in lung slices in situ: role of endogenous dilator hormones

Small airway and vessels play a critical role in chronic airway and pulmonary vascular diseases, but their pharmacology has not been well characterised. We have studied airway and vascular responses in rat lung slices and separately in vitro using myography. In lung slices, under basal conditions, acetylcholine contracted airways, but had no vascular effect. The thromboxane mimetic, U46619 contracted both vessels and airways. In the presence of U46619, acetylcholine dilated vessels, but further contracted airways, an effect that was blocked by the nitric oxide synthase inhibitor L-NG-nitro-L-arginine or apamin plus charybdotoxin, which inhibit endothelial-derived hyperpolarising factor. Airway responses in lung slices were unaffected by L-NGnitro-L-arginine methyl ester, indomethacin or apamin plus charybdotoxin. By contrast, apamin plus charybdotoxin contracted bronchi studied in isolation. Our observations are the first to identify mechanisms of endothelium dependent dilations in precision cut lung slices and the potential for transverse hormonal communication between airways and vessels.

Clinical and pathological correlations in male breast cancer (MBC): Intratumoral aromatase expression (ITA) via tissue microarray (TMA)

10553

Background: Most cases of MBC are hormone-receptor (HR) positive and there is anecdotal evidence of disease response to aromatase inhibitors in the metastatic setting. Study objectives were to (i) assess clinical-pathologic characteristics in a cohort of MBC, (ii) evaluate intratumoral aromatase expression and (iii) assess its’ prognostic impact. Methods: A retrospective chart review was conducted for all cases of MBC seen at the Nova Scotia Cancer Centre between 1985–2005. Data abstracted included disease stage, tumor grade, HR status (ER/PR), HER2-neu and ITA expression as well as dates of disease recurrence and death. Tumor blocks were incorporated into 3 TMA’s with control specimens (gynecomastia, benign breast tissue, liver). Four 1.0 mm cores were taken of each tumor. Immunohistochemistry (IHC) was performed with the following antibodies; 6F11 ER primary Ab (Ventana, USA), 1A6 PR primary Ab (Ventana, USA), TAB250 monoclonal mouse anti-HER2 (Zymed, USA), DAKO 0185 rabbit anti-human c-erbB2 (DAKO, Canada), mouse anti-human p450 aromatase Ab (Cedarlane, Canada). ITA staining intensity and distribution was compared to benign hepatic tissue and if > or = to liver was called ’strong’ while < liver was called ’weak’. The log-rank test was used for survival comparisons. Kaplan-Meyer curves were used to estimate 5year disease-free (DFS) and overall (OS) survival probabilities. Results: 54 cases were identified with median age at diagnosis of 64 (31–85 yrs). Median tumor size was 2.6 cms (0.9–8cms) and 22 (41%) had nodal metastases. 45 cases had tissue available for IHC. Of these, 40 (89%) were ER and 33 (73%) were PR positive. HER2-neu was overexpressed in 4/42 (9.5%) and 12/45 (27%) had strong ITA expression. 5 yr DFS was 71% and OS was 64%. In univariate analysis strong (vs weak) ITA expression was associated with improved 5 yr OS (92% vs 49%, p = 0.038) but not DFS (82% vs 76%, p = 0.44) rates. Conclusion: The suggestion of improved OS but not DFS for those tumors with strong ITA expression may imply that these were more responsive to hormonal therapy in the metastatic setting or had a more indolent pace of progression. It is suggested that further investigation of ITA and response to hormonal therapy in MBC is warranted.

No significant financial relationships to disclose.

