Is the prevalence of asthma declining? Systematic review of epidemiological studies

Transforming growth factor-beta1 in inflammatory airway disease: a key for understanding inflammation and remodeling

Airway diseases such as chronic rhinosinusitis, asthma, and chronic obstructive pulmonary disorder are characterized by inflammation and remodeling. Among inflammatory and extracellular matrix regulatory cytokines, transforming growth factor-beta (TGF-β) stands central, as it possesses both important immunomodulatory and fibrogenic activities, and should be considered a key for understanding inflammation and remodeling processes. This review will briefly summarize the recent findings on the role of TGF-β1, from the view points of inflammation and remodeling, and discuss the role of TGF-β in the upper and lower airway diseases. This may reveal new perspectives in the understanding of airway inflammation and remodeling processes and may open innovative treatment strategies for the regulation of TGF-β1.

Asthma and proinflammatory conditions: a population-based retrospective matched cohort study

OBJECTIVE

To determine the association between asthma and proinflammatory conditions.

PARTICIPANTS AND METHODS

This population-based retrospective matched cohort study enrolled all asthmatic patients among Rochester, Minnesota, residents between January 1, 1964, and December 31, 1983. For each asthmatic patient, 2 age-and sex-matched nonasthmatic individuals were drawn from the same population. The asthmatic and nonasthmatic cohorts were followed forward in the Rochester Epidemiology Project diagnostic index for inflammatory bowel disease (IBD), rheumatoid arthritis (RA), diabetes mellitus (DM), and coronary heart disease (CHD) as outcome events. Data were fitted to Cox proportional hazards models.

RESULTS

We identified 2392 asthmatic patients and 4784 nonasthmatic controls. Of the asthmatic patients, 1356 (57%) were male, and mean age at asthma onset was 15.1 years. Incidence rates of IBD, RA, DM, and CHD in nonasthmatic controls were 32.8, 175.9, 132.0, and 389.7 per 100,000 person-years, respectively; those for asthmatic patients were 41.4, 227.9, 282.6, and 563.7 per 100,000 person-years, respectively. Asthma was associated with increased risks of DM (hazard ratio, 2.11; 95% confidence interval, 1.43-3.13; P<.001) and CHD (hazard ratio, 1.47; 95% confidence interval, 1.05-2.06; P=.02) but not with increased risks of IBD or RA.

CONCLUSION

Although asthma is a helper T cell type 2-predominant condition, it may increase the risks of helper T cell type 1-polarized proinflammatory conditions, such as CHD and DM. Physicians who care for asthmatic patients need to address these unrecognized risks in asthmatic patients.

PELICAN: A quality of life instrument for childhood asthma: study protocol of two randomized controlled trials in primary and specialized care in the Netherlands

Background

Asthma is one of the major chronic health problems in children in the Netherlands. The Pelican is a paediatric asthma-related quality of life instrument for children with asthma from 6–11 years old, which is suitable for clinical practice in primary and specialized care. Based on this instrument, we developed a self-management treatment to improve asthma-related quality of life. The Pelican intervention will be investigated in different health care settings. Results of intervention studies are often extrapolated to other health care settings than originally investigated. Because of differences in organization, disease severity, patient characteristics and care provision between health care settings, extrapolating research results could lead to unnecessary health costs without the desired health care achievements. Therefore, interventions have to be investigated in different health care settings when possible. This study is an example of an intervention study in different health care settings. In this article, we will present the study protocol of the Pelican study in primary and specialized care.

Method/design

This study consists of two randomized controlled trials to assess the effectiveness of the Pelican intervention in primary and specialized care. The trial in primary care is a multilevel design with 170 children with asthma in 16 general practices. All children in one general practices are allocated to the same treatment group. The trial in specialized care is a multicentre trial with 100 children with asthma. Children in one outpatient clinic are randomly allocated to the intervention or usual care group. In both trials, children will visit the care provider four times during a follow-up of nine months. This study is registered and ethically approved.

Discussion

This article describes the study protocol of the Pelican study in different health care settings. If the Pelican intervention proves to be effective and efficient, implementation in primary and specialized care for paediatric asthma in the Netherlands will be recommended.

Trial registration

This study is registered by clinicaltrial.gov (NCT01109745)

Environmental tobacco smoke and male sex modify the influence of IL-13 genetic variants on cord blood IgE levels

Elevated cord blood IgE (cIgE) levels enhance the risk of childhood atopic diseases. However, genetic determinants of cIgE elevation and their potential modifiers remain inconclusive. We aimed to investigate the associations of single-nucleotide polymorphisms (SNPs) in the IL-13 gene (IL-13) with cIgE elevation and their interactions with prenatal environmental tobacco smoke (ETS) and neonatal sex. A structured questionnaire regarding prenatal environmental exposures was completed during pregnancy. Birth information was extracted from the medical records. Cord blood from 794 term neonates was genotyped for three SNPs (rs1800925, rs20541, and rs848) of IL-13 and measured for cIgE levels. SNP rs20541 and a 3-SNP haplotype containing rs1800925, rs20541, and rs848 (denoted as h011) were significantly associated with cIgE elevation (p = 0.04 and 0.003, respectively). Two-way interaction analysis revealed that the associations of IL-13 rs20541 and h011 with cIgE elevation were synergistically enhanced by prenatal ETS (p for interaction = 0.03 and 0.03, respectively), but not by male sex. If the association analyses were stratified by prenatal ETS and neonatal sex simultaneously, IL-13 rs20541 and h011 had the highest risks for cIgE elevation in male babies prenatally exposed to ETS, with adjusted odds ratios (95% confidence interval) being 3.03 (1.56-5.88) and 2.81 (1.54-5.15), respectively. When three-way interactions were examined, both IL-13 rs20541 and h011 exhibited significant interactions with male sex and ETS (p for interaction = 0.03 and 0.007, respectively). In conclusion, the influence of IL-13 genetic variants on cIgE elevation was modified by male sex and prenatal ETS.

Motor vehicle air pollution and asthma in children: a meta-analysis

BACKGROUND

Asthma affects more than 17 million people in the United States;1/3 of these are children. Children are particularly vulnerable to airborne pollution because of their narrower airways and because they generally breathe more air per pound of body weight than adults, increasing their exposure to air pollutants. However, the results from previous studies on the association between motor vehicle emissions and the development of childhood wheeze and asthma are conflicting. Therefore, we conducted a meta-analysis to clarify their potential relationship.

METHODS

MEDLINE, Highwire, and The Cochrane Library databases were searched for relevant studies. Adjusted odds ratio (OR) with corresponding 95% confidence interval (CI) for the association between traffic air pollutants and wheeze or asthma were retrieved from individual studies and pooled to generate summary effect estimates (meta-OR) in STATA 11.1.

