Lack of association between indoor allergen sensitization and asthma morbidity in inner-city adults

[Role of non pharmacological Interventions for asthma]

Smoking cessation remains a major issue for asthmatic smokers. Respiratory rehabilitation and respiratory physiotherapy have shown a benefit in controlling symptoms, preventing exacerbations and improving the quality of life. The control of the environment is crucial and must be approached in a global way. Management of obesity and psychological disorders should be systematically proposed. Allergen immunotherapy may be discussed in allergic persistent asthma to house dust mites. Certain dietary interventions or alternative medicines have not proved their worth.

Allergen Sensitization and Asthma Outcomes among World Trade Center Rescue and Recovery Workers

A large number of World Trade Center (WTC) rescue and recovery workers are affected by asthma. While physical and mental health comorbidities have been associated with poor asthma control in this population, the potential role of allergen sensitization is unknown. This study examined the association of indoor sensitization and exposure as a risk factor for increased asthma morbidity in WTC workers. We used data from a prospective cohort of 331 WTC workers with asthma. Sensitization to indoor allergens was assessed by measurement of antigen-specific serum immunoglobulin E (IgE) levels. We used validated tools to evaluate the exposure to indoor allergens. Asthma morbidity outcomes included level of control (Asthma Control Questionnaire, ACQ), quality of life (Asthma Quality of Life Questionnaire, AQLQ) and acute resource utilization. The prevalence of sensitization to cat, dog, mouse, dust mite, cockroach, and mold allergens were 33%, 21%, 17%, 40%, 17%, and 17%, respectively. Unadjusted and regression analyses showed no significant relationship between sensitization and increased asthma morbidity (p > 0.05 for all comparisons), except for sensitization to Aspergillus Fumigatus, cat and mouse epithelium, which were associated with decreased morbidity.

[How to consider triggers and comorbid conditions in severe asthma in adults]

Triggers and precipitating factors as well as comorbid conditions are associated with asthma and severe asthma. They interfere with the potential to control the disease and represent an additional burden for the patients. Allergen exposure is well known to induce loss of control and exacerbations. Comorbid conditions belong to various fields of medicines including cardiovascular diseases, osteoporosis, obesity and sleep apneas and GERD. They should be diagnosed and treated for themselves according to the best state of the art. Their precise role et their contribution to severe asthma pathophysiology is largely unknown and longitudinal cohort studies are needed to better understand and treat the patients with severe asthma.

The risk of respiratory symptoms on allergen exposure increases with increasing specific IgE levels

BACKGROUND

The relation between IgE sensitization and allergic respiratory symptoms has usually been evaluated by dichotomizing specific IgE levels. The aim of this study was to evaluate the association between specific IgE levels and risk of symptoms on allergen-related exposure, with special reference to allergen-related asthma-rhinitis comorbidity.

METHODS

We considered 6391 subjects enrolled within the European Community Respiratory Health Survey 2, having information on cat/grass/D. pteronyssinus IgE levels and symptoms on exposure to animals/pollen/dust. The risk of oculonasal/asthmalike/both symptoms was evaluated by a multinomial logistic model.

RESULTS

A clear positive association was observed between specific IgE levels to cat/grass/mite and the risk of symptoms on each allergen-related exposure (test for trend with P < 0.001). This trend was particularly pronounced when considering the coexistence of asthmalike and oculonasal symptoms. Compared to non-sensitized subjects, subjects with specific IgE to cat >= 3.5 kU/l presented relative risk ratios of 11.4 (95% CI 6.7-19.2), 18.8 (8.2-42.8), and 55.3 (30.5-100.2) when considering, respectively, only oculonasal symptoms, only asthmalike symptoms, or both. A similar pattern was observed when considering specific IgE to grass/mite and symptoms on exposure to pollen/dust. Also the proportion of people using inhaled medicines or visiting a general practitioner for breathing problems in the previous year increased with increasing sum of specific IgE to cat/grass/mite.

CONCLUSION

Specific IgE level is the most important predictor of allergen-related symptoms. The risk of both oculonasal/asthmalike symptoms increases with specific IgE levels, suggesting that specific IgE contributes to the 'united airways disease'.

