Aeroallergen sensitization correlates with PC(20) and exhaled nitric oxide in subjects with mild-to-moderate asthma

Diagnostic and therapeutic approaches for elderly asthma patients: the importance of multidisciplinary and multidimensional management

INTRODUCTION

Asthma is commonly considered a disease of younger ages; however, it is not infrequent to pose a diagnosis of the disease in older individuals. Although current recommendations do not distinguish between young and old asthmatics in terms of diagnostic and therapeutic approaches, asthma in the elderly may present with peculiar features that contribute to complicate its management.

AREAS COVERED

The current review focuses on the challenges that arise when approaching an older individual with suspected asthma. Age-associated changes of the lung may complicate the diagnostic approach. Measurement of the forced expiratory volume in the first 6 s (FEV6) in an easier and faster alternative to FVC estimation, and residual volume should always be assessed. Older individuals are often affected by concomitant diseases, both age- and drug-related, that need to be considered when approaching elderly asthmatics, since they can affect the efficacy of the treatment as well as the control of the disease.

EXPERT OPINION

The potential drug to drug interaction should be routinely investigated, and documented in medical records. The effect of aging on the response to pharmacological therapy in older asthmatics should be explored. Therefore, the need of a multidisciplinary and multidimensional approach to the elderly asthmatics is strongly encouraged.

Food and Aeroallergen Sensitization in IgE -Mediated Asthma in Egypt

Purpose:

Identifying the distribution of allergens is valuable to the effective diagnosis and treatment of allergic disease. So, our aim is to explore the sensitization of food and aeroallergens in Egyptian patients with atopic asthma.

Methods:

Cross-sectional study recruited 268 Egyptian patients with atopic asthma. Asthmatic patients were assessed by the enzyme allegro sorbent test (EAST) method for specific IgE to a panel of 19 common regional inhaled allergens and 15 food allergens.

Results and Discussion:

One hundred percent of the patients were sensitive to at least one allergen. Allergy to food allergens only was 2.9%; inhaled allergens only were 26.2% and both were70.9%. Fungi (62%) were the most frequent sensitizing aeroallergen amongst our asthmatic patients, followed by the pollen allergens (42.5%) and house dust mites (HDMs) (26%). Cows’ milk (30.5%) was the most frequent sensitizing food amongst our asthmatic patients, followed by eggs (22.4%) and fish (21.6%). Mono-sensitized patients accounted for 6.7% of all cases, while polysensitized was 93.3%. Moderate and severe asthma showed a significantly higher frequency of polysensitization compared to mild asthma.

Conclusion:

Fungi and cow's milk are the chief sensitizing allergens in Egyptian patients with atopic asthma. This study represents the first report of sensitization in atopic adult asthma using a large extract panel in Upper Egypt.

To mix or not to mix in allergy immunotherapy vaccines

PURPOSE OF REVIEW

European and US allergists generally do not agree on the approach to subcutaneous allergy immunotherapy in patients with multiple allergies. The North American approach is to treat with a mixture that contains all the allergen extracts to which the patient has evident clinical sensitivity, whereas the European approach is to select for treatment the one or at the most two allergens that are clinically most important for the patient.

RECENT FINDINGS

Recent society guidelines continue to recommend these differing practices of treating the polyallergic patient and reviews of prescribing practices indicate these divergent recommendations are followed in Europe and the USA.

SUMMARY

The objections by European allergists to the practice by US allergists are that multiallergen immunotherapy leads to dilution of allergens to less than effective doses, that proteases in some extracts can degrade allergens in other extracts, that there is a problem of safety and inability to determine which component extract caused a systemic reaction, and finally that there is alack of convincing studies demonstrating efficacy of multiallergen mixtures. Each of these contentions is addressed.

Concordance of Skin Prick Test, Intradermal Testing, Serum IgE Levels and Symptoms in Patients with Allergic Rhinitis

Background: Diagnosis of allergic rhinitis is achieved by a combination of patient history and different screening tools, followed by specific provocation testing. Screening tools usually involve a skin prick test (SPT), specific serum IgE or a combination of both. Objective: The purpose of this study was to evaluate the correlation of SPT, intradermal testing and specific serum IgE testing in certain allergens and to evaluate sensitization rates, symptom patterns and time of symptoms in a cohort of patients with suspected allergic rhinitis. Methods: Data on 4653 patients with suspected allergic rhinitis were included and divided into five groups: spring bloomers (birch, hazel, etc.), summer bloomers (grasses and rye), autumn bloomers (ribwort and mugwort), mites and mold. Correlation of SPT, intradermal testing and specific IgE test results using Cohen’s kappa and logistic regression were carried out to evaluate the probability of symptoms. Results: Comparison of SPT and specific serum IgE led to kappa coefficients between 0.33 and 0.47, corresponding to a minor to moderate concordance. Comparing the symptoms reported by patients with sensitization diagnosed by SPT, a correlation was only found for spring and summer bloomers with an odds ratio of 1.5 and 2.1, respectively. The most prevalent symptom in the study cohort was rhinitis, followed by others such as asthma, sense of smell and atopic dermatitis. Conclusions: SPT seems to be more sensitive than specific IgE for detection of sensitization. Patients’ symptoms as well as the timing of symptoms, especially for perennial allergies, are not always very pronounced.

Sex-based differences in factors associated with bronchial hyperresponsiveness in adolescents with childhood asthma

BACKGROUND

Bronchial hyperresponsiveness (BHR), an important physiological feature of asthma, is a prognostic marker of childhood asthma.

PURPOSE

We aimed to investigate the factors associated with BHR in adolescents with childhood asthma.

METHODS

Two hundred and fifteen adolescents (≥13 years of age; 149 males, 66 females) who were diagnosed with asthma during childhood were enrolled, underwent methacholine challenge tests, and were divided into the BHR group (<25 mg/mL of provocation concentration causing a 20% fall in forced expiratory volume in 1 second [FEV1] [PC20], n=113) or non-BHR group (≥25 mg/mL of PC20, n=102). We examined longitudinal changes in BHR and the risk factors for its persistence in the 108 adolescents for whom baseline data, including methacholine PC20 at age 6 years, were available. Multivariate logistic regression analyses were performed to assess the factors associated with BHR in adolescents.

RESULTS

Mold sensitization (adjusted odds ratio [aOR], 5.569; P=0.005) and increased blood eosinophil count (aOR, 1.002; P=0.026) were independently associated with BHR in boys but not girls. The odds of BHR decreased by 32% with each 1-year increase in age in boys (aOR, 0.683; P=0.010) but not girls. A reduced FEV1/forced vital capacity ratio (<90%) was independently related with BHR in female patients only (aOR, 7.500; P=0.007). BHR decreased with age throughout childhood. A low methacholine PC20 at age 6 years was independently associated with persistent BHR throughout childhood in male and female patients, whereas early mold sensitization was a risk factor for persistent BHR in male patients only (aOR, 7.718; P=0.028).

CONCLUSION

Our study revealed sex-specific differences in the factors associated with BHR in adolescents with childhood asthma. Our findings suggest the risk factors that might affect asthma transition from childhood to adolescence and adulthood.

Sublingual immunotherapy for asthma

BACKGROUND

Asthma is a common long-term respiratory disease affecting approximately 300 million people worldwide. Approximately half of people with asthma have an important allergic component to their disease, which may provide an opportunity for targeted treatment. Sublingual immunotherapy (SLIT) aims to reduce asthma symptoms by delivering increasing doses of an allergen (e.g. house dust mite, pollen extract) under the tongue to induce immune tolerance. Fifty-two studies were identified and synthesised in the original Cochrane Review in 2015, but questions remained about the safety and efficacy of sublingual immunotherapy for people with asthma.

OBJECTIVES

To assess the efficacy and safety of sublingual immunotherapy compared with placebo or standard care for adults and children with asthma.

SEARCH METHODS

The original searches for trials from the Cochrane Airways Group Specialised Register (CAGR), ClinicalTrials.gov, WHO ICTRP, and reference lists of all primary studies and review articles found trials up to 25 March 2015. The most recent search for trials for the current update was conducted on 29 October 2019.

SELECTION CRITERIA

We included parallel randomised controlled trials, irrespective of blinding or duration, that evaluated sublingual immunotherapy versus placebo or as an add-on to standard asthma management. We included both adults and children with asthma of any severity and with any allergen-sensitisation pattern. We included studies that recruited participants with asthma, rhinitis, or both, providing at least 80% of trial participants had a diagnosis of asthma. We selected outcomes to reflect recommended outcomes for asthma clinical trials and those most important to people with asthma. Primary outcomes were asthma exacerbations requiring a visit to the emergency department (ED) or admission to hospital, validated measures of quality of life, and all-cause serious adverse events (SAEs). Secondary outcomes were asthma symptom scores, exacerbations requiring systemic corticosteroids, response to provocation tests, and dose of inhaled corticosteroids (ICS).