RESULTS

Nineteen studies were included in the meta-analysis. Exposure to nitrogen dioxide (meta-OR: 1.05, 95% CI: 1.00-1.11), nitrous oxide (meta-OR: 1.02, 95% CI: 1.00-1.04), and carbon monoxide (meta-OR: 1.06, 95% CI: 1.01-1.12) were positively associated with a higher prevalence of childhood asthma. Exposure to sulfur dioxide (meta-OR: 1.04, 95% CI: 1.01-1.07) was positively associated with a higher prevalence of wheeze in children. Exposure to nitrogen dioxide was positively associated with a higher incidence of childhood asthma (meta-OR: 1.14, 95% CI: 1.06-1.24), and exposures to particulate matter was positively associated with a higher incidence of wheeze in children (meta-OR: 1.05, 95% CI: 1.04-1.07).

CONCLUSIONS

Living or attending schools near high traffic density roads exposes children to higher levels of motor vehicle air pollutants, and increases the incidence and prevalence of childhood asthma and wheeze.

Is the asthma epidemic still ascending?

Asthma is a phenotypically heterogeneous disorder of multifactorial origins that affects 300 million people suffering from asthma and more than 250,000 asthma-related deaths each year. Although treatment for asthma has improved, its prevalence continues to increase, particularly in low and middle income countries, or in some ethnic groups in which prevalence was previously low. Observed spatio-temporal variations in the increased prevalence of asthma depend on exposure to environmental factors. Recently, several arguments are also in favor of the involvement of host susceptibility and stress in the observed increase of asthma prevalence. Further investigations are warranted to better understand mechanisms underlying asthma increase or stagnation.

Investigating international time trends in the incidence and prevalence of atopic eczema 1990-2010: a systematic review of epidemiological studies

The prevalence of atopic eczema has been found to have increased greatly in some parts of the world. Building on a systematic review of global disease trends in asthma, our objective was to study trends in incidence and prevalence of atopic eczema. Disease trends are important for health service planning and for generating hypotheses regarding the aetiology of chronic disorders. We conducted a systematic search for high quality reports of cohort, repeated cross-sectional and routine healthcare database-based studies in seven electronic databases. Studies were required to report on at least two measures of the incidence and/or prevalence of atopic eczema between 1990 and 2010 and needed to use comparable methods at all assessment points. We retrieved 2,464 citations, from which we included 69 reports. Assessing global trends was complicated by the use of a range of outcome measures across studies and possible changes in diagnostic criteria over time. Notwithstanding these difficulties, there was evidence suggesting that the prevalence of atopic eczema was increasing in Africa, eastern Asia, western Europe and parts of northern Europe (i.e. the UK). No clear trends were identified in other regions. There was inadequate study coverage worldwide, particularly for repeated measures of atopic eczema incidence. Further epidemiological work is needed to investigate trends in what is now one of the most common long-term disorders globally. A range of relevant measures of incidence and prevalence, careful use of definitions and description of diagnostic criteria, improved study design, more comprehensive reporting and appropriate interpretation of these data are all essential to ensure that this important field of epidemiological enquiry progresses in a scientifically robust manner.

Pulmonary toxicity and adjuvant effect of di-(2-exylhexyl) phthalate in ovalbumin-immunized BALB/c mice

BACKGROUND

Asthma is a complex pulmonary inflammatory disease, which is characterized by airway hyperresponsiveness, variable airflow obstruction and inflammation in the airways. The majority of asthma is allergic asthma, which is a disease caused by type I hypersensitivity mediated by IgE. Exposures to a number of environmental chemicals are suspected to lead to asthma, one such pollutant is di-(2-ethylheyl) phthalate (DEHP). DEHP is a manufactured chemical that is commonly added in plastic products to make them flexible. Epidemiological studies have revealed a positive association between DEHP exposure and asthma prevalence.

METHODOLOGY/PRINCIPAL FINDINGS

The present study was aimed to determine the underlying role of DEHP exposure in airway reactivity, especially when combined with allergen exposure. The biomarkers include pulmonary histopathology, airway hyperresponsiveness (lung function), IgE, IL-4, IFN-γ and eosinophils. Healthy balb/c mice were randomly divided into eight exposure groups (n = 8 each): (1) saline control, (2) 30 µg/(kg•d) DEHP, (3) 300 µg/(kg•d) DEHP, (4) 3000 µg/(kg•d) DEHP, and (5) ovalbumin (OVA)-sensitized group, (6) OVA-combined with 30 µg/(kg•d) DEHP, (7) OVA-combined with 300 µg/(kg•d) DEHP, and (8) OVA-combined with 3000 µg/(kg•d) DEHP. Experimental tests were conducted after 52-day DEHP exposure and subsequently one week of challenge with aerosolized OVA. The principal findings include: (1) Strong postive associations exist between OVA-combined DEHP exposure and serum total IgE (T-IgE), as well as histological findings. These positive associations show a dose-dependent low dose sensitive effect of DEHP. (2) IL-4, eosinophil recruitment and lung function are also indicators for adjuvant effect of DEHP.

CONCLUSIONS/SIGNIFICANCE

Our results suggest that except the significant changes of immunological and inflammatory biomarkers (T-IgE, IL-4, IFN-γ and eosinophils), the pulmonary histological (histopathological examination) and physiological (lung function) data also support that DEHP may promote and aggravate allergic asthma by adjuvant effect.

The management of asthma and chronic obstructive pulmonary disease: current status and future perspectives

Asthma and chronic obstructive pulmonary disease (COPD) represent the leading chronic respiratory diseases of interest in the word, owing to their high prevalence and burden on the health system. Care of these patients, undergoing frequent exacerbations, is a heavy burden on healthcare systems. In the last few years, large improvements in the management of asthma and COPD have been made, owing to new drugs and management strategies, and to the improvement of the nonpharmacologic treatment of COPD. There are still many unmet needs in the treatment of these diseases. In asthma, strategies to improve control should be implemented. There is a need to use more biomarkers to tailor treatment, in the assessment and choice of appropriate therapy, especially in severe patients. In COPD, there is growing evidence of individual differences in lung function decline rate and associated differences in appropriate management strategies. Early effective and prolonged bronchodilation can slow disease progression and reduce the frequency of exacerbations. New perspectives include the use of biologic drugs (anticytokine monoclonal antibodies) in selected categories of severe asthmatics, potential new inhibitors of chemokines and cytokines involved in the pathobiology of asthma and COPD, and a further improvement of current drugs and better implementation of management strategies, particularly in COPD patients.

Evidence of association between interferon regulatory factor 5 gene polymorphisms and asthma

Asthma is a heterogeneous disorder hallmarked by chronic inflammation in the respiratory system. Exacerbations of asthma are correlated with respiratory infections. Considering the implication of interferon regulatory factor 5 (IRF5) in innate and adaptive immunity, we investigated the preferential transmission patterns of ten IRF5 gene polymorphisms in two asthmatic family cohorts. A common IRF5 haplotype was found to be associated with asthma and the severity of asthmatic symptoms. Stratified analysis of subgroups of asthmatic individuals revealed that the associations were more pronounced in nonatopic asthmatic individuals. In addition, the risk alleles of IRF5 polymorphisms for asthma were almost completely opposite to those for autoimmune disorders. Our study provides the first evidence of association between IRF5 and asthma, and sheds light on the related but potentially distinct roles of IRF5 alleles in the pathogenesis of asthma and autoimmune disorders.

