Practical guide to skin prick tests in allergy to aeroallergens

Recombinant allergen-based provocation testing

Over the last 25 years, recombinant allergens from all important allergen sources have been cloned and are now available as recombinant proteins. These molecules can be produced in practically unlimited amounts without biological or batch-to-batch variability. It has been shown in provocation tests that recombinant allergens have similar clinical effects as their natural counterparts. With the help of these tools it is possible to reveal the precise reactivity profiles of patients and to uncover and differentiate cross-reactivity from genuine sensitization to an allergen source. Although it has been shown some time ago that it would be possible to replace crude allergen extracts with recombinant allergens for skin prick testing, and even though the use of allergen components can improve routine diagnosis, these tools are still not available for clinical routine applications. The use of provocation tests is a crucial step in the development of new, hypoallergenic vaccines for therapy of allergic disease. Here we describe important provocation methods (skin prick test, intradermal test, atopy patch test, nasal provocation, colonoscopic provocation test) and give an overview of the clinical provocation studies which have been performed with recombinant allergens so far.

[Choosing the best panel of aeroallergen prick-tests for patients in Lebanon with rhinitis and asthma: A retrospective study of 2350 patients]

INTRODUCTION

The aim of this study was to evaluate the profile of skin prick-test reactivity to different aeroallergens in patients with rhinitis and asthma in Lebanon and its geographic variation within the country. It was also to suggest a minimal panel of allergens that should be used to detect sensitized patients.

METHODS

All patients who underwent skin prick-testing, because of rhinitis and/or symptoms suggesting asthma, between 2004 to 2011 in the hôtel-Dieu de France university hospital of Beirut, were studied. The total number of patients was 2350 and all were tested with the same panel of 24 aeroallergens. A further series of 208 patients were added because Cupressaceae antigens were not included in the initial series.

RESULTS

The overall rate of sensitization to any allergen was 75.6%. A battery of eleven allergens (Dermatophagoides pteronyssinus, Dermatophagoides farinae, Blomia, Parietaria, grass, Salicaceae, oak, Oleaceae, dog, cat, and cockroaches) was found to identify sensitized patients with a sensitivity of 96% and a negative predictive value of 90%. Cupressaceae should be added to this battery in view of the results of the additional series. The Bekaa region had a unique profile of sensitization.

CONCLUSION

Twelve allergens are able to detect almost all sensitized patients suffering from respiratory symptoms in Lebanon.

Minimum prick test panel for adult patients with asthma and rhinitis in Ankara, Turkey

OBJECTIVE

Determination of the number and type of allergens needed to be tested in epidemiological studies is important in order to identify most of the sensitized subjects with a cost-effective approach. This study aimed to investigate the minimum skin prick test panel for the identification of at least 95% of the sensitized subjects with symptoms of asthma and/or allergic rhinitis (AR) in Ankara, Turkey.

METHODS

Skin prick test results of 7492 patients who were referred to our outpatient clinic with clinical symptoms of asthma and/or AR between 1991 and 2005 were evaluated retrospectively. Seven allergens were tested in all and 13 allergens in 4202 patients. The allergen group needed for detection of 95% of the sensitized subjects was determined for both the 7 and 13 allergen panels. The study protocol was approved by the local ethics committee of Hacettepe University.

RESULTS

The atopy prevalences in the whole study population and in 4202 patients tested with the 13 allergen panel were calculated as 32.2% and 42.6%, respectively. Three allergens (Phleum pratense, Dermatophagoides pteronyssinus and Artemisia vulgaris) within the 7 allergen panel were adequate for the identification of at least 95% of the sensitized subjects. Olea europae was added to the previous three allergens when the 13 allergen panel was applied.

CONCLUSION

Three to four allergens are sufficient for identification at least 95% of sensitized subjects with asthma and/or AR in Ankara, Turkey.

Pollen-induced allergic rhinitis in 1360 Italian children: comorbidities and determinants of severity

BACKGROUND

Pollen-induced allergic rhinoconjunctivitis (AR) is highly prevalent and rapidly evolving during childhood. General practitioners may not be fully aware of the nature and severity of symptoms experienced by patients and might underestimate the prevalence of moderate or severe disease. Thus, the relevance of early diagnosis and intervention may be overlooked.

OBJECTIVES

To investigate the severity of pollen-induced AR and its determinants in Italian children referred to allergy specialists and who had never received specific immunotherapy (SIT).

METHODS

Children (age 4-18 yr) affected by pollen-induced AR who had never undergone SIT were recruited between May 2009 and June 2011 in 16 pediatric outpatient clinics in 14 Italian cities. Recruited children's parents answered standardized questionnaires on atopic diseases (International Study of Allergy and Asthma in Childhood, Allergic Rhinitis and its Impact on Asthma, Global Initiative for Asthma). The children underwent skin-prick test (SPT) with several airborne allergens and six food allergens. Information on socio-demographic factors, parental history of allergic diseases, education, perinatal events, breastfeeding, nutrition and environmental exposure in early life was collected through an informatics platform shared by the whole network of clinical centers (AllergyCARD™).

RESULTS

Among the 1360 recruited patients (68% males, age 10.5 ± 3.4 yr), 695 (51%) had moderate-to-severe AR, 533 (39%) asthma, and 325 (23.9%) oral allergy syndrome (OAS). Reported onset of pollen-induced AR was on average at 5.3 ± 2.8 yr, and its mean duration from onset was 5.2 ± 3.3 yr. Only 6.2% of the patients were pollen-monosensitized, and 84.9% were sensitized to ≥3 pollens. A longer AR duration was significantly associated with moderate-to-severe AR symptoms (p 0.004), asthma (p 0.030), and OAS comorbidities (p < 0.001).

CONCLUSIONS

This nationwide study may raise awareness of the severity of pollen-induced AR among Italian children who have never received pollen SIT. The strong association between pollen-induced AR duration and several markers of disease severity needs replication in longitudinal studies, while suggesting that countrywide initiatives for earlier diagnosis and intervention should be planned.

