The relationship of skin test positivity, high serum total IgE levels, and peripheral blood eosinophilia to symptomatic and asymptomatic airway hyperresponsiveness

K-means cluster analysis of characteristic patterns of allergen in different ages: Real life study

BACKGROUND

Atopy varies in people of different ages owing to different physical conditions and exposure to allergens. We aimed to cluster ages based on atopic severity using K-means cluster analysis and identify atopic incidence, severity, as well as the association among peripheral eosinophils, IgE and sensitisation.

METHODS

Consecutive patients (n = 7654) with allergic symptoms and undergoing allergen-specific IgE tests were included from 2013 to 2017. Age, sex, specific-IgE, peripheral eosinophil counts and total-IgE were collected.

RESULTS

Five age categories were identified: 1-17, 18-36, 37-52, 53-69 and 70-100 years. The incidences of atopy and poly-sensitisation decreased with increasing age. Similar trend was observed for aeroallergens, egg and milk but not for peanuts, soy or seafood. Dust mites remain the crucial factor bothering patients with allergic symptoms, especially for children and adolescents. In patients aged <52 years, sensitisation to aeroallergens was more prevalent than food. In group 37-52 years, incidence of females' atopy was higher than that of males. The overlap of atopy, high eosinophils, and high total-IgE was found in only 19.18% of patients. The trend of allergen-test positivity is not parallel to total IgE and peripheral eosinophil counts.

CONCLUSION

Age-grouping based on cluster analysis helps to find the changes in atopic status and distribution of sensitised allergens with age. Allergen tests are still necessary in the clinical diagnosis and treatment. An innovative exploration of the influence of age and allergens on total-IgE and eosinophil counts is helpful for the development of bio-targeted precision therapy.

CLINICAL TRIAL REGISTRATION

ChiCTR2300067700.

The Role of Phadiatop Tests and Total Immunoglobulin E Levels in Screening Aeroallergens: A Hospital-Based Cohort Study

Background

Screening for the existence of aeroallergens in patients with possible allergic rhinitis using venous blood samples has become more popular, with advantages of increased convenience and less consumption of time.

Objective

The aim of this study was to investigate the sensitivities and specificities of Phadiatop tests and total immunoglobulin E (IgE) levels in both adults and children.

Methods

This study was conducted prospectively in a tertiary center. The process of recruitment took place from Jan 2015 to Dec 2019, and patients with clinical symptoms that suggested persistent allergic rhinitis were recruited and their serum samples collected. The results of the total IgE and Phadiatop tests as well as the positive items in the ImmunoCAP assay were recorded and analyzed.

Results

A total of 9174 cases with complete data were enrolled, including 576 children and 8598 adults. A positive result in the ImmunoCAP assay was considered a positive atopic status towards aeroallergens. While using the total IgE levels to predict positive aeroallergens, the sensitivities and specificities were 65.7% and 85.7%, respectively, for adults and 86.3% and 77.4%, respectively, for children. When we used Phadiatop tests for allergy screening, the sensitivities and specificities was 94.5% and 98.2%, respectively, for the adult group and 98.5% and 96.8%, respectively, for the pediatric group.

Conclusion

The Phadiatop test had better diagnostic power for aeroallergen detection than the serum total IgE levels, or even the dual test, for both the adult and pediatric groups in this hospital-based study. We suggest that the Phadiatop test is more cost-effective in aeroallergen screening for patients with suspected atopic airway diseases.

Bronchoprovocation Testing in Asthma: An Update

Bronchial hyperresponsiveness (BHR) is defined as a heightened bronchoconstrictive response to airway stimuli. It complements the cardinal features in asthma, such as variable or reversible airflow limitation and airway inflammation. Although BHR is considered a pathophysiologic hallmark of asthma, it should be acknowledged that this property of the airway is dynamic, because its severity and even presence can vary over time with disease activity, triggers or specific exposure, and with treatment. In addition, it is important to recognize that there is a component that is not reflective of a specific disease entity.

Interactions between polycyclic aromatic hydrocarbons and epoxide hydrolase 1 play roles in asthma

Asthma, as one of the most common chronic diseases in children and adults, is a consequence of complex gene-environment interactions. Polycyclic aromatic hydrocarbons (PAHs), as a group of widespread environmental organic pollutants, are involved in the development, triggering and pathologic changes of asthma. Various previous studies reported the critical roles of PAHs in immune changes, oxidative stress and environment-gene interactions of asthma. EPHX1 (the gene of epoxide hydrolase 1, an enzyme mediating human PAH metabolism) had a possible association with asthma by influencing PAH metabolism. This review summarized that (1) the roles of PAHs in asthma-work as risk factors; (2) the possible mechanisms involved in PAH-related asthma-through immunologic and oxidative stress changes; (3) the interactions between PAHs and EPHX1 involved in asthma-enzymatic activity of epoxide hydrolase 1, which affected by EPHX1 genotypes/SNPs/diplotypes, could influence human PAH metabolism and people's vulnerability to PAH exposure. This review provided a better understanding of the above interactions and underlying mechanisms for asthma which help to raise public's concern on PAH control and develop strategies for individual asthma primary prevention.

Asthma control using fluticasone propionate/salmeterol in Asian and non-Asian populations: a post hoc analysis of the GOAL study

Background

To analyse the efficacy of fluticasone propionate (FP) alone and combined with salmeterol (SAL) in achieving guideline-defined asthma control in Asian patients.

Methods

A post hoc analysis of the GOAL study in which patients were stratified by prior-medication use into inhaled corticosteroid (ICS)-naïve (Stratum [S] 1), low-dose ICS (S2), and medium-dose ICS (S3), and randomised to receive FP/SAL or FP. Doses were stepped-up every 12 weeks until Totally Controlled asthma or maximum dose was reached (PhI) and then maintained until study end (PhII). The primary endpoint was the proportion of patients achieving Well-Controlled asthma during PhI. Additional endpoints included Total Control and adverse events. Asian and non-Asian patients were analysed separately.

Results

In Asian patients in PhI, 74% (n = 87/118) in S1 achieved Well-Controlled asthma with FP/SAL versus 74% (n = 89/121) with FP alone (p = 0.839); corresponding values were 76% (n = 81/107) versus 60% (n = 62/104; p = 0.005) in S2, and 58% (n = 59/102) versus 43% (n = 41/95; p = 0.015) in S3. More patients in all three strata achieved Totally Controlled asthma with FP/SAL versus FP alone. Control was achieved more rapidly and with lower ICS doses with FP/SAL versus FP. A high proportion of patients who achieved control during PhI maintained control during PhII. Similar trends were found in non-Asian patients. No new safety concerns were identified.

Conclusions

A greater proportion of Asian patients (S2 and S3, for Well-Controlled; all strata, for Totally Controlled) achieved guideline-defined asthma control with FP/SAL versus FP alone. High proportions of Asian patients in S1 achieved Well-Controlled asthma in both treatment groups.

Electronic supplementary material

The online version of this article (doi:10.1186/s12890-017-0410-x) contains supplementary material, which is available to authorized users.