Prevalence of allergic disorders among primary school-aged children in Madinah, Saudi Arabia: two-stage cross-sectional survey

BACKGROUND

There are limited data on the epidemiology of allergic disorders in Saudi Arabia. Such data are needed for, amongst other things, helping to plan service provision at a time when there is considerable investment taking place in national healthcare development. We sought to estimate the prevalence of atopic eczema, allergic rhinitis and asthma in primary school children in Madinah, Saudi Arabia.

METHODS AND FINDINGS

We conducted a two-stage cross-sectional survey of schoolchildren in Madinah. Children were recruited from 38 randomly selected schools. Questionnaires were sent to the parents of all 6,139 6-8 year old children in these schools. These parental-completed questionnaires incorporated questions from the International Study of Asthma and Allergies in Childhood (ISAAC), which had previously been validated for use in Arab populations. We undertook descriptive analyses, using the Generalized Estimating Equation (GEE) to calculate 95% confidence intervals. The overall response rate was 85.9% (n = 5,188), 84.6% for girls and 86.2% for boys, respectively. Overall, parents reported symptoms suggestive of a history of eczema in 10.3% (95%CI 9.4, 11.4), rhinitis in 24.2% (95%CI 22.3, 26.2) and asthma in 23.6% (95%CI 21.3, 26.0) of children. Overall, 41.7% (95%CI 39.1, 44.4) of children had symptoms suggestive of at least one allergic disorder, with a substantial minority manifesting symptoms indicative of co-morbid allergic disease. Comparison of these symptom-based prevalence estimates with reports of clinician-diagnosed disease suggested that the majority of children with eczema and asthma had been diagnosed, but only a minority (17.4%) of children had been diagnosed with rhinitis. International comparisons indicated that children in Madinah have amongst the highest prevalence of allergic problems in the world.

CONCLUSIONS

Symptoms indicative of allergic disease are very common in primary school-aged children in Madinah, Saudi Arabia, with figures comparable to the highest risk regions in the world.

Attenuation of airway hyperreactivity and T helper cell type 2 responses by coumarins from Peucedanum praeruptorum Dunn in a murine model of allergic airway inflammation

ETHNOPHARMACOLOGICAL RELEVANCE

The root of Peucedanum praeruptorum Dunn (PPD) is a commonly used traditional Chinese medicine for the treatment of asthma. Its major constituents, coumarins, were presumed to be responsible for its efficacy.

AIM OF THE STUDY

The potential of coumarins from PPD (CPPD) as anti-asthma agent was investigated.

MATERIALS AND METHODS

Female BALB/c mice were sensitized and challenged with ovalbumin (OVA) to induce allergic airway inflammation. CPPD was administered intragastrically before every OVA challenge. Airway reactivity to the intravenous administration of acetylcholine chloride was measured 48h after final OVA inhalation. Airway inflammation was evaluated by leukocyte counts of bronchoalveolar lavage fluid (BALF) and histopathological analysis of lung lesions. Levels of interleukin (IL)-4, IL-5, IL-10, IL-13 and IFN-γ in BALF and OVA-specific immunoglobulin (Ig) E in serum, and activity of eosinophil peroxidase (EPO) in lung was measured. The percentage of CD4(+)CD25(+)Foxp3(+) regulatory T cells among CD4(+) T cells in spleen was analyzed by flow cytometry.

RESULTS

Compared with model group, CPPD significantly reduced airway hyperreactivity and airway eosinophilic inflammation, improved pathologic lesion of the lungs, reduced levels of IL-4, IL-5, IL-13 in BALF and OVA-specific IgE in serum, inhibited the activities of EPO in lung, and up-regulated levels of IL-10 and IFN-γ in BALF as well as the percentage of CD4(+)CD25(+)Foxp3(+) regulatory T cells in spleen.

CONCLUSION

CPPD can significantly suppress OVA-induced airway inflammation, airway hyperreactivity and Th2 predominant response in mice, showing great therapeutic potential for the treatment of allergic asthma.

Influence of asthma epidemiology on the risk for other diseases

Asthma is a multifactorial chronic disease affecting a significant proportion of people in the United States and worldwide. Numerous laboratory and epidemiological studies have attempted to understand the etiology and underlying mechanisms of asthma and to identify effective therapies. However, the impact of asthma on the risk for other diseases has drawn little attention. This paper discusses the potential effects of asthma as a risk factor for other diseases, explores the potential mechanisms, and reviews the implications of the findings to clinical practice, public health, and research.

Asthma, chronic obstructive pulmonary disease, and mortality in the U.S. population

BACKGROUND

COPD and asthma are common diseases in the U.S. population and can coexist. Our goal was to determine the prevalence of self-reported, physician-diagnosed asthma and COPD in a sample of the U.S. population and their association with lung function impairment and mortality.

METHODS

We used baseline data from NHANES III and the follow-up mortality data. We used logistic regression and Cox Proportional Hazards models, adjusting for age, sex, race/ethnicity, education level, smoking status, and disease stage.

RESULTS

The sample consisted of 15,203 subjects, of whom 4,542 died during the follow-up period. Coexisting COPD and asthma was reported by 357 (2.7%), COPD by 815 (5.3%), and asthma by 709 (5.3%). Subjects with both conditions had a higher proportion of obstruction (30.9%) than those with COPD (24.3%), asthma (13.3%), or no lung disease (5.4%). In survival models adjusting for all factors except baseline lung function, coexisting COPD and asthma had the highest risk for mortality (Hazard Ratio [HR] 1.83, 95% confidence interval [CI] 1.34, 2.49), followed by COPD only (HR 1.44, 95% CI 1.28, 1.62), and asthma only (HR 1.16, 95% CI 0.94, 1.42). These affects were attenuated after controlling for baseline lung function: coexisting asthma and COPD (HR 1.45, 95% CI 1.06, 1.98), COPD only (1.28, 95% CI 1.13, 1.45), and asthma only (HR 1.04, 95% CI 0.85, 1.27).

CONCLUSION

In this analysis, subjects who report coexisting asthma and COPD have a higher risk of obstruction on spirometry and a higher risk of death during follow-up.

Does diversity of environmental microbial exposure matter for the occurrence of allergy and asthma?

This review describes the recent literature on microbial exposures and protective effects for asthma and atopy. Certain microorganism-associated molecular patterns have been identified as agents that might influence the development of the immune system, which in turn leads to protective effects for asthma and atopy. Endotoxins from gram-negative bacteria were the first agents associated with a reduced risk for asthma and atopy. In later studies, β(1→3)glucans, extracellular polysaccharides, and muramic acid from, respectively, molds and gram-positive bacteria were associated with a reduced risk of allergy and asthma separately in rural and urban populations. These results already suggested that not just one but several independent microbial signals from gram-negative and gram-positive bacteria, as well as molds, might play a role in explaining the protective effects. Recently, the diversity of microbial exposure has been associated with such a reduced risk in farmers' children. Surprisingly, the diversity of both fungal and bacterial exposure seemed to have protective effects. These results open new areas of research and create complex challenges. Methodological issues, such as environmental exposure characterization and assessment and elucidation of potential underlying mechanisms, are discussed because these aspects have a major influence on how microbial diversity can be studied in future studies in relation to protective effects for asthma and atopy.