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the search results for included trials, extracted numerical data, and assessed risk of bias, all of which were cross-checked for accuracy. Any disagreements were resolved by discussion. We analysed dichotomous data as odds ratios (ORs) or risk differences (RDs) using study participants as the unit of analysis; we analysed continuous data as mean differences (MDs) or standardised mean differences (SMDs) using random-effects models. We considered the strength of evidence for all primary and secondary outcomes using the GRADE approach.

MAIN RESULTS

Sixty-six studies met the inclusion criteria for this update, including 52 studies from the original review. Most studies were double-blind and placebo-controlled, varied in duration from one day to three years, and recruited participants with mild or intermittent asthma, often with comorbid allergic rhinitis. Twenty-three studies recruited adults and teenagers; 31 recruited only children; three recruited both; and nine did not specify. The pattern of reporting and results remained largely unchanged from the original review despite 14 further studies and a 50% increase in participants studied (5077 to 7944). Reporting of primary efficacy outcomes to measure the impact of SLIT on asthma exacerbations and quality of life was infrequent, and selective reporting may have had a serious effect on the completeness of the evidence; 16 studies did not contribute any data, and a further six studies could only be included in a post hoc analysis of all adverse events. Allocation procedures were generally not well described; about a quarter of the studies were at high risk of performance or detection bias (or both); and participant attrition was high or unknown in around half of the studies. The primary outcome in most studies did not align with those of interest to the review (mostly asthma or rhinitis symptoms), and only two small studies reported our primary outcome of exacerbations requiring an ED or hospital visit; the pooled estimate from these studies suggests SLIT may reduce exacerbations compared with placebo or usual care, but the evidence is very uncertain (OR 0.35, 95% confidence interval (CI) 0.10 to 1.20; n = 108; very low-certainty evidence). Nine studies reporting quality of life could not be combined in a meta-analysis and, whilst the direction of effect mostly favoured SLIT, the effects were often uncertain and small. SLIT likely does not increase SAEs compared with placebo or usual care, and analysis by risk difference suggests no more than 1 in 100 people taking SLIT will have a serious adverse event (RD -0.0004, 95% CI -0.0072 to 0.0064; participants = 4810; studies = 29; moderate-certainty evidence). Regarding secondary outcomes, asthma symptom and medication scores were mostly measured with non-validated scales, which precluded meaningful meta-analysis or interpretation, but there was a general trend of SLIT benefit over placebo. Changes in ICS use (MD -17.13 µg/d, 95% CI -61.19 to 26.93; low-certainty evidence), exacerbations requiring oral steroids (studies = 2; no events), and bronchial provocation (SMD 0.99, 95% CI 0.17 to 1.82; low-certainty evidence) were not often reported. Results were imprecise and included the possibility of important benefit or little effect and, in some cases, potential harm from SLIT. More people taking SLIT had adverse events of any kind compared with control (OR 1.99, 95% CI 1.49 to 2.67; high-certainty evidence; participants = 4251; studies = 27), but events were usually reported to be transient and mild. Lack of data prevented most of the planned subgroup and sensitivity analyses.

AUTHORS' CONCLUSIONS

Despite continued study in the field, the evidence for important outcomes such as exacerbations and quality of life remains too limited to draw clinically useful conclusions about the efficacy of SLIT for people with asthma. Trials mostly recruited mixed populations with mild and intermittent asthma and/or rhinitis and focused on non-validated symptom and medication scores. The review findings suggest that SLIT may be a safe option for people with well-controlled mild-to-moderate asthma and rhinitis who are likely to be at low risk of serious harm, but the role of SLIT for people with uncontrolled asthma requires further evaluation.

Age Differences in Pet Sensitization by Pet Ownership

OBJECTIVES

The association between pet sensitization and pet ownership remains unclear. Therefore, we aimed to elucidate the association between pet sensitization and pet ownership by age.

METHODS

We retrospectively reviewed 2,883 patients who visited our allergy clinic for nasal symptoms from January 2003 to December 2014, of whom 1,957 patients with data on skin-prick tests and questionnaire responses were included and divided into adults (age >19 years) and children (age ≤19 years). The association between pet sensitization and pet ownership was evaluated in both groups.

RESULTS

Among children, dog and cat sensitization showed no associations with dog and cat ownership, respectively. However, among adults, dog sensitization was significantly associated with dog ownership (odds ratio [OR], 3.283; P<0.001), and cat sensitization with cat ownership (OR, 13.732; P<0.001). After adjustment for age, sex, familial history of allergy, sinusitis, diabetes mellitus, other pet ownership, and non-pet sensitization, significant associations remained between dog sensitization and dog ownership (adjusted OR [aOR], 3.881; P<0.001), and between cat sensitization and cat ownership (aOR, 10.804; P<0.001) among adults. Dog ownership did not show any association with allergic rhinitis, asthma, or atopic dermatitis, whereas atopic dermatitis had a significant association with cat ownership in adults (aOR, 4.840; P<0.001).

CONCLUSION

Pet ownership in adulthood increased the risk of pet sensitization. However, pet ownership was not associated with the prevalence of atopic disorders, regardless of age, except for atopic dermatitis and cat ownership in adults.

Efficacy of a 3-year course of sublingual immunotherapy for mite-induced allergic rhinitis with a 3-year follow-up

Aim: To evaluate the long-term efficacy of sublingual immunotherapy (SLIT) in treating mite-sensitized allergic rhinitis (AR). Materials & methods: 150 AR children were randomly divided into SLIT and pharmacotherapy (PT) groups, receiving a 3-year course of SLIT along with PT or PT only. Results: The symptom and medication scores at the 3- and 6-year follow-up were significantly lower compared with the baseline levels in both groups, while the values were significantly lower in SLIT group than in PT group. No significant differences were observed between 3- and 6-year follow-up in SLIT group. Conclusion: 3-year SLIT along with PT appeared more effective compared with PT only for mite-induced AR in children, and the treatment was effective for at least 3 consecutive years even after SLIT ceased.

Fractional exhaled nitric oxide response to oral corticosteroids in children with mild-to-moderate asthma: Influence of race

BACKGROUND

Fractional exhaled nitric oxide (FeNO) is a noninvasive biomarker of type 2 asthma that can predict response to inhaled corticosteroid therapy. Little is known regarding the magnitude of FeNO reduction after an oral corticosteroid (OCS) course, and less is known whether there are differential responses based on race in children with mild-to-moderate asthma.

OBJECTIVE

To assess the effect of a short course of OCS on FeNO in children with asthma and to determine whether the effect is influenced by race.

METHODS

Children presenting with an acute asthma exacerbation, who had a FeNO measurement within the past 6 months when clinically stable, were enrolled. Spirometry and FeNO were obtained at the time of exacerbation and after a short course of prednisone.

RESULTS

A total of 92 children were identified (aged 11 ± 3.3 years; white, n = 46 [50%], Hispanics, n = 30 [33%], African Americans [AAs], n = 16 [7%]). At baseline, AAs were more atopic and had higher mean FeNO values than both white (48.9 vs 25.6 ppb; P < .05) and Hispanic children (22.5 ppb; P < .05), despite being prescribed similar inhaled corticosteroid doses. During the exacerbation, AAs had the highest FeNO values, whereas there was no difference in lung function between AAs and non-AAs. After prednisone therapy, there was a 56.6% reduction in FeNO, and although AAs maintained the highest FeNO levels, the relative reduction was similar between AAs and non-AAs (53.9% vs 57.8%, respectively).

CONCLUSION

FeNO levels reduced by more than 50% after an OCS course. African American children had a greater degree of type 2-driven airway inflammation at baseline, during an exacerbation and after a short course of OCS, compared with non-AAs, although the relative reduction in FeNO was similar between the groups.

Sensitization to Furry Animals and Clinical Relevance of House Dust Mite-Induced Allergic Rhinitis in Guangzhou, China

INTRODUCTION

The impact of furry animal allergens on house dust mite (HDM)-induced allergic rhinitis (AR) is unclear.

OBJECTIVE

We aimed to investigate the co-sensitization and cross-sensitization of furry animal allergens and assess their clinical relevance with HDM-induced AR.

METHODS

We enrolled 268 patients with HDM-induced AR who were diagnosed with skin prick tests positive for dogs and/or cats. Specific immunoglobulin E (sIgE) for dogs (e1) and cats (e2), their components (Can f 1-5 and Fel d 1-2), and other uncommon furry animal extracts were measured. Symptoms and quality of life were assessed with a visual analog scale (VAS).