Eosinophil Count Is a Common Factor for Complex Metabolic and Pulmonary Traits and Diseases: The LifeLines Cohort Study

There is ongoing debate on the association between eosinophil count and diseases, as previous studies were inconsistent. We studied the relationship of eosinophil count with 22 complex metabolic, cardiac, and pulmonary traits and diseases. From the population-based LifeLines Cohort Study (N = 167,729), 13,301 individuals were included. We focused on relationship of eosinophil count with three classes of metabolic (7 traits, 2 diseases), cardiac (6 traits, 2 diseases), and pulmonary (2 traits, 2 diseases) outcomes. Regression analyses were applied in overall, women and men, while adjusted for age, sex, BMI and smoking. A p-value of <0.00076 was considered statistically significant. 58.2% of population were women (mean±SD 51.3±11.1 years old). In overall, one-SD higher of ln-eosinophil count was associated with a 0.04 (±SE ±0.002;p = 6.0×10⁻⁶) SD higher levels in ln-BMI, 0.06 (±0.007;p = 3.1×10⁻¹²) SD in ln-TG, 0.04 (±0.003;p = 7.0×10⁻⁶) SD in TC, 0.04 (±0.004;p = 6.3×10⁻⁷) SD in LDL, 0.04 (±0.006;p = 6.0×10⁻⁶) SD in HbA1c; and with a 0.05 (±0.004;p = 1.7×10⁻⁸) SD lower levels in HDL, 0.05 (±0.007;p = 3.4×10⁻²³) SD in FEV1, and 0.09 (±0.001;p = 6.6×10⁻²⁸) SD in FEV1/FVC. A higher ln-eosinophil count was associated with 1.18 (95%CI 1.09–1.28;p = 2.0×10⁻⁵) odds ratio of obesity, 1.29 (1.19–1.39;p = 1.1×10⁻¹⁰) of metabolic syndrome, 1.40 (1.25–1.56;p = 2.7×10⁻⁹) of COPD and 1.81 (1.61–2.03;p = 1.0×10⁻²³) of asthma. Similar results were found in women. We found no association between ln-eosinophil count either with blood pressure indices in overall, women and men; or with BMI, LDL, HbA1c and obesity in men. In a large population based cohort, we confirmed eosinophil count as a potential factor implicated in metabolic and pulmonary outcomes.

Nasal lavage, blood or sputum: Which is best for phenotyping asthma?

BACKGROUND AND OBJECTIVE

Determination of asthma phenotypes, particularly inflammatory phenotypes, helps guide treatment and management of this heterogeneous disease. Induced sputum cytology has been the gold standard for determination of inflammatory phenotypes, but sputum induction is fairly invasive and technically challenging. Blood and nasal lavage cytology have been suggested as substitutes, but have not been fully verified. The aim of this study is to determine the accuracy of blood and nasal lavage cytometry as indicators of inflammatory phenotypes in asthma.

METHODS

Clinical evaluation, Asthma Control Questionnaire (ACQ) and spirometry were performed for 121 adult asthma patients, and blood, nasal lavage and induced sputum samples were taken. Eosinophils and neutrophils were counted in three samples from each subject. Inflammatory phenotypes (eosinophilic, neutrophilic, mixed and paucicellular) and cells counts were analysed using Venn diagram and receiver operating characteristic (ROC) curve, respectively.

RESULTS

ACQ score, spirometry and bronchodilator response did not differ among subjects with different inflammatory phenotypes. Inflammatory phenotypes defined by nasal lavage cytometry were in better concordance than those defined by blood cell counts with phenotypes determined by sputum cytology, and were significantly correlated with sputum phenotypes. For eosinophilia, nasal lavage cytology showed better accuracy than blood cytology (area under the curve (AUC): 0.89 vs 0.65). For all phenotypes, sensitivity and positive and negative predictive power were higher for nasal lavage cytometry than for blood. Blood cell counts gave a high level of false positives for all inflammatory phenotypes.

CONCLUSION

We recommend nasal lavage cytology over blood cell count as a substitute for sputum cytology to identify inflammatory phenotypes in asthma.

Revisiting the Dutch hypothesis

The Dutch hypothesis was first articulated in 1961, when many novel and advanced scientific techniques were not available, such as genomics techniques for pinpointing genes, gene expression, lipid and protein profiles, and the microbiome. In addition, computed tomographic scans and advanced analysis techniques to dissect (small) airways disease and emphysema were not available. At that time, the group of researchers under the visionary guidance of Professor N. G. M. Orie put forward that both genetic and environmental factors can determine whether one would have airway obstructive diseases, such as asthma and chronic obstructive pulmonary disease (COPD). Moreover, they stipulated that the phenotype of obstructive airway disease could be affected by sex and changes with aging. Orie and colleagues' call to carefully phenotype patients with obstructive airways diseases has been adopted by many current researchers in an attempt to determine the heterogeneity of both asthma and COPD to better define these diseases and optimize their treatment. The founders of the Dutch hypothesis were far ahead of their time, and we can learn from their insights. We should fully characterize all patients in our clinical practice and not just state that they have asthma, COPD, or asthma and COPD overlap syndrome. This detailed phenotyping can help in understanding these obstructive airway diseases and provide guidance for disease management.

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

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

Airway epithelial cytokine responses in childhood wheeze are independent of atopic status

BACKGROUND

Airway epithelial cells (AEC) are key contributors to immune function in the lungs but little is known about their role and function in children.

OBJECTIVES

Having previously established that nasal AEC mediator release correlates with that of bronchial AEC, we assessed AEC responses in children with and without a history of wheeze.

METHODS

Nasal AEC cultures were established from children (0.6-14.9 years) undergoing elective surgical procedures under general anaesthetic categorised as atopic asthmatic (n = 12), virus-induced wheeze (n = 8) or children without wheeze (n = 32). Mediator release by AEC monolayers at passage 2 was determined by cytometric bead array assay or ELISA.

RESULTS

Unstimulated AEC from children with a history of wheeze produced significantly less IL-8, IL-6, MCP-1 and G-CSF than AEC from healthy controls. There were no group differences in AEC release of VEGF, RANTES, MMP-9 or TIMP-1. After stimulation with the pro-inflammatory cytokines IL-1β and TNFα, AEC from children with current wheeze produced significantly less IL-8, IL-6 and MCP-1 than children without wheeze. Release of G-CSF, VEGF, MMP-9 and TIMP-1 did not differ between the wheeze and control group. There were no differences in mediator release between subjects with atopic asthma and those with virus-induced wheeze or between atopic and non-atopic controls. On multivariate analysis, wheeze was the only significant predictor of AEC mediator release.

CONCLUSION & CLINICAL RELEVANCE

Intrinsic differences in AEC from children with a history of wheeze may reflect a defect in cytokine production in vivo or an altered state of differentiation in vitro, independent of atopic status.

Objective allergy markers and risk of cancer mortality and hospitalization in a large population-based cohort

Purpose

There are indications that a history of allergy may offer some protection against cancer. We studied the relation of three objectively determined allergy markers with cancer mortality and hospitalization risk.

Methods

Associations between three allergy markers (number of peripheral blood eosinophil counts, skin test positivity, and serum total IgE) with mortality and hospitalization from any type and four common types of cancer (lung, colorectal, prostate, and breast cancer) were assessed in the Vlagtwedde–Vlaardingen cohort (1965–1990), with follow-up of mortality until 31 December 2008. Hospitalization data were available since 1 January 1995.

Results

There were no significant associations between objective allergy markers and cancer mortality or hospitalization. We found several associations in specific subgroups. A higher number of eosinophils was associated with a decreased risk of colorectal cancer mortality in ever smokers HR (95 % CI) = 0.61 (0.45–0.83) and in males 0.59 (0.42–0.83); however, no overall association was observed 0.84 (0.64–1.09). Skin test positivity was associated with a decreased risk of any cancer mortality only among females 0.59 (0.38–0.91) and showed no overall association 0.83 (0.67–1.04). Serum total IgE levels were associated with an increased risk of lung cancer mortality among females 4.64 (1.04–20.70), but with a decreased risk of cancer hospitalization in ever smokers 0.77 (0.61–0.97) and males 0.72 (0.55–0.93); however, no overall associations were observed [mortality 0.99 (0.79–1.25), and hospitalization 0.86 (0.71–1.04)].

Conclusions

We found no associations between objective allergy markers and cancer in the total population. However, skin test positivity and a high number of eosinophils were associated with a reduced risk to die of cancer in specific subgroups. Hence, it seems important to study specific subgroups defined by gender and smoking habits in order to identify allergy markers of predictive value for cancer mortality.

Electronic supplementary material

The online version of this article (doi:10.1007/s10552-014-0489-9) contains supplementary material, which is available to authorized users.

