A randomised trial of a T2-composite-biomarker strategy adjusting corticosteroidtreatment in severe asthma, a post- hoc analysis by sex

BACKGROUND

Approximately 5-10% of patients with asthma have severe disease with a consistent preponderance in females. Current asthma guidelines recommend stepwise treatment to achieve symptom control with no differential treatment considerations for either sex.

OBJECTIVES

To examine whether patient sex affects outcomes when using a composite T2-biomarker score to adjust corticosteroid treatment in patients with severe asthma compared to standard care.

METHODS

Post-hoc analysis stratifying patient outcomes by sex of a 48-week, multicentre, randomised controlled clinical trial comparing a biomarker-defined treatment algorithm with standard care. The primary outcome was the proportion of patients with a reduction in corticosteroid treatment (inhaled (ICS) and oral (OCS) corticosteroids). Secondary outcomes included exacerbation rates, hospital admissions and lung function.

RESULTS

Of 301 patients randomised; 194 (64.5%) were females and 107 (35.5%) were males. The biomarker algorithm led to a greater proportion of females being on a lower corticosteroid dose vs standard care which was not seen in males (effects estimate females: 3.57, 95% CI: 1.14, 11.18 vs. males 0.54, 95% CI: 0.16, 1.80). In T2-biomarker low females, reducing corticosteroid dose was not associated with increased exacerbations. Females scored higher in all ACQ-7 domains, but with no difference when adjusted for BMI/ anxiety and/or depression. Dissociation between symptoms and T2-biomarkers were noted in both sexes, with a higher proportion of females being symptom high/T2-biomarker low (22.8% vs. 15.6%; p=0.0002), whereas males were symptom low/T2-biomarker high (11.4% vs. 22.3%; p<0.0001).

CONCLUSION

This exploratory post-hoc analysis identified females achieved a greater benefit from biomarker-directed corticosteroid optimisation versus symptom-directed treatment.

Heavy silicone oil tamponade: a multicentre experience

OBJECTIVE

To report multicentred use of the heavy silicone oil Densiron 68 for anatomical reattachment following rhegmatogenous retinal detachment (RRD) repair and its associated complications.

METHODS AND ANALYSIS

Patients from seven vitreoretinal units within the UK that underwent RRD repair with Densiron 68 between January 2015 and December 2019 were identified. Primary outcome measures were primary and final reattachment rate, retained Densiron and failure rate. Secondary outcome measures were duration of tamponade, final visual acuity (VA) and complications of heavy silicone oil.

RESULTS

134 eyes of 134 patients were involved in the study. Primary surgical success was achieved in 48.5%, while a final reattachment rate of 73.4% was observed. The mean duration of Densiron 68 tamponade was 139.5 days. Mean final VA was 1.01 (range 0-2.9). 8 eyes (6.0%) required long-term topical steroids for anterior uveitis, whereas none of the eyes required long-term pressure-lowering treatment. Emulsification rate was 10.7% (6 eyes).

CONCLUSION

This is the largest real-world study on Densiron 68 in the UK. Densiron 68 facilitates tamponade of inferior retinal pathology and may be considered as an option for tamponade of inferior retinal pathologies.

Evaluation of Simvastatin as a Disease-Modifying Treatment for Patients With Parkinson Disease: A Randomized Clinical Trial

Importance

Current treatments manage symptoms of Parkinson disease (PD), but no known treatment slows disease progression. Preclinical and epidemiological studies support the potential use of statins as disease-modifying therapy.

Objective

To determine whether simvastatin has potential as a disease-modifying treatment for patients with moderate PD.

Design, Setting, and Participants

This randomized clinical trial, a double-blind, parallel-group, placebo-controlled futility trial, was conducted between March 2016 and May 2020 within 23 National Health Service Trusts in England. Participants aged 40 to 90 years with a diagnosis of idiopathic PD, with a modified Hoehn and Yahr stage of 3.0 or less while taking medication, and taking dopaminergic medication with wearing-off phenomenon were included. Data were analyzed from May 2020 to September 2020, with additional analysis in February 2021.

Interventions

Participants were allocated 1:1 to simvastatin or matched placebo via a computer-generated random sequence, stratified by site and Hoehn and Yahr stage. In the simvastatin arm, participants entered a 1-month phase of simvastatin, 40 mg daily, followed by 23 months of simvastatin, 80 mg daily, before a 2-month washout period.

Main Outcomes and Measures

The prespecified primary outcome was 24-month change in Movement Disorder Society Unified Parkinson Disease Rating Scale (MDS-UPDRS) part III score measured while not taking medication (high scores indicate worse outcome). The primary futility analysis included participants who commenced the 80-mg phase and had valid primary outcome data. The safety analysis included all participants who commenced trial treatment and is reported by dose at time of event.

Results

Of 332 patients assessed for eligibility, 32 declined and 65 were ineligible. Of 235 recruited participants, 97 (41%) were female, 233 (99%) were White, and the mean (SD) age was 65.4 (9.4) years. A total of 216 patients progressed to the 80-mg dose. Primary outcome analysis (n = 178) indicated the simvastatin group had an additional deterioration in MDS-UPDRS III score while not taking medication at 24 months compared with the placebo group (1.52 points; 2-sided 80% CI, -0.77 to 3.80; 1-sided futility test P = .006). A total of 37 serious adverse events (AEs), including 3 deaths, and 171 AEs were reported for participants receiving 0-mg simvastatin; 37 serious AEs and 150 AEs were reported for participants taking 40 mg or 80 mg of simvastatin. Four participants withdrew from the trial because of an AE.

Conclusions and Relevance

In this randomized clinical trial, simvastatin was futile as a disease-modifying therapy in patients with PD of moderate severity, providing no evidence to support proceeding to a phase 3 trial.

Trial Registration

ISRCTN Identifier: 16108482.

110 Outcome and mortality of hospital admission with COVID-19 for individuals with parkinsonian syndromes

Objective

To evaluate features of Parkinson’s disease (PD) and atypical Parkinson’s syndromes (APS) associated with poor outcome and mortality in people with COVID-19 in a hospital setting.

Background

Previous studies have demonstrated increased mortality of COVID-19 in people with PD. However, it is not known whether this is associated with disease-related factors (eg autonomic dysfunc- tion, dysphagia).

Methods

An online survey tool captured anonymised patient data from hospital admission records of people with PD and APS who tested positive for COVID-19 between February 2020 and July 2021. We will use Cox proportional hazards and linear regression models to evaluate which characteristics are associ- ated with mortality, increased care requirement and more severe COVID-19 infection. Models will be adjusted for known associations with poor outcome, such as co-morbidities, age and sex.