RESULTS

The VAS scores for the AR and asthma (AS; n = 166), moderate-to-severe persistent-AR (n = 132), and e1P (positive)-e2P (n = 89) groups were higher than those for single AR (n = 102), other AR classifications, and other AR sensitization profiles, respectively. The IgE positivity rates for components such as Can f 1-3 and Fel d 2 and those for rats, sheep, mice, cows, and horses were highest in e1P-e2P patients. Can f 1-4, Fel d 1, Fel d 2, or the combined allergens were positively correlated with VAS scores. AR combined with AS and sensitization to Can f 4, Fel d 1, or mice were risk factors for HDM-induced AR with VAS scores ≥5.

CONCLUSIONS

Extensive cross-sensitization or co-sensitization was found between Can f 1-3, Fel d 2, or rat, sheep, mouse, cow, and horse extracts. Higher sIgE levels for Can f 1-4 and Fel d 1-2 or a higher number of furry animal allergens lead to more severe symptoms and a reduced quality of life. Combined with AS, sensitization to Can f 4, Fel d 1, or mice were risk factors for moderate-to-severe HDM-induced AR.

[Diagnosis of allergy in asthma]

Allergy is a hypersensitivity reaction induced by immunological mechanisms. In asthma, allergy has a complex role and is usually IgE mediated. Allergy must be evaluated during the work up but evidence of IgE sensitivity does not mean that allergens play a role in the pathophysiology of the disease. The clinical relevance of the sensitivity has to be considered. This paper describes current available tools to screen for IgE sensitivity, allergen exposure and their role in asthma.

Are biological drugs effective and safe in older severe asthmatics?

INTRODUCTION

The treatment of asthma in older ages follows the recommendations of international guidelines for the management of asthma in younger ages, although older age has always represented an exclusion criterion for eligibility to pharmacological trials. This poses a clinical challenge when deciding whether elderly severe asthmatics are candidates for biological drugs.

AREAS COVERED

The current article has a narrative structure to review the current literature on efficacy and safety of novel pharmacological drugs against immunoglobulins and interleukins that mediate and orchestrate the main inflammatory pathways in severe asthma, in order to explore whether older subjects (i.e. > 65 years of age) are included.

EXPERT OPINION

Asthma in older ages is not a rare entity, and loss of symptom control is common in most advanced ages. Current evidence from randomized clinical trials (RCTs) on the safety of biological drugs in elderly asthmatics is scarce and does not allow drawing definitive conclusions. An urgent call for studies specifically designed for elderly populations is needed, with the purpose to assess the efficacy and safety of target biological therapies in advanced ages. We envision the design of large multi-center clinical trials to decide whether and when geriatric population could benefit from biological therapies.

Immunologic modification in mono- and poly-sensitized patients after sublingual immunotherapy

OBJECTIVES/HYPOTHESIS

To compare immunologic modification and treatment outcomes after 2 years of sublingual immunotherapy (SLIT) with house dust mite extracts (HDM) between monosensitized and polysensitized patients with allergic rhinitis.

STUDY DESIGN

Retrospective cohort study.

METHODS

Among the patients who were prospectively enrolled in the SLIT cohort study, patients with allergic rhinitis who were sensitized to HDM and treated with SLIT for at least 2 years were studied. All participants underwent serologic tests at baseline and after SLIT to evaluate changes in immunologic parameters. The total nasal symptom score (TNSS) was measured before and after SLIT, and effective and less effective responder groups were categorized depending on whether patients had a TNSS reduction of 50%, as compared with baseline.

RESULTS

The increase in Dermatophagoides pteronyssinus and Dermatophagoides farinae specific immunoglobulin G4 levels was significantly higher in monosensitized patients than in polysensitized patients (P = .020 and P = .005, respectively). The TNSS significantly improved after SLIT in both the monosensitized and polysensitized groups (P < .001 in both groups). However, the difference in the changes in TNSS from baseline was not significant between the two groups (P = .374).

CONCLUSIONS

This study demonstrated different immunologic modifications after SLIT between monosensitized and polysensitized patients. However, patients in the polysensitized group who were treated with single-allergen SLIT experienced clinical improvement in TNSS that was comparable with that in the monosensitized group despite demonstrating different immunologic changes.

LEVEL OF EVIDENCE

2b Laryngoscope, 129:E170-E177, 2019.

Immunotherapy: Treating with Fewer Allergens?

Polysensitization, sensitization to more than one allergen, is a common feature of patients with allergic rhinitis, and may be a risk factor for subsequent development of allergic diseases, especially allergic asthma. However, a polysensitized patient does not necessarily have polyallergy, a documented, causal relationship between exposure to 2 or more specific, sensitizing allergens and the subsequent occurrence of relevant clinical symptoms of allergy. Allergen immunotherapy treatment strategy for the polysensitized patient in Europe is to treat the single or 2 most clinically relevant allergen(s), whereas patients in the United States are usually treated for all potential clinically relevant allergens.

Different clinical effect of several types of airborne allergens on the severity of bronchial hyperreactivity

BACKGROUND

Atopic sensitization belongs to the most common risk factors for bronchial asthma. However, in clinical practice, it is not clear whether sensitization against pollen and perennial allergens is differently associated with the severity of bronchial hyperresponsiveness (BHR).

AIM

To find out whether patients sensitized to perennial allergens differ in severity of bronchial hyperresponsiveness from patients sensitized to pollen allergens.

METHODS

The study includes 109 patients. Based on the results of skin prick tests, patients were divided into three groups: sensitivity to pollen allergens - group A; sensitivity to perennial allergens - group B; sensitivity to both pollen and perennial allergens - group C. Based on the histamine bronchoprovocation test, we compared the values of histamine provocative concentration causing a 20% drop in FEV₁ (PC₂₀) among particular groups of patients. Mild bronchial hyperresponsiveness was determined if the value of PC₂₀ was >4 mg/ml, while if the value of PC₂₀ was <4 mg/ml, the bronchial hyperresponsiveness was considered as moderate/severe.

RESULTS

A statistically significant difference was found in the degrees of bronchial hyperresponsiveness between the three groups of patients, namely, group A with the patients sensitized only to the pollen allergens, group B comprising patients sensitized to the perennial allergens only, and group C, involving patients sensitized to the combination of both pollen and perennial allergens. The PC₂₀ values were higher among the patients from the group A (7.46 mg/ml) compared to group B (4.25 mg/ml) and C (4.52 mg/ml). The odds ratio for moderate/severe BHR was 5.21 and 5.04 in group B and group C, respectively.

CONCLUSION

Severity of bronchial hyperresponsiveness shows differences according to sensitization to particular allergens. Perennial allergens are more often associated with serious forms of bronchial hyperresponsiveness which also have an impact on the severity and prognosis of bronchial asthma.

Allergen immunotherapy (AIT) for the multiple-pollen sensitive patient

INTRODUCTION

The majority of allergic subjects are polysensitized. In Europe, allergy immunotherapy (AIT) in these patients is usually limited to their single clinically most troublesome allergy while in the U.S. the immunotherapy prescription usually includes all allergen extracts to which the patient has evidence of clinical sensitivity. Areas covered: This article will review the evidence supporting the U.S. practice. It will also review the major new development in the management of polysensitized patients, the introduction of component-resolved diagnosis (CRD). Expert commentary: This allows, in many cases, distinguishing in polysensitized patients between sensitization to the major allergens of several unrelated allergen extracts and to panallergens that cause broad patterns of cross-reactivity.

Allergic asthma is distinguished by sensitivity of allergen-specific CD4+ T cells and airway structural cells to type 2 inflammation

Despite systemic sensitization, not all allergic individuals develop asthma symptoms upon airborne allergen exposure. Determination of the factors that lead to the asthma phenotype in allergic individuals could guide treatment and identify novel therapeutic targets. We used segmental allergen challenge of allergic asthmatics (AA) and allergic nonasthmatic controls (AC) to determine whether there are differences in the airway immune response or airway structural cells that could drive the development of asthma. Both groups developed prominent allergic airway inflammation in response to allergen. However, asthmatic subjects had markedly higher levels of innate type 2 receptors on allergen-specific CD4+ T cells recruited into the airway. There were also increased levels of type 2 cytokines, increased total mucin, and increased mucin MUC5AC in response to allergen in the airways of AA subjects. Furthermore, type 2 cytokine levels correlated with the mucin response in AA but not AC subjects, suggesting differences in the airway epithelial response to inflammation. Finally, AA subjects had increased airway smooth muscle mass at baseline measured in vivo using novel orientation-resolved optical coherence tomography. Our data demonstrate that the development of allergic asthma is dependent on the responsiveness of allergen-specific CD4+ T cells to innate type 2 mediators as well as increased sensitivity of airway epithelial cells and smooth muscle to type 2 inflammation.

Management of the polyallergic patient with allergy immunotherapy: a practice-based approach

Background

The great majority (60–80 %) of patients consulting specialist physicians for allergic respiratory disease are polysensitized and thus may be potentially clinically polyallergic. However, management approaches to allergen immunotherapy (AIT) in polysensitized and polyallergic patients are not standardized.

