Adherence to inhaled corticosteroids and long-acting β2-agonists in asthma: A MASK-air study

INTRODUCTION

Adherence to controller medication is a major problem in asthma management, being difficult to assess and tackle. mHealth apps can be used to assess adherence. We aimed to assess the adherence to inhaled corticosteroids+long-acting β2-agonists (ICS+LABA) in users of the MASK-air® app, comparing the adherence to ICS+formoterol (ICS+F) with that to ICS+other LABA.

MATERIALS AND METHODS

We analysed complete weeks of MASK-air® data (2015-2022; 27 countries) from patients with self-reported asthma and ICS+LABA use. We compared patients reporting ICS+F versus ICS+other LABA on adherence levels, symptoms and symptom-medication scores. We built regression models to assess whether adherence to ICS+LABA was associated with asthma control or short-acting beta-agonist (SABA) use. Sensitivity analyses were performed considering the weeks with no more than one missing day.

RESULTS

In 2598 ICS+LABA users, 621 (23.9%) reported 4824 complete weeks and 866 (33.3%) reported weeks with at most one missing day. Higher adherence (use of medication ≥80% of weekly days) was observed for ICS+other LABA (75.1%) when compared to ICS+F (59.3%), despite both groups displaying similar asthma control and work productivity. The ICS+other LABA group was associated with more days of SABA use than the ICS+F group (median=71.4% versus 57.1% days). Each additional weekly day of ICS+F use was associated with a 4.1% less risk in weekly SABA use (95%CI=-6.5;-1.6%;p=0.001). For ICS+other LABA, the percentage was 8.2 (95%CI=-11.6;-5.0%;p<0.001).

CONCLUSIONS

In asthma patients adherent to the MASK-air app, adherence to ICS+LABA was high. ICS+F users reported lower adherence but also a lower SABA use and a similar level of control.

Rhinitis associated with asthma is distinct from rhinitis alone: The ARIA-MeDALL hypothesis

Asthma, rhinitis and atopic dermatitis (AD) are interrelated clinical phenotypes that partly overlap in the human interactome. The concept of "one-airway-one-disease", coined over 20 years ago, is a simplistic approach of the links between upper- and lower-airway allergic diseases. With new data, it is time to reassess the concept. This article reviews (i) the clinical observations that led to Allergic Rhinitis and its Impact on Asthma (ARIA), (ii) new insights into polysensitisation and multimorbidity, (iii) advances in mHealth for novel phenotype definition, (iv) confirmation in canonical epidemiologic studies, (v) genomic findings, (vi) treatment approaches and (vii) novel concepts on the onset of rhinitis and multimorbidity. One recent concept, bringing together upper- and lower-airway allergic diseases with skin, gut and neuropsychiatric multimorbidities, is the "Epithelial Barrier Hypothesis". This review determined that the "one-airway-one-disease" concept does not always hold true and that several phenotypes of disease can be defined. These phenotypes include an extreme "allergic" (asthma) phenotype combining asthma, rhinitis and conjunctivitis. Rhinitis alone and rhinitis and asthma multimorbidity represent two distinct diseases with the following differences: (i) genomic and transcriptomic background (Toll-Like Receptors and IL-17 for rhinitis alone as a local disease; IL-33 and IL-5 for allergic and non-allergic multimorbidity as a systemic disease), (ii) allergen sensitisation patterns (mono- or pauci-sensitisation versus polysensitisation), (iii) severity of symptoms and (iv) treatment response. In conclusion, rhinitis alone (local disease) and rhinitis with asthma multimorbidity (systemic disease) should be considered as two distinct diseases, possibly modulated by the microbiome, and may be a model for understanding the epidemics of chronic and auto-immune diseases.

[Prevalence of asthma among adults in France, data from the Constances cohort study]

INTRODUCTION

The objectives of our study were to estimate the prevalence of asthma in adults in France and to study the effects of gender on the associations of asthma with the corpulence and socio-economic characteristics of individuals.

METHODS

We estimated the prevalence of current asthma (asthma attack in the past 12 months or current treatment for asthma) from data collected at inclusion in the Constances cohort study in 2013-2014. Analyses were performed separately in men and women, using robust Poisson regression for multivariate analysis.

RESULTS

Using data from 34,100 participants in the cohort (men: 47.7 %; mean age: 44.6 years), the prevalence of current asthma was estimated to be 5.8 % (5.1 % in men, 6.4 % in women). The risk of asthma was increased in women with high body mass index (BMI) or waist circumference. In men, only a high waist circumference was associated with an increased risk of asthma. An association with low socioeconomic status was observed only among women.

CONCLUSION

The associations of asthma with corpulence and socioeconomic status differed between men and women. Additional analyses should provide a better understanding of the mechanisms responsible for these differences.