Results

Data were collected from 556 admissions from 21 UK sites: 66.2% male; median (IQR) age 80 (11) years; median disease duration 5 (7) years. 19.2% were asymptomatic, 28.8% had mild symptoms and 52.5% required respiratory support. 38.3% died within 4 weeks of a positive COVID-19 test. Preliminary Kaplan-Meier curves suggest that co-existing dementia, marked motor fluctuations and more advanced Hoehn and Yahr stage may be associated with 28-day mortality. Full statistical analysis is in progress.

Conclusions

Identification of Parkinson’s features associated with poor in-hospital COVID-19 outcome will allow a more informed discussion relating to individual COVID-19 risk.

Protocol for Rhapsody: a longitudinal observational study examining the feasibility of speech phenotyping for remote assessment of neurodegenerative and psychiatric disorders

INTRODUCTION

Neurodegenerative and psychiatric disorders (NPDs) confer a huge health burden, which is set to increase as populations age. New, remotely delivered diagnostic assessments that can detect early stage NPDs by profiling speech could enable earlier intervention and fewer missed diagnoses. The feasibility of collecting speech data remotely in those with NPDs should be established.

METHODS AND ANALYSIS

The present study will assess the feasibility of obtaining speech data, collected remotely using a smartphone app, from individuals across three NPD cohorts: neurodegenerative cognitive diseases (n=50), other neurodegenerative diseases (n=50) and affective disorders (n=50), in addition to matched controls (n=75). Participants will complete audio-recorded speech tasks and both general and cohort-specific symptom scales. The battery of speech tasks will serve several purposes, such as measuring various elements of executive control (eg, attention and short-term memory), as well as measures of voice quality. Participants will then remotely self-administer speech tasks and follow-up symptom scales over a 4-week period. The primary objective is to assess the feasibility of remote collection of continuous narrative speech across a wide range of NPDs using self-administered speech tasks. Additionally, the study evaluates if acoustic and linguistic patterns can predict diagnostic group, as measured by the sensitivity, specificity, Cohen's kappa and area under the receiver operating characteristic curve of the binary classifiers distinguishing each diagnostic group from each other. Acoustic features analysed include mel-frequency cepstrum coefficients, formant frequencies, intensity and loudness, whereas text-based features such as number of words, noun and pronoun rate and idea density will also be used.

ETHICS AND DISSEMINATION

The study received ethical approval from the Health Research Authority and Health and Care Research Wales (REC reference: 21/PR/0070). Results will be disseminated through open access publication in academic journals, relevant conferences and other publicly accessible channels. Results will be made available to participants on request.

TRIAL REGISTRATION NUMBER

NCT04939818.

Study protocol: randomised controlled hybrid type 2 trial evaluating the scale-up of two arts interventions for postnatal depression and Parkinson's disease

INTRODUCTION

Research on the benefits of 'arts' interventions to improve individuals' physical, social and psychological well-being is growing, but evidence on implementation and scale-up into health and social care systems is lacking. This protocol reports the SHAPER-Implement programme (Scale-up of Health-Arts Programmes Effectiveness-Implementation Research), aimed at studying the impact, implementation and scale-up of: Melodies for Mums (M4M), a singing intervention for postnatal depression; and Dance for Parkinson's (PD-Ballet) a dance intervention for Parkinson's disease. We examine how they could be embedded in clinical pathways to ensure their longer-term sustainability.

METHODS AND ANALYSIS

A randomised two-arm effectiveness-implementation hybrid type 2 trial design will be used across M4M/PD-Ballet. We will assess the implementation in both study arms (intervention vs control), and the cost-effectiveness of implementation. The design and measures, informed by literature and previous research by the study team, were refined through stakeholder engagement. Participants (400 in M4M; 160 in PD-Ballet) will be recruited to the intervention or control group (2:1 ratio). Further implementation data will be collected from stakeholders involved in referring to, delivering or supporting M4M/PD-Ballet (N=25-30 for each intervention).A mixed-methods approach (surveys and semi-structured interviews) will be employed. 'Acceptability' (measured by the 'Acceptability Intervention Measure') is the primary implementation endpoint for M4M/PD-Ballet. Relationships between clinical and implementation outcomes, implementation strategies (eg, training) and outcomes will be explored using generalised linear mixed models. Qualitative data will assess factors affecting the acceptability, feasibility and appropriateness of M4M/PD-Ballet, implementation strategies and longer-term sustainability. Costs associated with implementation and future scale-up will be estimated.

ETHICS AND DISSEMINATION

SHAPER-PND (the M4M trial) and SHAPER-PD (the PD trial) are approved by the West London and GTAC (20/PR/0813) and the HRA and Health and Care Research Wales (REC Reference: 20/WA/0261) Research Ethics Committees. Study findings will be disseminated through scientific peer-reviewed journals and scientific conferences.

TRIAL REGISTRATION NUMBERS

Both trials are registered with NIH US National Library of Medicine, ClinicalTrials.gov. The trial registration numbers, URLs of registry records, and dates of registration are: (1) PD-Ballet: URL: NCT04719468 (https://eur03.safelinks.protection.

OUTLOOK

com/?url=https%3A%2F%2Fwww.clinicaltrials.gov%2Fct2%2Fshow%2FNCT04719468%3Fterm%3DNCT04719468%26draw%3D2%26rank%3D1&data=04%7C01%7Crachel.davis%40kcl.ac.uk%7C11a7c5142782437919f808d903111449%7C8370cf1416f34c16b83c724071654356%7C0%7C0%7C6375441942616) (date of registration: 22 Jan 2021). (2) Melodies for Mums: NCT04834622 (https://clinicaltrials.gov/ct2/show/NCT04834622?term=shaper-pnd&draw=2&rank=1) (date of registration: 8 Apr 2021).

Impact of COVID-19 pandemic and lockdown on eye emergencies

BACKGROUND

To characterise and compare ocular pathologies presenting to an emergency eye department (EED) during the COVID-19 pandemic in 2020 against an equivalent period in 2019.

METHODS

Electronic patient records of 852 patients in 2020 and 1818 patients in 2019, attending the EED at a tertiary eye centre (University Hospitals of Leicester, UK) were analysed. Data was extracted over a 31-day period during: (study period 1 (SP1)) COVID-19 pandemic lockdown in UK (24th March 2020-23rd April 2020) and (study period 2 (SP2)) the equivalent 2019 period (24th March 2019-23rd April 2019).

RESULTS

A 53% reduction in EED attendance was noted during lockdown. The top three pathologies accounting for >30% of the caseload were trauma-related, keratitis and uveitis in SP1 in comparison to conjunctivitis, trauma-related and blepharitis in SP2. The overall number of retinal tears and retinal detachments (RD) were lower in SP1, the proportion of macula-off RD's (84.6%) was significantly (p = 0.0099) higher in SP1 (vs 42.9% in SP2).