Increased risk of pertussis in patients with asthma

BACKGROUND

The recent pertussis outbreak in California highlights the effect of pertussis on public health. In 2004, a pertussis outbreak occurred in Olmsted County, Minnesota, despite a high vaccine uptake. This outbreak provided a natural experiment to assess the relationship between asthma and pertussis.

OBJECTIVE

We sought to determine whether asthmatic subjects have a higher risk of pertussis than nonasthmatic subjects.

METHODS

We conducted a population-based case-control study. There were 223 pertussis cases identified by means of PCR in 2004 and 2005. We identified age- and sex-matched control subjects from 5537 patients with negative test results for pertussis. We conducted a comprehensive medical record review and applied predetermined criteria to ascertain asthma status. Conditional logistic regression was fit to assess the effect of asthma status on the risk of pertussis.

RESULTS

Of the 223 subjects, 164 were eligible for the study, and 328 matched control subjects (1:2 matching) were enrolled. Of these 164 subjects, 50% were male, and 82% were white. The median age at the index date of pertussis was 14 years. Sixty-two (38%) of the 164 cases had asthma before the index date of pertussis compared with 85 (26%) of the 328 control subjects (odds ratio, 1.73; 95% CI, 1.12-2.67; P = 013). The population attributable risk percentage of asthma for risk of pertussis was 17%.

CONCLUSIONS

Given the high prevalence of asthma and the ongoing risk of pertussis throughout the United States, consideration of defining asthmatic subjects as a target group for pertussis vaccination (eg, replacing decennial tetanus-diphtheria booster with tetanus, diphtheria, and acellular pertussis vaccine for adolescents and adults) should be given.

Effects of (±)-praeruptorin A on airway inflammation, airway hyperresponsiveness and NF-κB signaling pathway in a mouse model of allergic airway disease

The root of Peucedanum praeruptorum Dunn is a traditional Chinese medicine commonly used to treat asthma in China. (±)-praeruptorin A (PA) is the most abundant constituent of P. praeruptorum Dunn, the effects of which on asthma were investigated using a murine model of allergic airway disease. BALB/c mice were sensitized and challenged by ovalbumin to induce airway inflammation. PA was administered intragastrically before every OVA challenge. Airway responsiveness was measured by a lung function analysis system. The number of total leukocytes in bronchoalveolar lavage fluid was counted using a hemocytometer, and differential cell counts were determined using Diff-Quick-stained smears. Histopathology of lung tissue was analyzed by hematoxylin-eosin and Congo red staining. Levels of inflammatory mediators in bronchoalveolar lavage fluid and immunoglobulins in serum were measured by enzyme-linked immunosorbent assay. The expression of pulmonary eotaxin was detected by immunohistochemistry and reverse transcription polymerase chain reaction. The activation of NF-κB was evaluated by electrophoretic mobility shift assay and western blot analysis. Compared with model group, PA significantly reduced airway hyperresponsiveness and airway eosinophilic inflammation, improved pathologic lesion of the lungs, reduced levels of interleukin (IL)-4, IL-5, IL-13 and LTC₄ in bronchoalveolar lavage fluid and immunoglobulin (Ig) E in serum, and inhibited eotaxin protein and mRNA expression, IκBα degradation, NF-κB nuclear translocation, NF-κB DNA-binding activity and RelA/p65 phosphorylation in lung, which suggested that PA can significantly suppress OVA-induced airway inflammation and airway hyperresponsiveness in mice, showing great therapeutic potential for the treatment of allergic asthma.

A long-term follow-up of allergic diseases in Iceland

INTRODUCTION

Allergic disorders are an increasing health problem in many countries, in particular among children. We have evaluated the prevalence and manifestations of allergy in a cohort of young Icelanders for more than two decades. Variations in the epidemiology and clinical expression of allergy in different communities may help to identify etiological factors contributing to these disorders.

METHODS

A cohort of 179 children has been monitored for allergic manifestations for two decades, at the ages of two, four, eight, and 15 years, and most recently at the age of 21 years involving 120 of the participants.

RESULTS

Cumulative prevalences of 40%, 45%, and 29% have been observed, respectively, for rhinoconjunctivitis, eczema, and asthma during the study period. None had developed rhinoconjunctivitis at the age of about 2 years, but the point prevalence gradually increased to 33% at the age of 21 years. Conversely, the prevalence of eczema was 31% at the age of 2 years, but gradually declined to 8% at the age of 21 years. The prevalence of asthma peaked at 28% at the age of 4 years, but declined thereafter and has remained stable at about 13% from the age of eight to 21 years.

DISCUSSION

The prevalence of allergic diseases is high in Iceland among children and young individuals. Asthma and atopic eczema are very common in childhood, but decreases with age while the prevalence of rhinoconjunctivitis increases markedly. The very high and increasing prevalence of rhinoconjunctivitis among 15- to 21-year-old individuals is noteworthy.

Time trend of asthma in children and adolescents in Brazil, 1998-2008

OBJECTIVE

To analyze the trends in asthma prevalence in children and adolescents between 1998 and 2008 in Brazil.

METHODS

Data on asthma prevalence from the 1998, 2003 and 2008 National Household Sample Surveys were analyzed. The sample was comprised of 141,402, 144,443 and 134,032 individuals in 1998, 2003 and 2008, respectively, and the analysis was adjusted for the sample design. Trends in asthma prevalence were described for sex, Brazilian regions and place of residence of children (zero to nine years of age) and adolescents (ten to 19 years of age).

RESULTS

The prevalence of asthma in children was 7.7% in 1998, 8.1% in 2003 and 8.5% in 2008, with an annual increase of 1%. The highest annual increase was observed in the Southeast and North regions (1.4%). Among adolescents, the prevalence of asthma was 4.4% in 1998, 5.0% in 2003 and 5.5% in 2008, with an increase of 2.2% per year. In the Northeast region, the annual increase in the prevalence of asthma was 3.5%. The greatest increases were observed in boys and in residents of rural areas.

CONCLUSIONS

Although asthma has decreased in some developing countries, the results found in Brazil point to an increase in this disease in children and adolescents between 1998 and 2008, especially in rural areas.

An update on emerging drugs for asthma

INTRODUCTION

It is recognized that airway inflammation is key to asthma pathogenesis. Biopharmaceutical approaches have identified new therapies that target key cells and mediators that drive the inflammatory responses in the asthmatic lung. Such an approach resulted in the development of biologics including IL-4, IL-5 and IL-13. However, clinical trials with these biologics in patients with asthma were for the most part disappointing even though they proved to be highly effective in animal models of asthma.