Methods

An international group of clinicians with in-depth expertise in AIT product development, clinical trials and clinical practice met to generate up-to-date, unambiguous, pragmatic guidance on AIT in polysensitized and polyallergic patients. The guidance was developed after reviewing (1) the current stance of regulatory bodies and learned societies, (2) the literature data on single- and multi-AIT and (3) the members’ confirmed clinical experience with polysensitized patients.

Results

AIT is safe and effective in polysensitized and polyallergic patients, and should always be based on the identification of one or more clinically relevant allergens (based on the type and severity of symptoms, the duration of induced symptoms, the impact on quality of life and how difficult an allergen is to avoid). Single-AIT is recommended in polyallergic patients in whom one of the relevant allergens is nevertheless clearly responsible for the most intense and/or bothersome symptoms. Parallel 2-allergen immunotherapy or mixed 2-allergen immunotherapy is indicated in polyallergic patients in whom two causal relevant allergens have a marked clinical and QoL impact. In parallel 2-allergen immunotherapy (whether subcutaneous or sublingual), high-quality, standardized, single-allergen formulations must be administered with an interval of 30 min. Mixing of allergen extracts may be considered, as long as (1) the mixture is technically feasible, (2) the mixture is allowed from a regulatory standpoint, (3) the allergen doses are reduced in proportion to the number of components but are still at concentrations with demonstrated efficacy.

Conclusions

Physicians can prescribe AIT (preferably with high-quality, standardized, single-allergen formulations) with confidence in polysensitized and polyallergic patients by focusing on clinical/QoL relevance and safety.

Sublingual immunotherapy for asthma

BACKGROUND

Asthma is a common long-term respiratory disease affecting approximately 300 million people worldwide. Approximately half of people with asthma have an important allergic component to their disease, which may provide an opportunity for targeted treatment. Sublingual immunotherapy (SLIT) aims to reduce asthma symptoms by delivering increasing doses of an allergen (e.g. house dust mite, pollen extract) under the tongue to induce immune tolerance. However, it is not clear whether the sublingual delivery route is safe and effective in asthma.

OBJECTIVES

To assess the efficacy and safety of sublingual immunotherapy compared with placebo or standard care for adults and children with asthma.

SEARCH METHODS

We identified trials from the Cochrane Airways Group Specialised Register (CAGR), ClinicalTrials.gov (www.ClinicalTrials.gov), the World Health Organization (WHO) trials portal (www.who.int/ictrp/en/) and reference lists of all primary studies and review articles. The search is up to date as of 25 March 2015.

SELECTION CRITERIA

We included parallel randomised controlled trials (RCTs), irrespective of blinding or duration, that evaluated sublingual immunotherapy versus placebo or as an add-on to standard asthma management. We included both adults and children with asthma of any severity and with any allergen-sensitisation pattern. We included studies that recruited participants with asthma, rhinitis, or both, providing at least 80% of trial participants had a diagnosis of asthma.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the search results for included trials, extracted numerical data and assessed risk of bias, all of which were cross-checked for accuracy. We resolved disagreements by discussion.We analysed dichotomous data as odds ratios (ORs) or risk differences (RDs) using study participants as the unit of analysis; we analysed continuous data as mean differences (MDs) or standardised mean differences (SMDs) using random-effects models. We rated all outcomes using GRADE (Grades of Recommendation, Assessment, Development and Evaluation) and presented results in the 'Summary of findings' table.

MAIN RESULTS

Fifty-two studies met our inclusion criteria, randomly assigning 5077 participants to comparisons of interest. Most studies were double-blind and placebo-controlled, but studies varied in duration from one day to three years. Most participants had mild or intermittent asthma, often with co-morbid allergic rhinitis. Eighteen studies recruited only adults, 25 recruited only children and several recruited both or did not specify (n = 9).With the exception of adverse events, reporting of outcomes of interest to this review was infrequent, and selective reporting may have had a serious effect on the completeness of the evidence. Allocation procedures generally were not well described, about a quarter of the studies were at high risk of bias for performance or detection bias or both and participant attrition was high or unknown in around half of the studies.One short study reported exacerbations requiring a hospital visit and observed no adverse events. Five studies reported quality of life, but the data were not suitable for meta-analysis. Serious adverse events were infrequent, and analysis using risk differences suggests that no more than 1 in 100 are likely to suffer a serious adverse event as a result of treatment with SLIT (RD 0.0012, 95% confidence interval (CI) -0.0077 to 0.0102; participants = 2560; studies = 22; moderate-quality evidence).Within secondary outcomes, wide but varied reporting of largely unvalidated asthma symptom and medication scores precluded meaningful meta-analysis; a general trend suggested SLIT benefit over placebo, but variation in scales meant that results were difficult to interpret.Changes in inhaled corticosteroid use in micrograms per day (MD 35.10 mcg/d, 95% CI -50.21 to 120.42; low-quality evidence), exacerbations requiring oral steroids (studies = 2; no events) and bronchial provocation (SMD 0.69, 95% CI -0.04 to 1.43; very low-quality evidence) were not often reported. This led to many imprecise estimates with wide confidence intervals that included the possibility of both benefit and harm from SLIT.More people taking SLIT had adverse events of any kind compared with control (OR 1.70, 95% CI 1.21 to 2.38; low-quality evidence; participants = 1755; studies = 19), but events were usually reported to be transient and mild.Lack of data prevented most of the planned subgroup and sensitivity analyses.

AUTHORS' CONCLUSIONS

Lack of data for important outcomes such as exacerbations and quality of life and use of different unvalidated symptom and medication scores have limited our ability to draw a clinically useful conclusion. Further research using validated scales and important outcomes for patients and decision makers is needed so that SLIT can be properly assessed as clinical treatment for asthma. Very few serious adverse events have been reported, but most studies have included patients with intermittent or mild asthma, so we cannot comment on the safety of SLIT for those with moderate or severe asthma. SLIT is associated with increased risk of all adverse events.

Allergic sensitization is age-dependently associated with rhinitis, but less so with asthma

BACKGROUND

Epidemiologic data describing the association between allergic sensitization and asthma and allergic rhinitis in adults are scarce.

OBJECTIVE

To determine the prevalence and impact of specific sensitization to airborne allergens on asthma and allergic rhinitis among adults in relation to age.

METHODS

A random population sample (age 21-86 years) was examined with structured interview and analysis of specific IgE to 9 common airborne allergens. Of those invited, 692 (68%) subjects participated in blood sampling. IgE level of 0.35 U/mL or more to the specific allergen was defined as a positive test result.

RESULTS

Allergic sensitization decreased with increasing age, both in the population sample and among subjects with asthma and allergic rhinitis. In a multivariate model, sensitization to animal was significantly positively associated with asthma (odds ratio [OR], 4.80; 95% CI, 2.68-8.60), whereas sensitization to both animal (OR, 3.90; 95% CI, 2.31-6.58) and pollen (OR, 4.25; 95% CI, 2.55-7.06) was significantly associated with allergic rhinitis. The association between allergic sensitization and rhinitis was consistently strongest among the youngest age group, whereas this pattern was not found for asthma. The prevalence of allergic sensitization among patients with asthma decreased by increasing age of asthma onset, 86% with asthma onset at age 6 y or less, 56% at age 7 to 19 years, and 26% with asthma onset at age 20 years or more.

CONCLUSIONS

Sensitization to animal was associated with asthma across all age groups; allergic rhinitis was associated with sensitization to both pollen and animal and consistently stronger among younger than among older adults. Early onset of asthma was associated with allergic sensitization among adults with asthma.

Selection of patients for sublingual versus subcutaneous immunotherapy

Allergen immunotherapy is the sole treatment for IgE-mediated allergic diseases directed at the underlying mechanism. The two widely accepted administration routes are sublingual (SLIT) and subcutaneous (SCIT). We reviewed how patients should best be selected for immunotherapy and how the optimal administration route can be defined. Before deciding SCIT or SLIT, appropriate selection of patients for allergen immunotherapy (AIT) is mandatory. To be eligible for AIT, subjects must have a clear medical history of allergic disease, with exacerbation of symptoms on exposure to one or more allergens and a corresponding positive skin or in vitro test. Then the route of administration should be based on: published evidence of clinical and immunologic efficacy (which varies per allergic disease and per allergen); mono- or multi-allergen immunotherapy, for SLIT multi-allergen immunotherapy was not effective; safety: adverse events with SLIT are more frequent, but less severe; and, costs and patient preferences, closely related to adherence issues. All these are discussed in the article.