Targeting membrane-expressed IgE B cell receptor with an antibody to the M1 prime epitope reduces IgE production

Elevated serum levels of both total and allergen-specific immunoglobulin E (IgE) correlate with atopic diseases such as allergic rhinitis and allergic asthma. Neutralization of IgE by anti-IgE antibodies can effectively treat allergic asthma. Preclinical studies indicate that targeting membrane IgE-positive cells with antibodies against M1 prime can inhibit the production of new IgE and significantly reduce the levels of serum IgE. We report results from two trials that investigated the safety, pharmacokinetics, and activity of quilizumab, a humanized monoclonal antibody targeting specifically the M1 prime epitope of membrane IgE, in subjects with allergic rhinitis (NCT01160861) or mild allergic asthma (NCT01196039). In both studies, quilizumab treatment was well tolerated and led to reductions in total and allergen-specific serum IgE that lasted for at least 6 months after the cessation of dosing. In subjects with allergic asthma who were subjected to an allergen challenge, quilizumab treatment blocked the generation of new IgE, reduced allergen-induced early and late asthmatic airway responses by 26 and 36%, respectively, and reduced allergen-induced increases in sputum eosinophils by ~50% compared with placebo. These studies indicate that targeting of membrane IgE-expressing cells with anti-M1 prime antibodies can prevent IgE production in humans.

The relationship between a specific IgE level and asthma outcomes: results from the 2005-2006 National Health and Nutrition Examination Survey

BACKGROUND

Allergen exposure is associated with increased specific IgE (sIgE), and allergen exposure plus sensitization is predictive of asthma outcomes. However, it is not known if sIgE is predictive of asthma outcomes in the absence of exposure data.

OBJECTIVE

To investigate whether IgE to indoor allergens is predictive of and has a dose-response relationship with asthma emergency department (ED) visits and wheeze.

METHODS

In the 2005-2006 National Health and Nutrition Examination Survey, 351 children and 390 adults reported current asthma. Continuous sIgE to 9 indoor allergens were considered. Asthma morbidity in the past year was measured by wheezing. Health care utilization was defined as any asthma ED visits in the past year.

RESULTS

Analyses were adjusted for race, age, education, poverty index ratio and (in adults) tobacco use. In children, ED visits were associated with cockroach (odds ratio [OR] 1.5 [95% CI, 1.1-2 .1), rat (OR 1.9 [95% CI, 1.2-2.8]), and Aspergillus (OR 1.6 [95% CI, 1.001-2.60]). Continuous Aspergillus (OR 1.5 [95% CI, 1.04-2.1), Alternaria (OR 1.4 [95% CI, 1.1-1.6]), and total IgE (OR 1.2 [95% CI, 1.1-1.4]) were associated with wheeze in children. Adult ED visits were associated with sIgE for dust mites (Dermatophagoides pteronyssinus OR 1.6 [95% CI, 1.3-2.1]; Dermatophagoides farinae OR 1.6 [95% CI, 1.3-1.9]), total IgE (OR 1.4 [95% CI, 1.04- 1.9]), and the sum of sIgEs (OR 1.6 [95% CI, 1.2-2.2]).

CONCLUSIONS

Sensitization to particular indoor environmental allergens was found to be a risk factor for wheeze and asthma ED visits. These outcomes increased as the concentration of sIgE to these allergens increased.

Environmental assessment and exposure reduction of cockroaches: a practice parameter

This parameter was developed by the Joint Task Force on Practice Parameters, representing the American Academy of Allergy, Asthma & Immunology (AAAAI); the American College of Allergy, Asthma & Immunology (ACAAI); and the Joint Council of Allergy, Asthma & Immunology. The AAAAI and the ACAAI have jointly accepted responsibility for establishing "Environmental assessment and remediation: a practice parameter." This is a complete and comprehensive document at the current time. The medical environment is a changing environment, and not all recommendations will be appropriate for all patients. Because this document incorporated the efforts of many participants, no single person, including those who served on the Joint Task Force, is authorized to provide an official AAAAI or ACAAI interpretation of these practice parameters. Any request for information about or an interpretation of these practice parameters by the AAAAI or ACAAI should be directed to the Executive Offices of the AAAAI, the ACAAI, and the Joint Council of Allergy, Asthma & Immunology. These parameters are not designed for use by pharmaceutical companies in drug promotion. The findings and conclusions in this manuscript are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention (CDC).

Home/social environment and asthma profiles in a vulnerable community from Caracas: lessons for urban Venezuela?