Wheal and flare reactions in skin prick tests of patients treated with montelukast alone or in combination with antihistamines

Background

Because antileukotrienes may inhibit inflammation, it is plausible that montelukast administered for a long time could suppress skin wheal and flare reaction, and thus, it should be discarded prior to the tests. This study assessed the effect of long-lasting treatment with montelukast alone or in combination with antihistamines on wheal and flare in skin pricks tests (SPT) in patients sensitized to perennial allergens.

Methods

We conducted a 32-week, double-blind, placebo-controlled, cross-over and randomized trial that implicated two arms: arm A, 20 patients received levocetirizine, montelukast with or without levocetirizine or placebo; arm B, 20 patients received desloratadine, montelukast with or without desloratadine or placebo. All treatment periods lasted 6 weeks and were separated by 2-week washouts. At baseline and on the last day of each treatment period, SPT were performed in all participants.

Results

Both levocetirizine and desloratadine in monotherapy, or in combination with montelukast, were effective in reducing wheal and flare in SPT. Monotherapy with montelukast did not change the size of the wheal for either histamine or for house dust mites, in either arm of the study, but significantly reduced the size of flare for histamine in arm A. Addition of montelukast to antihistamine did not exceed efficacy of monotherapy with antihistamine in both arms of the study.

Conclusions

Since the size of wheal determines the results of SPT, montelukast, even taken for a long time, does not have to be discarded prior to the tests.

Encasing bedding in covers made of microfine fibers reduces exposure to house mite allergens and improves disease management in adult atopic asthmatics

BACKGROUND

Studies of avoidance of exposure to group 1 allergens of the Dermatophagoides group (Der p 1) have not yielded consistent improvements in adult asthma through avoidance. We explored whether the use of pillow and bed covers and allergen-avoidance counseling resulted in Der 1-level reduction, as measured by enzyme-linked immunosorbent assay, and thus improved asthma symptoms in adult patients.

METHODS

Twenty-five adult patients with moderate or severe atopic asthma were randomized into intervention and control groups. Intervention patients slept on pillows and mattresses or futons encased in microfine-fiber covers and were counseled in allergen avoidance through bedroom cleaning. Control patients received neither special covers nor counseling. In the period August to October in 2009 (pre-intervention) and 2010 (post-intervention), dust samples were collected in open Petri dishes placed in bedrooms for 2 weeks and by rapid lifting of dust from bedding and skin using adhesive tape on the morning of 1 day of Petri dish placement. We examined the associations between changes in Der 1 level (as measured by enzyme-linked immunosorbent assay) and clinical symptom score, minimum % peak expiratory flow, and fraction of exhaled nitric oxide.

RESULTS

Der 1 allergen levels on the mattress/futon covers and near the floor of the bedrooms of intervention patients, but not controls, were lower in 2010 than in 2009. From 2009 to 2010, asthma symptom scores decreased significantly, and minimum % peak expiratory flow increased significantly, in intervention patients. The fall in Der p 1 concentration was correlated with a reduction in the fraction of exhaled nitric oxide.

CONCLUSIONS

Minimization of Der 1 allergen exposure by encasing pillows and mattresses or futons and receiving counseling on avoiding exposure to indoor allergens improved asthma control in adult patients.

Improving allergy management in the primary care network--a holistic approach

The incidence, prevalence and costs of allergy have increased substantially in recent decades in many parts of Europe. The dominant model of allergy care within Europe is at the moment specialist-based. This model will become unsustainable and undeliverable with increasing disease prevalence. One solution to increase provision of allergy services is to diversify the providers. A new model for the provision of allergy care in the community with the general practitioner at the forefront is proposed. Pre- and postgraduate allergy education and training, implementation of pathways of care, allergy specialization and political will to generate resources and support are essential to achieve this new model. In parallel the holistic view of allergic diseases should be maintained, including assessment of severity and risk, psychological factors and health-care related costs in the context of the patient-centered decision making process.

Nasal hyper-reactivity is a common feature in both allergic and nonallergic rhinitis

BACKGROUND

Nasal hyper-reactivity is an increased sensitivity of the nasal mucosa to various nonspecific stimuli. Both allergic rhinitis (AR) and nonallergic rhinitis (NAR) patients can elicit nasal hyper-reactivity symptoms. Differences in the prevalence or type of nasal hyper-reactivity in AR and NAR patients are largely unknown. In this study, we quantitatively and qualitatively assessed nasal hyper-reactivity in AR and NAR.

METHODS

In the first part, an analysis of a prospectively collected database was performed to reveal patient-reported symptoms of hyper-reactivity. In the second part, cold dry air provocation (CDA) was performed as a hyper-reactivity measure in AR and NAR patients and healthy controls, and symptoms scores, nasal secretions and peak nasal inspiratory flow were measured. Comparisons were made between AR and NAR patients in both studies.

RESULTS

The database analysis revealed high hyper-reactivity prevalence in AR (63.4%) and NAR (66.9%). There were no differences between AR and NAR in terms of the number or type of hyper-reactivity stimuli. Hyper-reactivity to physical stimuli did not exclude a response to chemical stimuli, or vice versa. CDA provocation resulted in a significant increase in rhinitis symptoms and the amount of nasal secretions in AR and NAR patients, but not in controls.

CONCLUSIONS

We found no quantitative or qualitative differences in nasal hyper-reactivity between AR and NAR patients. It is not possible to differentiate NAR subpopulations based on physical or chemical stimuli.

Th17 response to Dermatophagoides pteronyssinus is related to late-phase airway and systemic inflammation in allergic asthma

BACKGROUND

Th17 cells may play a role in the development of late-phase allergen-induced airway and systemic inflammation in allergic asthma, although the mechanisms involved remain to be elucidated.