Efficacy of Sublingual Immunotherapy with Dermatophagoides farinae Extract in Monosensitized and Polysensitized Patients with Allergic Rhinitis: Clinical Observation and Analysis

AIM

To investigate differences in the efficacy of sublingual immunotherapy with Dermatophagoides farinae drops in monosensitized and polysensitized allergic rhinitis patients.

METHODS

The patients enrolled in the study were treated for more than one year by sublingual immunotherapy (SLIT) using Dermatophagoides farinae drops and were divided into a monosensitized group (n = 20) and a polysensitized group (n = 30). Total nasal symptom scores of patients before and after SLIT were analyzed to evaluate the curative effect. The phylogenetic tree of dust mite allergens as well as other allergens that were tested by skin prick test was constructed to help the analysis.

RESULTS

There was no significant difference in the efficacy of SLIT between dust mite monosensitized and polysensitized patients.

CONCLUSIONS

Both dust mite monosensitized and polysensitized patients could be cured by SLIT using Dermatophagoides farinae drops. This study provides a reference for the selection of allergens to be used in immunotherapy for polysensitized AR patients.

Getting control of uncontrolled asthma

Despite various treatment modalities, a large proportion of patients have asthma that remains uncontrolled. These patients remain at an increased risk of developing severe exacerbations, have a poor quality of life, and pose a high economic healthcare burden, with an estimated mean annual cost more than double that of patients with good symptom control. It is therefore important to accurately diagnose asthma and continually assess asthma control. Several validated tools are available to do this, including questionnaires, biomarker analysis, and bronchoscopy. Current guidelines advise physicians to establish a self-management program for the patient to assess and monitor asthma control. A further recommendation is the establishment of an educational action plan to increase treatment adherence and to improve asthma control. National and international guidelines provide long-term management strategies for these patients and recommend a stepwise approach for achieving and maintaining asthma control. Despite availability of a wide range of controller and reliever therapies, uncontrolled asthma remains a challenge and reflects the need for new therapeutic options. This review discusses current global guidelines for the assessment and management of asthma control and summarizes the broad spectrum of novel therapeutic agents currently under development for the treatment of asthma, including anticholinergics, chemoattractant receptor-homologous molecules expressed on T-helper 2 lymphocyte antagonists, and anti-interleukin (IL)-5, anti-IL-13, and anti-IL-4 agents.

Efficacy and safety of house dust mite sublingual immunotherapy in monosensitized and polysensitized children with respiratory allergic diseases

BACKGROUND

The efficacy of single-allergen-specific immunotherapy in polysensitized subjects is a matter of debate. This study aimed to investigate the efficacy of house dust mite (HDM) sublingual immunotherapy (SLIT) in monosensitized and polysensitized children.

METHODS

A total of 112 children, aged 4 to 13 years old, with HDM-induced respiratory allergic diseases were allocated to a monosensitized group (n = 56) or a polysensitized group (n = 56). Both groups were treated by standard pharmacotherapy and SLIT with Dermatophagoides farinae (American HDM) extracts for 52 weeks. Symptoms, medications, visual analogue scale (VAS), and presence of adverse events (AEs) were assessed once a month. Skin-prick test (SPT) was done before and after treatment. After treatment, subjects in the polysensitized group who completed the study were further analyzed as subgroup 1 (n = 20) and subgroup 2 (n = 15) according to the number of coexisting allergens.

RESULTS

Forty-one subjects in the monosensitized group and 35 subjects in the polysensitized group completed the study. The global clinical parameters had significantly improved after treatment, with no significant difference between the monosensitized and polysensitized group throughout this period (all p > 0.05). The comparison among the monosensitized group, subgroup 1, and subgroup 2 indicated that there was no significant difference in symptoms scores and VAS at each scheduled follow-up visit. There was also no significant difference in total medications score (TMS) in the monosensitized group, subgroup 1, and subgroup 2 after week 24 (all p > 0.05). No severe systemic AEs were reported.

CONCLUSION

No significant difference was observed in the clinical effects of HDM SLIT between polysensitized and monosensitized children with respiratory allergic diseases.

Types of sensitization to aeroallergens: definitions, prevalences and impact on the diagnosis and treatment of allergic respiratory disease

The type of allergic sensitization is of central importance in the diagnosis and treatment of respiratory allergic diseases. At least 10% of the general population (and more than 50% of patients consulting for respiratory allergies) are polysensitized. Here, we review the recent literature on (i) the concepts of polysensitization, paucisensitization, co-sensitization, co-recognition, cross-reactivity, cross-sensitization, and polyallergy, (ii) the prevalence of polysensitization and (iii) the relationships between sensitization status, disease severity and treatment strategies. In molecular terms, clinical polysensitization can be divided into cross-sensitization (also known as cross-reactivity, in which the same IgE molecule binds to several allergens with common structural features) and co-sensitization (the simultaneous presence of different IgEs binding to allergens that may not necessarily have common structural features). There is a strong overall association between sensitization in skin prick tests and total IgE values but there is debate as to whether IgE thresholds are useful guides to the presence or absence of clinical symptoms in individual cases. Molecular information from component-resolved techniques appears to be of value for diagnosis and treatment decisions. Polysensitization develops over time and is a risk factor for respiratory allergy (being associated with disease severity) and therefore has clinical relevance for treatment decisions. The subterm polysensitization has been defined as polysensitization to between two and four allergens. Polyallergy is defined as clinically confirmed allergy to two or more allergens. Single-allergen grass pollen allergen immunotherapy (AIT) is safe and effective in polysensitized patients, whereas multi-allergen AIT requires more supporting evidence. Given that AIT may be more efficacious in moderate-to-severe disease than in mild disease, polysensitization could be an indication for this type of treatment. There is a need for flowcharts or decision trees for choosing the allergens for AIT in polysensitized patients and polyallergic patients.

Eosinophilic airway inflammation and airway hyperresponsiveness according to aeroallergen sensitization pattern in patients with lower airway symptoms

Purpose

Sensitization to specific allergens may be important in the development of allergic airway inflammation and airway hyperresponsiveness (AHR). We evaluated the effect of specific aeroallergen sensitization on eosinophilic airway inflammation and AHR.

Methods

We reviewed retrospectively the clinical data of subjects who underwent skin prick tests to aeroallergens, induced sputum analysis, and methacholine bronchial provocation tests to evaluate lower airway symptoms as well as analyzed the associations between the pattern of aeroallergen sensitization and sputum eosinophilia or AHR.

Results

Of the 1,202 subjects be enrolled, 534 (44.4%) were sensitized to at least one aeroallergen in skin tests. AHR was demonstrated in 23.5% and sputum eosinophilia in 38.8%. Sputum eosinophilia was significantly associated with sensitization to perennial allergens (OR, 1.9; 95% CI, 1.4-2.5), house dust mite (OR, 1.7; 95% CI, 1.3-2.3), dog (OR, 1.9; 95% CI, 1.1-3.3), and cat (OR, 2.1; 95% CI, 1.4-3.4). AHR was associated with sensitization to perennial allergens (OR, 2.7; 95% CI, 2.0-3.7), house dust mite (OR, 2.2; 95% CI, 1.6 3.2), Alternaria (OR, 2.3; 95% CI, 1.2-4.7), and cat (OR, 2.7; 95% CI, 1.7-4.3). Sensitization to more perennial allergens increased the risk for sputum eosinophilia and AHR. There was no relationship with individual seasonal allergens.

Conclusion

The development of airway eosinophilic inflammation and AHR in an adult Korean population was associated with sensitization to perennial allergens rather than seasonal allergens.

Multiallergen-specific immunotherapy in polysensitized patients: where are we?

Allergen-specific immunotherapy administered by the subcutaneous route was introduced a century ago and has been shown to be effective in the management of allergic rhinitis and asthma. More recently, the sublingual administration of allergen extracts has become popular, especially in European countries, and has also demonstrated efficacy in respiratory allergic diseases. Both modes of allergen administration during immunotherapy have been shown not only to reduce symptoms and the need for medication, but also to prevent the development of additional sensitivities in monosensitized patients, as well as asthma development in patients with allergic rhinitis, with a long-lasting effect after the completion of several years of treatment. Almost all of the well-designed and double-blinded, placebo-controlled studies evaluated treatment with single-allergen extracts. Therefore, most meta-analyses published to date evaluated immunotherapy with single allergen or extracts containing several cross-reactive allergens. As a result, in general, multiallergen immunotherapy in polysensitized patients (mixture of noncross-reactive allergens) is not recommended owing to lack of evidence. Although some guidelines have recommended against the use of multiallergen mixtures, allergists commonly use mixtures to which the patient is sensitive with the rationale that effective immunotherapy should include all major sensitivities. Literature on this subject is scarce in spite of the widespread use worldwide. Here, this issue will be extensively discussed based on currently available literature and future perspectives will also be explored.