BACKGROUND

Asthma is a significant public health problem in Venezuela affecting the predominantly urban and poor majority of the population. Information regarding home and the social environment, key elements in asthma, is found to be deficient in these deprived socioeconomic sectors. This study was carried out to depict a life with asthma in this context which has been served over the years by a National Asthma Control Program.

METHODS

A survey of families residing in a socioeconomically deprived community of Caracas was carried out with the assumption that this community reflects the image of a life with asthma emanating from our deprived urban areas. Home physical settings were inspected for the following items: moldy walls, floors, ceilings, windows, sewage, garbage disposal, running water, plumbing, electricity, telephone, construction debris, furniture, bathrooms, food storage, and home appliances. In addition, we also gathered information regarding smoking habits, fumes exposure, pets and/or animals, and sighting of roaches and/or rodents. The presence of people with asthma was observed and their status of control was assessed through the asthma control test (ACT). Comparisons were made between families with asthmatics and those without asthmatics.

RESULTS

Randomly, 242 of 750 families (32.26%) were surveyed, with "head of family" providing information (75.6%) on most occasions. No significant association was found with respect to the previously explored items in those families with or without the presence of asthmatics. Medically diagnosed asthma was found in 14.91%, with ACT scores of <19 points in two-thirds of these adults and asthmatic children. Asthmatics reported symptoms occurring mostly during the night and an almost exclusive use of rescue medications. Families provided most treatments and children preferred to use the oral route for control medications. Significant work and school absenteeism were detected in more than 50% of these asthmatics.

CONCLUSIONS

No physical home environmental/risk factors turned out to be significantly associated with families reporting the presence of asthmatics. The high impact of asthma found in this Caracas slum underscores the realities of Venezuela's impoverished urban majority. To properly address this important challenge, our National Asthma Control Program needs to be reassessed.

Application of the asthma phenotype algorithm from the Severe Asthma Research Program to an urban population

Rationale

Identification and characterization of asthma phenotypes are challenging due to disease complexity and heterogeneity. The Severe Asthma Research Program (SARP) used unsupervised cluster analysis to define 5 phenotypically distinct asthma clusters that they replicated using 3 variables in a simplified algorithm. We evaluated whether this simplified SARP algorithm could be used in a separate and diverse urban asthma population to recreate these 5 phenotypic clusters.

Methods

The SARP simplified algorithm was applied to adults with asthma recruited to the New York University/Bellevue Asthma Registry (NYUBAR) to classify patients into five groups. The clinical phenotypes were summarized and compared.

Results

Asthma subjects in NYUBAR (n = 471) were predominantly women (70%) and Hispanic (57%), which were demographically different from the SARP population. The clinical phenotypes of the five groups generated by the simplified SARP algorithm were distinct across groups and distributed similarly to those described for the SARP population. Groups 1 and 2 (6 and 63%, respectively) had predominantly childhood onset atopic asthma. Groups 4 and 5 (20%) were older, with the longest duration of asthma, increased symptoms and exacerbations. Group 4 subjects were the most atopic and had the highest peripheral eosinophils. Group 3 (10%) had the least atopy, but included older obese women with adult-onset asthma, and increased exacerbations.

Conclusions

Application of the simplified SARP algorithm to the NYUBAR yielded groups that were phenotypically distinct and useful to characterize disease heterogeneity. Differences across NYUBAR groups support phenotypic variation and support the use of the simplified SARP algorithm for classification of asthma phenotypes in future prospective studies to investigate treatment and outcome differences between these distinct groups.

Trial Registration

Clinicaltrials.gov NCT00212537

[Respiratory allergens and asthma exacerbation]

INTRODUCTION

Asthma exacerbations are characterized by a progressive aggravation of respiratory symptoms such as dyspnea, cough, wheezing or chest tightness.

BACKGROUND

The relationship between allergy and asthma exacerbations has been evaluated by epidemiological studies based on various criteria such as oral corticosteroid requirement, emergency room visits and hospital admission for asthma. Many studies have observed that deteriorating asthma can be related to increased exposure to allergens, particularly allergens from house dust mite, cockroach, cat, rodent, mold or pollen. Several studies have demonstrated that sensitization to respiratory allergens and allergen exposure increases the risk of exacerbation of asthma. When asthma exacerbations are work-related, occupational allergens may be implicated.