METHODS

A total of 36 subjects were enrolled into the study: 15 allergic asthma patients with early asthmatic reaction (n=7) or dual asthmatic reaction (n=8) developed to inhaled D. pteronyssinus, 13 patients with allergic rhinitis, and 8 healthy subjects. Peripheral blood and induced sputum were collected 24h before as well as 7h and 24h after a bronchial challenge with D. pteronyssinus. Th17 cells were analyzed by FACS; IL-17 levels were determined by ELISA.

RESULTS

At baseline, the percentage of peripheral blood Th17 cells and serum and sputum IL-17 levels were significantly higher in all groups of studied patients compared with those of healthy subjects. After the bronchial challenge, there was a significant increase in the percentage of peripheral blood Th17 cells and in serum and sputum IL-17 levels in rhinitis and asthma patients compared with their baseline values, particularly in allergic asthma patients with the dual asthmatic reaction. Positive correlations were found between the percentage of Th17 cells and IL-17 levels in serum (Rs=0.649; P=0.009) as well in sputum (Rs=0.583; P=0.022) in allergic asthma patients 24h after the bronchial challenge.

CONCLUSIONS

The Th17 response is associated with the development of late-phase airway and systemic inflammation after the inhalation of D. pteronyssinus in patients with allergic asthma.

Monitoring immune modulation by nutrition in the general population: identifying and substantiating effects on human health

Optimal functioning of the immune system is crucial to human health, and nutrition is one of the major exogenous factors modulating different aspects of immune function. Currently, no single marker is available to predict the effect of a dietary intervention on different aspects of immune function. To provide further guidance on the assessment and interpretation of the modulation of immune functions due to nutrition in the general population, International Life Sciences Institute Europe commissioned a group of experts from academia, government and the food industry to prepare a guidance document. A draft of this paper was refined at a workshop involving additional experts. First, the expert group defined criteria to evaluate the usefulness of immune function markers. Over seventy-five markers were scored within the context of three distinct immune system functions: defence against pathogens; avoidance or mitigation of allergy; control of low-grade (metabolic) inflammation. The most useful markers were subsequently classified depending on whether they by themselves signify clinical relevance and/or involvement of immune function. Next, five theoretical scenarios were drafted describing potential changes in the values of markers compared with a relevant reference range. Finally, all elements were combined, providing a framework to aid the design and interpretation of studies assessing the effects of nutrition on immune function. This stepwise approach offers a clear rationale for selecting markers for future trials and provides a framework for the interpretation of outcomes. A similar stepwise approach may also be useful to rationalise the selection and interpretation of markers for other physiological processes critical to the maintenance of health and well-being.

Clinical characterization and IgE profiling of birch (Betula verrucosa)--allergic individuals suffering from allergic reactions to raw fruits and vegetables

BACKGROUND

Hypersensitivity to raw fruits and vegetables is often associated with respiratory allergy to birch (Betula verrucosa) pollen and is considered to be the most prevalent form of food allergy in adults sensitized to birch pollen.

OBJECTIVE

The aim of the study was to investigate the association of clinical allergy and IgE profiles in individuals with birch pollen allergy and hypersensitivity to raw fruits and vegetables.

METHODS

A total of 59 adults with clinical and skin prick test confirmed birch pollen allergy were included in the study. All the subjects were interviewed by using a structured questionnaire and were examined in vivo by the open test, with the appropriate fruits and vegetables. ImmunoCAP and ImmunoCAP ISAC were used as in vitro diagnostics to assess sensitization profiles for each individual, and principal components analysis was used to analyze the IgE data sets.

RESULTS

Of 59 individuals, 54 (92%) had positive prick-prick test with raw potato, carrot, apple, and/or hazelnut, and the skin prick test was always positive when the corresponding skin challenge was defined as positive. Specific IgE in the ImmunoCAP and inhibition assays with rMal d 1 and rBet v 1 demonstrated that Bet v 1 is driving the sensitization against pathogenesis related-10 proteins. However, positive IgE in vitro results could not be used to predict clinical reactivity to raw fruits and vegetables.

CONCLUSIONS

The present study showed that component-based IgE profiling does not enhance the diagnostic potential in case of pollen-food syndrome, which may be associated with other as yet unidentified components.

Paediatric rhinitis: position paper of the European Academy of Allergy and Clinical Immunology

Rhinitis is a common problem in childhood and adolescence and impacts negatively on physical, social and psychological well-being. This position paper, prepared by the European Academy of Allergy and Clinical Immunology Taskforce on Rhinitis in Children, aims to provide evidence-based recommendations for the diagnosis and therapy of paediatric rhinitis. Rhinitis is characterized by at least two nasal symptoms: rhinorrhoea, blockage, sneezing or itching. It is classified as allergic rhinitis, infectious rhinitis and nonallergic, noninfectious rhinitis. Similar symptoms may occur with other conditions such as adenoidal hypertrophy, septal deviation and nasal polyps. Examination by anterior rhinoscopy and allergy tests may help to substantiate a diagnosis of allergic rhinitis. Avoidance of relevant allergens may be helpful for allergic rhinitis (AR). Oral and intranasal antihistamines and nasal corticosteroids are both appropriate for first-line AR treatment although the latter are more effective. Once-daily forms of corticosteroids are preferred given their improved safety profile. Potentially useful add-on therapies for AR include oral leukotriene receptor antagonists, short bursts of a nasal decongestant, saline douches and nasal anticholinergics. Allergen-specific immunotherapy is helpful in IgE-mediated AR and may prevent the progression of allergic disease. There are still a number of areas that need to be clarified in the management of rhinitis in children and adolescents.

IgE-mediated immune responses and airway detection of Aspergillus and Candida in adult cystic fibrosis

BACKGROUND

The recovery of Aspergillus and Candida from the respiratory secretions of patients with cystic fibrosis (CF) is common. Their relationship to the development of allergic sensitization and effect on lung function has not been established. Improved techniques to detect these organisms are needed to increase knowledge of these effects.