CONCLUSION

COVID-19 pandemic related lockdown has had a significant impact on the range of presenting conditions to the EED. Measures to stop spread of COVID-19 such as awareness of hand hygiene practices, social distancing measures and school closures could have an indirect role in reducing spread of infective conjunctivitis. The higher proportion of macula-off RD and lower number of retinal tears raises possibility of delayed presentation in these cases. Going forward, we anticipate additional pressures on EED and other subspecialty services due to complications and associated morbidity from delayed presentations.

Exenatide once weekly over 2 years as a potential disease-modifying treatment for Parkinson's disease: protocol for a multicentre, randomised, double blind, parallel group, placebo controlled, phase 3 trial: The 'Exenatide-PD3' study

INTRODUCTION

Parkinson's disease (PD) is a common neurodegenerative disorder with substantial morbidity. No disease-modifying treatments currently exist. The glucagon like peptide-1 receptor agonist exenatide has been associated in single-centre studies with reduced motor deterioration over 1 year. The aim of this multicentre UK trial is to confirm whether these previous positive results are maintained in a larger number of participants over 2 years and if effects accumulate with prolonged drug exposure.

METHODS AND ANALYSIS

This is a phase 3, multicentre, double-blind, randomised, placebo-controlled trial of exenatide at a dose of 2 mg weekly in 200 participants with mild to moderate PD. Treatment duration is 96 weeks. Randomisation is 1:1, drug to placebo. Assessments are performed at baseline, week 12, 24, 36, 48, 60, 72, 84 and 96 weeks.The primary outcome is the comparison of Movement Disorders Society Unified Parkinson's Disease Rating Scale part 3 motor subscore in the practically defined OFF medication state at 96 weeks between participants according to treatment allocation. Secondary outcomes will compare the change between groups among other motor, non-motor and cognitive scores. The primary outcome will be reported using descriptive statistics and comparisons between treatment groups using a mixed model, adjusting for baseline scores. Secondary outcomes will be summarised between treatment groups using summary statistics and appropriate statistical tests to assess for significant differences.

ETHICS AND DISSEMINATION

This trial has been approved by the South Central-Berkshire Research Ethics Committee and the Health Research Authority. Results will be disseminated in peer-reviewed journals, presented at scientific meetings and to patients in lay-summary format.

TRIAL REGISTRATION NUMBERS

NCT04232969, ISRCTN14552789.

Synthesis and activity of the salicylic acid ester of bakuchiol in psoriasis-surrogate keratinocytes and skin substitutes

BACKGROUND

Topical retinoids are effective in retarding skin ageing and restoring homeostasis in skin conditions such as psoriasis. However their adverse effects (AEs), which include irritation (retinoid dermatitis), photosensitivity and teratogenicity, limit their use and patient compliance. Development of retinoid analogues with minimal AEs would allow a broader and more compliant use.

AIM

To synthesise a novel molecule, bakuchiol salicylate (bakusylan), with a modulatory gene expression profile similar to retinoids, using as reference three prescription retinoids: tretinoin, tazarotene and adapalene.

METHODS

We hypothesized that because bakuchiol salicylate has a structure entirely different from existing retinoids, there would be at least a partial uncoupling of AEs from the skin-normalizing activity of this retinoid. This hypothesis was tested at the transcriptional level in psoriatic cytokine-treated cultures of keratinocytes and organotypic skin substitutes, using DNA microarrays and custom PCR arrays.

RESULTS

Evaluation of the gene expression profile of bakuchiol salicylate revealed elimination of several components of the retinoid-like proinflammatory response and teratogenic signature, without a substantial loss of normalizing potential. A possible mechanism of action, consisting of keratinocyte desensitization to psoriatic cytokine signalling through inhibition of the signal transducer and regulator of transcription (STAT)1/3/interferon inflammatory signal transduction axis was also identified.

CONCLUSION

Bipartite materials obtained by merging two skin-active entities with specific, complementary bioactivities, such as bakuchiol and salicylic acid, may yield a new class of functional retinoids.

Findings from a pilot Randomised trial of an Asthma Internet Self-management Intervention (RAISIN)

OBJECTIVE

To evaluate the feasibility of a phase 3 randomised controlled trial (RCT) of a website (Living Well with Asthma) to support self-management.

DESIGN AND SETTING

Phase 2, parallel group, RCT, participants recruited from 20 general practices across Glasgow, UK. Randomisation through automated voice response, after baseline data collection, to website access for minimum 12 weeks or usual care.

PARTICIPANTS

Adults (age≥16 years) with physician diagnosed, symptomatic asthma (Asthma Control Questionnaire (ACQ) score ≥1). People with unstable asthma or other lung disease were excluded.

INTERVENTION

'Living Well with Asthma' is a desktop/laptop compatible interactive website designed with input from asthma/ behaviour change specialists, and adults with asthma. It aims to support optimal medication management, promote use of action plans, encourage attendance at asthma reviews and increase physical activity.

OUTCOME MEASURES

Primary outcomes were recruitment/retention, website use, ACQ and mini-Asthma Quality of Life Questionnaire (AQLQ). Secondary outcomes included patient activation, prescribing, adherence, spirometry, lung inflammation and health service contacts after 12 weeks. Blinding postrandomisation was not possible.

RESULTS

Recruitment target met. 51 participants randomised (25 intervention group). Age range 16-78 years; 75% female; 28% from most deprived quintile. 45/51 (88%; 20 intervention group) followed up. 19 (76% of the intervention group) used the website, for a mean of 18 min (range 0-49). 17 went beyond the 2 'core' modules. Median number of logins was 1 (IQR 1-2, range 0-7). No significant difference in the prespecified primary efficacy measures of ACQ scores (-0.36; 95% CI -0.96 to 0.23; p=0.225), and mini-AQLQ scores (0.38; -0.13 to 0.89; p=0.136). No adverse events.

CONCLUSIONS

Recruitment and retention confirmed feasibility; trends to improved outcomes suggest use of Living Well with Asthma may improve self-management in adults with asthma and merits further development followed by investigation in a phase 3 trial.

TRIAL REGISTRATION NUMBER

ISRCTN78556552; Results.

Decreased FEV1 % in asthmatic adults in Scottish homes with high Environmental Relative Moldiness Index values

BACKGROUND

Exposures to indoor biological contaminants have been implicated in asthma's aetiology but their effect on lung function is not well quantified.

OBJECTIVE

The aim of this cross-sectional study of non-smoking, asthmatic adults in Scotland was to determine the correlation between the results from a standard spirometry test, forced expiratory volume in one-second percent (FEV1 %), and quantitative estimates of some biological exposures.