Less small airway dysfunction in asymptomatic bronchial hyperresponsiveness than in asthma

BACKGROUND

Bronchial hyperresponsiveness (BHR) can be present in subjects without any respiratory symptoms. Little is known about the role of the small airways in asymptomatic subjects with BHR.

METHODS

We investigated small airway function assessed by spirometry and impulse oscillometry, as well as Borg dyspnea scores at baseline and during a methacholine provocation test in 15 subjects with asymptomatic BHR, 15 asthma patients, and 15 healthy controls.

RESULTS

At baseline, small airway function (R5 -R20 and X5 ) was comparable between subjects with asymptomatic BHR and healthy controls, whereas asthma patients showed small airway dysfunction as reflected by higher R5 -R20 and lower X5 values. During methacholine provocation, small airway dysfunction was more severe in asthma patients than in subjects with asymptomatic BHR. Interestingly, a higher increase in small airway dysfunction during methacholine provocation was associated with a higher increase in Borg dyspnea scores in subjects with asymptomatic BHR, but not in asthma patients.

CONCLUSION

Subjects with asymptomatic BHR may experience fewer symptoms in daily life because they have less small airway dysfunction.

Clinical utility of asthma biomarkers: from bench to bedside

Asthma is a chronic disease characterized by airway inflammation, bronchial hyperresponsiveness, and recurrent episodes of reversible airway obstruction. The disease is very heterogeneous in onset, course, and response to treatment, and seems to encompass a broad collection of heterogeneous disease subtypes with different underlying pathophysiological mechanisms. There is a strong need for easily interpreted clinical biomarkers to assess the nature and severity of the disease. Currently available biomarkers for clinical practice - for example markers in bronchial lavage, bronchial biopsies, sputum, or fraction of exhaled nitric oxide (FeNO) - are limited due to invasiveness or lack of specificity. The assessment of markers in peripheral blood might be a good alternative to study airway inflammation more specifically, compared to FeNO, and in a less invasive manner, compared to bronchoalveolar lavage, biopsies, or sputum induction. In addition, promising novel biomarkers are discovered in the field of breath metabolomics (eg, volatile organic compounds) and (pharmaco)genomics. Biomarker research in asthma is increasingly shifting from the assessment of the value of single biomarkers to multidimensional approaches in which the clinical value of a combination of various markers is studied. This could eventually lead to the development of a clinically applicable algorithm composed of various markers and clinical features to phenotype asthma and improve diagnosis and asthma management.

Atopy is a risk factor for respiratory symptoms in COPD patients: results from the EUROSCOP study

BACKGROUND

The pathogenesis of COPD is complex and remains poorly understood. The European Respiratory Society Study on Chronic Obstructive Pulmonary Disease (EUROSCOP) investigated long-term effects of budesonide; 18% of the COPD participants were atopic. So far effects of atopy on the long-term course of COPD have not been elucidated.

METHODS

Factors related to the presence of atopy (positive phadiatop) in 1277 mild-to-moderate COPD patients participating in EUROSCOP were analysed using regression analysis. Incidence and remission of respiratory symptoms during 3-year follow-up were analysed using generalised estimating equations models, and association of atopy with lung function decline using linear mixed effects models.

RESULTS

Independent predisposing factors associated with the presence of atopy were: male gender (OR: 2.21; 95% CI: 1.47-3.34), overweight/obese (OR: 1.41; 95% CI: 1.04-1.92) and lower age (OR: 0.98; 95% CI: 0.96-0.99). Atopy was associated with a higher prevalence of cough (OR: 1.71; 95% CI: 1.26-2.34) and phlegm (OR: 1.50; 95% CI: 1.10-2.03), but not with lung function levels or FEV1 decline. Atopic COPD patients not treated with budesonide had an increased incidence of cough over time (OR: 1.79, 95% CI: 1.03-3.08, p = 0.038), while those treated with budesonide had increased remission of cough (OR: 1.93, 95% CI: 1.11-3.37, p = 0.02) compared to non-atopic COPD patients.

CONCLUSIONS

Atopic COPD patients are more likely male, have overweight/obesity and are younger as compared with non-atopic COPD patients. Atopy in COPD is associated with an increased incidence and prevalence of respiratory symptoms. If atopic COPD patients are treated with budesonide, they more often show remission of symptoms compared to non-atopic COPD patients who are treated with budesonide. We recommend including atopy in the diagnostic work-up and management of COPD.

Bronchoprovocation testing in asthma

This article covers the relationships between BHR and airway inflammation. Recent evidence suggests that various commonly used bronchoprovocation challenges (BPCs) differ in their potential to serve as inflammatory biomarkers. The response to direct stimuli depends on the smooth muscle's response to the chemical, whereas in indirect challenges, the reaction is caused by the smooth muscle's responsiveness to the mediators induced by the stimuli. The information obtained from studies with BPC has provided insights into the pathogenesis and pathophysiology of asthma, and the relationships between airway inflammation and bronchial hyper-responsiveness.

Budesonide/formoterol maintenance and reliever therapy in primary care asthma management: effects on bronchial hyperresponsiveness and asthma control

BACKGROUND

The management of asthma has changed since the introduction of budesonide/formoterol (Symbicort®) as both maintenance and reliever therapy (SMART). SMART and its effects on bronchial hyperresponsiveness (BHR) have not been studied in primary care.

AIMS

To compare the effects of SMART and guideline-driven usual care (UC) on BHR and clinical asthma severity in primary care practice.

METHODS

Patients with mild-to-moderate stable asthma were randomised to receive SMART treatment (n=54) (budesonide/formoterol 80/4.5 μg Turbuhaler®, two puffs once daily and extra inhalations as needed) or UC treatment (n=48) for 12 months. Diary data, Asthma Control Questionnaire scores, forced expiratory volume in 1 second (FEV1), and peak expiratory flow (PEF) measurements were collected during run-in and after 1, 3, 6, and 12 months of treatment. BHR, measured as the dose of histamine provoking a fall in FEV1 of 20% (PD20-histamine), was determined at randomisation and after 12 months.

RESULTS

One hundred and two patients with asthma participated in the study. The change in PD20-histamine during the study was not significantly different between the SMART and UC groups (p=0.26). The mean inhaled corticosteroid (ICS) dose was 326 μg beclomethasone dipropionate (BDP) equivalents/day (95% CI 254 to 399) with SMART, which was significantly lower (p<0.0001) than the mean ICS dose with UC treatment (798 μg BDP equivalents/day (95% CI 721 to 875). Morning and evening PEF values increased significantly with SMART treatment compared with UC; FEV1, symptoms and asthma control did not differ.

CONCLUSIONS

Despite a 59% lower dose of ICS, BHR and other clinical outcomes remained stable during SMART treatment while PEF values improved.

Skin prick test reactivity to common aeroallergens and ARIA classification of allergic rhinitis in patients of Central Greece

Allergic rhinitis (AR) is prevalent in Mediterranean countries, but there are no epidemiological studies in the Hellenic milieu in accordance with the recent ARIA guidelines. We investigated aetiological aeroallergens in AR patients of Central Greece using the ARIA classification. Between 2002 and 2006, 911 patients with rhinitis symptomatology were interviewed and underwent Skin prick testing and 623 completed the study. Seasonal rhinitis (SAR) represented 37.6%, Perennial rhinitis (PAR) 46.4% and SAR + PAR 16%. Intermittent mild and moderate/severe AR was evident in 9.3 and 24.5%, persistent mild and moderate/severe in 23.2 and 43.0%. Persistent AR appeared in overall 66.2% of patients and was prevalent in PAR and SAR + PAR (p < 0.0001). Severity of AR symptoms did not correlate more with ARIA than with the traditional subgroups. Marked statistical (p < 0.05) differences were evident for seven aeroallergens between the four geographic areas of the study. Pollen allergy was found in 77.8% but all pollens were significantly lower in coastal areas (p < 0.001), besides Parietaria (p < 0.003). Mite sensitivity manifested in 43.2%. Alternaria affected mostly the paediatric population (p < 0.0001). 12.4% (N = 77) was monosensitive, 58.7% (N = 366) oligosensitive, and 28.9% (N = 180) polysensitive. Rhinitis and asthma comorbidity was high (45.3%) and occurrence of asthma was related with PAR (p < 0.007) and SAR + PAR (p < 0.023) but not with the ARIA classification subgroups. This study provides compelling evidence of a typical Mediterranean allergic profile of patients of Central Greece with significant regional variability. Both classifications had approximately equal diagnostic value in our study besides the fact that ARIA subdivision is considered superior in determining treatment.