METHODS

A 2-year prospective observational cohort study was performed. Fifty-five adult patients with CF had sputum monitored for Aspergillus by culture and real-time polymerase chain reaction and Candida by CHROMagar and carbon assimilation profile (API/ID 32C). Skin prick tests and ImmunoCAP IgEs to a panel of common and fungal allergens were performed. Lung function and pulmonary exacerbation rates were monitored over 2 years.

RESULTS

Sixty-nine percent of patient sputum samples showed chronic colonization with Candida and 60% showed colonization with Aspergillus. There was no association between the recovery of either organism and the presence of specific IgE responses. There was no difference in lung function decline for patients with Aspergillus or Candida colonization compared with those without (FEV₁ percent predicted, P = .41 and P = .90, respectively; FVC % predicted, P = .87 and P = .37, respectively). However, there was a significantly greater decline in FEV1 and increase in IV antibiotic days for those sensitized to Aspergillus (FEV₁ decline, P = .03; IV antibiotics days, P = .03).

CONCLUSIONS

Allergic sensitization is not associated with recovery of Candida or Aspergillus from the sputum of patients with CF. Aspergillus but not Candida sensitization is associated with greater lung function decline and pulmonary exacerbations.

The general characteristics of acute urticaria attacks and the factors predictive of progression to chronic urticaria

BACKGROUND

The natural history of progression from acute urticaria (AU) to chronic urticaria (CU) remains poorly understood. This study aimed to investigate the potential triggers of AU attacks and factors associated with their duration, as well as the factors which may be predictive of progression to CU.

METHODS

The study included 281 AU patients (AU group). Data were obtained from 207 AU patients retrospectively and from 74 AU patients prospectively. The CU group consisted of 953 patients, whose data were previously published.

RESULTS

According to the medical history, the most common potential triggers of AU attacks were drugs (38.1%); infections (35.2%); stress (24.7%); and foods (17.8%). Attack duration was shorter in cases in which food (p=0.04) or infection (p=0.04) was the suspected trigger. Patients with a history of rhinitis (p=0.04) and food allergy (p=0.04), and positive skin prick test results for pollens (p=0.02) and dog (p=0.02) also had attacks of shorter duration. Patients with asthma had attacks of longer duration (p=0.01). Based on history and/or provocation test results, the prevalence of non-steroidal anti-inflammatory drug hypersensitivity (NSAIDH) was significantly higher in the CU group than the AU group (24.9% vs. 4.3%, respectively, (p<0.01)), as was antibiotic hypersensitivity (10.6% vs. 4.6%, respectively, (p<0.01)) and food allergy (18.3% vs. 3.9%, respectively, (p<0.01)).

NSAIDH (OR

7.97; 95%CI: 4.33-14.66; p<0.01) and food allergy (OR: 5.17; 95%CI: 2.71-9.85; p<0.01) were observed to be independent factors associated with CU.

CONCLUSIONS

As NSAIDH and food allergy were associated with CU, their presence should be carefully evaluated in patients with AU in order to predict progression to CU.

Oral breathing and speech disorders in children

OBJECTIVE

To assess speech alterations in mouth-breathing children, and to correlate them with the respiratory type, etiology, gender, and age.

METHOD

A total of 439 mouth-breathers were evaluated, aged between 4 and 12 years. The presence of speech alterations in children older than 5 years was considered delayed speech development. The observed alterations were tongue interposition (TI), frontal lisp (FL), articulatory disorders (AD), sound omissions (SO), and lateral lisp (LL). The etiology of mouth breathing, gender, age, respiratory type, and speech disorders were correlated.

RESULTS

Speech alterations were diagnosed in 31.2% of patients, unrelated to the respiratory type: oral or mixed. Increased frequency of articulatory disorders and more than one speech disorder were observed in males. TI was observed in 53.3% patients, followed by AD in 26.3%, and by FL in 21.9%. The co-occurrence of two or more speech alterations was observed in 24.8% of the children.

CONCLUSION

Mouth breathing can affect speech development, socialization, and school performance. Early detection of mouth breathing is essential to prevent and minimize its negative effects on the overall development of individuals.

Optimizing the use of a skin prick test device on children

BACKGROUND

Studies comparing skin prick test (SPT) devices have revealed varying results in performance and there is little known about their use on children.

METHODS

We performed 2 complementary studies to test the sensitivity, reproducibility and acceptability of commercially available SPT devices (Stallerpoint, Antony, France) using different application techniques. In the first part, histamine/saline was put on as a drop by use of a vial (V), and in the second part it was transferred from a well with the aid of the test device (W). The techniques were as follows: apply vertical pressure (Stallerpoint-VP or Stallerpoint-WP), apply vertical pressure with 90° clockwise rotation (Stallerpoint-VC or Stallerpoint-WC) and apply vertical pressure with 90° clockwise and counter-clockwise rotations (Stallerpoint-VCC or Stallerpoint-WCC). For comparison, ALK Lancet was used with a technique of 'drop and apply vertical pressure'.

RESULTS

In the first part, sensitivities of the Stallerpoint-VC (96.6%), Stallerpoint-VCC (95.5%) and ALK Lancet (93.2%) techniques were superior (p < 0.001) to the other Stallerpoint-VP and Stallerpoint-WP techniques (76.1 and 46.6%). Intrapatient coefficient of variation (CV) values were 15.0, 18.9, 15.4, 22.4 and 48.5%, respectively. Interpatient CV ranged between 22.8 and 55.1%. In the second part, the Stallerpoint-WC (98.8%), WCC (97.5%) and ALK Lancet (98.8%) techniques yielded high sensitivities, whereas the sensitivity of Stallerpoint-WP (28.7%) was very low. There were false-positive reactions in the Stallerpoint-VCC and WCC techniques.

CONCLUSION

In children, the SPT technique was found to be as important as the testing device. Stallerpoint-VC and WC techniques are reliable, tolerable and comparable with the ALK Lancet technique.

Novel immunologic classification of aspergillosis in adult cystic fibrosis

BACKGROUND

Patients with cystic fibrosis (CF) demonstrate a wide range of hypersensitivity responses to Aspergillus, beyond allergic bronchopulmonary aspergillosis, which require classification.