Increase in sensitization to common airborne allergens among adults - two population-based studies 15 years apart

BACKGROUND

Studies on time trends of allergic sensitization among adults are rare. The aim of the study was to compare the prevalence of allergic sensitization to common airborne allergens among adults 15 years apart and to identify risk factors for allergic sensitization.

METHODS

Clinical examinations including skin prick test (SPT) and structured interviews were performed in two random population samples in 1994 and 2009. Furthermore, specific IgE was analyzed in 2009. SPT data were available for 483 subjects in 1994 and for 463 subjects in 2009 in ages 20-60 years. Specific IgE was analyzed in 692 subjects in ages 20-79 years.

RESULTS

Sensitization to cat (16% to 26%, p < 0.001), dog (13% to 25%, p < 0.001), birch (13% to 18%, p = 0.031) and timothy (12% to 21%, p < 0.001), based on SPT, increased significantly from 1994 to 2009. Sensitization to any positive SPT increased from 35% to 39%, p = 0.13.The proportion of having ≥3 positive SPT reactions increased from 40% to 56%, p = 0.002. The sensitization pattern yielded similar results based on specific IgE. Risk factors for allergic sensitization were having a family history of allergy (OR 3.1, 95% CI 2.0-4.8 for any positive SPT; OR 2.7, 95% CI 1.8-4.0 for any elevated IgE) and urban living (OR 1.7, 95% CI 1.0-2.7; OR 1.5, 95% CI 1.0-2.4).

CONCLUSIONS

The prevalence of allergic sensitization to major airborne allergens as well as multi-sensitization increased significantly between the study years. Young age, a family history of allergy and urban living were significant risk factors for allergic sensitization.

Sensitization profile in differential diagnosis: allergic asthma vs. chronic (nonspecific) cough syndrome

BACKGROUND

In the subgroup of children with chronic cough, distinguishing children with allergic asthma from those with non-specific respiratory symptoms is difficult. We have focused on determination of diagnostic efficiency of serum total IgE, sIgE, and skin prick test in differentiation of asthmatic children from children with nonspecific respiratory symptoms.

MATERIAL AND METHODS

A total of 131 children with median age of 7.5 years were enrolled in study and divided into 2 groups; children with allergic asthma (N=71) and children with chronic cough (N=60). Participants underwent the standard allergological examination, including skin prick test and measurement of total IgE, and following 3 allergen-specific IgE antibodies against aeroallergens: Dermatophagoides pteronyssinus, Ambrosia artemisiifolia, and Phleum pratense.

RESULTS

The percentage of patients with elevated level of total and sIgE was higher in children with allergic asthma than in children with chronic cough syndrome (P=0.0001). In children with asthma, sIgE had a better diagnostic value than total IgE. The best diagnostic efficiency of cut-off values for sIgE was shown for Der p sIgE. Skin prick test to all allergens had 78.82% sensitivity and 91.3% specificity in differentiating the 2 tested groups. The highest sensitivity and specificity in skin prick test was proved for Dermatophagoides pteronyssinus.

CONCLUSIONS

The sensitization profile consisting of total IgE, sIgE levels, and SPT clearly distinguishes children with allergic asthma from children with chronic nonspecific cough, but still with overlap. Therefore, diagnosis should always be confirmed by a thorough allergy investigation.

Asthma in the elderly: the role of exhaled nitric oxide measurements

Asthma in the elderly is poorly understood because only a small minority of asthma studies have investigated this patients group. Fractional exhaled nitric oxide (FENO) has been extensively studied in children and adults with asthma, but little is known about FENO in elderly asthmatics. We studied the role of serial measurements of FENO in elderly subjects with asthma. Thirty stable asthmatics 65 years old and older were followed for one year with evaluations at baseline and every three months. We looked for associations between FENO and subjects' demographics, comorbidities, asthma treatment, spirometric values and asthma control test (ACT) scores. FENO was not elevated in our study subjects throughout the study period (mean < 30 ppb). FENO significantly increased and FEV1% decreased between first and last study visit, while ACT scores and steroid dose remained unchanged. No significant correlation was found between FENO and FEV1/FVC, other spirometric values, inhaled steroid dose or ACT scores at any time point. No associations of FENO were found with age, sex, body mass index (BMI), atopic status, disease duration, presence of rhinitis or gastroesophageal reflux disease (GERD), or other medications used. Moderate asthma exacerbations did not consistently cause an increase of FENO. In stable elderly asthmatic patients, FENO was not elevated and did not correlate with subjects' demographics, comorbidities, treatment, symptoms or spirometric values. Routine measurements of FENO may not be clinically valuable in elderly asthmatics.

Fractional exhaled nitric oxide in healthy non-asthmatic 7-year olds and prenatal exposure to polycyclic aromatic hydrocarbons: nested regression analysis

The main goal of the study was to assess possible association between transplacental exposure to genotoxic PAH compounds assessed by the cord blood PAH-DNA adducts and fractional exhaled nitric oxide (FeNO) measured in healthy non-asthmatic children at the age of 7 years. The subjects included the subsample of 89 children who took part in the ongoing population based birth cohort study in Krakow and attended FeNO testing. The effect of transplacental PAH exposure was adjusted for potential confounders, such as maternal allergy and children's specific atopy to common domestic allergens.

RESULTS

FeNO values were significantly elevated in children with higher prenatal PAH exposure (gmean = 7.7 ppb; 95% CI: 5.8-10.2 ppb) compared with those at low exposure level (gmean = 3.8 ppb; 95% CI: 2.3-6.3) (P = 0.011). Children with maternal allergy had also significantly higher mean FeNO values (gmean = 13.7 ppb, 95% CI: 8.8-21.4 ppb) compared with the subjects whose mothers denied allergy (gmean = 5.6 ppb, 95% CI: 4.3-7.3 ppb) (P = 0.012). Similarly, FeNO values in atopic children were higher (gmean = 11.2 ppb; 95% CI: 3.8-32.8 ppb) than in non-atopic individuals (gmean = 6.0 ppb; 95% CI: 4.7-7.7 ppb, P = 0.079). The results of the nested multivariable linear regression analysis showed that both maternal allergy and sensitization of children to domestic aeroallergens jointly explained 10.4% of FeNO variance, however, the additional 10.9% was determined by prenatal PAH exposure.

CONCLUSION

FeNO is more than a marker useful for screening atopy or symptomatic bronchial inflammation and may also be a proxy for cytokine deregulation and "allergic response" phenotype possibly established in fetal period due to transplacental PAH exposure. Preliminary results of our study should encourage more studies on intrauterine PAH exposure and later respiratory symptoms.

GSDMB/ORMDL3 variants contribute to asthma susceptibility and eosinophil-mediated bronchial hyperresponsiveness

In 2007, a genome-wide association study identified associations between variants involved in the regulation of ORMDL3 expression and asthma. These observations were subsequently replicated in case-control studies in several ethnic groups. We investigated the possible contribution of GSDMB/ORMDL3 variants to asthma susceptibility and intermediate asthma phenotypes in Korean children. The polymorphisms rs7216389, rs4794820, rs4065275, and rs11650680 were genotyped using the TaqMan assay in 931 asthmatics and 480 normal controls in a case-control study, and in 1907 elementary school children in a general population study. Each subject also underwent peripheral blood analysis of immunoglobulin E levels, eosinophil cationic protein (ECP) levels, and eosinophil percentage. Pulmonary function testing (FEV(1) and MMEF) and a methacholine provocation test (PC(20)) were also performed. The case-control study revealed a significant association between a linkage disequilibrium block, including rs7216389, rs4794820, and rs4065275, and susceptibility to asthma and atopic asthma. The CT and TT genotypes of rs11650680 were associated with lower logECP levels than the CC genotype in asthmatics, while the GA and AA genotypes of rs4794820 were associated with higher logPC(20) values than the GG genotype in atopic asthmatics. The haplotype (CAA) of rs7216389, rs4794820 and rs4065275 was associated with a lower risk of asthma susceptibility and a higher logPC(20). In the general population study, rs11650680 was significantly associated with a diagnosis of asthma. Moreover, the GA and AA genotypes of rs4794820 were associated with higher logPC(20) values and lower eosinophil percentages than the GG genotype in subjects who had been diagnosed with asthma, or showed bronchial hyperresponsiveness (PC(20)≤16). The GSDMB/ORMDL3 gene block, which includes rs7216389, rs4065275, rs4794820, and rs11650680, may be associated with asthma susceptibility in Korean children because it promotes eosinophilic inflammation, which induces bronchial hyperresponsiveness.

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.