METHODS

A population (n = 55) of non-smoking, adult asthmatics in Scotland was included in this study and each completed a questionnaire that allowed the determination of the Asthma Control Questionnaire scores (ACQ) and St. George's Respiratory Questionnaire scores (SGRQ), as well as corticosteroid use. Spirometry testing was completed and the pre-bronchodilator FEV1 % value calculated. At about the same time, floor dust samples were collected in the living room and in the bedroom. These dust samples were analysed for mould contamination, as described by the Environmental Relative Moldiness Index (ERMI) values and by (1, 3)-β-D-glucan concentrations, for endotoxin, and for dust mite, cat, and dog allergen concentrations. The asthmatics' FEV1 % values were tested for correlation (Pearson) to questionnaire-based estimates of health. Also, each biological exposure was tested for correlation (Pearson) to the FEV1 % values.

RESULTS

FEV1 % results were correlated with ACQ scores (ρ -0.586, P < 0.001), SGRQ scores (ρ -0.313, P = 0.020), and weakly with corticosteroid use (ρ -0.221, P = 0.105). The ERMI values in the homes (average 5.3) were significantly correlated with FEV1 % values (ρ -0.378, P = 0.004). There was no correlation between FEV1 % and concentrations of endotoxin, (1, 3)-β-D-glucan, or any of the allergens.

CONCLUSION AND CLINICAL RELEVANCE

Although these results do not prove that mould exposures caused the deficit in lung function observed in this study, it might be advisable for asthmatics to avoid high ERMI environments.

Arachidonic acid metabolites and enzyme transcripts in asthma are altered by cigarette smoking

BACKGROUND

Arachidonic acid metabolites are implicated in the pathogenesis of asthma although only limited information is available on the impact of current smoking history on these metabolites. The aim of the study was to examine the effect of smoking status on urinary, sputum, and plasma eicosanoid concentrations and relevant enzyme transcripts in asthma.

METHODS

In 108 smokers and never smokers with asthma and 45 healthy controls [smokers and never smokers], we measured urinary tetranor prostaglandin (PG)D2 (PGDM) and leukotriene (LT)E4 , induced sputum fluid LTB4 , LTE4 , PGD2 , and PGE2 , plasma secretory phospholipase A2 (sPLA2 ), and 11β prostaglandin F2α (11βPGF2α ), and, in a subgroup with severe asthma, airway leukocyte and epithelial cell mRNA expression levels of arachidonic acid metabolic enzymes.

RESULTS

Smokers with asthma had higher urinary LTE4 ; 83 (59, 130) vs 59 (40, 90) pg/mg creatinine, P = 0.008, and PGDM; 60 (35, 100) vs 41 (28, 59) ng/mg creatinine, P = 0.012 concentrations, respectively, and lower sputum PGE2 concentrations 80 (46, 157) vs 192 (91, 301) pg/ml, P = 0.001 than never smokers with asthma. Sputum LTB4 (P = 0.013), and plasma 11βPGF2α (P = 0.032), concentrations, respectively, were increased in smokers with asthma compared with healthy smokers. Asthma-specific and smoking-related increases (>1.5-fold expression) in arachidonate 15-lipoxygenase and gamma-glutamyltransferase transcripts were demonstrated.

CONCLUSIONS

Several arachidonic acid metabolites and enzyme transcripts involving both lipoxygenase and cyclooxygenase pathways are increased in smokers with asthma and differ from never smokers with asthma. Possibly targeting specific lipoxygenase and cyclooxygenase pathways that are activated by asthma and cigarette smoking may optimize therapeutic responses.

Effects of a FLAP inhibitor, GSK2190915, in asthmatics with high sputum neutrophils

Patients with refractory asthma frequently have neutrophilic airway inflammation and respond poorly to inhaled corticosteroids. This study evaluated the effects of an oral 5-lipoxygenase-activating protein (FLAP) inhibitor, GSK2190915, in patients with asthma and elevated sputum neutrophils. Patients received 14 (range 13-16) days treatment with GSK2190915 100 mg and placebo with a minimum 14 day washout in a double-blind, cross-over, randomised design (N = 14). Sputum induction was performed twice pre-dose in each treatment period to confirm sputum neutrophilia, and twice at the end of each treatment period. The primary endpoint was the percentage and absolute sputum neutrophil count, averaged for end-of-treatment visits. GSK2190915 did not significantly reduce mean percentage sputum neutrophils (GSK2190915-placebo difference [95% CI]: -0.9 [-12.0, 10.3]), or mean sputum neutrophil counts (GSK2190915/placebo ratio [95% CI]: 1.06 [0.43, 2.61]). GSK2190915 resulted in a marked suppression (>90%) of sputum LTB4 and urine LTE4, but did not alter clinical endpoints. There were no safety issues. Despite suppressing the target mediator LTB4, FLAP inhibitor GSK2190915 had no short-term effect on sputum cell counts or clinical endpoints in patients with asthma and sputum neutrophilia.

Long-term macrolide treatment of chronic inflammatory airway diseases: risks, benefits and future developments

Macrolide antibiotics were discovered over 50 years ago and following their use as antimicrobials it became apparent that this group of antibiotics also possessed anti-inflammatory properties. Subsequent clinical trials showed benefits of macrolides as long-term adjuncts in the treatment of a spectrum of chronic inflammatory respiratory diseases, particularly diffuse panbronchiolitis, cystic fibrosis, post-transplant bronchiolitis obliterans and more recently chronic obstructive pulmonary disease (COPD). The evidence for efficacy of macrolides in the long-term treatment of chronic asthma and bronchiectasis is less well established. The mechanism(s) of action of macrolides in the treatment of these diseases remains unexplained, but may be due to their antibacterial and/or anti-inflammatory actions, which include reductions in interleukin-8 production, neutrophil migration and/or function. Macrolides have additional potentially beneficial properties including anti-viral actions and an ability to restore corticosteroid sensitivity. The increased prescribing of macrolides for long-term treatment could result in the development of microbial resistance and adverse drug effects. New macrolides have been developed which do not possess any antimicrobial activity and hence lack the ability to produce microbial resistance, but which still retain immunomodulatory effects. Potentially novel macrolides may overcome a significant barrier to the use of this type of drug for the long-term treatment of chronic inflammatory airway diseases.