AREAS COVERED

This review based on English-language original articles in PubMed or MedLine published in the last 5 years will update the current status, therapeutic potential and potential problems of recent drug developments in asthma therapy.

EXPERT OPINION

It is becoming apparent that significant clinical effects with anti-cytokine-based therapies are more likely in carefully selected patient populations that take asthma phenotypes into account. It might also be more clinically effective if more than one cytokine and/or chemokine were to be targeted rather than a single mediator.

The impact of asthma and COPD in sub-Saharan Africa

BACKGROUND

Many countries in sub-Saharan Africa have the highest risk of developing chronic diseases and are the least able to cope with them.

AIMS

To assess the current knowledge of the prevalence and impact of asthma and chronic obstructive pulmonary disease (COPD) in sub- Saharan Africa.

METHODS

A literature search was conducted using Medline (1995-2010) and Google Scholar.

RESULTS

Eleven studies of the prevalence of asthma in sub-Saharan Africa were identified, all of which showed a consistent increase, particularly in urban regions. The data on asthma show a wide variation (5.7-20.3%), with the highest prevalence in 'westernised' urban areas. Only two studies of the prevalence of COPD in sub-Saharan Africa have been performed. Nevertheless, COPD has become an increasing health problem in sub-Saharan Africa due to tobacco smoking and exposure to biomass fuels. In most countries of sub-Saharan Africa, 90% of the rural households depend on biomass fuel for cooking and heating, affecting young children (acute lower respiratory infections) and women (COPD). This is the cause of significant mortality and morbidity in the region.

CONCLUSIONS

Asthma and COPD in sub-Saharan Africa are under-recognised, under-diagnosed, under-treated, and insufficiently prevented. A major priority is to increase the awareness of asthma and COPD and their risk factors, particularly the damage caused by biomass fuel. Surveys are needed to provide local healthcare workers with the possibility of controlling asthma and COPD.

Importance of allergy in asthma: an epidemiologic perspective

There has been a global epidemic of asthma during the past half-century. More recently, the prevalence has leveled off or declined in many Western countries, whereas the prevalence in less affluent nations is still increasing. The reasons for this and the different geographical patterns of asthma prevalence remain unclear. This paper provides an epidemiologic perspective on whether allergen exposure and allergies can explain these trends. In particular, the paper discusses 1) geographical and temporal trends in asthma and the role of allergens and allergy, 2) the importance of nonallergic mechanisms, 3) nonallergenic exposures that may modify the risk of allergies and asthma, and 4) new and emerging risk and protective factors. Although allergy and asthma are closely related, allergen exposure and allergy alone cannot explain current time trends and geographical patterns of asthma. Population-based studies focusing on recently identified risk and protective factors may provide further insight.

Omalizumab reduces corticosteroid use in patients with severe allergic asthma: real-life experience in Israel

OBJECTIVE

Approved by the FDA in 2003, omalizumab is the first recombinant humanized monoclonal anti-immunoglobulin E antibody developed for the treatment of allergic asthma. Due to the heterogeneity of asthma symptoms, investigation of the efficacy of omalizumab in patients outside controlled trials is particularly important. The purpose of the current study was to evaluate the efficacy of omalizumab as an add-on treatment for allergic asthma in a real-life setting in Israel.

METHODS

This was a retrospective study based on patient records and computerized database for drug dispensing, emergency room visits, and hospital admissions.

RESULTS

The sample comprised 33 individuals (18 men, 15 women; mean age 50.0 ± 12.2, range 25-79) who were treated with omalizumab for severe allergic asthma for a duration of at least 16 weeks. After the initiation of omalizumab therapy, the number of patients who used oral or injected corticosteroids decreased (p < .003, .03, respectively), as did the median dosage of oral corticosteroids (p < .02). Visits to the emergency room decreased from an incidence of 0.526 visits per person-year to an incidence of 0.246 per person-year (p < .05). No adverse reactions to omalizumab were observed.

CONCLUSION

Omalizumab as an add-on therapy reduced the use of corticosteroids and improved the control of asthma, as evidenced by reduced asthma-related emergency room visits. This study supports both controlled and uncontrolled studies that have demonstrated the efficacy and safety of omalizumab, and particularly those that demonstrated effectiveness among severe asthma patients. "Real-life" studies are important to identify patients who will most benefit from omalizumab therapy.

Lifestyle factors and sensitization in children - the ALADDIN birth cohort

BACKGROUND

Several cross-sectional studies indicate that an anthroposophic lifestyle reduces the risk of allergy in children. We initiated the Assessment of Lifestyle and Allergic Disease During Infancy (ALADDIN) birth cohort to elucidate the role of specific factors supposed to mediate this effect. The aims of this study are to describe the ALADDIN cohort and to report patterns of exposure and allergic sensitization during the first years of life.

METHODS

The ALADDIN study is a prospective birth cohort study of 330 children from families with an anthroposophic, partly anthroposophic, or nonanthroposophic lifestyle. The children and their parents were following an extensive data collection scheme, including repeated questionnaires and biological samples. Blood samples were collected from the parents and from the child at birth as well as at 6, 12, and 24 months of age.

RESULTS

Several lifestyle factors differed between the groups, such as diet, medication, and place of delivery. Children of families with an anthroposophic lifestyle had a markedly decreased risk of sensitization during the first 2 years of life compared with children of nonanthroposophic families with adjusted OR 0.25 (95% CI 0.10-0.64) and P-value 0.004. A similar situation held true for children from families with a partly anthroposophic lifestyle, adjusted OR 0.31 (95% CI 0.15-0.54), and P-value 0.002.

CONCLUSIONS

The anthroposophic lifestyle comprises several factors of interest for allergy development and is here shown to be associated with reduced risk of IgE sensitization already in infancy. Identifying the factors responsible for this association would be of significant clinical importance.

Health care costs in persons with asthma and comorbid mental disorders: a systematic review

OBJECTIVE

The aim of this study was to systematically review the impact of comorbid mental disorders on health care costs in adult persons with asthma.

METHOD

A comprehensive search for studies investigating adult persons (≥18 years) with asthma was conducted. All studies were included, which allowed a comparison of health care utilization and costs between asthma patients with mental disorders and asthma patients without.

RESULTS

The literature search revealed 1977 potentially relevant studies. Eighteen primary studies (20 publications) fulfilled the inclusion criteria. Mood disorders (n=14) and anxiety disorders (n=9) were studied most often. Increased rates of hospitalizations (odds ratio range, 0.9-6.1; n=7), emergency department visits (odds ratio range, 1.8-17.2; n=7) and general practitioner visits (standardized mean difference range, 0.1-1.1; n=6) were found in asthma patients with mental comorbidity. Indirect costs of work absence were investigated in two studies pointing in the same direction of increased costs. Evidence is sparse regarding other outcomes due to a lack of primary studies.