Nasal Polyps: An Independent Risk Factor for Bronchial Hyperresponsiveness in Patients with Allergic Rhinitis

Background

Many studies were conducted to figure out the relationship between allergic rhinitis (AR) and lower airway diseases. This study was designed to elucidate the clinical parameters that could predict the coexistence of bronchial hyperresponsiveness (BHR) in AR and suggest a guideline for lower airway evaluation in these patients.

Methods

One hundred seventy-three patients newly diagnosed with AR were evaluated for the lower airway with the methacholine bronchoprovocation test.

Results

BHR was more prevalent in patients with nasal polyps (p = 0.01), in patients complaining of moderate to severe symptoms (p = 0.023), with higher serum total IgE levels (p = 0.001), and with blood eosinophil count (p = 0.008). No statistically significant difference was observed between intermittent and persistent AR patients (p = 0.364). Blood eosinophil count that could predict BHR was calculated as 320 cells/μL (p = 0.004).

Conclusion

Instead of a routine lower airway evaluation for all AR patients, we recommend lower airway evaluation for the selected patients with nasal polyps, moderate to severe symptoms, and high blood eosinophil count.

Airway hyperresponsiveness in children with sickle cell anemia

BACKGROUND

The high prevalence of airway hyperresponsiveness (AHR) among children with sickle cell anemia (SCA) remains unexplained.

METHODS

To determine the relationship between AHR, features of asthma, and clinical characteristics of SCA, we conducted a multicenter, prospective cohort study of children with SCA. Dose response slope (DRS) was calculated to describe methacholine responsiveness, because 30% of participants did not achieve a 20% decrease in FEV1 after inhalation of the highest methacholine concentration, 25 mg/mL. Multiple linear regression analysis was done to identify independent predictors of DRS.

RESULTS

Methacholine challenge was performed in 99 children with SCA aged 5.6 to 19.9 years (median, 12.8 years). Fifty-four (55%) children had a provocative concentration of methacholine producing a 20% decrease in FEV1<4 mg/mL. In a multivariate analysis, independent associations were found between increased methacholine responsiveness and age (P<.001), IgE (P=.009), and lactate dehydrogenase (LDH) levels (P=.005). There was no association between methacholine responsiveness and a parent report of a doctor diagnosis of asthma (P=.986). Other characteristics of asthma were not associated with methacholine responsiveness, including positive skin tests to aeroallergens, exhaled nitric oxide, peripheral blood eosinophil count, and pulmonary function measures indicating airflow obstruction.

CONCLUSIONS

In children with SCA, AHR to methacholine is prevalent. Younger age, serum IgE concentration, and LDH level, a marker of hemolysis, are associated with AHR. With the exception of serum IgE, no signs or symptoms of an allergic diathesis are associated with AHR. Although the relationship between methacholine responsiveness and LDH suggests that factors related to SCA may contribute to AHR, these results will need to be validated in future studies.

Recent advances in pediatric asthma treatment

Although wheezing illness is at its most prevalent in infancy and early childhood, its self-limiting nature in the majority poses considerable challenges in offering a long-term prognosis and in initiating long-term prophylaxis. Many of the established treatments in adults have not been adequately assessed in children. Evidence is also emerging for a number of different wheezing syndromes, several of which do not to respond well to currently available medicines. Much research interest is being directed to underlying changes within the airway that appear to be independent of allergic mechanisms and that may lead to novel therapeutic approaches. The aim of this review is to restate and update current best-practice based on evidence, to encourage effective and safe use of asthma medication in children and to point to areas of ongoing research that are likely to influence management decisions in the near future.

Clinical characteristics according to sensitized allergens in adult korean patients with bronchial asthma

Purpose

Allergic sensitization is a risk factor for the development of bronchial asthma. This study was conducted to investigate clinical manifestations according to sensitized allergens in adult Korean patients with bronchial asthma.

Methods

In total, 523 adult patients who were diagnosed with bronchial asthma between March 2002 and March 2008 were included in the study. All patients underwent skin prick tests for approximately 45 allergens or a specific IgE test. Sensitized allergens were grouped into the following categories: house dust mites, fungus, pollen, and animal dander. Atopy was defined as a positive skin prick test response or the presence of a specific IgE to one or more allergens.

Results

Of the 523 patients, 295 (56%) were sensitized to one or more allergens. A younger median age, greater proportion of males, higher eosinophil counts, and higher total IgE levels were observed in the atopic asthma group compared to the non-atopic asthma group. The PC20 value was negatively correlated with eosinophil counts and total IgE in the atopic asthma group. In the subgroup analysis, patients sensitized to Cladosporium showed poorer pulmonary function and a higher response to bronchodilators. In addition, patients sensitized to Alternaria showed severer bronchial hyperresponsiveness than non-atopic patients with asthma. Finally, a gradual increase in the number of sensitized allergens was noted with increasing age, eosinophil counts, and total IgE levels.

Conclusions

We suggest the need for identifying the existence of atopy and exact offending allergens at the time of asthma diagnosis, since significant differences in sex, age, blood test results, and lung function were observed according to atopy and sensitized allergens.

Nasal endothelial interleukin-10 expression is negatively correlated with nasal symptoms after allergen provocation

BACKGROUND

Despite major efforts, factors that predict or correspond to the level of allergic symptoms remain elusive. Given our previous observations of mucosal interleukin-10 (IL-10) expression by local tissue cells and its described role as immune modulator, we hypothesized that, in allergic rhinitis, nasal mucosal IL-10 expression could influence the severity of symptoms.

METHODS

In this study, we investigated endothelial IL-10 expression in nasal mucosa of healthy- and house dust mite allergic patients, both before and after provocation, and under nasal steroid therapy. Nasal turbinate biopsies were taken from healthy individuals as well as from house dust mite allergic patients, both before and after provocation. Allergic patients received fluticasone proprionate aqueous nasal spray or control treatment. In the allergic patients, endothelial IL-10 scores based on immunohistochemical stainings were correlated with allergic symptoms, measured by visual analog scores.

RESULTS

At baseline, variable levels of endothelial IL-10 were detected in nasal biopsies. After nasal provocation, but not at baseline, endothelial IL-10 expression corresponded very closely to the allergic symptoms after allergen provocation. Low symptom scores were correlated with high endothelial IL-10 scores. This correlation disappeared after fluticason propionate treatment.

CONCLUSIONS

There is a large variation in the level of endothelial IL-10 expression both in healthy individuals and in house dust mite allergic patients. Endothelial IL-10 expression may affect local immune reactions resulting in reduced levels of allergic symptoms.

Predictors of bronchial hyperresponsiveness in chronic rhinosinusitis with nasal polyp

BACKGROUND

Chronic rhinosinusitis with nasal polyposis (CRSNP) and asthma are inflammatory lesions of the respiratory epithelium. This study was conducted to evaluate predictive factors of bronchial hyperresponsiveness (BHR) in patients with CRSNP.

METHODS

BHR was evaluated using a methacholine bronchoprovocation test (MBPT) in 122 consecutive patients newly diagnosed with CRSNP at Seoul National University Hospital from January 2004 to June 2006. The following parameters were analyzed and compared between the BHR and non-BHR groups: symptoms, atopic status, current smoking, disease severity of CRSNP based on the Lund-Mackay scoring system of sinus CT, and counts of eosinophils in the serum and nasal tissues.