Corticosteroid effects on cell signalling

Corticosteroids are the most effective anti-inflammatory therapy for asthma. Inflammation in asthma is characterised by the increased expression of multiple inflammatory genes regulated by pro-inflammatory transcription factors, such as nuclear factor-kappaB and activator protein-1, which bind to and activate coactivator molecules that acetylate core histones and switch on gene transcription. Corticosteroids suppress the multiple inflammatory genes that are activated in asthmatic airways, mainly by reversing histone acetylation of activated inflammatory genes through binding of glucocorticoid receptors to coactivators and recruitment of histone deacetylase 2 to the activated transcription complex. Activated glucocorticoid receptors also bind to recognition sites in the promoters of certain genes in order to activate their transcription, resulting in secretion of anti-inflammatory proteins, such as mitogen-activated protein kinase phosphatase-1, which inhibits mitogen-activated protein kinase signalling pathways. Glucocorticoid receptors may also interact with other recognition sites to inhibit transcription, for example of several genes linked to their side-effects. In some patients with steroid-resistant asthma, there are abnormalities in glucocorticoid receptor signalling pathways. In chronic obstructive pulmonary disease patients and asthmatic patients who smoke, histone deacetylase 2 is markedly impaired as a result of oxidative/nitrative stress, and so inflammation is resistant to the anti-inflammatory effects of corticosteroids. The therapeutic implications of these new findings are discussed.

Topical corticosteroid inhibits interleukin-4, -5 and -13 in nasal secretions following allergen challenge

BACKGROUND

Cytokines and chemokines produced by allergen-reactive T-helper type 2 (Th2) cells may be pivotal to the pathophysiology of allergic disorders.

OBJECTIVE

This study was performed to assess the effect of 7 days of topical corticosteroid on nasal allergen challenge (NAC) in terms of eosinophils, cytokines and chemokines obtained by nasal lavage and filter paper methods.

METHODS

Patients with grass pollen seasonal-allergic rhinitis (n = 13) out of season received nasal challenge following matched placebo (twice daily into each nostril for 7 days) and fluticasone propionate (100 microg twice daily into each nostril for 7 days). Chemokine and cytokine levels were analysed using a sensitive automated bead immunoassay system at intervals up to 8 h after NAC.

RESULTS

Levels of cytokines and chemokines from filter paper were generally higher than from nasal lavage. Fluticasone propionate caused a reduction in symptoms, total leukocyte counts and eosinophils, and abrogation of IL-4, IL-5, IL-6 and IL-13 responses in the filter paper taken in the late phase (P < 0.05 for IL-4 and IL-13, P < 0.01 for IL-5 and IL-6). Levels of chemokines (eotaxin, RANTES, MCP-1, MIP-1alpha, IL-8 and IP-10) were also reduced in the late phase (P < 0.01 at 8 h). However, levels of IL-2, IL-3, IL-7, IL-12 (p40 and p70), -15, TNF-alpha, IFN-gamma and GM-CSF were not affected.

CONCLUSION

Fluticasone propionate has selective inhibitory effects on Th2 cytokine synthesis following nasal challenge, while also decreasing release of chemokines, but not affecting levels of Th1 cytokines.

Effects of a reversible beta-tryptase and trypsin inhibitor (RWJ-58643) on nasal allergic responses

BACKGROUND

beta-Tryptase is a multifunctional mast cell serine protease released during mast cell degranulation and tryptase/trypsin inhibitors are a novel potential therapeutic approach for allergic inflammatory diseases.

OBJECTIVES

This study was performed to assess the effects of RWJ-58643 on nasal symptoms, eosinophil influx, and cytokine and chemokine release following nasal allergen challenge (NAC).

METHODS

Male patients with grass pollen allergic rhinitis (n=16) out of season received single doses of RWJ-58643 (100, 300, 600 microg) or matched placebo given 30 min before NAC in a double-blind, randomized crossover design. A single dose of 200 microg budesonide was studied in an open-label extension phase. NAC was performed with Timothy grass pollen (ALK) via a nasal device, and nasal lavage was performed at times 0 (pre-drug, pre-allergen), 0.5 (30 min post-drug, pre-NAC) 1.5, 2.5, 4.5, 6.5, 8.5, and 24 h after drug administration. Nasal lavage mediators were analysed using a sensitive multiplexed bead immunoassay system.