Long-term macrolide treatment of chronic inflammatory airway diseases: risks, benefits and future developments

Macrolide antibiotics were discovered over 50 years ago and following their use as antimicrobials it became apparent that this group of antibiotics also possessed anti-inflammatory properties. Subsequent clinical trials showed benefits of macrolides as long-term adjuncts in the treatment of a spectrum of chronic inflammatory respiratory diseases, particularly diffuse panbronchiolitis, cystic fibrosis, post-transplant bronchiolitis obliterans and more recently chronic obstructive pulmonary disease (COPD). The evidence for efficacy of macrolides in the long-term treatment of chronic asthma and bronchiectasis is less well established. The mechanism(s) of action of macrolides in the treatment of these diseases remains unexplained, but may be due to their antibacterial and/or anti-inflammatory actions, which include reductions in interleukin-8 production, neutrophil migration and/or function. Macrolides have additional potentially beneficial properties including anti-viral actions and an ability to restore corticosteroid sensitivity. The increased prescribing of macrolides for long-term treatment could result in the development of microbial resistance and adverse drug effects. New macrolides have been developed which do not possess any antimicrobial activity and hence lack the ability to produce microbial resistance, but which still retain immunomodulatory effects. Potentially novel macrolides may overcome a significant barrier to the use of this type of drug for the long-term treatment of chronic inflammatory airway diseases.

Interleukin-33 amplifies IgE synthesis and triggers mast cell degranulation via interleukin-4 in naïve mice

Background

The regulation and function of IgE in healthy individuals and in antigen-naïve animals is not well understood. IL-33 administration increases serum IgE in mice with unknown mechanism. We tested the hypothesis that IL-33 provides an antigen-independent stimulus for IgE production and mast cell degranulation.

Methods

IL-33 was administered to naïve wild-type (WT), nude and ST2^−/−, IL-4^−/−, IL4Rα^−/− and T-or B-cell-specific IL-4Rα^−/− mice. IgEand cytokines were quantified by ELISA. T- and B-lymphocyte numbers and CD40L expression were determined by flow cytometry. Anaphylaxis was measured by temperature, mast cell degranulation and histamine release.

Results

IL-33 enhanced IgE production in naïve WT, T-IL-4Rα^−/− but not in ST2^−/−, IL-4^−/−, IL-4Rα^−/− or B-cell-specific IL-4Rα^−/− mice, demonstrating IL-33 specificity and IL-4 dependency. Moreover, IL-4 was required for IL-33-induced B-cell proliferation and T-cell CD40L expression, which promotes IgE production. IL-33-induced IL-4 production was mainly from innate cells including mast cells and eosinophils. IL-33 increased mast cell surface IgE and triggered degranulation and systemic anaphylaxis in allergen-naïve WT but not in IL-4Rα^−/− mice.

Conclusion

IL-33 amplifies IgE synthesis and triggers anaphylaxis in naïve mice via IL-4, independent of allergen. IL-33 may play an important role in nonatopic allergy and idiopathic anaphylaxis.

Genome-wide association study to identify genetic determinants of severe asthma

BACKGROUND

The genetic basis for developing asthma has been extensively studied. However, association studies to date have mostly focused on mild to moderate disease and genetic risk factors for severe asthma remain unclear.

OBJECTIVE

To identify common genetic variants affecting susceptibility to severe asthma.

METHODS

A genome-wide association study was undertaken in 933 European ancestry individuals with severe asthma based on Global Initiative for Asthma (GINA) criteria 3 or above and 3346 clean controls. After standard quality control measures, the association of 480 889 genotyped single nucleotide polymorphisms (SNPs) was tested. To improve the resolution of the association signals identified, non-genotyped SNPs were imputed in these regions using a dense reference panel of SNP genotypes from the 1000 Genomes Project. Then replication of SNPs of interest was undertaken in a further 231 cases and 1345 controls and a meta-analysis was performed to combine the results across studies.

RESULTS

An association was confirmed in subjects with severe asthma of loci previously identified for association with mild to moderate asthma. The strongest evidence was seen for the ORMDL3/GSDMB locus on chromosome 17q12-21 (rs4794820, p=1.03×10((-8)) following meta-analysis) meeting genome-wide significance. Strong evidence was also found for the IL1RL1/IL18R1 locus on 2q12 (rs9807989, p=5.59×10((-8)) following meta-analysis) just below this threshold. No novel loci for susceptibility to severe asthma met strict criteria for genome-wide significance.

CONCLUSIONS

The largest genome-wide association study of severe asthma to date was carried out and strong evidence found for the association of two previously identified asthma susceptibility loci in patients with severe disease. A number of novel regions with suggestive evidence were also identified warranting further study.

Variance as a signature of neural computations during decision making

Traditionally, insights into neural computation have been furnished by averaged firing rates from many stimulus repetitions or trials. We pursue an analysis of neural response variance to unveil neural computations that cannot be discerned from measures of average firing rate. We analyzed single-neuron recordings from the lateral intraparietal area (LIP), during a perceptual decision-making task. Spike count variance was divided into two components using the law of total variance for doubly stochastic processes: (1) variance of counts that would be produced by a stochastic point process with a given rate, and loosely (2) the variance of the rates that would produce those counts (i.e., "conditional expectation"). The variance and correlation of the conditional expectation exposed several neural mechanisms: mixtures of firing rate states preceding the decision, accumulation of stochastic "evidence" during decision formation, and a stereotyped response at decision end. These analyses help to differentiate among several alternative decision-making models.

Peripheral blood dendritic cell subtypes are significantly elevated in subjects with asthma

BACKGROUND

Dendritic cells (DCs) are crucial for the processing of antigens, T lymphocyte priming and the development of asthma and allergy. Smokers with asthma display altered therapeutic behaviour and a reduction in endobronchial DC CD83 expression compared with non-smokers with asthma. No information is available on the impact of smoking on peripheral blood DC profiles.

OBJECTIVE

Determine peripheral blood DC profiles in subjects with and without asthma with differing smoking histories.

METHODS

Forty-three asthmatics (17 smokers, nine ex-smokers and 17 never-smokers) and 16 healthy volunteers (nine smokers and seven never-smokers) were recruited. Spirometry, exhaled nitric oxide and venesection was performed. DC elution was by flow cytometry via the expression of DC surface markers [plasmacytoid (pDC) (BDCA-2, CD303), type 1 conventional (cDC) (BDCA-1, CD1c), and type 2 cDC (BDCA-3, CD141)].

RESULTS

Subjects with asthma displayed increases in all DC subtypes compared with normal never-smokers: [type 1 cDCs - asthma [median% (IQR)]: 0.59% (0.41, 0.74), normal never-smokers: 0.35% (0.26, 0.43), P=0.013]; type 2 cDCs - asthma: 0.04% (0.02, 0.06), normal never-smokers: 0.02% (0.01, 0.03), P=0.008 and pDCs - asthma: 0.32% (0.27, 0.46), normal never-smokers: 0.22% (0.17, 0.31), P=0.043, and increased pDC and type 1 cDCs compared with normal smokers. Smoking did not affect DC proportions in asthma. Cigarette smoking reduced pDC proportions in normal subjects [normal never-smokers: 0.22% (0.17, 0.31); normal smokers: 0.09% (0.08, 0.15), P=0.003].