RESULTS

Thirty-five percent of the patients were found to have BHR, and BHR was found to occur more frequently in patients that were currently suffering from sneezing (P = 0.007). In addition, the mean eosinophil counts of the serum and nasal tissues were higher in the BHR group than in the non-BHR group (P = 0.001 for the serum, P = 0.045 for the nasal tissues), and the eosinophil counts of the serum correlated to those of the nasal tissues (r = 0.334, P = 0.013). The disease severity, as determined by the Lund-Mackay scoring system, was not different between the two groups (P > 0.05). The best cutoff serum eosinophil count for predicting BHR in CRSNP patients was determined to be 300 cells/microl (sensitivity 70%, specificity 70%).

CONCLUSION

Taken together, these results indicate that moderate to severe sneezing and a serum eosinophil count > or = 300 cells/microl may be predictive factors for BHR in patients with CRSNP.

Asthma control over 3 years in a real-life study

This was a 3-year "real-life" study, during which patients' medication was increased and decreased to achieve sustained asthma control. Patients (282) were randomised to receive treatment with SAL 50microg, FP 250microg, or SFC 50/250microg via a Diskustrade mark inhaler, bid. A 12-month double-blind period was followed by a 2-year open phase. The physician increased or decreased patients' medication to achieve and maintain asthma control at regular clinical assessments using criteria based on the asthma treatment guidelines. On completion 73% (168/229) of the subjects were receiving SFC to maintain control of their asthma, compared with 21% (49/229) receiving FP and 5% (12/229) receiving SAL. Odds ratio for requiring increased treatment were 2.66 (p=0.002) for patients initially randomised to FP and 9.38 (p<0.0001) SAL, compared with SFC. Time until 25% of patients first required an increase in study medication was 6months for patients initially treated with SAL compared to 12months for FP and 21months for SFC. Symptoms and use of rescue medication improved first, followed rapidly by PEF with the greatest improvements occurring over the first year. Airway hyperresponsiveness continued to improve throughout the study. The majority of patients achieved and maintained control of asthma over a 3-year period with physician-driven medication changes. Patients treated with SFC were more likely to achieve control than patients treated with FP or SAL alone. Continuing improvements in airway hyperresponsiveness indicate the importance of maintaining treatment after clinical control of symptoms and lung function are achieved.

Factors affecting bronchial hyperreactivity in asthmatic children

Bronchial hyperresponsiveness (BHR), the exaggerated airway narrowing in response to nonspesific stimuli, is a common characteristic of asthma. One hundred thirty-five children who were diagnosed asthma in the outpatient clinic of Gazi University Hospital, Pediatric Allergy and Asthma Department between January 2007 and January 2008 were retrospectively analysed from the asthma database of the division. BHR was not found to be different according to sex. Younger the age of the patient, more severe was BHR (p = 0.096, r = 0.164). Younger the age at onset of the symptoms, the more severe was the BHR (p < 0.001, r = 0.307). Patients who had an asthmatic first degree relative and who were exposed to passive smoking at home, had more severe BHR (p = 0.006 and p = 0.032, respectively). There were more hospitalizations among the asthmatic children with moderate-severe BHR (p = 0.027) however no correlation was found between chronic asthma severity and the degree of BHR). In this study we found that age, age at onset of symptoms, having a parent with asthma, exposure to tobacco smoke and baseline lung function are related to BHR measured at referral. Serum levels of Ig E or skin prick test positivity were not found to have any effect on BHR severity. Considering BHR severity, we could not reveal any relation between atopic and nonatopic children. However among atopic subjects, the ones with indoor allergen sensitization had more severe BHR.

Airway responsiveness in mild to moderate childhood asthma: sex influences on the natural history

RATIONALE

Airway responsiveness is a prognostic marker for asthma symptoms in later life.

OBJECTIVES

To evaluate characteristics responsible for persistence of airway responsiveness in children with asthma.

METHODS

A total of 1,041 children, initially aged 5-12 years, with mild to moderate persistent asthma enrolled in the Childhood Asthma Management Program (CAMP) were studied prospectively for 8.6 +/- 1.8 years with methacholine challenges yearly.

MEASUREMENTS AND MAIN RESULTS

Least squares geometric mean models were fit to determine effects of sex and age on airway responsiveness (provocative concentration producing 20% decrease in FEV(1) [PC(20)]). Multiple linear regression analysis was performed to determine factors at baseline and over time, which were associated with PC(20) at end of follow-up. A total of 7,748 methacholine challenges were analyzed. PC(20) increased with age, with boys having greater increase after age 11 years than girls (P < 0.001). The divergence coincided with the mean age for Tanner stage 2. Postpubertal girls had greater airway responsiveness, even after adjustment for FEV(1) and other potential confounders. Although multivariable regression analyses noted a variety of factors that influenced airway responsivness in both sexes, a history of hay fever (beta= -0.30, P = 0.005), respiratory allergy (beta= -0.32, P = 0.006), or recent inhaled corticosteroid usage (beta= -0.18, P = 0.02) were associated with decrements in final log PC(20) only in girls.

CONCLUSIONS

Airway responsiveness (PC(20)) is more severe in the postpubertal female with asthma than in males. Although there are factors associated with airway responsiveness in both males and females, sex-specific factors may contribute to new insights into asthma pathogenesis.

Bronchoprovocation testing in asthma

Bronchial hyperresponsiveness (BHR) is an important feature of asthma and is useful in diagnosis, monitoring, and prognostication. It probably represents inherent elements of the disease process such as genetic predisposition, airway inflammation, and airway remodeling. Airway inflammation likely accounts for the variable component of BHR, whereas the persistent component of BHR correlates significantly with structural changes in the airway, such as basement membrane thickness and epithelial damage. It might be this component that is resistant or refractory to the effects of available interventions. A few trials of immunomodulatory therapy have shown considerable improvements in markers of airway inflammation, without significantly modifying airway reactivity. Interventions to impact the more permanent feature of BHR are needed.

Nasal epithelial cells express IL-10 at levels that negatively correlate with clinical symptoms in patients with house dust mite allergy

BACKGROUND

Despite constant exposure to micro-organisms and other immunogenic environmental factors, relatively very few immunological responses are initiated in the nasal mucosa. Although several mechanisms could play a role in maintaining this immune suppressive milieu, none of them have been validated. Previous data from our group suggested that locally produced interleukin (IL)-10 could be involved in maintaining local homeostasis.

METHODS

To investigate the role of epithelial IL-10 expression in the manifestation of allergic symptoms, we used immunohistochemistry to study the expression of IL-10 in the nasal epithelium of healthy individuals and house dust mite allergic patients. In the allergic patients, we determined potential correlations of epithelial expression with allergic symptoms, both at baseline and after allergen provocation.

RESULTS

IL-10 is expressed in the basal and differentiated epithelial cells of both healthy individuals and allergic rhinitis patients. In the allergic individuals, there is a strong negative correlation at baseline between the epithelial expression level of IL-10 and rhinorrhoea and sneezing, but not between that expression level and nasal blockage or peak nasal inspiratory flow (PNIF). This correlation disappears with steroid treatment or after allergen provocation, although the expression at baseline seems to predict PNIF scores after provocation.

CONCLUSIONS

Our data not only reveals IL-10 expression by human nasal epithelial cells, but also suggests that nasal epithelial IL-10 regulates allergic symptoms. Targeting the regulation mechanisms affecting IL-10 or targeting the regulation mechanism affected by IL-10 could constitute new options for the treatment of allergic disease.

Interrelationships of quantitative asthma-related phenotypes in the Epidemiological Study on the Genetics and Environment of Asthma, Bronchial Hyperresponsiveness, and Atopy

BACKGROUND

Delineating asthma subphenotypes is of interest to understand the cause of the disease. Few studies have addressed the interrelationships of quantitative asthma-related traits.