Multiple-allergen and single-allergen immunotherapy strategies in polysensitized patients: looking at the published evidence

In allergen immunotherapy there is debate as to whether polysensitized patients are best treated with many allergens simultaneously (chosen according to the sensitization profile, a predominantly North American approach) or a single allergen (chosen according to the most clinically problematic allergy, a predominantly European approach). In patients seeking treatment for moderate-to-severe respiratory allergies, polysensitization is more prevalent (range, 50% to 80%) than monosensitization in both the United States and Europe. Safe, effective, single-allergen preparations will most likely have been tested in polysensitized patients. In robust, large-scale clinical trials of grass pollen sublingual tablets, polysensitized patients benefited at least as much from allergen immunotherapy as monosensitized patients. A recent review of multiallergen immunotherapy concluded that simultaneous delivery of multiple unrelated allergens can be clinically effective but that there was a need for additional investigation of therapy with more than 2 allergen extracts (particularly in sublingual allergen immunotherapy). More work is also required to determine whether single-allergen and multiallergen immunotherapy protocols elicit distinct immune responses in monosensitized and polysensitized patients. Sublingual and subcutaneous multiallergen immunotherapy in polysensitized patients requires more supporting data to validate its efficacy in practice.

Quantification of atopy, lung function and airway hypersensitivity in adults

BACKGROUND

Studies in children have shown that concentration of specific serum IgE (sIgE) and size of skin tests to inhalant allergens better predict wheezing and reduced lung function than the information on presence or absence of atopy. However, very few studies in adults have investigated the relationship of quantitative atopy with lung function and airway hyperresponsiveness (AHR).

OBJECTIVE

To determine the association between lung function and AHR and quantitative atopy in a large sample of adults from the UK.

METHODS

FEV1 and FVC (% predicted) were measured using spirometry and airway responsiveness by methacholine challenge (5-breath dosimeter protocol) in 983 subjects (random sample of 800 parents of children enrolled in a population-based birth cohort enriched with 183 patients with physician-diagnosed asthma). Atopic status was assessed by skin prick tests (SPT) and measurement of sIgE (common inhalant allergens). We also measured indoor allergen exposure in subjects' homes.

RESULTS

Spirometry was completed by 792 subjects and 626 underwent methacholine challenge, with 100 (16.0%) having AHR (dose-response slope>25). Using sIgE as a continuous variable in a multiple linear regression analysis, we found that increasing levels of sIgE to mite, cat and dog were significantly associated with lower FEV1 (mite p = 0.001, cat p = 0.0001, dog p = 2.95 × 10-8). Similar findings were observed when using the size of wheal on skin testing as a continuous variable, with significantly poorer lung function with increasing skin test size (mite p = 8.23 × 10-8, cat p = 3.93 × 10-10, dog p = 3.03 × 10-15, grass p = 2.95 × 10-9). The association between quantitative atopy with lung function and AHR remained unchanged when we repeated the analyses amongst subjects defined as sensitised using standard definitions (sIgE>0.35 kUa/l, SPT-3 mm>negative control).

CONCLUSIONS

In the studied population, lung function decreased and AHR increased with increasing sIgE levels or SPT wheal diameter to inhalant allergens, suggesting that atopy may not be a dichotomous outcome influencing lung function and AHR.

Monosensitization and polysensitization in allergic rhinitis

BACKGROUND

Polysensitization is common in patients with allergic rhinitis (AR) and may affect clinical feature. However, there are patients who remain monosensitized.

OBJECTIVE

This cross-sectional study aimed at evaluating a large cohort of AR patients to define the percentage and the features of mono- and poly-sensitized subjects.

METHODS

This observational cross-sectional study included a large group of AR patients: 2415 subjects (1958 males, mean age 24.6 ± 5 years) were consecutively evaluated. Symptom severity, type and number of sensitizations, and AR duration were considered.

RESULTS

621 patients (25.7%) were monosensitized: 377 to Parietaria, 194 to house dust mites, 19 to birch, 17 to grasses, 12 to molds, 2 to olive, and 1 to cypress. There was no difference between mono- and polysensitized patients concerning the duration of rhinitis (6 ± 2.14 years vs 6 ± 3.7). Severity of symptoms was higher in polysensitized patients than in monosensitized (p<0.05); in addition, there was a difference among monosensitized patients: Parietaria-allergy induces the most severe symptoms.

CONCLUSION

This study conducted in a large AR population might suggest that monosensitized and polysensitized AR patients could constitute two different categories. In addition, the specific type of allergy may condition the clinical feature.

18F-FDG uptake rate is a biomarker of eosinophilic inflammation and airway response in asthma

In asthma, the relationship among airway inflammation, airway hyperresponsiveness, and lung function is poorly understood. Methods to noninvasively assess these relationships in human subjects are needed. We sought to determine whether (18)F-FDG uptake rate (K(i), min(-1)) could serve as a biomarker of eosinophilic inflammation and local lung function.

METHODS

We used PET/CT to assess regional pulmonary perfusion (Q), specific ventilation per unit volume (sV(A)), fractional gas content (Fgas), airway wall thickness, and regional K(i) 10 h after segmental allergen challenge to the right middle lobe in 6 asthmatic subjects with demonstrated atopy. Q, sV(A), and Fgas in the allergen-challenged lobe were compared with the right upper lobe, where diluent was applied as a control. The airway wall thickness aspect ratio (ω) of the allergen-challenged airway was compared with those of similarly sized airways from unaffected areas of the lung. Differences in K(i) between allergen and diluent segments were compared with those in cell counts obtained 24 h after the allergen challenge by a bronchoalveolar lavage of the respective segments.

RESULTS

We found systematic reductions in regional Q, sV(A), and Fgas and increased ω in all subjects. The ratio of eosinophil count (allergen to diluent) was linearly related (R(2) = 0.9917, P < 0.001) to the ratio of K(i).

CONCLUSION

Regional K(i) measured with PET is a noninvasive and highly predictive biomarker of eosinophilic airway inflammation and its functional effects. This method may serve to help in the understanding of allergic inflammation and test the therapeutic effectiveness of novel drugs or treatments.

Polysensitization as a challenge for the allergist: the suggestions provided by the Polysensitization Impact on Allergen Immunotherapy studies

INTRODUCTION

Polysensitization, that is, sensitization to more than one allergen family, is a common feature of patients with allergic rhinitis (AR) and significantly impairs their quality of life (QoL). Allergen-specific immunotherapy is the only causal treatment for AR. However, the polysensitization phenomenon may represent a crucial obstacle as far as it concerns the choice of the allergen extract to be used for immunotherapy.

AREAS COVERED

A series of real-life based multi-center studies, named POLISMAIL (Polysensitization Impact on Allergen Immunotherapy), have been designed with the aim of evaluating the behavior of allergists in managing polysensitized AR patients. The effect of immunotherapy treatment in these patients was also evaluated. A single allergen extract was used in two-thirds of patients, whereas a mix of two allergens was chosen in the remaining. The severity grade of AR and the QoL were significantly improved by immunotherapy. Both outcomes confirmed that immunotherapy with one or two allergen extracts achieves a significant improvement in polysensitized patients.

EXPERT OPINION

In conclusion, POLISMAIL studies demonstrate that polysensitization should not represent a counter-indication for prescribing immunotherapy. The choice of limiting sublingual immunotherapy to one to two allergen extracts, preferably separated and at high dosages, is sufficient and effective in improving symptoms and QoL.

Exhaled nitric oxide discriminates children with and without allergic sensitization in a population-based study

BACKGROUND

Fraction of exhaled nitric oxide (FeNO) as a biomarker of airway inflammation in children warrants better clarification.

OBJECTIVE

To identify the determinants of FeNO in children and assess the validity of FeNO as a discriminative tool for asthma, rhinitis or allergic sensitization in a population setting.

METHODS

Children aged 5-18 years (N=1717) were evaluated using online FeNO measurements, questionnaires, anthropometric measurements, pulmonary function tests and total and specific serum IgE.

RESULTS

FeNO levels were age-dependent, with an average increase of 7.4% per year of age. It decreased with increasing body mass index (BMI), estimated at 1.5% decrease per kg/m(2) . Children with allergic sensitization had elevated FeNO independent of allergic symptoms. In the combined analyses of asthma, rhinitis and allergic sensitization, elevated FeNO levels were confined mainly to children having allergic sensitization. After adjusting for allergic sensitization, a significant association between rhinitis and FeNO remained, but no such association was seen with asthma. The sensitivity, specificity, and positive (PPV) and negative predictive values (NPV) of FeNO at the optimum cut-off of 28 p.p.b. for diagnosing asthma were 64.3%, 69.9%, 8.8%, and 97.7%, respectively (area under the ROC curve [AUC] 0.67), and were slightly better for diagnosing allergic asthma: 70.0%, 70.4%, 9.0%, 98.3%, respectively (AUC 0.71). FeNO had modest accuracy in discriminating rhinitis with an AUC value of 0.70, and performed better in discriminating allergic rhinitis (AUC 0.78). FeNO was a robust discriminator of allergic sensitization independent of symptoms at a cut-off of 15.4 p.p.b. (AUC 0.80; sensitivity 72.2%; specificity 71.2%; PPV 76.9%; NPV 65.8%).