OBJECTIVE

This study integrated 2 new methods of Aspergillus detection-sputum galactomannan (GM) and real-time PCR-alongside established serologic markers, to reclassify aspergillosis in CF.

METHODS

A total of 146 adult patients with CF had serologic tests (ImmunoCap total IgE, specific Aspergillus fumigatus IgE, and specific A fumigatus IgG), sputum real-time Aspergillus PCR, and sputum GM. Patients were classified by using latent class analysis.

RESULTS

Both RT-PCR and GM were more sensitive than culture in detecting Aspergillus in sputum (culture 37%, RT-PCR 74%, and GM 46%). Intraassay and interassay reproducibility of PCR and GM was excellent. Latent class analysis of triazole-naive patients identified a nondiseased group and 3 disease classes: class 1 (n = 49, 37.7%) represented patients with or without positive RT-PCR but no immunologic response to A fumigatus and negative GM (nondiseased); class 2 (n = 23, 17.7%) represented patients with positive RT-PCR, elevated total and specific A fumigatus IgE/IgG, and positive GM (serologic allergic bronchopulmonary aspergillosis); class 3 (n = 19, 14.6%) represented patients with or without positive RT-PCR, elevated A fumigatus IgE (not IgG), and negative GM (Aspergillus sensitized); and class 4 (n = 39, 30%) represented patients with positive RT-PCR, elevated A fumigatus IgG (not IgE), and positive GM (Aspergillus bronchitis).

CONCLUSIONS

Three distinct classes of aspergillosis in CF were identified by latent class analysis by using serologic, RT-PCR, and GM data. This novel classification will facilitate improved phenotyping, pathogenesis studies, and management evaluations.

Differences in IgE mediated basophil degranulation induced by proteic fractions from whole flea body extract in patients with papular urticaria by flea bite and healthy controls

Background

Papular urticaria by flea bite (PUFB) is a chronic inflammatory disease in children. The aim of this study was to assess the functional activity of IgE to protein fractions from flea body extract, through basophil degranulation in PUFB patients and controls.

Methods

Basophil degranulation, measured by overexpression of CD63 surface molecules, was evaluated by flow cytometry in samples from patients and controls. Cell stimulation was performed with three fractions with different molecular weight from flea body extract using a Basotest® modified protocol. Mann–Whitney U-test was used for comparisons.

Results

Specific IgE from PUFB patients and healthy controls induced basophil degranulation to flea body extract with no significant differences between them (16.2 ± 3.1% vs 13.6 ± 2.8% p = 0.77). However, when flea extract was analyzed in fractions with proteins ranging different molecular weights, significant differences were observed on the response from patients compared with controls to <50 kD (14.9 ± 5.1% vs 9.7 ± 2.1% p = 0.0058) and 50–100 kD proteic fractions (8.3 ± 3.2% vs 2.8 ± 1.6% p = 0.0021).

Conclusion

In this study, was established that the differential response by IgE, in PUFB, depends from the molecular weight of the antigens contained in the flea extract. These antigens may be related to 30–35 kD proteins previously described as major allergens.

Role of exhaled nitric oxide as a predictor of atopy

BACKGROUND

The fractional exhaled nitric oxide (FeNO) is a quantitative, noninvasive and safe measure of airways inflammation that may complement the assessment of asthma. Elevations of FeNO have recently been found to correlate with allergic sensitization. Therefore, FeNO may be a useful predictor of atopy in the general population. We sought to determine the diagnostic accuracy of FeNO in predicting atopy in a population-based study.

METHODS

We conducted a cross-sectional study in an age- and sex- stratified random sample of 13 to 15 year-olds in two communities in Peru. We asked participants about asthma symptoms, environmental exposures and sociodemographics, and underwent spirometry, assessment of FeNO and an allergy skin test. We used multivariable logistic regression to model the odds of atopy as a function of FeNO, and calculated area-under-the-curves (AUC) to determine the diagnostic accuracy of FeNO as a predictor of atopy.

RESULTS

Of 1441 recruited participants, 1119 (83%) completed all evaluations. Mean FeNO was 17.6 ppb (SD=0.6) in atopics and 11.6 ppb (SD=0.8) in non-atopics (p<0.001). In multivariable analyses, a FeNO>20 ppb was associated with an increase in the odds of atopy in non-asthmatics (OR=5.3, 95% CI 3.3 to 8.5) and asthmatics (OR=16.2, 95% CI 3.4 to 77.5). A FeNO>20 ppb was the best predictor for atopy with an AUC of 68% (95% CI 64% to 69%). Stratified by asthma, the AUC was 65% (95% CI 61% to 69%) in non-asthmatics and 82% (95% CI 71% to 91%) in asthmatics.

CONCLUSIONS

FeNO had limited accuracy to identify atopy among the general population; however, it may be a useful indicator of atopic phenotype among asthmatics.

Knowledge of their own allergic sensitizations in asthmatic patients and its impact on the level of asthma control

BACKGROUND

Asthma guidelines recommend the adoption of allergen avoidance measures (AAM). To do so, patients need to know their own allergies. However, this degree of knowledge has not yet been assessed. The aims of this study were to determine, in allergic asthma patients: i)the degree of knowledge of their own allergic sensitizations; ii)the percentage of those who knew all their allergies and, in addition, adopted AAM against all of them, and iii)the possible impact of this degree of knowledge on the level of asthma control.

PATIENTS AND METHODS

Descriptive, prospective and multicentre study, including 147patients from 9 Respiratory Medicine outpatient clinics. After confirming the previous allergic asthma diagnosis, a questionnaire was completed. It included asthma control and severity levels, results of previous allergy tests, and the description and number of allergic sensitizations known by the patients and AAM followed.

RESULTS

Only 72 (49%) patients knew all their allergic sensitizations and only 48 (33%) were also following AAM against all the allergens to which they were allergic. No relationship was established between the degree of knowledge of their own allergies and the level of asthma control (P=.544).