RESULTS

Low-dose RWJ-58643 (100 microg) and budesonide (200 microg) significantly reduced symptoms, eosinophils and levels of IL-5 following NAC. However, higher doses of RWJ-58643 (300 and 600 microg) caused a late eosinophilia and preceding increases in IL-5 compared with placebo.

CONCLUSIONS

This study suggests that combined beta-tryptase and trypsin inhibition has therapeutic potential in allergic inflammation, however, this property is dose responsive and higher doses are ineffective and may cause eosinophilia.

The need to improve inhalation technique in Europe: a report from the Aerosol Drug Management Improvement Team

Although the principles of asthma management are well established in Europe, the available data indicate that asthma in patients is not well controlled. Many patients derive incomplete benefit from their inhaled medication because they do not use inhaler devices correctly and this may compromise asthma control. The Aerosol Drug Management Improvement Team (ADMIT), incorporating clinicians from the UK, Germany, France, Italy, Spain and The Netherlands, reviewed published evidence to examine ways to improve the treatment of reversible airways disease in Europe. Data indicate that there is a clear need for specific training of patients in correct inhalation technique for the various devices currently available, and this should be repeated frequently to maintain correct inhalation technique. Devices which provide reassurance to patients and their physicians that inhalation is performed correctly should help to improve patient compliance and asthma control. Educational efforts should also focus on primary prescribers of inhaler devices. ADMIT recommends dissemination of information on the correct inhalation technique for each model of device by the use of an accessible dedicated literature base or website which would enable to match the appropriate inhaler to the individual patient. There is also a need for standardisation of prescribing practices throughout Europe. Regular checking of inhalation technique by prescribers is crucial as correct inhalation is one of the keystones of successful asthma management.

Epigenetics and airways disease

Epigenetics is the term used to describe heritable changes in gene expression that are not coded in the DNA sequence itself but by post-translational modifications in DNA and histone proteins. These modifications include histone acetylation, methylation, ubiquitination, sumoylation and phosphorylation. Epigenetic regulation is not only critical for generating diversity of cell types during mammalian development, but it is also important for maintaining the stability and integrity of the expression profiles of different cell types. Until recently, the study of human disease has focused on genetic mechanisms rather than on non-coding events. However, it is becoming increasingly clear that disruption of epigenetic processes can lead to several major pathologies, including cancer, syndromes involving chromosomal instabilities, and mental retardation. Furthermore, the expression and activity of enzymes that regulate these epigenetic modifications have been reported to be abnormal in the airways of patients with respiratory disease. The development of new diagnostic tools might reveal other diseases that are caused by epigenetic alterations. These changes, despite being heritable and stably maintained, are also potentially reversible and there is scope for the development of 'epigenetic therapies' for disease.

Single dose topical corticosteroid inhibits IL-5 and IL-13 in nasal lavage following grass pollen challenge

BACKGROUND

Nasal lavage is a noninvasive method of obtaining inflammatory exudates following nasal allergen challenge (NAC), and permits cells and released mediators to be evaluated.

OBJECTIVE

To determine the effects of a single dose of topical steroid on eosinophils and levels of chemokines and cytokines in nasal lavage fluid following NAC in patients with allergic rhinitis.

METHODS

Patients with grass pollen seasonal allergic rhinitis (n = 32) out of the allergy season received either nasal budesonide (100 microg per nostril) or matched placebo before allergen challenge in a double blind two-way crossover design. A semi-automated mixed bead array system was employed to measure multiple chemokines and cytokines in small volumes (50 microl) of nasal lavage supernatants.

RESULTS

Following NAC there was a rapid onset of nasal symptoms together with nasal eosinophilia, and the appearance of IL-5 and IL-13 in lavages between 4 and 8 h. Elevated levels of eotaxin, RANTES, IL-8 and MCP-1 were also detected following allergen challenge. A single dose of nasal budesonide caused a decrease in symptoms (P < 0.05) and nasal eosinophils (P < 0.05) with selective abrogation of IL-5 and IL-13 responses (P < 0.05), but a lack of effect on levels of eotaxin, RANTES, IL-8 and MCP-1.