The CONSTANCES Cohort Biobank: An Open Tool for Research in Epidemiology and Prevention of Diseases

“General-purpose cohorts” in epidemiology and public health are designed to cover a broad scope of determinants and outcomes, in order to answer several research questions, including those not defined at study inception. In this context, the general objective of the CONSTANCES project is to set up a large population-based cohort that will contribute to the development of epidemiological research by hosting ancillary projects on a wide range of scientific domains, and to provide public health information. CONSTANCES was designed as a randomly selected sample of French adults aged 18–69 years at study inception; 202,045 subjects were included over an 8-year period. At inclusion, the selected participants are invited to attend one of the 24 participating Health Prevention Centers (HPCs) for a comprehensive health examination. The follow-up includes a yearly self-administered questionnaire, and a periodic visit to an HPC. Procedures have been developed to use the national healthcare databases to allow identification and validation of diseases over the follow-up. The biological collection (serum, lithium heparinized plasma, EDTA plasma, urine and buffy coat) began gradually in June 2018. At the end of the inclusions, specimens from 83,000 donors will have been collected. Specimens are collected according to a standardized protocol, identical in all recruitment centers. All operations relating to bio-banking have been entrusted by Inserm to the Integrated Biobank of Luxembourg (IBBL). A quality management system has been put in place. Particular attention has been paid to the traceability of all operations. The nature of the biological samples stored has been deliberately limited due to the economic and organizational constraints of the inclusion centers. Some research works may require specific collection conditions, and can be developed on request for a limited number of subjects and in specially trained centers. The biological specimens that are collected will allow for a large spectrum of biomarkers studies and genetic and epigenetic markers through candidate or agnostic approaches. By linking the extensive data on personal, lifestyle, environmental, occupational and social factors with the biomarker data, the CONSTANCES cohort offers the opportunity to study the interplays between these factors using an integrative approach and state-of-the-art methods.

Air pollution and rhinitis in the Constances cohort

The prevalence of rhinitis has increased in the past decades. We aim to study the effect of air pollution, as one of the environmental factors that may explain the increase of rhinitis prevalence. A total of 21507 (80%); of the 26737 participants included until December 2013 in Constances, a large French population-based cohort, answered standardized questions on rhinitis in 2014. Ever rhinitis was defined by a positive response to “Have you ever had a problem with sneezing or a runny or a blocked nose when you did not have a cold or the flu?”. Current rhinitis was defined among those reporting ever rhinitis and nasal symptoms in the past 12 months. Annual exposure to nitrogen dioxide (NO2), particulate matter ≤2.5 µm (PM2.5) and black carbon (BC) was estimated at the participants' residential address by extrapolating European land-use regression models for 2010 to year 2014. Associations between annual exposure to air pollution and rhinitis were estimated using a logistic model adjusted for age, gender, smoking and education level.

After exclusions, 18506 participants were included (mean age: 52, 45% men, 13% ever asthma). Ever and current prevalence of rhinitis were 58% and 41% respectively. Significant and positive associations were found between each pollutant and current rhinitis. Adjusted ORs were 1.26 [1.16-1.36] per 15 µg.m-3 increase in NO2, 1.28 [1.17-1.41] per 5 µg.m-3 increase in PM2.5, and 1.36 [1.22-1.51] per 10-5.m-1 increase in BC. Results were similar for non-smoking participants and those whose address had not changed since inclusion.

Exposure to air pollution is associated with current rhinitis in adults in the general population. In view of the high prevalence of rhinitis and its costs, these findings have an important public health impact and reinforce the need to reduce the population's exposure to air pollution.

Key messages

Exposure to air pollution is associated with current rhinitis in adults in general population. These results contribute to a better understanding of health effects of air pollution.

Correlation between work impairment, scores of rhinitis severity and asthma using the MASK-air® App

BACKGROUND

In allergic rhinitis, a relevant outcome providing information on the effectiveness of interventions is needed. In MASK-air (Mobile Airways Sentinel Network), a visual analogue scale (VAS) for work is used as a relevant outcome. This study aimed to assess the performance of the work VAS work by comparing VAS work with other VAS measurements and symptom-medication scores obtained concurrently.

METHODS

All consecutive MASK-air users in 23 countries from 1 June 2016 to 31 October 2018 were included (14 189 users; 205 904 days). Geolocalized users self-assessed daily symptom control using the touchscreen functionality on their smart phone to click on VAS scores (ranging from 0 to 100) for overall symptoms (global), nose, eyes, asthma and work. Two symptom-medication scores were used: the modified EAACI CSMS score and the MASK control score for rhinitis. To assess data quality, the intra-individual response variability (IRV) index was calculated.