CONCLUSIONS

Overall knowledge about the allergic nature of their disease among asthmatic patients attending Spanish Respiratory Medicine Departments is inadequate. Furthermore, a higher degree of knowledge of their allergies does not seem to lead, by itself, to better asthma control. Both findings seem to question the effectiveness of current educational strategies in this field and consequently, they should be revised.

Correcting for possible tissue distortion between provocation and assessment in skin testing: the divergent beam UVB photo-test

BACKGROUND

In tissue viability imaging (TiVi), an assessment method for skin erythema, correct orientation of skin position from provocation to assessment optimizes data interpretation. Image processing algorithms could compensate for the effects of skin translation, torsion and rotation realigning assessment images to the position of the skin at provocation.

METHODS

A reference image of a divergent, UVB phototest was acquired, as well as test images at varying levels of translation, rotation and torsion. Using 12 skin markers, an algorithm was applied to restore the distorted test images to the reference image.

RESULTS

The algorithm corrected torsion and rotation up to approximately 35 degrees. The radius of the erythemal reaction and average value of the input image closely matched that of the reference image's 'true value'.

CONCLUSION

The image 'de-warping' procedure improves the robustness of the response image evaluation in a clinical research setting and opens the possibility of the correction of possibly flawed images performed away from the laboratory setting by the subject/patient themselves. This opportunity may increase the use of photo-testing and, by extension, other late response skin testing where the necessity of a return assessment visit is a disincentive to performance of the test.

Evaluation of commercial skin prick test solutions for selected occupational allergens

BACKGROUND

Skin prick testing (SPT) is an important step in the diagnosis of IgE-mediated occupational allergic diseases. The outcome of SPT is related to the quality of allergen extracts. Thus, the aim of the study was to assess different commercially available SPT solutions for selected occupational allergens.

METHODS

SPT was performed in 116 bakers, 47 farmers and 33 subjects exposed to natural rubber latex (NRL), all with work-related allergic symptoms. The SPT solutions from different manufacturers (n = 3-5) for wheat flour, rye flour, soy, cow hair/dander, storage mites (Tyrophagus putrescentiae, Lepidoglyphus destructor, Acarus siro) and NRL were analysed with respect to their protein and antigen contents. SPT was carried out in 16 allergy centres in six European countries using standardized procedures. Specific IgE values were used as the gold standard to calculate the sensitivity and specificity of SPT solutions. The optimal cut-point for each SPT solution was determined by Youden Index.

RESULTS

Protein and antigen contents and patterns of the SPT solutions varied remarkably depending on the manufacturer. While SPT solutions for wheat flour and soy reached overall low sensitivities, sensitivities of other tested SPT solutions depended on the manufacturer. As a rule, solutions with higher protein and antigen content showed higher sensitivities and test efficiencies.

CONCLUSIONS

There is a wide variability of SPT solutions for occupational allergens, and the sensitivity of several solutions is low. Thus, improvement and standardization of SPT solutions for occupational allergens is essential.

EAACI position paper: skin prick testing in the diagnosis of occupational type I allergies

Skin prick testing (SPT) in combination with the clinical history of the patient is one important step in the diagnosis of IgE-mediated occupational allergies. However, skin test performance is related to the quality of allergen extracts. The present consensus document was prepared by an EAACI Task Force consisting of an expert panel of allergologists and occupational physicians from Germany, Italy, Spain, France, Austria, and Poland. All members of the panel were also involved in the data collection within the European multicentre study STADOCA (Standard diagnosis for occupational allergy). The aim of this Task Force was the assessment of the quality of commercially available SPT solutions for selected occupational allergens under standardized procedure conditions in different European centres and institutes of Occupational Medicine. The data evaluation shows a wide variability among SPT solutions and also indicates that the sensitivity of several SPT solutions is low. Therefore, improvement and standardization of SPT solutions for occupational allergens is highly recommended. Clinical practitioners should also not presume that their SPT solutions are fully reliable. The main objective of the document is to issue consensus suggestions for the use of SPT with occupational allergens based on the European multicentre study STADOCA, on existing scientific evidence and the expertise of a panel of allergologists.

Allergic bronchopulmonary mycosis due to fungi other than Aspergillus: a global overview

Allergic bronchopulmonary mycosis (ABPM) is a hypersensitivity-mediated disease of worldwide distribution. We reviewed 143 reported global cases of ABPM due to fungi other than aspergilli. The commonest etiologic agent was Candida albicans, reported in 60% of the cases, followed by Bipolaris species (13%), Schizophyllum commune (11%), Curvularia species (8%), Pseudallescheria boydii species complex (3%) and rarely, Alternaria alternata, Fusarium vasinfectum, Penicillium species, Cladosporium cladosporioides, Stemphylium languinosum, Rhizopus oryzae, C. glabrata, Saccharomyces cerevisiae and Trichosporon beigelii. India accounted for about 47% of the globally reported cases of ABPM, attributed predominantly to C. albicans, followed by Japan (16%) where S. commune predominates, and the remaining one-third from the USA, Australia and Europe. Notably, bronchial asthma was present in only 32% of ABPM cases whereas its association with development of allergic bronchopulmonary aspergillosis (ABPA) is known to be much more frequent. The cases reviewed herein revealed a median IgE value threefold higher than that of ABPA, suggesting that the etiologic agents of ABPM incite a stronger immunological response than that by aspergilli in ABPA. ABPM is currently underdiagnosed, warranting comprehensive basic and clinical studies in order to elucidate its epidemiology and to devise a more effective therapy.