CONCLUSION

This study suggests that a single dose of nasal steroid has the capacity to selectively abolish IL-5 and IL-13 responses following NAC. This model should be convenient for testing novel anti-inflammatory and immunoregulatory agents intended for the treatment of allergic rhinitis.

Effects of cyclo-oxygenase inhibition on exhaled eicosanoids in patients with COPD

BACKGROUND

Leukotriene (LT) B4 concentrations are increased and prostaglandin (PG) E2 concentrations are decreased in exhaled breath condensate (EBC) in patients with chronic obstructive pulmonary disease (COPD). A study was undertaken to investigate the short term effects of cyclo-oxygenase (COX) inhibition on exhaled LTB4 and PGE2 concentrations in patients with COPD and to identify the COX isoform responsible for exhaled PGE2 production.

METHODS

Two studies were performed. A double blind, crossover, randomised, placebo controlled study with ibuprofen (400 mg qid for 2 days), a non-selective COX inhibitor, was undertaken in 14 patients with stable COPD, and an open label study with oral rofecoxib (25 mg once a day for 5 days), a selective COX-2 inhibitor, was undertaken in a different group of 16 COPD patients. EBC was collected before and after drug treatment. Exhaled LTB4 and PGE2 concentrations were measured with specific immunoassays.

RESULTS

All patients complied with treatment as indicated by a reduction in ex vivo serum thromboxane B2 concentrations (ibuprofen) and a reduction in lipopolysaccharide induced increase in ex vivo plasma PGE2 values (rofecoxib) of more than 80%. Exhaled LTB4 was increased after ibuprofen (median 175.5 (interquartile range 128.8-231.5) pg/ml v 84.0 (70.0-98.5) pg/ml, p < 0.001) and exhaled PGE2 was reduced (93.5 (84.0-105-5) pg/ml v 22.0 (15.0-25.5) pg/ml, p < 0.0001). Rofecoxib had no effect on exhaled LTB4 (p = 0.53) or PGE2 (p = 0.23).

CONCLUSIONS

Non-selective COX inhibition decreases PGE2 and increases LTB4 in EBC, whereas selective COX-2 inhibition has no effect on these eicosanoids. PGE2 in EBC is primarily derived from COX-1 activity, and COX inhibition may redirect arachidonic acid metabolism towards the 5-lipoxygenase pathway.

Asthma is not a common cause of severe chronic respiratory failure in non-smokers: ALOT study

BACKGROUND

Little is known about the long-term natural history of asthma and the long-term clinical and functional consequences in non-smoking patients. From a functional point of view, non-smoking asthmatic patients may have a significantly greater decline in forced expiratory volume in one second (FEV1) compared with non-asthmatic subjects and may develop chronic irreversible (fixed) airflow limitation. This has been related to the physiological consequences of chronic airway inflammation causing airway remodeling. However these lesions are all potentially reversible and there is little radiological evidence indicating lung destruction (pulmonary emphysema), which is potentially irreversible, in non-smoking asthmatics. Severe chronic respiratory failure is the major cause of mortality in patients with severe chronic lung diseases. Domiciliary long-term oxygen therapy (LTOT) is an accepted treatment for patients with severe chronic respiratory failure. Our reasoning, therefore, was that if asthma is a cause of severe chronic respiratory failure in non-smokers we should be able to find non-smoking asthmatics within a large population of patients on LTOT. The aim of our study (Asthma and Long-term Oxygen Therapy, "ALOT") was to investigate the prevalence of non-smoking asthmatics in patients on LTOT in a multi-centre, cross-sectional study.

METHODS

Between June and September 2003 we screened all subjects on long-term domiciliary oxygen therapy in three different hospitals in the North-East area of Italy (within the provinces of Ferrara and Bologna). Taken collectively, we have found one-hundred and eighty-four patients on LTOT. We have reviewed their clinical data (age, sex, smoking, history and physical examination, arterial blood gas analysis, pulmonary function).