RESULTS

A strong correlation was observed between VAS work and other VAS. The highest levels for correlation with VAS work and variance explained in VAS work were found with VAS global, followed by VAS nose, eye and asthma. In comparison with VAS global, the mCSMS and MASK control score showed a lower correlation with VAS work. Results are unlikely to be explained by a low quality of data arising from repeated VAS measures.

CONCLUSIONS

VAS work correlates with other outcomes (VAS global, nose, eye and asthma) but less well with a symptom-medication score. VAS work should be considered as a potentially useful AR outcome in intervention studies.

The asthma-rhinitis multimorbidity is associated with IgE polysensitization in adolescents and adults

BACKGROUND

Children with multimorbid asthma and rhinitis show IgE polysensitization to several allergen sources. This association remains poorly studied in adolescents and adults using defined allergen molecules. We investigated IgE sensitization patterns towards a broad panel of aeroallergen components in adults and adolescents with a focus on individuals with asthma and rhinitis multimorbidity.

METHODS

IgE reactivity to 64 micro-arrayed aeroallergen molecules was determined with the MeDALL-chip in samples from the French EGEA study (n = 840, age = 40.7 ± 17.1) and the Swedish population-based birth cohort BAMSE (n = 786, age = 16 ± 0.26). The age- and sex-adjusted associations between the number of IgE-reactive allergen molecules (≥0.3 ISU) and the asthma-rhinitis phenotypes were assessed using a negative binomial model.

RESULTS

Groups representing 4 phenotypes were identified: no asthma-no rhinitis (A-R-; 30% in EGEA and 54% in BAMSE), asthma alone (A+R-; 11% and 8%), rhinitis alone (A-R+; 15% and 24%) and asthma-rhinitis (A+R+; 44% and 14%). The numbers of IgE-reactive aeroallergen molecules significantly differed between phenotypes (median in A-R-, A+R-, A-R+ and A+R+: 0, 1, 2 and 7 in EGEA and 0, 0, 3 and 5 in BAMSE). As compared to A-R- subjects, the adjusted ratio of the mean number of IgE-reactive molecules was higher in A+R+ than in A+R- or A-R+ (10.0, 5.4 and 5.0 in EGEA and 7.2, 0.7 and 4.8 in BAMSE).

CONCLUSION

The A+R+ phenotype combined the sensitization pattern of both the A-R+ and A+R- phenotypes. This multimorbid polysensitized phenotype seems to be generalizable to various ages and allergenic environments and may be associated with specific mechanisms.

The sensitization pattern differs according to rhinitis and asthma multimorbidity in adults: the EGEA study

BACKGROUND

Mono- and polysensitization are different IgE-mediated allergic phenotypes in children. Allergic sensitization is associated with both allergic asthma and allergic rhinitis, however, associations between the sensitization pattern and particularly polysensitization with asthma and rhinitis remains poorly studied in adults.

AIM

The aim of this study was to assess how the allergic sensitization pattern associates with asthma, rhinitis and their multimorbidity.

METHODS

1199 adults from the EGEA study, with extensive phenotypic characterization and all data available on skin prick tests to 10 allergens, total IgE and blood eosinophils were included. Using questionnaires only, participants were classified into 6 groups: asymptomatic (no asthma, no rhinitis), non-allergic rhinitis alone, allergic rhinitis alone, asthma alone, asthma+non-allergic rhinitis and asthma+allergic rhinitis. Mono- and polysensitization were defined by a positive skin prick test to one or more than one allergen respectively.

RESULTS

Asymptomatic participants and those with non-allergic rhinitis alone were mostly non-sensitized (around 72%) while around 12% were polysensitized. Between 32% and 43% of participants with allergic rhinitis alone, asthma alone and asthma+non-allergic rhinitis were non-sensitized and between 37% and 46% of them were polysensitized. 65% of the participants with asthma+allergic rhinitis were polysensitized. The level of total IgE followed a similar trend to that of allergic sensitization. Eosinophils were increased in asthma, especially when associated with rhinitis. Nasal symptoms were more severe and eczema more common in participants with both asthma and allergic rhinitis than in the other groups.

CONCLUSIONS

Allergic sensitization and particularly polysensitization rates widely differ according to asthma and rhinitis status. This study emphasized the importance of taking into account multimorbidity between asthma and rhinitis and showed that allergic sensitization is not a dichotomic variable.