OBJECTIVE

We sought to study the interrelationships of allergy markers and FEV(1) in relation to asthma and sex in children and adults.

METHODS

Total IgE levels, skin prick test (SPT) positivity, eosinophil counts, and FEV(1) were assessed in 299 asthmatic cases (children and adults) recruited in chest clinics and 309 nonasthmatic population-based control subjects in the French Epidemiological Study on the Genetics and Environment of Asthma, Bronchial Hyperresponsiveness, and Atopy.

RESULTS

Allergy parameters were significantly higher in asthmatic cases than in control subjects for children and adults and for both sexes. Sex and age modified the pattern of concordance of high IgE levels, SPT positivity, and eosinophilia among asthmatic cases, with the greatest overlap in male children (64%) and the lowest in male adults (18%). Patterns of change over the lifespan of IgE levels, eosinophil counts, and FEV(1)/height(2) varied, with the acceleration of FEV(1) decrease being particularly evident in asthmatic adults. In adult cases and control subjects, SPT positivity (particularly to indoor allergens) was significantly related to IgE levels but not to eosinophil counts. The association of eosinophil counts with IgE levels was evident only in children. Environmental factors (smoking, pets, and country living) did not alter the patterns observed.

CONCLUSIONS

Each allergy-related phenotype showed a distinct relation with asthma, with the role for eosinophils being different than that for IgE levels and SPT responses.

CLINICAL IMPLICATIONS

Taking age and sex into account is essential for understanding the interrelationships of the various allergy-related phenotypes to asthma status.

Factors responsible for differences between asymptomatic subjects and patients presenting an IgE sensitization to allergens. A GA2LEN project

The synthesis of allergen-specific IgE is required for the development of allergic diseases including allergic rhinitis and allergic asthma (patients), but many individuals with allergen-specific IgE do not develop symptoms (asymptomatic subjects). Differences may exist between asymptomatic subjects and patients. Whether the presence of allergen-specific IgE translates into clinical allergy most likely depends on a complex interplay of multiple factors. These include a family history of atopy, the levels of total serum IgE and, allergen-specific IgE or IgG, epitope-specificity of IgE and their degree of polyclonality (mono- vs polysensitized), as yet unidentified serum factors, the balance of T regulatory cells (Treg) and Th1/Th2 cells, the polymorphisms of the high affinity receptor for IgE (FcepsilonRI) and other factors regulating the activation of FcepsilonRI-bearing cells. Asymptomatic subjects may be more often monosensitized than patients who may be more often polysensitized. There are many unanswered important questions that need to be addressed in order to better understand how IgE sensitization translates into clinical allergy. The assessment of differences between the asymptomatic and symptomatic groups of subjects represent one of the scientific programs of Global Allergy and Asthma European Network funded by the European Union and the hypotheses underlying these differences are presented in this paper.

Airway hyperresponsiveness to methacholine at age 6 to 8 years in nonasthmatic patients is not related to increased health-care utilization for asthma in the ensuing 5 years: a longitudinal study of a birth cohort

BACKGROUND

Children with heightened airway responsiveness have a greater tendency to develop asthma symptoms. Many existing studies describing this relationship have relied on self-reported symptoms that may be prone to recall bias. In addition, few studies have examined the relationship of airway hyperresponsiveness (AHR) to indicators of asthma severity such as health-care utilization.

OBJECTIVE

To determine whether a positive response to methacholine challenge in children without current or physician-diagnosed asthma at age 6 to 8 years is predictive of the subsequent onset of asthma requiring medical evaluation or treatment in the ensuing 5 years.

METHODS

Data were obtained from subjects in a population-based birth cohort (n = 835) enrolled from 1987 to 1989, who were members of a large medical group practice component of a health maintenance organization (HMO). We analyzed a subset of subjects (n = 245) who had completed a methacholine challenge at age 6 to 8 years, had no current or physician-diagnosed asthma, and were still served by the same medical group. These children were followed up from the time of methacholine challenge until HMO disenrollment or through June 2001 (ages 11 to 13 years), whichever came first. Pharmacy claims data and diagnostic codes from physician-patient encounters were evaluated for incident asthma. Incident cases of clinical asthma were defined as any child with two outpatient visits or one hospitalization, one emergency department encounter associated with an asthma diagnostic code (ie, 493.XX), or any child filling prescriptions for two bronchodilators or one antiinflammatory asthma medicine. Methacholine responsiveness was interpreted using American Thoracic Society criteria.

RESULTS

Asthma incidence did not differ based on methacholine challenge results for children with normal, borderline, and mild AHR. No child in the study demonstrated moderate-to-severe AHR.

CONCLUSION

Our data suggest that AHR with a borderline or weakly positive result in a methacholine challenge in children 6 to 8 years old without current or physician-diagnosed asthma is not related to increased health-care utilization for asthma in the ensuing 5 years.

Additive effect of eosinophilia and atopy on exhaled nitric oxide levels in children with or without a history of respiratory symptoms

Although atopy and blood eosinophilia both influence exhaled nitric oxide (eNO) measurements, no study has quantified their single or combined effect. We assessed the combined effect of atopy and blood eosinophilia on eNO in unselected schoolchildren. In 356 schoolchildren (boys/girls: 168/188) aged 9.0-11.5 yr, we determined eNO, total serum IgE, blood eosinophil counts and did skin prick tests (SPT) and spirometry. Parents completed a questionnaire on their children's current or past respiratory symptoms. Atopy was defined by a SPT >3 mm and eosinophilia by a blood cell count above the 80th percentile (>310 cells/ml). eNO levels were about twofold higher in atopic-eosinophilic subjects than in atopic subjects with low blood eosinophils [24.3 p.p.b. (parts per billion) vs. 14.1 p.p.b.] and than non-atopic subjects with high or low blood eosinophils (24.3 p.p.b. vs. 12.2 p.p.b. and 10.9 p.p.b.) (p <0.001 for both comparisons). The additive effect of atopy and high eosinophil count on eNO levels remained unchanged when subjects were analyzed separately by sex or by a positive history of wheeze (n=60), respiratory symptoms other than wheeze (n=107) or without respiratory symptoms (n=189). The frequency of sensitization to Dermatophagoides (Dpt or Dpf) was similar in atopic children with and without eosinophilia (66.2% and 67.4%, respectively); eosinophilia significantly increased eNO levels in Dp-sensitized children as well in children sensitized to other allergens. In a multiple linear regression analysis, eNO levels were mainly explained by the sum of positive SPT wheals and a high blood eosinophil count (t=4.8 and 4.3, p=0.000), but also by the presence of respiratory symptoms (especially wheeze) and male sex (t=2.6 and 2.0, p=0.009 and 0.045, respectively). Measuring eNO could be a simple, non-invasive method for identifying subjects at risk of asthma in unselected school populations.

Asthma is associated with single-nucleotide polymorphisms in ADAM33

BACKGROUND

The ADAM33 gene has recently been associated with asthma and bronchial hyper-reactivity. It codes for a disintegrin and metalloproteinase that triggers intra- and extracellular signalling by protein shedding.

OBJECTIVE

We examined whether polymorphisms in ADAM33 are associated with asthma and related traits in two German populations.

METHODS

We genotyped 15 intragenic single-nucleotide polymorphisms (SNPs) by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry of allele-specific primer extension products. The transmission disequilibrium test was used for association analysis in the German asthma family study. Additionally, we tested for association of these SNPs in a case-control sample from the European Community Respiratory Health Study using Armitage's trend test.

RESULTS

In both studies, we found SNPs that were significantly associated with asthma and related traits. In the family study, significant associations were observed for the SNPs F+1, ST+4 and ST+5 (with the lowest P-value for F+1, P=0.005). Remarkably, this association is seen even in the absence of linkage with two microsatellite markers from a previous genome scan either 3.1 million bases (Mb) up- or 5.6 Mb downstream. In the case-control study, SNP ST+7 (P=0.008) was significantly associated with asthma. Some of these SNPs overlapped with those found to be associated with elevated total IgE levels and bronchial hyper-responsiveness.