Poor reproducibility of allergic rhinitis SNP associations

Replication of reported associations is crucial to the investigation of complex disease. More than 100 SNPs have previously been reported as associated with allergic rhinitis (AR), but few of these have been replicated successfully. To investigate the general reproducibility of reported AR-associations in candidate gene studies, one Swedish (352 AR-cases, 709 controls) and one Singapore Chinese population (948 AR-cases, 580 controls) were analyzed using 49 AR-associated SNPs. The overall pattern of P-values indicated that very few of the investigated SNPs were associated with AR. Given published odds ratios (ORs) most SNPs showed high power to detect an association, but no correlations were found between the ORs of the two study populations or with published ORs. None of the association signals were in common to the two genome-wide association studies published in AR, indicating that the associations represent false positives or have much lower effect-sizes than reported.

Using a symptom diary to investigate work-related urticaria

BACKGROUND

The strategy of keeping a diary may not be considered by many treating clinicians, but this approach has been recommended for occupational asthma and proved useful in this case of chronic urticaria associated with work.

AIMS

To report a case of a health care worker who had significant allergic reactions that were found to be associated with exposure to test allergens while working in an asthma clinic.

METHODS

The patient, a nurse working in a paediatric asthma clinic, was known to be allergic to common allergens that were used to test patients in the clinic. She developed reactions including swelling of the eyelids and urticarial reactions on the forehead, torso and upper and lower limbs on different occasions. A symptom diary was used to collect information on the reactions and the activity performed at the time they occurred.

RESULTS

She recorded symptoms that were mainly urticarial, with additional rhinitis or wheeze on occasion, on 20 (74%) working days and only 5 (28%) non-work days, indicating a significant association (P < 0.01) between her symptoms and working days.

CONCLUSIONS

Medical management had not controlled her symptoms, which improved on removal from the work activity and was confirmed by further diary recording.

Allergic Rhinitis and its Impact on Asthma (ARIA): achievements in 10 years and future needs

Allergic rhinitis (AR) and asthma represent global health problems for all age groups. Asthma and rhinitis frequently coexist in the same subjects. Allergic Rhinitis and its Impact on Asthma (ARIA) was initiated during a World Health Organization workshop in 1999 (published in 2001). ARIA has reclassified AR as mild/moderate-severe and intermittent/persistent. This classification closely reflects patients' needs and underlines the close relationship between rhinitis and asthma. Patients, clinicians, and other health care professionals are confronted with various treatment choices for the management of AR. This contributes to considerable variation in clinical practice, and worldwide, patients, clinicians, and other health care professionals are faced with uncertainty about the relative merits and downsides of the various treatment options. In its 2010 Revision, ARIA developed clinical practice guidelines for the management of AR and asthma comorbidities based on the Grading of Recommendation, Assessment, Development and Evaluation (GRADE) system. ARIA is disseminated and implemented in more than 50 countries of the world. Ten years after the publication of the ARIA World Health Organization workshop report, it is important to make a summary of its achievements and identify the still unmet clinical, research, and implementation needs to strengthen the 2011 European Union Priority on allergy and asthma in children.

Validation of the modified allergic rhinitis and its impact on asthma (ARIA) severity classification in allergic rhinitis children: the PEDRIAL study

BACKGROUND

A modified allergic rhinitis and its impact on asthma (ARIA) (m-ARIA) criterion to classify the severity of allergic rhinitis (AR) has recently been validated in both treated and untreated adult patients; however, such information in children is lacking. The aim of this study was to validate this m-ARIA severity criterion, which allows for discrimination between moderate and severe AR, in a large pediatric patient sample population.

METHODS

The m-ARIA classification categorizes AR severity into mild (no affected items), moderate (1-3 affected items), and severe (all four affected items). We applied this modified criterion to untreated AR pediatric patients aged 6-12 years, through an observational, cross-sectional, and multicenter study. AR symptoms were assessed using the Total Four Symptom Score (T4SS), and the severity was evaluated by both ARIA severity items and visual analogue scale (VAS).

RESULTS

Allergic rhinitis pediatric patients (N = 1269) from 271 centers were included. Among them, 59.5% had intermittent and 40.5% persistent disease; 89.9% had moderate/severe AR using the original ARIA (o-ARIA) classification and 59.5% had moderate, while 30.5% had severe AR using the m-ARIA criterion. Using the m-ARIA, significantly higher T4SS and VAS scores were obtained when comparing severe with moderate AR.

CONCLUSIONS

The m-ARIA severity classification is a useful clinical tool to discriminate moderate from severe AR among untreated pediatric patients.

Low frequency of filaggrin null mutations in Croatia and their relation with allergic diseases

Filaggrin gene (FLG) null mutations are considered associated with atopic dermatitis. This study was conducted to determine the prevalence of FLG null mutations R501X, 2282del4, R2447X and S3247X in the Croatian population and their role in the occurrence of allergic diseases including atopic dermatitis, allergic rhinitis, asthma and allergic contact dermatitis (ACD). Study enrolled 440 freshmen with defined allergic diseases by means of both present symptoms in International Study of Asthma and Allergies in Childhood questionnaire (relevant respiratory and/or skin symptoms) and markers of allergic sensitization (positive skin prick and/or patch test). FLG null mutations were successfully genotyped in 423 students of which 11 (2.6%) were carriers of FLG null mutation: 1/423 (0.2%) was heterozygous for R501X and 10/423 (2.4%) were heterozygous for 2282del4. No carriers of R2447X and S3247X mutations were identified. In wild-type FLG carriers (412 subjects), atopic dermatitis was present in 45 (11%), allergic rhinitis in 70 (17%) and allergic asthma in 29 (7%) students. Twenty-five of 393 (7%) patch-tested wild-type FLG carriers had ACD. Among 11 FLG null mutation carriers, four had one or more allergic diseases, and five had reported skin symptoms without defined allergic sensitization (positive skin prick test and/or patch test). FLG null mutations were not confirmed as a predictor of analysed allergic diseases, but were confirmed as an independent predictor of skin symptoms (OR 17.19, 95% CI 3.41-86.6, P < 0.001). Our results in general indicate a low frequency of FLG null mutations in the studied Croatian population supporting a theory of a latitude-dependent distribution of FGL null mutations in Europe, with a decreasing north-south gradient of R501X and 2282del4 mutation frequency. The relation between FLG null mutations and skin disorders was confirmed.