CONCLUSIONS AND CLINICAL RELEVANCE

This study shows for the first time that subjects with asthma display a large increase in peripheral blood DC proportions. Cigarette smoking in asthma did not affect the peripheral blood DC profile but did suppress pDC proportions in non-asthmatic subjects. Asthma is associated with a significant increase in circulating DCs, reflecting increased endobronchial levels and the importance of DCs to the development and maintenance of asthma. (Clinical trials.gov identifier: NCT00411320)

Effect of improved home ventilation on asthma control and house dust mite allergen levels

BACKGROUND

The warm, humid environment in modern homes favours the dust mite population, but the effect of improved home ventilation on asthma control has not been established. We tested the hypothesis that a domestic mechanical heat recovery ventilation system (MHRV), in addition to allergen avoidance measures, can improve asthma control by attenuating re-colonization rates.

METHODS

We conducted a randomized double-blind placebo-controlled parallel group trial of the installation of MHRV activated in half the homes of 120 adults with asthma, allergic to Dermatophagoides pteronyssinus. All homes had carpets steam cleaned and new bedding and mattress covers at baseline. The primary outcome was morning peak expiratory flow (PEF) at 12 months.

RESULTS

At 12 months, the primary end-point; change in mean morning PEF as compared with baseline, did not differ between the MHRV group and the control group (mean difference 13.5 l/min, 95% CI: -2.6 to 29.8, P = 0.10). However, a secondary end-point; evening mean PEF, was significantly improved in the MHRV group (mean difference 24.5 l/min, 95% CI: 8.9-40.1, P = 0.002). Indoor relative humidity was reduced in MHRV homes, but there was no difference between the groups in Der p 1 levels, compared with baseline.

CONCLUSIONS

The addition of MHRV to house dust mite eradication strategies did not achieve a reduction in mite allergen levels, but did improve evening PEF.

Effect of low-dose theophylline plus beclometasone on lung function in smokers with asthma: a pilot study

Smoking is common in asthma and is associated with worse asthma control and a reduced therapeutic response to corticosteroids. The present authors hypothesised that treating smokers with asthma with low-dose theophylline added to inhaled corticosteroids would enhance steroid sensitivity and thereby improve lung function and symptoms. In a double-blind, parallel group exploratory trial, 68 asthmatic smokers were randomised to one of three treatments for 4 weeks: inhaled beclometasone (200 microg day(-1)), theophylline (400 mg day(-1)) or both treatments combined. Outcome measures included change in lung function and Asthma Control Questionnaire (ACQ) scores. At 4 weeks, theophylline added to inhaled beclometasone produced an improvement in peak expiratory flow (39.9 L min(-1), 95% confidence intervals (CI) 10.9-68.8) and ACQ score (-0.47, 95% CI -0.91- -0.04) and a borderline improvement in pre-bronchodilator forced expiratory volume in one second (mean difference 165 mL, 95% CI -13-342) relative to inhaled corticosteroid alone. Theophylline alone improved the ACQ score (-0.55, 95% CI -0.99- -0.11), but not lung function. In the present pilot study, the combination of low-dose theophylline and inhaled beclometasone produced improvements in both lung function and symptoms in a group of smokers with asthma. Larger trials are required to extend and confirm these findings.

Role of bilirubin as antioxidant in neonatal jaundice and effect of ethanolic extract of sweet lime peel on experimentally induced jaundice in rat

Bilirubin above a threshold level is toxic to human system and is excreted in urinary and through gastrointestinal tract. The role of bilirubin as antioxidant is debatable. This paper aims at elucidating the role of bilirubin as an antioxidant in neonatal jaundice patients. It is observed that bilirubin up to 6 mg/dl in blood acts as an antioxidant and above 12.5 mg/dl is strongly prooxidant. Phototherapy is the accepted therapeutic management of neonatal jaundice and has been shown to enhance the oxidative stress. Approaches have been taken to formulate a herbal medication which will reduce bilirubin level in the neonates without inducing additional damages. The ethanolic extract of sweet lime peel, administered orally at a dose of 72 microg is found to reduce the oxidative stress in erythrocytes of phenylhydrazine-induced jaundiced rats treated with phototherapy.

Perspectives on advancing preventative medicine through vaccinology at the comparative veterinary, human and conservation medicine interface: not missing the opportunities

Vaccination has historically and remains one of the most cost-effective and safest forms of medicine today. Along with basic understanding of germ theory and sanitation, vaccination, over the past 50 years, has transformed lives and economies in both rich and poor countries by its direct impact on human and animal life--resulting in the eradication of small pox, huge reductions in the burden of previously common human and animal diseases such as polio, typhoid, measles in human medicine and contagious bovine pleuropneumonia, foot-and-mouth disease, screwworm and hog cholera and the verge of eradicating brucellosis, tuberculosis, and pseudorabies in veterinary medicine. In addition vaccination along with other animal production changes has provided the ability to produce otherwise unaffordable animal protein and animal health worldwide. The landscape however on which vaccinology was discovered and applied over the past 200 years, even in the past 10 years has and is undergoing continuous change. For vaccination as a public health tool to have its greatest impacts in human and veterinary medicine, these great medical sciences will have to come together, policy-relevant science for sustainable conservation in developing and developed countries needs to become the norm and address poverty (including lack of basic health care) in communities affected by conservation, and to consider costs and benefits (perceived or not) affecting the well-being of all stakeholders, from the local to the multinational. The need to return to and/or develop new education-based models for turning the tide from the heavily return-on-investment therapeutic era of the last century into one where the investment into the preventative sciences and medicine lead to sustainable cultural and cost-effective public health and economic changes of the future is never more evident than today. The new complex problems of the new millennium will require new educational models that train para- and professional people for thinking and solving complex inter-related biological, ecological, public-, political/economic problems. The single profession that is best positioned to impact vaccinology is Veterinary Medicine. It's melding with human medicine and their role in future comparative and conservation-based programs will be critical to the successful application of vaccines into the 21st century.

Effects of atorvastatin added to inhaled corticosteroids on lung function and sputum cell counts in atopic asthma

BACKGROUND

Statins have anti-inflammatory properties that may be beneficial in the treatment of asthma. A study was undertaken to test the hypothesis that atorvastatin added to inhaled corticosteroids improves lung function and airway inflammation in atopic adults with asthma.

METHODS

54 adults with atopic asthma were recruited to a double-blind randomised controlled crossover trial comparing the effect of oral atorvastatin 40 mg daily with that of a matched placebo on asthma control and airway inflammation. Each treatment was administered for 8 weeks separated by a 6-week washout period. The primary outcome was morning peak expiratory flow (PEF). Secondary outcomes included forced expiratory volume in 1 s, asthma control questionnaire score, airway hyper-responsiveness to methacholine, induced sputum cytology and inflammatory biomarkers.