Building Bridges for Innovation in Ageing: Synergies between Action Groups of the EIP on AHA

The Strategic Implementation Plan of the European Innovation Partnership on Active and Healthy Ageing (EIP on AHA) proposed six Action Groups. After almost three years of activity, many achievements have been obtained through commitments or collaborative work of the Action Groups. However, they have often worked in silos and, consequently, synergies between Action Groups have been proposed to strengthen the triple win of the EIP on AHA. The paper presents the methodology and current status of the Task Force on EIP on AHA synergies. Synergies are in line with the Action Groups' new Renovated Action Plan (2016-2018) to ensure that their future objectives are coherent and fully connected. The outcomes and impact of synergies are using the Monitoring and Assessment Framework for the EIP on AHA (MAFEIP). Eight proposals for synergies have been approved by the Task Force: Five cross-cutting synergies which can be used for all current and future synergies as they consider overarching domains (appropriate polypharmacy, citizen empowerment, teaching and coaching on AHA, deployment of synergies to EU regions, Responsible Research and Innovation), and three cross-cutting synergies focussing on current Action Group activities (falls, frailty, integrated care and chronic respiratory diseases).

ARIA 2016: Care pathways implementing emerging technologies for predictive medicine in rhinitis and asthma across the life cycle

The Allergic Rhinitis and its Impact on Asthma (ARIA) initiative commenced during a World Health Organization workshop in 1999. The initial goals were (1) to propose a new allergic rhinitis classification, (2) to promote the concept of multi-morbidity in asthma and rhinitis and (3) to develop guidelines with all stakeholders that could be used globally for all countries and populations. ARIA—disseminated and implemented in over 70 countries globally—is now focusing on the implementation of emerging technologies for individualized and predictive medicine. MASK [MACVIA (Contre les Maladies Chroniques pour un Vieillissement Actif)-ARIA Sentinel NetworK] uses mobile technology to develop care pathways for the management of rhinitis and asthma by a multi-disciplinary group and by patients themselves. An app (Android and iOS) is available in 20 countries and 15 languages. It uses a visual analogue scale to assess symptom control and work productivity as well as a clinical decision support system. It is associated with an inter-operable tablet for physicians and other health care professionals. The scaling up strategy uses the recommendations of the European Innovation Partnership on Active and Healthy Ageing. The aim of the novel ARIA approach is to provide an active and healthy life to rhinitis sufferers, whatever their age, sex or socio-economic status, in order to reduce health and social inequalities incurred by the disease.

Paving the way of systems biology and precision medicine in allergic diseases: the MeDALL success story: Mechanisms of the Development of ALLergy; EU FP7-CP-IP; Project No: 261357; 2010-2015

MeDALL (Mechanisms of the Development of ALLergy; EU FP7-CP-IP; Project No: 261357; 2010-2015) has proposed an innovative approach to develop early indicators for the prediction, diagnosis, prevention and targets for therapy. MeDALL has linked epidemiological, clinical and basic research using a stepwise, large-scale and integrative approach: MeDALL data of precisely phenotyped children followed in 14 birth cohorts spread across Europe were combined with systems biology (omics, IgE measurement using microarrays) and environmental data. Multimorbidity in the same child is more common than expected by chance alone, suggesting that these diseases share causal mechanisms irrespective of IgE sensitization. IgE sensitization should be considered differently in monosensitized and polysensitized individuals. Allergic multimorbidities and IgE polysensitization are often associated with the persistence or severity of allergic diseases. Environmental exposures are relevant for the development of allergy-related diseases. To complement the population-based studies in children, MeDALL included mechanistic experimental animal studies and in vitro studies in humans. The integration of multimorbidities and polysensitization has resulted in a new classification framework of allergic diseases that could help to improve the understanding of genetic and epigenetic mechanisms of allergy as well as to better manage allergic diseases. Ethics and gender were considered. MeDALL has deployed translational activities within the EU agenda.

A common variant in RAB27A gene is associated with fractional exhaled nitric oxide levels in adults

BACKGROUND

Exhaled nitric oxide (FeNO) is a biomarker for eosinophilic inflammation in the airways and for responsiveness to corticosteroids in asthmatics.

OBJECTIVE

We sought to identify in adults the genetic determinants of fractional exhaled nitric oxide (FeNO) levels and to assess whether environmental and disease-related factors influence these associations.

METHODS

We performed a genome-wide association study of FeNO through meta-analysis of two independent discovery samples of European ancestry: the outbred EGEA study (French Epidemiological study on the Genetics and Environment of Asthma, N = 610 adults) and the Hutterites (N = 601 adults), a founder population living on communal farms. Replication of main findings was assessed in adults from an isolated village in Sardinia (Talana study, N = 450). We then investigated the influence of asthma, atopy and tobacco smoke exposure on these genetic associations, and whether they were also associated with FeNO values in children of the EAGLE (EArly Genetics & Lifecourse Epidemiology, N = 8858) consortium.