CONCLUSION

The present systematic review highlights a meaningful impact of comorbid mental disorders on health care utilization and costs in adult patients with asthma. Thus, psychodiagnostic routines and appropriate mental health treatments are needed to reduce health care costs in asthma care.

Effect of maternal exposure to ozone on reproductive outcome and immune, inflammatory, and allergic responses in the offspring

There is growing concern that exposure to air pollutants during pregnancy affects health outcomes in the offspring due to alterations in the development of immune and other homeostatic processes. To assess the risks of maternal inhalation exposure to ozone (O(3)), timed pregnant BALB/c mice were exposed to different concentrations of O(3) (0, 0.4, 0.8, and 1.2 ppm) for 4 h/day for 10 days during gestation (GD9-GD18), and pulmonary inflammation and immune responses were assessed in the offspring at 6 weeks-of-age. Maternal O(3) exposure reduced the number of productive dams by 25% at the highest O(3) concentration (1.2 ppm) and decreased the rate of weight gain in the offspring. Delayed-type hypersensitivity responses to bovine serum albumin were suppressed in the female offspring by maternal exposure to the two highest concentrations of O(3), whereas humoral immune responses to sheep red blood cells were not altered in either sex. Maternal exposure to 1.2 ppm O(3) increased lactate dehydrogenase (LDH) activity in bronchoalveolar lavage fluid (BALF) of the offspring but did not affect the number of inflammatory cells or levels of total protein, IFN-γ, IL-17, and IL-4 cytokines in BALF, or CD4(+), CD8(+), CD25(+), and TCRβ(+)CD1d(+) T-cells in the spleen. Offspring born from air-exposed dams sensitized early in life (postnatal day [PND] 3) to ovalbumin (OVA) antigen and then challenged as adults developed eosinophilia, elevated levels of LDH activity and total protein in BALF, and increased pulmonary responsiveness to methacholine, compared with animals sensitized at PND42. Maternal O(3) exposure in the 1.2 ppm O(3) group decreased BALF eosinophilia and serum OVA-specific IgE in the female offspring sensitized early in life but did not affect development of allergic airway inflammation by offspring sensitized late in life. In summary, maternal exposure to O(3) affected reproductive outcome and produced modest decreases in immune function and indicators of allergic lung disease in surviving offspring.

Telehealthcare for asthma: a Cochrane review

BACKGROUND

Telehealthcare has the potential to provide care for long-term conditions that are increasingly prevalent, such as asthma. We conducted a systematic review of studies of telehealthcare interventions used for the treatment of asthma to determine whether such approaches to care are effective.

METHODS

We searched the Cochrane Airways Group Specialised Register of Trials, which is derived from systematic searches of bibliographic databases including CENTRAL (the Cochrane Central Register of Controlled Trials), MEDLINE, Embase, CINAHL (Cumulative Index to Nursing and Allied Health Literature) and PsycINFO, as well as other electronic resources. We also searched registers of ongoing and unpublished trials. We were interested in studies that measured the following outcomes: quality of life, number of visits to the emergency department and number of admissions to hospital. Two reviewers identified studies for inclusion in our meta-analysis. We extracted data and used fixedeffect modelling for the meta-analyses.

RESULTS

We identified 21 randomized controlled trials for inclusion in our analysis. The methods of telehealthcare intervention these studies investigated were the telephone and video- and Internet-based models of care. Meta-analysis did not show a clinically important improvement in patients' quality of life, and there was no significant change in the number of visits to the emergency department over 12 months. There was a significant reduction in the number of patients admitted to hospital once or more over 12 months (risk ratio 0.25 [95% confidence interval 0.09 to 0.66]).

INTERPRETATION

We found no evidence of a clinically important impact on patients' quality of life, but telehealthcare interventions do appear to have the potential to reduce the risk of admission to hospital, particularly for patients with severe asthma. Further research is required to clarify the cost-effectiveness of models of care based on telehealthcare.

Update on optimal use of omalizumab in management of asthma

Omalizumab is a humanized monoclonal anti-IgE antibody recently approved for the treatment of severe allergic asthma. This drug inhibits allergic responses by binding to serum IgE, thus preventing interaction with cellular IgE receptors. Omalizumab is also capable of downregulating the expression of high affinity IgE receptors on inflammatory cells, as well as the numbers of eosinophils in both blood and induced sputum. The clinical effects of omalizumab include improvements in respiratory symptoms and quality of life, paralleled by a reduction of asthma exacerbations, emergency room visits, and use of systemic corticosteroids and rescue bronchodilators. Omalizumab is relatively well-tolerated, and only rarely induces anaphylactic reactions. Therefore, this drug represents a valid option as add-on therapy for patients with severe persistent allergic asthma inadequately controlled by high doses of standard inhaled treatments.

Trends in occupational airway diseases in German hairdressers: frequency and causes

BACKGROUND

Hairdressers are exposed to several allergens and irritants known to cause obstructive airway diseases (OAD). In the early 1990s, high incidence rates of OAD were observed in German hairdressers. It was expected that modification of formulations would resolve the problem of high OAD rates in hairdressers.

METHODS

The numbers of confirmed cases are reported of allergen-, latex- and irritant-induced OAD in German hairdressers, as registered by the responsible compensation board during 1998 and 2007. Hairdressing components reported as causative for OAD in hairdressers were analyzed. The incidence rates of OAD in hairdressers were compared with rates in healthcare professionals, as both occupations had high rates of OAD in the 1990s.

RESULTS

From 1998 until 2003, the total number of confirmed cases of allergen-, latex- and irritant-induced OAD stayed at a plateau of 60 cases annually in hairdressers, after which a downward trend was apparent. The number of irritant-induced OAD cases did not fall during this overall downward trend. Hair dyes and acid perms were most often identified as the substances causing OAD in hairdressers. In healthcare professionals, the downward trend in OAD is more pronounced than in hairdressers, mainly due to a decrease in latex-induced cases.

CONCLUSIONS

The number of allergen- and irritant-induced cases of OAD in German hairdressers is still high. Exposure to known airway irritants is still occurring in spite of modification of the formulations. Continuous medical surveillance of hairdressers is recommended, in order to detect individual susceptibility, especially in apprentices.

Asthma in an urban population in Portugal: a prevalence study

Background

The prevalence and incidence of asthma are believed to be increasing but research on the true incidence, prevalence and mortality from asthma has met methodological obstacles since it has been difficult to define and diagnose asthma in epidemiological terms. New and widely accepted diagnostic criteria for asthma present opportunities for progress in this field. Studies conducted in Portugal have estimated the disease prevalence between 3% and 15%. Available epidemiological data present a significant variability due to methodological obstacles.

Aim

To estimate the true prevalence of asthma by gender and age groups in the population of the area covered by one urban Health Centre in Portugal.

Method

An observational study was conducted between February and July 2009 at the Horizonte Family Health Unit in Matosinhos, Portugal. A random sample of 590 patients, stratified by age and gender was obtained from the practice database of registered patients. Data was collected using a patient questionnaire based on respiratory symptoms and the physician's best knowledge of the patient's asthma status. The prevalence of asthma was calculated by age and gender.