RESULTS

At 8 weeks the change in mean morning PEF compared with baseline did not differ substantially between the atorvastatin and placebo treatment periods (mean difference -0.5 l/min, 95% CI -10.6 to 9.6, p = 0.921). Values for other clinical outcomes were similar between the atorvastatin and placebo treatment periods. The absolute sputum macrophage count was reduced after atorvastatin compared with placebo (mean difference -45.0 x 10(4) cells, 95% CI -80.1 to -9.7, p = 0.029), as was the sputum fluid leucotriene B4 (mean difference -88.1 pg/ml, 95% CI -156.4 to -19.9, p = 0.014).

CONCLUSION

The addition of atorvastatin to inhaled corticosteroids results in no short-term improvement in asthma control but reduces sputum macrophage counts in mild to moderate atopic asthma. The change in sputum macrophage count suggests potential areas for investigation of statins in other chronic lung diseases.

Role of symptoms and lung function in determining asthma control in smokers with asthma

BACKGROUND

Cigarette smoking in asthma increases the severity and accelerates the decline in lung function. The relative role of symptoms and lung function in determining asthma control in smokers with asthma is not known.

AIM OF THE STUDY

The aim of this study was to compare asthma control in smokers vs never-smokers with asthma, using the validated Juniper asthma control questionnaire (ACQ), and assess if any difference was because of a particular symptom or the forced expiratory volume in one second (FEV(1)) value.

METHODS

This was a cross-sectional study of 134 asthmatics (74 never-smokers and 60 smokers) with >or=15% reversibility in FEV(1) after salbutamol. All subjects completed the ACQ, recording FEV(1) and asthma symptoms (night awakening, morning symptoms, dyspnoea, wheeze, activity limitation and use of reliever inhaler).

RESULTS

Compared with the never-smokers, smokers with asthma had significantly worse median (IQR) total asthma control score [1.6 (1.1-2.3) vs 2.8 (1.7-3.4); (P < 0.0001)] and in each of the six individual symptom question scores (P < 0.001), but no difference in FEV(1) levels (P = 0.908).

CONCLUSION

Asthma control is significantly worse in asthmatics who smoke compared with never-smokers, with all symptoms related to asthma control uniformly worse in smokers, independent of FEV(1).

Systemic sensitivity to corticosteroids in smokers with asthma

Cigarette smokers with asthma are insensitive to the therapeutic effects of corticosteroids. It is not known whether this insensitivity to corticosteroids in smokers affects tissue sites beyond the airways. A total of 75 asthmatic subjects (39 smokers) and 78 healthy controls (30 smokers) were recruited to an observational study. The cutaneous and peripheral blood lymphocyte responses to corticosteroids were measured. The cutaneous vasoconstrictor response to topical beclometasone was measured by applying different concentrations of beclometasone solutions to the skin in a random double-blind manner. The degree of blanching at each concentration was graded after 18 h. The sensitivity of peripheral blood lymphocytes to corticosteroids was assessed by measuring the suppressive effect of dexamethasone on lymphocyte proliferation stimulated by phytohaemagglutinin (PHA). Total mean+/-sd cutaneous vasoconstrictor response score to beclometasone was reduced in smokers with asthma to 5.39+/-3.58 versus 7.26+/-3.05 in never-smokers with asthma; and in all smokers to 6.47+/-3.33 versus 7.86+/-2.81 in all never-smokers. The sensitivity to corticosteroids of lymphocytes stimulated by PHA was similar between groups. In conclusion, smokers with asthma have an impaired cutaneous vasoconstrictor response to topical corticosteroids compared with never-smokers with asthma. This finding suggests that the insensitivity to corticosteroids in smokers with asthma affects tissue sites other than the airways.

The radiological appearances of thalassaemia

The skeletal changes of untreated thalassaemia result from ineffective erythropoiesis and expansion of the bone marrow and affect every part of the skeleton. These changes include osteoporosis, growth retardation, platyspondyly and kyphosis. Erythropoiesis occurs at extra-medullary sites, most commonly resulting in a paraspinal mass but occasionally affecting organs containing pluripotential stem cells. Repeated transfusion unaccompanied by iron chelation causes haemosiderosis; iron is deposited at various sites causing functional impairment. Iron-chelation therapy with desferrioxamine (DFX) prevents haemosiderosis but causes a skeletal dysplasia predominantly affecting the rapidly growing long bones, in particular the distal ulna, and causing irregularity and sclerosis of the physeal-metaphyseal junction and splaying of the metaphysis. DFX also exacerbates the observed growth retardation. DFX-induced skeletal dysplasia may herald toxicity, which is associated with visual and auditory impairment. Therefore, careful balancing of the transfusion regimen and iron-chelation therapy is required. Magnetic resonance imaging (MRI) is the most sensitive technique for the detection of DFX-induced dysplasia.

Serum and sputum neurotrophin levels in chronic persistent cough

BACKGROUND

Neurotrophins (NTs) are a family of growth factors, including nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF) and neurotrophin3 (NT-3) that are involved in inflammation. Serum and induced sputum NT levels are increased in asthma and in cough because of idiopathic pulmonary fibrosis, respectively. Neurogenic inflammation is implicated in the pathogenesis of chronic cough in individuals with normal chest radiography, but the role of NTs in this condition is unknown.

OBJECTIVE

To assess if NT levels are elevated in the serum and airways in subjects with chronic persistent cough.

METHODS

Eighty-one subjects with chronic cough persistent for over 1 year; with normal chest radiography and spirometry were included. Thirty healthy subjects were controls. Serum NGF, BDNF and NT-3 were measured by enzyme immunoassay. In a subset, NGF was measured in induced sputum. Sputum cell counts and allergen-specific serum IgE were measured and all patients received specific sequential treatment trials to achieve a final diagnosis for the cough.

RESULTS

There was no significant difference either in the levels of serum or sputum NTs in chronic cough subjects compared with controls or between the most common causes of cough: post-nasal drip syndrome, gastro-oesophageal reflux disease, asthma and bronchiectasis. The median (inter-quartile range) for sputum NGF (pg/mL) was 516 (296-772) in healthy controls and 580 (312-880) in subjects with chronic cough (P=0.284). There was no correlation between NT levels and sputum cell counts. Sputum NGF levels correlated with duration of cough (r=0.34, P=0.002).

CONCLUSION

NTs are not elevated in induced sputum or serum of subjects with chronic persistent cough. This implies that NTs do not have a central role in perpetuating airway inflammation in chronic persistent cough.

Occupational injuries: is job security a factor?

CONTEXT

Although a large number of contributing factors of occupational injury causation are explored meticulously to explain the phenomenon of higher occupational injury occurrence in some subjects, it has remained a matter of controversy.

AIMS

In this study, an effort is made to explore whether job security has any contribution in explaining higher susceptibility of some workers.