RESULTS

We detected a common variant in RAB27A (rs2444043) associated with FeNO that reached the genome-wide significant level (P = 1.6 × 10(-7) ) in the combined discovery and replication adult data sets. This SNP belongs to member of RAS oncogene family (RAB27A) and was associated with an expression quantitative trait locus for RAB27A in lymphoblastoid cell lines from asthmatics. A second suggestive locus (rs2194437, P = 8.9 × 10(-7) ) located nearby the sodium/calcium exchanger 1 (SLC8A1) was mainly detected in atopic subjects and influenced by inhaled corticosteroid use. These two loci were not associated with childhood FeNO values.

CONCLUSIONS AND CLINICAL RELEVANCE

This study identified a common variant located in RAB27A gene influencing FeNO levels specifically in adults and with a biological relevance to the regulation of FeNO levels. This study provides new insight into the biological mechanisms underlying FeNO levels in adults.

Are allergic multimorbidities and IgE polysensitization associated with the persistence or re-occurrence of foetal type 2 signalling? The MeDALL hypothesis

Allergic diseases [asthma, rhinitis and atopic dermatitis (AD)] are complex. They are associated with allergen-specific IgE and nonallergic mechanisms that may coexist in the same patient. In addition, these diseases tend to cluster and patients present concomitant or consecutive diseases (multimorbidity). IgE sensitization should be considered as a quantitative trait. Important clinical and immunological differences exist between mono- and polysensitized subjects. Multimorbidities of allergic diseases share common causal mechanisms that are only partly IgE-mediated. Persistence of allergic diseases over time is associated with multimorbidity and/or IgE polysensitization. The importance of the family history of allergy may decrease with age. This review puts forward the hypothesis that allergic multimorbidities and IgE polysensitization are associated and related to the persistence or re-occurrence of foetal type 2 signalling. Asthma, rhinitis and AD are manifestations of a common systemic immune imbalance (mesodermal origin) with specific patterns of remodelling (ectodermal or endodermal origin). This study proposes a new classification of IgE-mediated allergic diseases that allows the definition of novel phenotypes to (i) better understand genetic and epigenetic mechanisms, (ii) better stratify allergic preschool children for prognosis and (iii) propose novel strategies of treatment and prevention.

Do young adults with childhood asthma avoid occupational exposures at first hire?

Information on the healthy worker hire effect in relation to asthma is scant. We aimed to assess whether and how childhood asthma-related characteristics (before hire) relate to occupational exposures at first hire. Analyses were conducted in 298 children examined at the first survey of the Epidemiological Study on the Genetics and Environment of Asthma (1991-1995), who reported a training period or a job at follow-up in 2003-2007 (aged 17-29 yrs; 53% males). Exposure likelihood to dust, gases and/or fumes in their first occupation was estimated by the ALOHA job exposure matrix. Asthma before the first occupation and two asthma classifications for severity (Global Initiative for Asthma 2002 guidelines) and symptoms were defined by questionnaire. In their first job, 47% of subjects were exposed. After adjustment (age, sex and education), pre-hire onset asthmatics (59%) were nonsignificantly less likely to be exposed (OR 0.67, 95% CI 0.41-1.11). Associations were stronger when considering those with severe asthma or high symptom score in childhood (OR 0.27 (95% CI 0.11-0.63) and OR 0.49 (95% CI 0.25-0.99), respectively). The association was observed in those who completed a university degree (OR 0.55, 95% CI 0.29-1.04) but not in the others (OR 0.98, 95% CI 0.44-2.22), with consistent results for all asthma characteristics. Results suggest a healthy worker hire effect in subjects with more severe or more symptomatic asthma in childhood. Education may modulate self-selection.

17q21 variants modify the association between early respiratory infections and asthma

Single nucleotide polymorphisms (SNPs) at chromosome 17q21 confer an increased risk of early-onset asthma. The objective was to study whether 17q21 SNPs modify associations between early respiratory infections and asthma. Association analysis was conducted in 499 children (268 with asthma, median age 11 yrs) from the Epidemiological Study on the Genetics and Environment of Asthma (EGEA). The 12-yr follow-up data were used to assess persistent or remittent asthma in young adulthood. Respiratory infection before 2 yrs of age was assessed retrospectively. For the 12 17q21 SNPs studied, the odds ratios (OR) for association between infection and early-onset asthma (age at onset <or=4 yrs) were higher in carriers of risk genotypes (OR 3.42-6.36) than in noncarriers (OR 1.84-2.44; p-value for interaction 0.02-0.04 for five SNPs). Risk genotypes also increased the association between infection and childhood asthma that remits in adulthood (OR 4.84-7.16 in carriers and 1.74-2.25 in noncarriers; p-value for interaction 0.008-0.05 for 10 SNPs). In children with 17q21 risk genotypes and early-life environmental tobacco smoke (ETS) exposure, associations between infection and asthma were further enhanced. 17q21 genetic variants and early ETS exposure enhance the association between early respiratory infections and early-onset asthma and childhood asthma that remits in adulthood.