Results

Data were obtained from 576 patients (97.6% response rate). The mean age for patients with asthma was 27.0 years (95% CI: 20.95 to 33.16). This was lower than the mean age for non-asthmatics but the difference was not statistically significant. Asthma was diagnosed in 59 persons giving a prevalence of 10.24% (95% CI: 8.16 to 12.32). There was no statistically significant difference in the prevalence of asthma by gender.

Conclusion

The prevalence of asthma found in the present study was higher than that found in some studies, though lower than that found in other studies. Further studies in other regions of Portugal are required to confirm these findings.

Rapid identification of allergenic and pathogenic molds in environmental air by an oligonucleotide array

Background

Airborne fungi play an important role in causing allergy and infections in susceptible people. Identification of these fungi, based on morphological characteristics, is time-consuming, expertise-demanding, and could be inaccurate.

Methods

We developed an oligonucleotide array that could accurately identify 21 important airborne fungi (13 genera) that may cause adverse health problems. The method consisted of PCR amplification of the internal transcribed spacer (ITS) regions, hybridization of the PCR products to a panel of oligonucleotide probes immobilized on a nylon membrane, and detection of the hybridization signals with alkaline phosphatase-conjugated antibodies.

Results

A collection of 72 target and 66 nontarget reference strains were analyzed by the array. Both the sensitivity and specificity of the array were 100%, and the detection limit was 10 pg of genomic DNA per assay. Furthermore, 70 fungal isolates recovered from air samples were identified by the array and the identification results were confirmed by sequencing of the ITS and D1/D2 domain of the large-subunit RNA gene. The sensitivity and specificity of the array for identification of the air isolates was 100% (26/26) and 97.7% (43/44), respectively.

Conclusions

Identification of airborne fungi by the array was cheap and accurate. The current array may contribute to decipher the relationship between airborne fungi and adverse health effect.

Abnormal vocal cord function in difficult-to-treat asthma

RATIONALE

Upper airway dysfunction may complicate asthma but has been largely ignored as an etiological factor. Diagnosis using endoscopic evaluation of vocal cord function is difficult to quantify, with limited clinical application.

OBJECTIVES

A novel imaging technique, dynamic 320-slice computerized tomography (CT), was used to examine laryngeal behavior in healthy individuals and individuals with asthma.

METHODS

Vocal cord movement was imaged using 320-slice CT larynx. Healthy volunteers were studied to develop and validate an analysis algorithm for quantification of normal vocal cord function. Further studies were then conducted in 46 patients with difficult-to-treat asthma.

MEASUREMENTS AND MAIN RESULTS

Vocal cord movement was quantified over the breathing cycle by CT using the ratio of vocal cord diameter to tracheal diameter. Normal limits were calculated, validated, and applied to evaluate difficult-to-treat asthma. Vocal cord movement was abnormal with excessive narrowing in 23 of 46 (50%) patients with asthma and severe in 9 (19%) patients (abnormal > 50% of inspiration or expiration time). Imaging also revealed that laryngeal dysfunction characterized the movement abnormality rather than isolated vocal cord dysfunction.

CONCLUSIONS

Noninvasive quantification of laryngeal movement was achieved using CT larynx. Significant numbers of patients with difficult-to-treat asthma had excessive narrowing of the vocal cords. This new approach has identified frequent upper airway dysfunction in asthma with potential implications for disease control and treatment.

Nutrients and foods for the primary prevention of asthma and allergy: systematic review and meta-analysis

BACKGROUND

Epidemiologic studies suggest that deficiencies of the nutrients selenium; zinc; vitamins A, C, D, and E; and low fruit and vegetable intake may be associated with the development of asthma and allergic disorders.

OBJECTIVES

To investigate the evidence that nutrient and food intake modifies the risk of children developing allergy.

METHODS

We systematically searched 11 databases. Studies were critically appraised, and meta-analyses were undertaken.

RESULTS

We identified 62 eligible reports. There were no randomized controlled trials. Studies used cohort (n = 21), case-control (n = 15), or cross-sectional (n = 26) designs. All studies were judged to be at moderate to substantial risk of bias. Meta-analysis revealed that serum vitamin A was lower in children with asthma compared with controls (odds ratio [OR], 0.25; 95% CI, 0.10-0.40). Meta-analyses also showed that high maternal dietary vitamin D and E intakes during pregnancy were protective for the development of wheezing outcomes (OR, 0.56, 95% CI, 0.42-0.73; and OR, 0.68, 95% CI, 0.52-0.88, respectively). Adherence to a Mediterranean diet was protective for persistent wheeze (OR, 0.22; 95% CI, 0.08-0.58) and atopy (OR, 0.55; 95% CI, 0.31-0.97). Seventeen of 22 fruit and vegetable studies reported beneficial associations with asthma and allergic outcomes. Results were not supportive for other allergic outcomes for these vitamins or nutrients, or for any outcomes in relation to vitamin C and selenium.

CONCLUSION

The available epidemiologic evidence is weak but nonetheless supportive with respect to vitamins A, D, and E; zinc; fruits and vegetables; and a Mediterranean diet for the prevention of asthma. Experimental studies of these exposures are now warranted.

Developments in the field of allergy in 2009 through the eyes of Clinical and Experimental Allergy

In 2009 the journal published in the region of 200 papers including reviews, editorials, opinion pieces and original papers that ran the full gamut of allergic disease. It is instructive to take stock of this output to determine patterns of interest and where the cutting edge lies. We have surveyed the field of allergic disease as seen through the pages of Clinical and Experimental Allergy (CEA) highlighting trends, emphasizing notable observations and placing discoveries in the context of other key papers published during the year. The review is divided into similar sections as the journal. In the field of Asthma and Rhinitis CEA has contributed significantly to the debate about asthma phenotypes and expressed opinions about the cause of intrinsic asthma. It has also added its halfpennyworth to the hunt for meaningful biomarkers. In Mechanisms the considerable interest in T cell subsets including Th17 and T regulatory cells continues apace and the discipline of Epidemiology continues to invoke a steady stream of papers on risk factors for asthma with investigators still trying to explain the post-second world war epidemic of allergic disease. Experimental Models continue to make important contributions to our understanding of pathogenesis of allergic disease and in the Clinical Allergy section various angles on immunotherapy are explored. New allergens continue to be described in the allergens section to make those allergen chips even more complicated. A rich and vibrant year helpfully summarized by some of our associate editors.