RESULTS

114 patients (all smokers) fulfilled the diagnostic criteria for COPD. Seventy patients (all smokers) had other diseases. We were unable to find any non-smokers in our screened population of subjects on long-term domiciliary oxygen therapy. Furthermore, there was no past history of asthma and/or acute wheezing episodes in either of the patient groups.

CONCLUSIONS

This data suggests that asthma is an uncommon cause of severe chronic respiratory failure necessitating long-term domiciliary oxygen therapy in non-smokers and supports the current consensus that asthma and COPD are different diseases with differing stages of severity and the concept that long-term avoidance of active smoking is fundamental for the prevention of severe chronic respiratory failure.

Exhaled breath condensate: methodological recommendations and unresolved questions

Collection of exhaled breath condensate (EBC) is a noninvasive method for obtaining samples from the lungs. EBC contains large number of mediators including adenosine, ammonia, hydrogen peroxide, isoprostanes, leukotrienes, nitrogen oxides, peptides and cytokines. Concentrations of these mediators are influenced by lung diseases and modulated by therapeutic interventions. Similarly EBC pH also changes in respiratory diseases. The aim of the American Thoracic Society/European Respiratory Society Task Force on EBC was to identify the important methodological issues surrounding EBC collection and assay, to provide recommendations for the measurements and to highlight areas where further research is required. Based on the currently available evidence and the consensus of the expert panel for EBC collection, the following general recommendations were put together for oral sample collection: collect during tidal breathing using a noseclip and a saliva trap; define cooling temperature and collection time (10 min is generally sufficient to obtain 1-2 mL of sample and well tolerated by patients); use inert material for condenser; do not use resistor and do not use filter between the subject and the condenser. These are only general recommendations and certain circumstances may dictate variation from them. Important areas for future research involve: ascertaining mechanisms and site of exhaled breath condensate particle formation; determination of dilution markers; improving reproducibility; employment of EBC in longitudinal studies; and determining the utility of exhaled breath condensate measures for the management of individual patients. These studies are required before recommending this technique for use in clinical practice.

Exhaled nitric oxide from lung periphery is increased in COPD

Single constant flow exhaled nitric oxide (eNO) cannot distinguish between the sources of NO. The present study measured eNO at multiple expired flows (MEFeNO) to partition NO into alveolar (Calv,NO) and bronchial (Jaw,NO) fractions to investigate peripheral lung contribution to eNO in chronic obstructive lung disease (COPD). MEFeNO were made in 81 subjects including 18 nonsmokers, 16 smokers and 47 COPD patients of different severity by the classification of the Global Initiative for Chronic Obstructive Lung Disease (GOLD): 0 (n = 14), 1 (n = 7), 2 (n = 11), 3 (n = 8) and 4 (n = 7). COPD severity was correlated with an increased Calv,NO regardless of the patient's smoking habit or current treatment. The levels of Calv,NO (in ppb) were 1.4+/-0.09 in nonsmokers, 2.1+/-0.1 in smokers categorised as GOLD stage 0 (smokers-GOLD0), 3.3+/-0.18 in GOLD1-2 and 3.4+/-0.1 in GOLD3-4. Jaw,NO levels (pL x s(-1)) were higher in nonsmokers than smokers-GOLD0 (716.2+/-33.3 versus 464.7+/-41.8), GOLD3-4 (609.4+/-71). Diffusion of NO in the airways (Daw,NO pL x ppb(-1) s(-1)) was higher (p<0.05) in GOLD3-4 than in nonsmokers (15+/-1.2 versus 11+/-0.5) and smokers-GOLD0 (11.6+/-0.5). MEFeNO measurements were reproducible, free from day-to-day and diurnal variation and were not affected by bronchodilators. In conclusion, chronic obstructive pulmonary disease is associated with elevated alveolar nitric oxide. Measurements of nitric oxide at multiple expired flows may be useful in monitoring inflammation and progression of chronic obstructive pulmonary disease, and the response to anti-inflammatory treatment.