Safety of intradermal skin tests for inhalants and foods: a prospective study

BACKGROUND

Intradermal skin testing is a useful allergy diagnostic tool. Although considered safe when properly performed, systemic reactions have been reported. This is the first large, prospective study to record and evaluate all systemic reactions from intradermal skin testing (IDT) to inhalant or food antigens.

METHODS

A 24-month prospective study by 40 physician practices, recording all IDT tests, including reactions, symptoms, severity, time after injection, and reaction treatments.

RESULTS

Eighty systemic reactions (22 major) occurred among 20,530 patients (878,583 wheals). Nine had epinephrine treatment, 4 were observed in an emergency department, and there were no hospitalizations or fatalities. The overall systemic reaction risk was 0.009%. The risk of having a major reaction was 0.003%, or 1 reaction per 933 patients.

CONCLUSION

Intradermal skin tests for inhalants or foods, when performed with appropriate precautions, have a safety profile comparable to skin prick tests.

Colonoscopic allergen provocation test with rBet v 1 in patients with pollen-associated food allergy

BACKGROUND

After consumption of fruits, nuts, and vegetables, several patients with pollen allergy experience gastrointestinal (GI) tract symptoms that are possibly caused by pollen-associated food allergy. The aim of this study was to evaluate the colonoscopic allergen provocation (COLAP) test using the recombinant birch pollen allergen Bet v 1 (rBet v 1) for in vivo diagnosis of pollen-associated food allergy manifesting in the GI tract.

METHODS

Thirty-four patients with a history of adverse reactions to food, GI tract symptoms, and birch pollen pollinosis and five healthy controls underwent COLAP test. Twenty minutes after endoscopic challenge of the cecal mucosa with rBet v 1, the mucosal wheal and flare reaction was registered semiquantitatively, and tissue biopsy specimens were examined for eosinophil mucosal activation.

RESULTS

The mucosal reaction to rBet v 1 was correlated with the presence of pollinosis (P = 0.004), history of adverse reaction to Bet v 1-associated food allergens (P = 0.001), and tissue eosinophils' activation (P < 0.001). A wheal and flare reaction in the COLAP test was observed in 13 of 16 patients (81%) with a history of GI tract symptoms associated with the ingestion of Bet v 1-related foods and in four of 18 (22%) patients with a negative history (P < 0.001). The control group did not develop visible mucosal reactions to rBet v 1. Systemic anaphylactic reactions did not occur.

CONCLUSIONS

The mucosal administration of rBet v 1 by COLAP test provides a new diagnostic tool that might support the diagnosis of Bet v 1-associated food allergy manifesting in the GI tract.

Prevalence and clinical relevance of local allergic rhinitis

BACKGROUND

Evidence demonstrates the existence of local allergic rhinitis (LAR) in nonatopic patients, although its prevalence in the rhinitis population remains unknown. The aim, therefore, of this study was to evaluate the prevalence, clinical characteristics, and severity of LAR in a Spanish rhinitis population, compared with patients having classical allergic rhinitis (AR) with systemic atopy or nonallergic rhinitis (NAR).

METHODS

A group of 452 adult rhinitis patients were randomly selected from a total of 3860 who attended our allergy service over 1 year. A clinical questionnaire, skin prick test (SPT), spirometry, and serum total and specific IgE (sIgE) were evaluated. A nasal allergen provocation test with multiple aeroallergens (NAPT-M), including Dermatophagoides pteronyssinus, pollens, alternaria, and dog epithelia, was performed in patients with negative SPT and serum sIgE.

RESULTS

A total of 428 patients completed the study; 24 were excluded because of nasal hyper-reactivity. LAR was diagnosed in 25.7%, AR in 63.1%, and NAR in 11.2%. The LAR and AR patients had a similar clinical profile: a nonsmoking woman with severe, persistent perennial rhinitis frequently associated with conjunctivitis and asthma. More than 36% of LAR patients reported rhinitis onset in childhood. NAPT-M detected aeroallergen polysensitization in 37.3% of the LAR patients. Dermatophagoides pteronyssinus was the main sensitizing aeroallergen in LAR and AR (60% vs 54%, P > 0.05).

CONCLUSIONS

Local allergic rhinitis is a prevalent entity in patients evaluated with rhinitis. Persistent and severe symptoms associated with conjunctivitis and/or asthma and polysensitization were likely to be detected in LAR and AR.

Toll-like receptor gene polymorphisms are associated with allergic rhinitis: a case control study

Background

The Toll-like receptor proteins are important in host defense and initiation of the innate and adaptive immune responses. A number of studies have identified associations between genetic variation in the Toll-like receptor genes and allergic disorders such as asthma and allergic rhinitis. The present study aim to search for genetic variation associated with allergic rhinitis in the Toll-like receptor genes.

Methods

A first association analysis genotyped 73 SNPs in 182 cases and 378 controls from a Swedish population. Based on these results an additional 24 SNPs were analyzed in one Swedish population with 352 cases and 709 controls and one Chinese population with 948 cases and 580 controls.

Results

The first association analysis identified 4 allergic rhinitis-associated SNPs in the TLR7-TLR8 gene region. Subsequent analysis of 24 SNPs from this region identified 7 and 5 significant SNPs from the Swedish and Chinese populations, respectively. The corresponding risk-associated haplotypes are significant after Bonferroni correction and are the most common haplotypes in both populations. The associations are primarily detected in females in the Swedish population, whereas it is seen in males in the Chinese population. Further independent support for the involvement of this region in allergic rhinitis was obtained from quantitative skin prick test data generated in both populations.

Conclusions

Haplotypes in the TLR7-TLR8 gene region were associated with allergic rhinitis in one Swedish and one Chinese population. Since this region has earlier been associated with asthma and allergic rhinitis in a Danish linkage study this speaks strongly in favour of this region being truly involved in the development of this disease.