CONCLUSION

This study replicates the recently published association between asthma and ADAM33 gene variants. However, most of the associated SNPs were at non-identical positions in the German, UK and US samples. As linkage disequilibrium is high among the tested SNPs, and there is no known functional polymorphism, either not-tested variants in ADAM33, unknown regulatory elements or a gene in close proximity is responsible for this association.

Total and allergen-specific IgE levels in serum reflect blood eosinophilia and fractional exhaled nitric oxide concentrations but not pulmonary functions in allergic asthmatic children sensitized to house dust mites

Although elevated levels of serum immunoglobulin E (IgE) are considered the hallmark of atopic diseases, their clinical value in evaluating subjects with allergic disorders is under debate. To evaluate possible relationships between serum IgE levels and a variety of clinical parameters, 83 mild asthmatic children [10.98-year-old (2.95)], sensitized to house dust mites (HDM) Dermatophagoides pteronyssinus (Dp) or D. farinae (Df), were enrolled. As compared with normal control reference values detected in our laboratory, children with allergic asthma had higher blood eosinophil counts (expressed both as percentage and as absolute number) and higher fractional exhaled nitric oxide (FeNO) levels but similar values in pulmonary function parameters. In the allergic asthmatic population, serum levels of total, Dp-specific or Df-specific IgE correlated positively with eosinophil counts (Rho > or = 0.30, p < 0.01, each correlation) and FeNO levels (Rho > or = 0.33, p < 0.01, each correlation) but not with pulmonary function parameters (p > 0.1, each correlation). Finally, significant correlations, although moderate, were found in the allergic asthmatic population between eosinophil counts and FeNO levels (Rho > or = 0.42, p < 0.001, each correlation). Thus, in atopic children sensitized to HDM with mild intermittent asthma, IgE levels in blood appear to reflect systemic (blood eosinophils) and organ-specific (FeNO) markers of allergic inflammation but not pulmonary volumes or the degree of airflow limitation.

TLR4 gene variants modify endotoxin effects on asthma

BACKGROUND

Environmental exposure to endotoxin might have a crucial role in immune maturation and development of asthma.

OBJECTIVE

The aim of this study was to investigate whether the effect of endotoxin concentration in settled house dust on asthma is modified by the presence of variation in the TLR4 gene.

METHODS

We performed a cross-sectional study within the German follow-up of the European Community Respiratory Health Survey. Multivariate logistic regression analysis and nonparametric effect estimates (S-Plus) were applied to examine the association between endotoxin exposure and diagnosed asthma, related clinical symptoms, and bronchial hyperreactivity (BHR) stratified for noncarriers and carriers of G299/I399 polymorphism in the TLR4 gene.

RESULTS

In the noncarrier group (n = 279), the prevalence of asthma was significantly increased with elevated endotoxin levels in house dust with adjusted odds ratio 6.24 (95% CI, 1.33-29.17) in the second tertile, and 4.54 (95% CI, 0.94-21.96) in the third tertile compared with the lowest endotoxin tertile. The carriers of the polymorphisms (n = 55) showed a nonsignificant trend to have a lower risk of asthma (crude odds ratio, 0.67; 95% CI, 0.06-8.06 for the second tertile and 1.33; 95% CI, 0.17-10.58 for the third tertile). We found a similar association for wheeze and endotoxin exposure that was also attenuated in subjects with G299/I399 polymorphisms.

CONCLUSIONS

The G299/I399 polymorphisms were associated with a modified response to endotoxin, but the functional relationship still needs clarification.

The relationship between inflammation and dipalmitoyl phosphatidycholine in induced sputum of children with asthma

BACKGROUND

Animal studies have shown elevated surfactant production in response to lung injury. In human airways, the contribution of surfactant to the airway epithelial barrier and importance of eosinophilic inflammation is increasingly appreciated. The relationship between blood and sputum inflammatory indices of childhood asthma to surfactant levels is unknown. In this study we hypothesized that the degree of inflammation influences the level of dipalmitoyl phosphatidycholine (DPPC) in airways of children with asthma.

METHODS

Sixteen children with asthma (ages 5.5-16 years) underwent venipuncture, skin prick test, spirometry, hypertonic saline challenge, and induced sputum during a nonacute phase. Sputum (sp) and blood (se) markers of inflammation (eosinophils, neutrophils, eosinophilic cationic protein [ECP]), were related to sputum DPPC levels and several markers of asthma severity (airway hyperresponsiveness, quality of life, FEV1).

RESULTS

On multiple regression, sp-DPPC significantly correlated to sp-ECP (r=0.53, P=0.0048). Se-ECP, se-Eo, sp-eosinophils, sp-neutrophils, se-neutrophils, and inhaled steroids dose did not significantly influence sp-DPPC. Exposure to smoke did not influence inflammatory markers. FEV1 and quality of life data did not relate to any blood or sputum variable. A significant association between AHR and se-eosinophils, but not between AHR and se-ECP, sp-eosinophils, or sp-ECP was found.

CONCLUSION

Elevated DPPC levels occur in the presence of chronic eosinophilic inflammation in airways of children with stable asthma. Whether this represents an inherent lung mechanism for epithelial protection remains to be elucidated.

Outcome in adulthood of asymptomatic airway hyperresponsiveness in childhood: a longitudinal population study

The clinical outcome of asymptomatic airway hyperresponsiveness (AHR) first detected in childhood is sparsely reported, with conflicting results. We used a birth cohort of 1,037 children followed to age 26 years to assess the clinical outcome of asymptomatic AHR to methacholine first documented in study members at age 9 years. Of 547 study members who denied wheezing symptoms ever at age 9 years, 41 (7.5%) showed AHR. Forty showed methacholine responsiveness, with a provocation concentration of methacholine that elicited a 20% drop in forced expired volume in 1 sec (PC(20)) < or = 8 mg/mL, and one had baseline airway obstruction with a bronchodilator response exceeding 10%. Of these 41 study members, 18 (44%), 11 (27%), and 4 (10%) maintained AHR in 1, 2, and 3 later assessments, respectively, while 23 (56%) manifested AHR only at age 9. Compared with asymptomatic study members without AHR, those with asymptomatic AHR at age 9 years were more likely to report asthma and wheeze at any subsequent assessment, were more likely to have high IgE levels and eosinophils at ages 11 and 21, and more often demonstrated positive responses to skin allergen testing at ages 13 and 21 years. Persistent AHR at later assessments increased these likelihoods further.In conclusion, asymptomatic children with AHR are more likely to develop asthma and atopy later in life compared with asymptomatic children without AHR. Persistent AHR, even though initially asymptomatic, was associated with an even greater increased risk of development of asthma. We suggest that rather than considering AHR as a marker of asthma, it should be regarded as a parallel pathological process that may lead to subsequent symptoms and clinical evidence of asthma.

Spirometric abnormalities associated with chronic bronchitis, asthma, and airway hyperresponsiveness among boilermaker construction workers

STUDY OBJECTIVES

In a 2-year longitudinal study of boilermaker construction workers, we found a significant association between working at oil-fired, coal-fired, and gas-fired industries during the past year and reduced lung function. In the present study, we investigated whether chronic bronchitis, asthma, or baseline methacholine airway responsiveness can explain the heterogeneity in lung function response to boilermaker work.

DESIGN

This study is part of an ongoing prospective cohort study of boilermakers. Exposure was assessed with a work history questionnaire. Spirometry was performed annually to assess lung function. A generalized estimating equation approach was used to account for the repeated-measures design.

SETTING

Boilermaker union members.

PARTICIPANTS

One hundred eighteen boilermakers participated in the study.

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

Self-reported history of chronic bronchitis and asthma were associated with a larger FEV1 reduction in response to workplace exposure at coal-fired and gas-fired industries. Although we found a high prevalence (39%) of airway hyperresponsiveness (provocative concentration of methacholine causing a 20% fall in FEV1 of < 8 mg/mL) among boilermakers, we did not find a consistent pattern of effect modification by airway responsiveness.