Cat sensitization according to cat window of exposure in adult asthmatics

BACKGROUND

In adults, there is limited information on tolerance to cat, which may be reflected by high IgG4 without IgE sensitization. Early exposure to cat may play a critical role.

OBJECTIVE

The aim was to assess among adults the association of Fel d 1 IgG4, Fel d 1 IgE, skin prick test (SPT) response to cat and pet-related symptoms in relation to exposure to cat considering the period of exposure.

METHODS

SPT response to cat, specific IgE and IgG4 to Fel d 1 were assessed in 167 asthmatics recruited in chest clinics (40 years of age in average) from the French Epidemiological study on the Genetics and Environment of Asthma (EGEA). Childhood and/or current exposure to cat were studied retrospectively.

RESULTS

IgG4 was higher in relation to current cat exposure (0.53 vs. 0.09 ng/mL; P<0.001) and higher in women than in men. The period of cat exposure was significantly related to Fel d 1 IgE, the IgE/IgG4 pattern and cat weal size. The lowest values of Fel d 1 IgE, cat weal size, pet-related nasal or respiratory symptoms were observed in those with both childhood and current exposure as well as the highest proportion of the IgE-/IgG4+ pattern observed in 1.4%, 4.0%, 38.1% and 12.5% of those with -/-, +/-, +/+, -/+ childhood/current exposure, respectively.

CONCLUSIONS

Adult asthmatics exposed to cats since childhood present an immunologic pattern with high IgG4 and low IgE. Continuous exposure may maintain a state of immunological tolerance to cat.

Heterogeneity of asthma according to blood inflammatory patterns

RATIONALE

There is increasing interest regarding asthma heterogeneity in relation to inflammatory patterns.

OBJECTIVES

To assess phenotypic characteristics, in particular clinical presentation of the disease, in 381 well-characterised adults with asthma from the French Epidemiological study on the Genetics and Environment of Asthma (EGEA) according to their blood inflammatory pattern.

METHODS

Four blood inflammatory patterns were defined according to eosinophil (EOS) and neutrophil (NEU) count cut-off points. Samples with > or =250 EOS/mm(3) were classified as EOS(hi) and those with > or =5000 NEU/mm(3) as NEU(hi). Clinical characteristics include typical asthma and chronic obstructive pulmonary disease (COPD)-like symptoms, as well as composite quantitative scores addressing the activity of the disease.

RESULTS

A substantial number of those with asthma (56.2%) had the EOS(lo) pattern (<250 EOS/mm(3)). Patients with asthma who had the EOS(hi) pattern had higher immunoglobulin E (IgE), a lower forced expiratory volume in 1 s (FEV(1)) and presented a more active asthma than those with the EOS(lo) pattern. Among those with the EOS(lo) pattern, neutrophil inflammation (NEU(hi)) was related to a less frequent positive skin prick test response (OR 0.44, 95% CI 0.20 to 0.96). Among those with the EOS(hi) pattern, neutrophil inflammation did not explain current asthma or asthma activity, and was significantly related to nocturnal symptoms (OR 5.21, 95% CI 1.44 to 18.8) independently of age, sex, smoking and inhaled corticosteroid treatment. In non-smokers with asthma, COPD-like symptoms, in particular chronic phlegm, were more frequent in those with neutrophil inflammation, independent of eosinophil inflammation (OR 2.35, 95% CI 1.08 to 5.10).

CONCLUSIONS

Besides eosinophilia, neutrophil inflammation assessed in the blood is related to specific characteristics of asthma. Considering simultaneously neutrophilic and eosinophilic inflammation may contribute to help to disentangle this complex disease.

Total serum IgE levels are associated with ambient ozone concentration in asthmatic adults

BACKGROUND

Effects of air pollution exposure on IgE-mediated response in asthmatics are poorly investigated. The aim was to examine the relationship between air pollution concentrations and total IgE levels in adult asthmatics.

METHODS

The present study relates to the 369 asthmatic adults from the French Epidemiological study on Genetics and Environment of Asthma (EGEA), with availability of data on both total serum IgE measurements and air pollution concentrations. Geo-statistical models were performed on 4 x 4 km grids to assess individual outdoor air pollution exposure. Annual outdoor concentrations of ozone (O(3)), nitrogen dioxide (NO(2)), sulphur dioxide (SO(2)), and particulate matter smaller than 10 microm size (PM(10)), and concentrations of summer ozone were assigned to subject's home address.