CONCLUSIONS AND PERSPECTIVES

Most studies provide evidence that allergen exposure contributes to the risk of asthma exacerbations, but other precipitating factors, such as viruses, can interact and increase the risk.

Effect of exposure and sensitization to indoor allergens on asthma control level

BACKGROUND

Reducing risk factors, such as exposure to allergens, and stepwise pharmacotherapy to achieve and maintain control of asthma are the mainstay of asthma care. The purpose of this study was to clarify the effect of exposure and sensitization to indoor allergens, including house dust mites, cats, and dogs, on the asthma control level.

METHODS

Dust samples were collected from the mattresses of 101 adult asthma patient homes and the Dermatophagoides mite group 1 (Der 1), Fel d 1, and Can f 1 concentrations were measured using ELISA. Sensitization was determined by positive specific IgE antibodies. The Asthma Control Test (ACT), lowest peak expiratory flow (PEF) during 1 week expressed as a percentage of the highest PEF (Min%Max PEF), and spirometry were measured for the assessment of asthma control. Univariate and multivariate regression analyses were used to assess the relationships.

RESULTS

Sixty-nine patients were exposed to high levels (>10μg/g dust for Der 1 and Can f 1 and >8μg/g dust for Fel d 1) of 1 or more allergens and 39 patients were sensitized to at least one allergen. Multivariate logistic regression analyses revealed that the FEV(1) (% of predicted value) was associated with low ACT scores (≤19) and that the number of highly exposed allergens and inhaled corticosteroid dose were associated with a low level of Min%Max PEF (<80%).

CONCLUSIONS

The level of exposure to multiple indoor allergens, but not sensitization, is associated with the asthma control level determined by PEF variation.

Do indoor environments influence asthma and asthma-related symptoms among adults in homes?: a review of the literature

This review summarizes the results of epidemiological studies focusing on the detrimental effects of home environmental factors on asthma morbidity in adults. We reviewed the literature on indoor air quality (IAQ), physical and sociodemographic factors, and asthma morbidity in homes, and identified commonly reported asthma, allergic, and respiratory symptoms involving the home environment. Reported IAQ and asthma morbidity data strongly indicated positive associations between indoor air pollution and adverse health effects in most studies. Indoor factors most consistently associated with asthma and asthma-related symptoms in adults included fuel combustion, mold growth, and environmental tobacco smoke. Environmental exposure may increase an adult's risk of developing asthma and also may increase the risk of asthma exacerbations. Evaluation of present IAQ levels, exposure characteristics, and the role of exposure to these factors in relation to asthma morbidity is important for improving our understanding, identifying the burden, and for developing and implementing interventions aimed at reducing asthma morbidity.

Skin test reactivity of allergic subjects to basidiomycetes' crude extracts in a tropical environment

Fungal allergies can be detected by the skin prick test with extracts of the organisms, but not all fungi, including the basidiomycetes, are being examined. We determined the level of sensitization to basidiomycetes in allergic subjects and compared their reactivity to commercial extracts commonly used to detect allergies. Crude spore extracts of the basidiomycetes Ganoderma applanatum, Chlorophyllum molybdites, and Pleurotus ostreatus, which are known to release numerous spores, were examined along with commercial extracts on 33 subjects with asthma, allergic or non-allergic rhinitis. Overall, affected subjects showed the highest reactivity to mites (36%), followed by Ganoderma applanatum (30%), grass (27%) Chlorophyllum molybdites (12%) and Pleurotus ostreatus (12%). Allergic rhinitis patients were most reactive to mites (58%), grass (42%), Ganoderma applanatum (25%), Penicillium spp. (25%), and cat (17%). Those with asthma primarily responded to mites (44%), Ganoderma applanatum (44%), grass (33%), and Pleurotus ostreatus (22%). IgE levels correlated with positive basidiomycetes extracts. This finding, coupled with higher reactivity to basidiospores as compared to mitospores, and the similar sensitivities of patients to G. applanatum and mites, suggest that basidiomycetes are important allergen sources in the tropics.

Detection of immunological biomarkers correlated with asthma control and quality of life measurements in sera from chronic asthmatic patients

BACKGROUND

Clinical outcomes of patients with asthma are highly variable. Immunological biomarkers associated with asthma control have not been elucidated.

OBJECTIVE

To identify the association between clinical control of asthma and serum immunological profiles of asthmatics and compare these profiles with those of healthy controls by using a multiplex assay.