Role of PD-L1 and PD-L2 in allergic diseases and asthma

Asthma is the result of chronic airway inflammation associated predominantly with CD4+ cells, eosinophils, mast cells, and basophils. Several T-cells subsets, including NKT cells, play a critical role in orchestrating the inflammation in the airways predominantly, by secreting interleukin-4 and interleukin-13. Recently, programmed death-1 (PD-1) with its ligands, programmed death ligand B7H1 (PD-L1) and B7DC (PD-L2), was shown to regulate T-cell activation and tolerance. PD-1 has been characterized as a negative regulator of conventional CD4+T cells. In addition, the relative roles of PD-L1 and PD-L2 in regulating the activation and function of T cells have recently been characterized. Recent studies have demonstrated that PD-L1 and PD-L2 have important but opposing roles in modulating and polarizing T-cell functions in airway hyperreactivity. Whereas the severity of asthma is greatly enhanced in absence of PD-L2, PD-L1 deficiency resulted in reduced airway hyperresponsiveness and only minimal inflammation. This observation is partially because of the polarization of NKT cells in PD-L1- and PD-L2-deficient mice. This review will discuss the recent literature regarding the role of PD-L1 and PD-L2 in allergic disease and asthma. Current understanding of the role of PD ligands in allergic asthma gives impetus to the development of novel therapeutic approaches.

Mediterranean diet and asthma in Spanish schoolchildren

There is still debate on the effect of dietetic factors on the prevalence or severity of asthma, as well as the interaction with other factors. We have analysed the prevalence and severity of asthma according to adherence to the Mediterranean diet (MD), its association with obesity and family life style. We performed a cross-sectional study on 14,700 children and adolescents in six health areas in our region. We used the International Study of Asthma and Allergies in Childhood questionnaire to collect asthma symptoms, dietary habits, anthropometric parameters, parental smoking habits and maternal education level. The diet pattern was analysed using a Mediterranean Diet Score. In the logistic regression we analysed the influence of adhering to the MD on the prevalence and severity of asthma, adjusted for the other parameters included. Greater adherence to the MD is associated with a higher risk of severe asthma (odds ratios = 2.26, 95% CI: 1.21-4.22) in girls of 6-7 yr. There was no significant relationship for the other asthma categories in the population studied. The results of our study do not support a protective effect of the MD on the prevalence or severity of asthma.

Telehealthcare for asthma

BACKGROUND

Healthcare systems internationally need to consider new models of care to cater for the increasing numbers of people with asthma. Telehealthcare interventions are increasingly being seen by policymakers as a potential means of delivering asthma care. We defined telehealthcare as being healthcare delivered from a distance, facilitated electronically and involving the exchange of information through the personalised interaction between a healthcare professional using their skills and judgement and the patient providing information.

OBJECTIVES

To assess the effectiveness of telehealthcare interventions in people with asthma.

SEARCH STRATEGY

We searched in the following databases: Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, CINAHL, AMED, and PsycINFO; this was supplemented by handsearching of respiratory journals. We also searched registers of ongoing and unpublished trials.

SELECTION CRITERIA

We selected completed randomised controlled trials of telehealthcare initiatives aiming to improve asthma care.

DATA COLLECTION AND ANALYSIS

Two review authors independently appraised studies for inclusion and extracted data and performed meta-analyses. We analysed dichotomous variables to produce an odds ratio (OR) and continuous variables to produce a mean difference.

MAIN RESULTS

We included 21 trials in this review. The 21 included studies investigated a range of technologies aiming to support the provision of care from a distance. These included: telephone (n = 9); video-conferencing (n = 2); Internet (n = 2); other networked communications (n = 6); text Short Messaging Service (n = 1); or a combination of text and Internet (n = 1). Meta-analysis showed that these interventions did not result in clinically important improvements in asthma quality of life (minimum clinically important difference = 0.5): mean difference in Juniper's Asthma Quality of Life Questionnaire (AQLQ) 0.08 (95% CI 0.01 to 0.16). Telehealthcare for asthma resulted in a non-significant increase in the odds of emergency department visits over a 12-month period: OR 1.16 (95% CI 0.52 to 2.58). There was, however, a significant reduction in hospitalisations over a 12-month period: OR 0.21 (95% CI 0.07 to 0.61), the effect being most marked in people with more severe asthma managed predominantly in secondary care settings.

AUTHORS' CONCLUSIONS

Telehealthcare interventions are unlikely to result in clinically relevant improvements in health outcomes in those with relatively mild asthma, but they may have a role in those with more severe disease who are at high risk of hospital admission. Further trials evaluating the effectiveness and cost-effectiveness of a range of telehealthcare interventions are needed.

Review: Collectins link innate and adaptive immunity in allergic airway disease

Although the lipoprotein complex of pulmonary surfactant has long been recognized as essential for reducing lung surface tension, its role in lung immune host defense has only relatively recently been elucidated. Surfactant-associated proteins A (SP-A) and D (SP-D) can attenuate bacterial and viral infection and inflammation by acting as opsonins and by regulating innate immune cell functions. Surfactant-associated protein A and D also interact with antigen-presenting cells and T cells, thereby linking the innate and adaptive immune systems. A recent study from our laboratory demonstrated that mice deficient in SP-A have enhanced susceptibility to airway hyper-responsiveness and lung inflammation induced by Mycoplasma pneumonia, an atypical bacterium present in the airways of approximately 50% of asthmatics experiencing their first episode, and further supports an important role for SP-A in the host response to allergic airway disease. Animal and human studies suggest that alterations in the functions or levels of SP-A and SP-D are associated with both infectious and non-infectious chronic lung diseases such as asthma. Future studies are needed to elucidate whether alterations in SP-A and SP-D are a consequence and/or cause of allergic airway disease.

Quality of care of Egyptian asthmatic children: clinicians adherence to asthma guidelines

BACKGROUND

Despite the development and dissemination of guidelines for the diagnosis and management of asthma, a gap remains between current recommendations and actual practice.

OBJECTIVES

To assess the physicians attitude towards asthma guidelines and their adherence to its recommendations.

METHODS

Three hundred and fifty two clinicians (101 General practitioners, 131 pediatric specialists, 35 pediatric consultants and 85 doctors did not report the qualification) engaged in direct childhood asthma care in Cairo, Egypt were subjected to a self-administered questionnaire with 35 questions of which most were multiple choices, aiming at assessment of three important aspects about the involved physicians; physician's knowledge, practice and attitude. 165 of the clinicians were working in governmental hospitals, 68 clinicians work in private clinics and 119 clinicians work in both.

RESULTS

Agreement with asthma guidelines was present in 76.2% of the studied physicians, however those who not in agreement with the guidelines claimed that this was mainly due to patient factors, firstly the poor socioeconomic standard of the patient (18.1%) and secondly due to poor patient compliance (16%). Poor knowledge was found in 28.5%, poor practice was found in 43.6% and poor attitude was found in 14.4% of the studied physicians. There was positive highly significant correlation between qualification and knowledge, (p<0.01), positive highly significant correlation between qualification and practice, (p<0.01), and positive highly significant correlation between qualification and attitude, (p<0.01).

CONCLUSION

The attitude of the studied physicians revealed agreement of their majority with the guidelines, while the disagreement was mainly explained by the poor socioeconomic standard of the patients. The degree of poor practice is more marked than that of poor knowledge or poor attitude reflecting resources limitations and applications obstacles in the physician's practice.