SETTINGS AND DESIGN

This was a retrospective occupational injury record study conducted in an industry of eastern India.

MATERIALS AND METHODS

Along with the study of injury records of 5 years, an interview was also conducted involving 726 workers (including permanent and temporary workers both) of the factory.

STATISTICAL ANALYSIS USED

Comparison was made between permanent and temporary workers by using the Mann-Whitney U-test and the chi-square test. A theoretical model of Poisson's distribution was used to compare between expected and real occurrence.

RESULTS

Although two worker groups were very similar in relation to age, level of education, habits, and nature of work, accident frequency and severity rates were found to be significantly higher in temporary workers.

CONCLUSIONS

This study concluded that the higher accident risk of the temporary workers might have been due to the less effective experience as well as due to lack of job security inherent in such workers.

Occupational injuries: is job security a factor?

CONTEXT

Although a large number of contributing factors of occupational injury causation are explored meticulously to explain the phenomenon of higher occupational injury occurrence in some subjects, it has remained a matter of controversy.

AIMS

In this study, an effort is made to explore whether job security has any contribution in explaining higher susceptibility of some workers.

SETTINGS AND DESIGN

This was a retrospective occupational injury record study conducted in an industry of eastern India.

MATERIALS AND METHODS

Along with the study of injury records of 5 years, an interview was also conducted involving 726 workers (including permanent and temporary workers both) of the factory.

STATISTICAL ANALYSIS USED

Comparison was made between permanent and temporary workers by using the Mann-Whitney U-test and the chi-square test. A theoretical model of Poisson's distribution was used to compare between expected and real occurrence.

RESULTS

Although two worker groups were very similar in relation to age, level of education, habits, and nature of work, accident frequency and severity rates were found to be significantly higher in temporary workers.

CONCLUSIONS

This study concluded that the higher accident risk of the temporary workers might have been due to the less effective experience as well as due to lack of job security inherent in such workers.

Efficacy of low and high dose inhaled corticosteroid in smokers versus non-smokers with mild asthma

BACKGROUND

Cigarette smokers with asthma are insensitive to short term inhaled corticosteroid therapy, but efficacy when given for a longer duration at different doses is unknown.

METHODS

Ninety five individuals with mild asthma were recruited to a multicentre, randomised, double blind, parallel group study comparing inhaled beclomethasone in doses of 400 microg or 2000 microg daily for 12 weeks in smokers and non-smokers. The primary end point was the change in morning peak expiratory flow (PEF). Secondary end points included evening PEF, use of reliever inhaler, number of asthma exacerbations, spirometric parameters, and asthma control score.

RESULTS

After 12 weeks of inhaled beclomethasone there was a considerable difference between the morning PEF measurements of smokers and non-smokers with asthma (-18 (95% CI -35 to -1), adjusted p = 0.035). Among those receiving 400 microg daily there was a difference between the mean (95% CI) morning PEF (l/min) in smokers and non-smokers (-25 (95% CI -45 to -4), adjusted p = 0.019) and in the number of asthma exacerbations (6 v 1 in smokers and non-smokers, respectively, p = 0.007). These differences were reduced between smokers and non-smokers receiving 2000 microg inhaled beclomethasone daily.

CONCLUSIONS

Compared with non-smokers, smokers with mild persistent asthma are insensitive to the therapeutic effect of low dose inhaled corticosteroid treatment administered for a 12 week period. The disparity of the response between smokers and non-smokers appears to be reduced with high dose inhaled corticosteroid. These findings have important implications for the management of individuals with mild asthma who smoke.

Asthma and cigarette smoking

In most developed countries approximately 25% of adults with asthma are current cigarette smokers. Asthma and active cigarette smoking interact to cause more severe symptoms, accelerated decline in lung function, and impaired short-term therapeutic response to corticosteroids. Cigarette smoking may modify inflammation that is associated with asthma, although there is limited published data on airway pathology in smokers with asthma. To date, the evidence points towards a combination of both heightened and suppressed inflammatory responses in smokers compared with nonsmokers with asthma. The mechanisms of corticosteroid resistance in asthmatic smokers are unexplained, but could be as a result of alterations in airway inflammatory cell phenotypes (e.g. increased neutrophils or reduced eosinophils), changes in the glucocorticoid receptor-alpha to -beta ratio (e.g. overexpression of glucocorticoid receptor beta), and increased activation of pro-inflammatory transcription factors (e.g. nuclear factor-kappaB) or reduced histone deacetylase activity. In conclusion, every effort should be made to encourage asthmatics who smoke to stop, although the effects of smoking cessation upon reversing the adverse effects of tobacco smoke on asthma control, therapeutic response to corticosteroids and airway pathology have yet to be fully elucidated. Alternative or additional therapies to inhaled corticosteroids are needed for asthmatic patients who are unable to quit smoking.

Interleukin-18 levels in induced sputum are reduced in asthmatic and normal smokers

BACKGROUND

IL-18 is a cytokine which is known to have an important role in the development of a Th1 lymphocyte response. As such, it may have a regulatory role in asthma by modifying Th2 lymphocyte responses. Cigarette smoking may amplify the airway inflammation associated with asthma.

OBJECTIVE

This study investigated if IL-18 could be detected in induced sputum from asthmatics and normal subjects and if smoking altered IL-18 levels.

METHODS

Induced sputum was obtained from asthmatic (31 smokers, 35 non-smokers) and normal (20 smokers, 20 non-smokers) subjects. All smokers had a smoking history of > or =15 pack years. IL-18 levels in sputum supernatant were measured by ELISA. IL-18 mRNA expression and cellular localization were assessed by quantitative PCR and immunocytochemistry, respectively.

RESULTS

Smoking was associated with a significant reduction in IL-18 levels (median (interquartile range) - smokers 20 (0-102) pg/mL vs. non-smokers 358 (50-876) pg/mL, P<0.001). This was more pronounced in asthmatics (smokers, 47 (40-64) pg/mL vs. non-smokers, 530 (30-1484) pg/mL; P<0.001) than in normal subjects (smokers, 25 (0-78) pg/mL vs. non-smokers, 247 (50-656) pg/mL; P<0.01). Within each of the smoking and non-smoking groups there was no significant difference in IL-18 levels between asthmatic and normal subjects. There was no correlation between sputum IL-18 levels and any specific cell type in the sputum samples nor serum IgE levels. IL-18 mRNA expression was reduced in asthmatic smokers compared with non-smokers. IL-18 production was localized to sputum macrophages by immunocytochemistry.

CONCLUSIONS

IL-18 is detectable in induced sputum samples from both asthmatic and normal subjects. Cigarette smoking significantly reduces sputum IL-18 levels. This effect is more pronounced in asthmatics than in normal subjects.