CONCLUSIONS

Although chronic bronchitis and asthma were associated with a greater loss in lung function in response to hours worked as a boilermaker, and therefore they acted as effect modifiers of the exposure-lung function relationship, airway hyperresponsiveness did not. However, the high prevalence of airway hyperresponsiveness found in the cohort may be a primary consequence of long-term workplace exposure among boilermakers.

A randomized, double-blind trial of the effect of treatment with montelukast on bronchial hyperresponsiveness and serum eosinophilic cationic protein (ECP), soluble interleukin 2 receptor (sIL-2R), IL-4, and soluble intercellular adhesion molecule 1 (sICAM-1) in children with asthma

BACKGROUND

Anti-inflammatory properties of leukotriene modifiers and their effect on bronchial hyperresponsiveness have not been studied in children with asthma.

OBJECTIVE

The primary objective of this study was to determine the changes in serum levels of inflammatory mediators, clinical efficacy, and bronchial hyperresponsiveness after treatment with montelukast.

METHODS

In this double-blind, randomized, placebo-controlled trial, 39 children with mild-to-moderate atopic asthma were randomly allocated to receive montelukast or placebo for 6 weeks. Main outcome measures were changes in serum concentrations of soluble interleukin 2 receptor (sIL-2R), IL-4, and soluble intercellular adhesion molecule 1 (sICAM-1); peripheral blood eosinophil count; and eosinophilic cationic protein (ECP). Asthma severity score, FEV(1), and bronchial hyperreactivity (BHR) for histamine were secondary end points.

RESULTS

Compared to placebo, serum concentrations of IL-4, sICAM-1, and ECP and eosinophil blood counts significantly decreased after 6 weeks of treatment with montelukast. Montelukast significantly improved asthma control and FEV(1). Montelukast resulted in within-group significant decrease in levels of serum sIL-2R (611 vs. 483 pg/mL), IL-4 (0.123 vs 0.102 pg/mL), sICAM-1 (280 vs. 244 ng/mL), and ECP (74 vs. 59 microg/mL) and in eosinophil blood counts (349 vs. 310 cells/mm(3)). Mean FEV(1) value changed from 85% of predicted to 95% (P <.001) and for histamine (PC(20)H) from 2.8 mg/mL to 3.8 mg/mL (P <.001) after treatment with montelukast. There was no significant difference between montelukast and placebo recipients in the serum concentrations of sIL-2R and PC(20)H after treatment.

CONCLUSION

Montelukast provides clinical benefit to patients with chronic asthma and decreases bronchial hyperresponsiveness. Montelukast caused a statistically significant decrease of serum concentrations in cytokine, ICAM-1, and ECP and peripheral blood eosinophil counts over the 6-week treatment period. This observation raises the possibility that leukotriene receptor antagonists, such as montelukast, may have effects on parameters of asthmatic inflammation.

Predictors for the severity of bronchial hyperreactivity in childhood asthma

Bronchial hyperreactivity (BHR) is a common characteristic of asthma and is shown to be a risk factor in the development and outcome of asthma. In this study, we aimed to assess the risk factors at referral for the severity of BHR, which was determined at the end of a mean of 3 yr of follow-up in 98 children with asthma [mean (+/- SD) age, 11.0 (+/- 3.4) yr, male/female = 50/48]. We also evaluated the cross-sectional risk factors for the severity of BHR in the observed children. Information on risk factors at referral was collected from the computer records of the patients followed by an end-of-study visit. Lung function, skin-prick, and bronchial provocation tests were done and total serum IgE level was measured on this visit. The relationship between BHR and risk factors was investigated by multiple linear regression analysis. A lower level of FEV1 % at referral was found to be an important predictor of more severe BHR at the end of the follow-up. None of the other risk factors evaluated predicted the severity of current BHR. We concluded that decreased lung function at referral is associated with a more severe BHR determined at the end of a 3-yr follow-up in children with asthma.

Sensitization to silk and childhood asthma in rural China

OBJECTIVE

Sensitization to perennial aeroallergens is associated with asthma in industrialized countries with a Western lifestyle. Because silk products are commonly used in Chinese society, we were interested in examining the relation between sensitization to silk and asthma.

DESIGN

Cross-sectional study of 871 children in 503 families living in Anqing, a predominantly rural province of China.

RESULTS

After adjustment for age, gender, familial correlations, and sensitization to other aeroallergens, skin test reactivity to silk was an independent predictor of asthma (odds ratio = 2.6; 95% confidence interval = 1.2-5.7). This association became stronger after inclusion of the eosinophil count and history of parasitic diseases of the participants in the multivariate model (odds ratio = 3.6; 95% confidence interval = 1.4-8.9).

CONCLUSION

Because sericulture is an important activity in China and other countries throughout the world, sensitization to silk may influence the pathogenesis and severity of asthma in people living in these nations.

[Gain, loss and agreement between respiratory specialists and generalists in the diagnosis of asthma]

OBJECTIVE

To determine and analyze the degree of agreement and disagreement in the diagnosis of bronchial asthma (BA) by respiratory disease specialists and generalists in regional hospital and primary care settings.

MATERIAL AND METHODS

Ninety-six outpatients (16 to 70 years of age) were studied; all had been assigned a diagnosis of BA by the referring physician or by the respiratory disease specialist. We recorded 1) clinical symptoms, determining the initial probability of a diagnosis (IPD)of BA to be high, medium or low; 2) results of spirometry and bronchodilator testing (BDT), peak flow variability and methacholine challenge testing; 3) prick test results, eosinophil levels and total serum IgE levels. Three diagnoses were recorded: the initial diagnosis (ID) by the referring physician to whom follow-up data were unavailable; diagnosis by the respiratory disease specialist based only on clinical symptoms (RSS); and the final diagnosis(FD). To arrive at a FD of BA, it was necessary to have a high or medium IPD and a positive BDT. A Kappa test was used to analyze the degree of agreement among the three diagnoses. Group features associated with greater or lesser agreement were analyzed by chi-square tests and analysis of variance.

RESULTS

Agreement was acceptable between RSS and FD (K = 0.63) but very low between ID and RSS and between ID and FD. In the latter two cases, agreement was greatest for patients diagnosed in hospital and for those with high IgE levels (p < 0.05), with high IPD, longer course of disease and a history of asthma (p < 0.01) (odds ratio =59.8). Diagnostic disagreement occurred mainly for patients for whom a BA diagnosis was gained later, the of under-diagnosis being 39%. The patients involved visited the physician only because they had observed an isolated symptom related to asthma (odds ratio = 119) and to arrive at a diagnosis bronchomotor tests other than BDT were required (p < 0.01).

CONCLUSIONS

a) The degree of agreement for a diagnosis of BA is low. b)The functional profile of patients for whom diagnostic agreement exists differs from that of patients for whom diagnosis is gained through testing. c) In the context of this study, a high rate of under-diagnosis is evident.

Allergy markers in respiratory epidemiology

Assessing allergy by measurement of serum immunoglobulin (Ig) E antibodies is fast and safe to perform. Serum antibodies can preferably be assessed in patients with dermatitis and in those who regularly use antihistamines and other pharmacological agents that reduce skin sensitivity. Skin tests represent the easiest tool to obtain quick and reliable information for the diagnosis of respiratory allergic diseases. It is the technique more widely used, specific and reasonably sensitive for most applications as a marker of atopy. Measurement of serum IgE antibodies and skin-prick testing may give complimentary information and can be applied in clinical and epidemiological settings. Peripheral blood eosinophilia is less used, but is important in clinical practice to demonstrate the allergic aetiology of disease, to monitor its clinical course and to address the choice of therapy. In epidemiology, hypereosinophilia seems to reflect an inflammatory reaction in the airways, which may be linked to obstructive airflow limitation.