METHODS

Sera were obtained from 28 nonsmokers 18 to 55 years of age with moderate and severe persistent asthma. Patients were classified as having well-controlled (WC, n = 14) or poorly controlled (PC, n = 14) asthma based on their responses to the Asthma Control Questionnaire and Asthma Quality of Life Questionnaire. Sera from nonasthmatic control individuals (NAC, n = 14) were used for comparison. Levels of 50 analytes, including cytokines, chemokines, angiogenic, and growth factors, were determined, using a multiplex assay.

RESULTS

Twelve of the 29 cytokines levels were significantly higher in patients with asthma than in NACs, but only interferon gamma levels were significantly lower in patients with asthma than in the NAC group. Among these, interleukin (IL)-3 and IL-18 levels were significantly higher in the PC group than the WC group. Five of the 12 tested chemokine levels were significantly higher in patients with asthma than in NACs. Five of six growth factor levels were significantly higher in patients with asthma than in NACs, and 3 were higher in PC than WC. Interleukin-18, fibroblast growth factor, hepatocyte growth factor, and stem cell growth factor-beta were positively correlated with poor asthma control and negatively with quality of life scores.

CONCLUSIONS

Increased serum levels of fibroblast growth factor, hepatocyte growth factor, and stem cell growth factor-beta might be useful biomarkers of asthma control status and targets of future asthma therapy.

Cockroach exposure independent of sensitization status and association with hospitalizations for asthma in inner-city children

BACKGROUND

Children with asthma living in urban environments experience disproportionately high asthma hospitalization rates. Excessive exposure to perennial allergens, including cockroach and house dust mite (HDM), have been implicated, but data are limited.

OBJECTIVE

To examine the relation between cockroach and HDM exposure and measures of asthma morbidity and health care utilization.

METHODS

Participants included 86 atopic asthmatic children living in New Orleans, Louisiana. Sensitization status was determined by means of serum specific IgE testing, and vacuum dust samples were collected for allergen analysis. Logistic regression analysis was used to assess the odds of persistent wheezing, emergency department visits, and asthma hospitalization in those with high vs low levels of allergen exposure.

RESULTS

Approximately 44% and 40% of children were exposed to Bla g 1 levels greater than 2 U/g and HDM levels greater than 2 μg/g, respectively, and 24% reported at least 1 hospitalization in the previous 4 months. The median Bla g 1 level was significantly higher in the homes of children hospitalized compared with those with no hospital admissions (7.2 vs 0.8 U/g). In multivariable models, the odds of hospitalization were significantly higher in children exposed to Bla g 1 levels greater than 2 U/g (adjusted odds ratio, 4.2; 95% confidence interval, 1.24-14.17), independent of sensitization status. Exposure to HDMs was not associated with any measure of morbidity.

CONCLUSIONS

Exposure to cockroach allergen was strongly associated with increased hospitalization in children with asthma. This effect cannot be explained entirely by IgE-mediated inflammation. Controlled interventional trials are needed to determine whether isolated cockroach abatement improves asthma control.

Use of herbal remedies and adherence to inhaled corticosteroids among inner-city asthmatic patients

BACKGROUND

Complementary and alternative medicines (CAM), such as herbal remedies, are widely used by patients with chronic diseases, such as asthma. However, it is unclear whether use of the herbal remedies is associated with decreased adherence to inhaled corticosteroids (ICSs), a key component of asthma management.

OBJECTIVE

To examine the association among use of herbal remedies, adherence to prescribed ICSs, and medication and disease beliefs.

METHODS

We surveyed 326 adults with persistent asthma who received care at 2 inner-city outpatient clinics. Patients were asked about CAM use (teas, herbs, and rubs) for the treatment of asthma in the prior 6 months. Medication adherence was assessed using the Medication Adherence Report Scale, a validated self-report measure. Univariate and multiple regression analyses were used to assess the relationship among herbal remedy use, adherence to ICSs, and medication and disease beliefs.

RESULTS

Overall, 25.4% (95% confidence interval, 20%-30%) of patients reported herbal remedy use. Univariate analyses showed that herbal remedy use was associated with decreased ICS adherence and increased asthma morbidity. In multivariable analysis, herbal remedy use was associated with lower ICS adherence (odds ratio, 0.4; 95% confidence interval, 0.2-0.8) after adjusting for confounders. Herbal remedy users were also more likely to worry about the adverse effects of ICSs (P = .01).