RESULTS

The geometric mean of total IgE was 161 IU/ml and the average of O(3) exposure was 44.9 +/- 9.5 microg/m(3). Ozone concentrations were positively related to total IgE levels and an increase of 10 microg/m(3) of O(3) resulted in an increase of 20.4% (95% CI = 3.0-40.7) in total IgE levels. Adjustment for age, gender, smoking habits and previous life in the countryside did not change the results, and an increase of 19.1% (2.4-38.6) in total IgE was observed with O(3). Negative associations observed between NO(2) and total IgE levels disappeared after including O(3) in the models. Neither SO(2) nor PM(10) were correlated with total IgE levels.

CONCLUSIONS

Results suggest that O(3) or related ambient pollutants may up-regulate total IgE levels among asthmatic adults.

IL18 and IL18R1 polymorphisms, lung CT and fibrosis: A longitudinal study in coal miners

It has been suggested that interleukin (IL)-18 plays a role in the development of inflammatory and fibrosing lung diseases. Associations of polymorphisms in the genes coding for IL-18 (IL18 /G-656T, C-607A, G-137C, T113G, C127T) and its receptor (IL18R1 /C-69T) with coal workers' pneumoconiosis (CWP) were studied in 200 miners who were examined in 1990, 1994 and 1999. Coal-dust exposure was assessed according to job history and ambient measures. The main health outcome was lung computed tomography (CT) score in 1990. Internal coherence was assessed by studying CT score in 1994, 4-yr change in CT score and CWP incidence and prevalence. CT score in 1990 was a good predictor of radiographic grade in 1999 and, therefore, an appropriate subclinical quantitative trait. The IL18 -137C allele was associated with lower CT score in 1990 and 1994 (1.24 versus 1.69 and 1.57 versus 2.46, respectively), slower progression of CT score between 1990 and 1994 and lower pneumoconiosis prevalence in 1999 relative to the G allele (0.33 versus 0.77 and 8.2 versus 19.6%, respectively). Smoking- or dust-adjustment, and stratification on IL18R1 genotype and adjustment for haplotype effects did not change the conclusions. In conclusion, the results of the present study suggest a role for IL18 in reducing the development of this fibrosing lung disease.

Effect of TNF and LTA polymorphisms on biological markers of response to oxidative stimuli in coal miners: a model of gene-environment interaction. Tumour necrosis factor and lymphotoxin alpha

INTRODUCTION

Interaction between genetic background and oxidative environmental stimuli in the pathogenesis of human lung disease has been largely unexplored.

METHODS

A prospective epidemiological study was undertaken in 253 coal miners. Intermediate quantitative phenotypes of response to oxidant exposure, including erythrocyte glutathione peroxidase (GSH-Px) and catalase activities, were studied. Oxidant exposures studied were smoking habits and cumulative dust exposure assessed by job history and ambient measures. Disease phenotypes included subclinical computed tomography score at the first survey and x ray profusion grades twice, five years apart, to assess established coal workers' pneumoconiosis (CWP). Miners were genotyped for common functional polymorphisms in the gene for tumour necrosis factor alpha (TNF) and lymphotoxin alpha (LTA), two proinflammatory cytokines that have been implicated in the pathogenesis of chronic lung diseases.

RESULTS

Regarding gene-environment interaction on intermediate phenotypes, results showed interaction of a promoter polymorphism at the -308 position in TNF with occupational exposure on erythrocyte GSH-Px activity with a significant association in those with high exposure (p=0.003), whereas no association was observed among those with low exposure (interaction p=0.06). Regarding gene intermediate phenotype interaction on clinical outcome, results showed an association of CWP prevalence with an NcoI polymorphism in LTA in those with low catalase activity (p=0.05), whereas no association was observed in those with high activity (interaction p=0.03). No other significant association was observed.

CONCLUSION

The results suggest that interactions of genetic background with environmental exposure and intermediate response phenotypes are important components in the pathogenesis of CWP.

Cross sectional and longitudinal study on selenium, glutathione peroxidase, smoking, and occupational exposure in coal miners

OBJECTIVES

To understand the variations of selenium (Se) concentration relative to changes in occupational exposure to coal dust, taking into account age and changes in smoking habits in miners surveyed twice, in 1990 and 1994. To better understand the relation of Se concentration with glutathione peroxidase activities (GSH-Px) in these miners.

METHODS

In 1994, blood samples were obtained from active (n=131) and retired (n=40) miners without coal worker's pneumoconiosis, in whom Se concentration was available at both surveys and in whom International Labour Organisation (ILO) profusion grade had not been changed. Active miners were exposed to high dust concentrations (n=48) or low dust concentrations (n=83). Miners were classified into three subgroups according to their estimated cumulative exposure to dust, and into three subgroups according to their smoking habits.