CONCLUSION AND CLINICAL RELEVANCE

FeNO measurement discriminates children with and without allergic sensitization independent of allergic symptoms. On the other hand, low FeNO levels in children may help exclude allergic asthma but high levels may be caused by allergic sensitization, older age, rhinitis, and lower BMI, in addition to asthma.

Role of aeroallergen nasal challenge in asthmatic children

BACKGROUND

The majority of allergic asthmatic patients are sensitised to several aeroallergens. Discrimination of the clinically relevant allergen is essential for the correct use of immunotherapy.

OBJECTIVE

To investigate nasal challenge and its role in screening clinically relevant allergens in asthmatic children.

METHODS

Aeroallergen nasal challenge was performed in five different groups of patients (asthma; asthma & rhinitis; rhinitis; atopic controls; and non-atopic controls). Differences between groups after challenge were evaluated by means of spirometry and acoustic rhinometry.

RESULTS

Nasal challenge was performed in 125 patients, 25 per group. The positive nasal response of immediate type was recorded in 21 patients with asthma only (P<0.001), 18 with asthma and rhinitis (P<0.001), 19 with rhinitis (P<0.001), two atopic control patients and in no healthy control patients. However, no differences were observed between the asthma group and the groups with rhinitis symptoms. The risk of a positive challenge was much higher in the asthma without rhinitis group compared to atopic controls (OR 29.57; 95%CI: 5.47-159.97).

CONCLUSION

Aeroallergen nasal challenge is a safe technique in asthmatic children and could be useful in establishing the clinically relevant allergen even in the absence of rhinitis.

Component-resolved diagnosis for phleum allergy: the role of recombinants

BACKGROUND

Conventional diagnostic tests (such as radioallergosorbent test [RAST] and skin prick test [SPT]) use native raw pollen allergen extracts to establish allergy. However, recombinant allergens may offer important advantages compared with their natural counterparts.

OBJECTIVE

This study evaluated serum immunoglobulin E (IgE) in patients with grass-induced allergic rhinitis (AR) or AR with asthma (ARA), comparing assays with natural or recombinant grass allergens.

METHODS

Sixty patients (33 AR, 27 ARA) positive with SPT and serum IgE for Phleum pratense were enrolled in the study. Serum IgE specific for conventional and recombinant Phleum pratense: rPhl p 1, rPhl p 2, nPhl p 4, rPhl 5b, rPhl p 6, rPhl p 7, rPhl p 11, rPhl p 12, were measured by the IFMA procedure (ImmunoCAP, Phadia, Uppsala, Sweden). Data were expressed as the median (md) and percentiles. Recombinant allergen results were expressed also as the percentage of positive concentrations. The Wilcoxon test was used to compare samples. Because diagnosis is a binary variable (AR/ARA), logistic regression analysis was performed to identify possible correlates.

RESULTS

IgE concentrations assessed with recombinant allergens were significantly higher in ARA patients (p = .05) than in AR patients. A value >5.8 kU/L is the optimal cut-off to discriminate AR and ARA patients. Model specificity was 76%, sensitivity 78%, and efficiency 77%.

CONCLUSION

This study shows that IgEs for natural and recombinant grass pollen allergens are significantly higher in patients with AR and asthma. Moreover, using recombinant allergens it is possible to define a prediction model for diagnosis with 77% efficiency. Therefore, this study may suggest that there are advantages of using recombinant or purified, native allergens over crude extracts.

Influence of atopy and asthma on exhaled nitric oxide in an unselected birth cohort study

BACKGROUND

Asthma is considered to be associated with elevated levels of exhaled nitric oxide (FeNO). The nature of this relationship and how it is influenced by atopy are still not resolved.

METHODS

The Isle of Wight birth cohort (N=1456) was reassessed at 18 years of age. Participants able to attend the research centre were assessed by questionnaires, skin prick testing and FeNO in order to explore the interrelationship between asthma, atopy and FeNO.

RESULTS

Atopy was significantly associated with higher levels of FeNO. However, the level of FeNO for non-atopic asthmatic participants was no different to the non-atopic no-asthma group. The highest levels of FeNO were seen in subjects with both atopy and asthma. In addition, FeNO was positively associated with increasing atopic burden as evidenced by increasing FeNO with increasing skin prick testing positivity, and with increasing severity of atopic asthma as evidenced by the number of attacks of wheezing. FeNO and current inhaled corticosteroid use were not significantly associated.

CONCLUSIONS

FeNO behaves as a biomarker of atopy and the "allergic asthma" phenotype rather than asthma itself. This may explain why FeNO-guided asthma treatment outcomes have proved to be of limited success where atopic status has not been considered and accounted for.

Comparison of allergen immunotherapy practice patterns in the United States and Europe

OBJECTIVE

To discuss important differences and similarities in the allergen specific immunotherapy (SIT) treatment practices for aeroallergen sensitivity in the United States and Europe.

DATA SOURCES

Information on regulation and standardization in the United States and Europe was obtained from a Food and Drug Administration Allergenic Products Advisory Committee meeting, published literature, personal communications, and information obtained from the extract manufacturers.

STUDY SELECTION

Information from the published literature included articles known to the authors and acknowledged consultants, textbooks, and PubMed, with search terms dependent on the particular subtopic.

RESULTS

Key differences between Europe and the United States include allergen extract regulation, standardization, formulation, types of allergen extracts, routes of administration, and reimbursement. Most SIT is formulated in US allergists' offices, whereas virtually all SIT is formulated by extract manufacturers in Europe. Sublingual immunotherapy represents a significant percentage of SIT treatment in Europe (approximately 45%), but only a small percentage of US allergists (approximately 5.9%) prescribe sublingual immunotherapy. Similarities between European and US allergist specialists lie in their perception of SIT and approach to providing optimal SIT care, which is detailed in their practice guidelines.

CONCLUSION

Significant differences and similarities exist in SIT practice patterns of US and European allergy specialists. The differences lie primarily in the availability of allergen extracts and how these extracts are formulated. A key similarity is that both recognize the need for ongoing research focused on developing safer and more effective SIT.

Exhaled nitric oxide in pregnant healthy and asthmatic women

BACKGROUND

Measurement of fractioned exhaled nitric oxide (FE(NO)) is useful for monitoring airway inflammation in asthma. Asthma is one of the most common diseases complicating pregnancy, and FE(NO) may be helpful for monitoring asthma in pregnancy. However, some physiological alterations of FE(NO) may be expected during healthy pregnancy due to vascular nitric oxide production. Until now no study assessed the level of FE(NO) in asthmatic pregnant patients.

OBJECTIVE

We aimed to assess the possible use and reproducibility of FE(NO) measurements in pregnant asthmatic women. We compared FE(NO) concentrations between four groups of subjects: healthy nonpregnant and pregnant females and asthmatic nonpregnant and pregnant patients. We also investigated the relationship between FE(NO) values and the level of asthma control in pregnant asthmatic patients.

METHODS

A total of 102 female subjects (35 healthy nonpregnant and 27 healthy pregnant females; 20 nonpregnant and 20 pregnant asthmatic women) were included in this cross-sectional study. Two FE(NO) measurements were performed in each subject using an electrochemical sensor based device (NIOX MINO, Aerocrine, Solna, Sweden). Data are given as median with range.

RESULTS

The repeatability of FE(NO) measurement was similar in pregnant and nonpregnant subjects. FE(NO) levels did not differ significantly between healthy pregnant versus nonpregnant subjects (16.0 [8, 31] vs. 16.0 [9, 35] ppb). FE(NO) levels were significantly increased in asthmatic women compared to healthy females (nonpregnant asthmatics: 38 [9, 54] ppb, p < 0.001 vs. healthy nonpregnant; pregnant asthmatic patients: 28 [10, 56] ppb; p < 0.05 vs. healthy pregnant).

CONCLUSIONS

FE(NO) level is not influenced by healthy pregnancy. In pregnant asthmatic patients FE(NO) level is elevated compared to healthy pregnant subjects and correlates with the level of asthma control. Further studies are required to assess the use of FE(NO) measurement to monitor asthma in this patient group.

Advances in adult asthma diagnosis and treatment and health outcomes, education, delivery, and quality in 2008

In 2008 the Journal reported new findings in management of asthma. Dosing schedules of inhaled steroids have been modified and individualized. New, more costly propellants are replacing ozone-depleting chlorofluorocarbons. An association of asthma with pneumococcal disease has been observed. Smoking bans in public places are eliminating second-hand smoke and reducing asthma-related emergency department visits among adults. In contrast with these advances, however, disparity in asthma morbidity persists: black persons compared with white persons have a 4-fold greater risk of an asthma-related emergency department visit.