CONCLUSIONS

The use of herbal remedies was associated with lower adherence to ICSs and worse outcomes among inner-city asthmatic patients. Medication beliefs, such as worry about ICS adverse effects, may in part mediate this relationship. Physicians should routinely ask patients with asthma about CAM use, especially those whose asthma is poorly controlled.

Assessing the validity of self-reported medication adherence among inner-city asthmatic adults: the Medication Adherence Report Scale for Asthma

BACKGROUND

A validated tool to assess adherence with inhaled corticosteroids (ICS) could help physicians and researchers determine whether poor asthma control is due to poor adherence or severe intrinsic asthma.

OBJECTIVE

To assess the performance of the Medication Adherence Report Scale for Asthma (MARS-A), a 10-item, self-reported measure of adherence with ICS.

METHODS

We interviewed 318 asthmatic adults receiving care at 2 inner-city clinics. Self-reported adherence with ICS was measured by MARS-A at baseline and 1 and 3 months. ICS adherence was measured electronically in 53 patients. Electronic adherence was the percentage of days patients used ICS. Patients with a mean MARS-A score of 4.5 or higher or with electronic adherence of more than 70% were defined as good adherers. We assessed internal validity (Cronbach alpha, test-retest correlations), criterion validity (associations between self-reported adherence and electronic adherence), and construct validity (correlating self-reported adherence with ICS beliefs).

RESULTS

The mean patient age was 47 years; 40% of patients were Hispanic, 40% were black, and 18% were white; 53% had prior asthma hospitalizations; and 70% had prior oral steroid use. Electronic substudy patients were similar to the rest of the cohort in age, sex, race, and asthma severity. MARS-A had good interitem correlation in English and Spanish (Cronbach alpha = 0.85 and 0.86, respectively) and good test-retest reliability (r = 0.65, P < .001). According to electronic measurements, patients used ICS 52% of days. Continuous MARS-A scores correlated with continuous electronic adherence (r = 0.42, P<.001), and dichotomized high self-reported adherence predicted high electronic adherence (odds ratio, 10.6; 95% confidence interval, 2.5-44.5; P < .001). Construct validity was good, with self-reported adherence higher in those saying daily ICS use was important and ICS were controller medications (P = .04).

CONCLUSIONS

MARS-A demonstrated good psychometric performance as a self-reported measure of adherence with ICS among English- and Spanish-speaking, low-income, minority patients with asthma.

Asthma, allergy, and IgE levels in NYC head start children

BACKGROUND

Among preschool-age children in New York City neighborhoods with high asthma hospitalization rates, we analyzed the associations of total immunoglobulin E (IgE), specific IgE to common indoor allergens, and allergy symptoms with asthma.

METHODS

Parents of children in New York City Head Start programs were asked to complete a questionnaire covering demographic factors, health history (including respiratory conditions), lifestyle, and home environment. Children's serum samples were analyzed for total IgE and specific IgE antibodies to cockroach, dust mite, mouse, and cat allergens by immunoassay. Logistic regression was used to model the association between asthma and IgE, controlling for age, gender, ethnicity/national origin, BMI, parental asthma, smokers in the household, and allergy symptoms (e.g., runny nose, rash).

RESULTS

Among 453 participating children (mean age 4.0+/-0.5 years), 150 (33%) met our criteria for asthma. In our multivariable logistic regression models, children with asthma were more likely than other children to be sensitized to each allergen, to be sensitized to any of the four allergens (OR=1.6, 95% CI 1.0-2.6), or to be in the highest quartile of total IgE (OR=3.1, 95% CI 1.5-6.4). Allergy symptoms based on questionnaire responses were independently associated with asthma (OR=3.7, 95% CI 2.3-5.9).

CONCLUSIONS

Among preschool-aged urban children, asthma was associated with total IgE and sensitization to cat, mouse, cockroach, and dust mite allergens. However, allergy symptoms were more prevalent and more strongly associated with asthma than was any allergen-specific IgE; such symptoms may precede elevated specific IgE or represent a different pathway to asthma.

Impact of positive and negative beliefs about inhaled corticosteroids on adherence in inner-city asthmatic patients

BACKGROUND

Daily inhaled corticosteroid (ICS) use is the cornerstone of asthma management, although it is often suboptimal, especially in inner-city populations.