RESULTS

Selenium concentration and GSH-Px activities were significantly lower in active than in retired miners (Se adjusted means: 62.6 v 72.2 ng/ml p=0.01). Moreover, Se concentration was lower in miners exposed to high compared with those exposed to low dust concentrations (adjusted means: 59.4 v 65.8). In miners exposed to high dust concentrations, Se concentration was significantly lower whereas erythrocyte GSH-Px activity was significantly higher in the subgroup with estimated cumulative exposure >68 mg/m(3).y. In all miners, plasma GSH-Px activity was correlated with Se concentration (r=0.22, p<0.005). The 4 year Se changes were negatively related to exposure to high dust concentrations and positively related to change in exposure from high to retirement and to change from smoker to ex-smoker (p=0.01).

CONCLUSION

The variations of Se concentration in relation to changes in occupational exposure to coal dust and in smoking habits, and the close correlation found between plasma Se concentration and GSH-Px activity suggest that both are required in antioxidant defence. These results agree well with the hypothesis that the decrease in Se concentration reflects its use against reactive oxygen species generated by exposure to coal mine dust and by smoking.

Relationship between blood antioxidants and occupational exposure to polycyclic aromatic hydrocarbons in coke oven workers

BACKGROUND

We investigated if blood Cu++/Zn++ superoxide dismutase, glutathione peroxidase, and catalase activities are increased and total plasma antioxidant concentration is decreased in coke oven workers exposed to polycyclic aromatic hydrocarbons.

METHODS

Ninety-six coke oven workers participated in the study. Nonexposed workers (n = 105) were randomly sampled among power plant workers in the same age range. The examination included a questionnaire on health status, occupational history, smoking, and dietary habits. Blood samples completed the examination. Coke oven workers were classified into low-, middle-, and high-exposure groups based on the benzo[a]pyrene (B[a]P) air concentrations and were further classified into the categories "topside" and "non-topside," according to their proximity to the ovens.

RESULTS

Erythrocyte glutathione peroxidase activity increased with age (r = 0.18, P = 0.061) in power plant workers, whereas plasma glutathione peroxidase activity decreased with age (r = -0.18, P = 0.068) and erythrocyte glutathione peroxidase activity was inversely correlated with the number of cigarettes per day (r = -0.28, P = 0.08) in coke oven workers. Comparison of blood antioxidant enzyme activities and total plasma antioxidant concentration between coke oven and power plant workers showed that erythrocyte glutathione peroxidase activity was significantly lower in coke oven workers, even after adjustment for potential confounding factors. No differences were found either in other blood antioxidant enzyme activities or in total plasma antioxidant concentration between coke oven and power plant workers. Moreover, no trends toward decreased glutathione peroxidase activity among the three subgroups of B[a]P exposure were observed, and no differences either in blood antioxidant enzyme activities or in total plasma antioxidant concentration between the two groups of job categories were found.

CONCLUSIONS

Production of reactive oxygen species seems not to be increased in coke oven workers.

Relations between occupational exposure to coal mine dusts, erythrocyte catalase and Cu++/Zn++ superoxide dismutase activities, and the severity of coal workers' pneumoconiosis

OBJECTIVES

To better understand the relations between occupational exposure, blood antioxidant enzyme activities, total plasma antioxidant concentration, and the severity of coal workers' pneumoconiosis (CWP).

METHODS

Blood samples were obtained from miners without CWP exposed to low dust concentrations for > or = 4 years at the time of the study (n = 105), or exposed to high dust concentrations for > or = 14 years at the time of the study (n = 58), and from retired miners with CWP (n = 19). Miners without CWP were classified into three subgroups according to their estimated cumulative exposure to dust. Chest x ray films were obtained for each miner. Miners were classified in five subgroups according to their International Labour Organisation (ILO) profusion grades. Univariate tests were completed by multiple linear regression analyses.

RESULTS

The estimated cumulative exposure to dust was strongly positively related to erythrocyte catalase activity and strongly negatively related to Cu++/Zn++ SOD activity only in miners exposed to high dust concentrations for > or = 14 years at the time of the study (F tests p = 0.006 and p = 0.004 respectively). Moreover, catalase activity was strongly related to the severity of CWP expressed as five subgroups of ILO profusion grades (F test p = 0.003); the greatest difference in the mean values was found between the group of 1/1 to 1/2 ILO profusion grades and the group of 2/1 to 3/3 ILO profusion grades.

CONCLUSION

These results are in good agreement with the hypothesis that production of reactive oxygen species may be an important event in the exposure to coal mine dusts and the severity of CWP. Erythrocyte catalase and Cu++/Zn++ SOD activities are more closely related to recent exposure to high dust concentrations than to cumulative exposure, and could be considered as biological markers of exposure rather than as markers of early adverse biological effect.