OBJECTIVE

To assess the impact of potentially modifiable medication beliefs on adherence with ICS therapy across time.

METHODS

Asthma history, medication beliefs, and ICS therapy adherence were determined in a prospective, observational cohort. Medication beliefs were based on self-regulation and self-efficacy theory. Self-reported adherence with ICS therapy was assessed using the Medication Adherence Reporting Scale, a validated 10-item instrument, at baseline and at 1 and 3 months. Repeated-measures multivariable regression identified beliefs independently associated with adherence across time after adjusting for age, sex, race, and asthma severity.

RESULTS

The 261 patients were low-income minorities with high rates of asthma hospitalization, emergency department visits, intubation, and oral corticosteroid use. Adherence with ICS therapy was stable across time, with 70% of patients saying that they used ICS all or most of the time when asymptomatic. Most patients (82%) thought it was important to use ICS when asymptomatic, although 49% worried about side effects and 37% worried about becoming addicted. Although 82% felt confident in using ICS, 7% felt that their regimen was hard to follow. In multivariable analyses, the odds of adherence increased for those who felt that using ICS when asymptomatic was important (odds ratio [OR], 4.15) and for those who were confident in using ICS (OR, 2.23) and decreased by worries about side effects (OR, 0.52) or feeling the regimen was hard to follow (OR, 0.48).

CONCLUSIONS

Several positive and negative beliefs about ICS were associated with adherence. Eliciting and addressing these potentially modifiable beliefs may help improve adherence and outcomes.

Phenotypic determinants of uncontrolled asthma

BACKGROUND

Although uncontrolled asthma remains frequent, determinants of asthma control are poorly studied.

OBJECTIVES

The aim was to estimate the distribution and the phenotypic characteristics of asthma control in 2 groups of subjects defined by the use of inhaled corticosteroids (ICS) in the past 12 months, in the Epidemiological study on the Genetics and Environment of Asthma, bronchial hyperresponsiveness and atopy (EGEA).

METHODS

Five hundred one adult current patients with asthma who participated in the follow-up of the EGEA study were included. Asthma control was assessed from survey questions reflecting asthma control, as defined in the 2006 Global Initiative for Asthma guidelines. The factors analyzed were age, sex, educational level, body mass index, active and passive smoking, sensitization to aeroallergens, total IgE, rhinitis, chronic cough/phlegm, and age at asthma onset. Analyses were stratified according to ICS use.

RESULTS

Uncontrolled asthma was more frequent in ICS users (27.6%, 35.0%, and 37.4% with controlled, partly-controlled, and uncontrolled asthma respectively) compared with non-ICS users (60.0%, 23.9%, and 16.1%, respectively). In ICS users, chronic cough or phlegm and female sex were independently and significantly related to uncontrolled asthma. In non-ICS users, high total IgE and sensitization to molds were associated with uncontrolled asthma. Smoking and rhinitis were not associated with asthma control.

CONCLUSION

Optimal asthma control remained unachieved in the majority of patients with asthma in this study. Factors associated with uncontrolled asthma were different in ICS users (chronic cough/phlegm, female sex) and non-ICS users (high total IgE and sensitization to molds).

Mediator release assay for assessment of biological potency of German cockroach allergen extracts

BACKGROUND

Cockroach is an important allergen in inner-city asthma. The diagnosis and treatment of cockroach allergy has been impeded by the lack of standardized cockroach extracts.

OBJECTIVE

We investigated the utility of a mediator release assay based on rat basophil leukemia (RBL) cells for comparing the potency of German cockroach extracts.

METHODS

RBL cells (line 2H3) transfected with human FcepsilonRI were passively sensitized with sera from subjects with cockroach allergy and stimulated with serial dilutions of 3 commercial cockroach extracts (1:10 weight/volume). In addition, the in-house prepared extract was tested in separate experiments with pooled sera that produced optimal performance in the RBL assay. N-hexosaminidase release (NHR) was used as a marker of RBL cell degranulation and was examined in relation to the intradermal skin test (ID(50)EAL) and serum cockroach-specific and total IgE levels.

RESULTS

The median cockroach-specific IgE concentration in 60 subjects was 0.72 kU(A)/L (interquartile range, 0.35-2.97 kU(A)/L); 19 sera (responders) produced a minimum 10% NHR to more than 1 extract. Responders had higher median cockroach-specific IgE (7.4 vs 1.0 kU(A)/L) and total IgE (429 vs 300 kU/L) levels than nonresponders. Ranking of extract potency was consistent between the mediator release assay and the ID(50)EAL. For the in-house prepared cockroach extract, the dose-response curves were shifted according to the concentration of the extract. NHR was reproducible between different experiments by using pooled sera.

CONCLUSION

The mediator release assay measures biologic potency and correlates with the ID(50)EAL. It should be further evaluated to determine whether it could be used to replace intradermal skin test titration for assessing the potency of cockroach extract.

Effect of environmental allergen sensitization on asthma morbidity in inner-city asthmatic children

BACKGROUND

Asthma causes significant morbidity in children, and studies have demonstrated that environmental allergies contribute to increased asthma morbidity.

OBJECTIVE

We investigated the differences between allergen skin tests and specific IgE (SIgE) and the role of IgG in regards to allergen exposure levels, and asthma morbidity in inner-city children.

METHODS

Five hundred and six serum samples from the National Cooperative Inner City Asthma Study (NCICAS) were evaluated for SIgE to cockroach (Blattella germanica), dust mite (Dermatophagoides farinae), and Alternaria as well as specific IgG (SIgG) and IgG(4) to cockroach (B. germanica) and total IgE levels. Associations between sensitization to these allergens, exposures, and asthma morbidity were determined.

RESULTS

Sensitization to environmental allergens and total IgE correlated with increased health care and medication use, but not with symptoms of wheeze. Sensitization with exposure to cockroach was associated with increased asthma morbidity, whereas dust mite sensitization was correlated with asthma morbidity independent of exposure. There was also a strong correlation between SIgE levels and skin test results, but the tests did not always agree. The relationship between SIgE and asthma morbidity is linear with no obvious cutoff value. Increased Bla g 1 in the home was a good predictor for sensitization; however, this relationship was not demonstrated for Der f 1. Cockroach SIgG correlated with increased health care use, however, there was no modifying effect of SIgG or SIgG(4) on the association between cockroach SIgE and asthma morbidity.

CONCLUSIONS

SIgE levels and skin prick test results to environmental allergens can serve as markers of severe asthma for inner-city children. Asthma morbidity increased in a linear manner with SIgE levels. IgG was not an important predictor or modifier of asthma morbidity.

The associations between area of residence, sexual violence victimization, and asthma episodes among US adult women in 14 states and territories, 2005-2007

Gaps in understanding of how area-based differences in exposure to violence are associated with asthma prevalence may limit the development of effective prevention programs and the identification of risk for asthma episodes. The current investigation examines the associations between sexual violence victimization and asthma episodes among US adult women across three different metropolitan settings. The association between sexual assault victimizations and asthma attacks in the past year was examined using data from the 2005, 2006, and 2007 Behavioral Risk Factor Surveillance System surveys. Cross-sectional analyses were based on adult women with current asthma (n = 4,099). Multivariate logistic regression models were used to identify associations between four categories of sexual violence victimization and asthma episodes across three categories of metropolitan and non-metropolitan settings. Our findings show that unwanted touching, attempted unwanted intercourse, forced unwanted intercourse, and any sexual violence victimization (touching, attempted intercourse, or forced intercourse) were significantly associated with asthma episodes (OR(adj.) = 3.67, 95% CI, 1.76-7.69; OR(adj.) = 1.77, 95% CI, 1.32-2.37; OR(adj.) = 2.24, 95% CI, 1.64-3.05, and OR(adj.) = 1.93, 95% CI, 1.47-2.53, respectively). While no significant differences in the associations between asthma episodes and metropolitan status were found, a significant interaction between non-metropolitan areas and attempted sexual intercourse was identified (OR(adj) = 0.53, 95% CI, 0.29-0.96). Sexual victimization appears to be an important, but understudied, correlate of asthma morbidity among adult women in the USA, suggesting that additional research is needed to better understand the associations between sexual violence, psychological distress, and asthma.

Advances in the care of adults with asthma and allergy in 2007

In 2007 the National Asthma Education and Prevention Program published the Expert Panel Report 3, updating its 1997 and 2002 guidelines for the diagnosis and management of asthma with new emphasis on assessment and attainment of control. This review focuses on the Journal articles published in 2007 pertaining to risk and impairment in adult asthma and interventions to improve its control.