Food allergy in EAACI journals (2016)

Over the last years we have observed considerable progress in the area of food allergy, particularly in children. This review article focusses on important contributions which have lately been published in the three journals of the European Academy of Allergy and Clinical Immunology. A better understanding of allergens as well as the mechanisms of sensitization and tolerance induction may hopefully lead to a more targeted management of food allergy in the near future.

Is fruit and vegetable intake associated with asthma or chronic rhino-sinusitis in European adults? Results from the Global Allergy and Asthma Network of Excellence (GA2LEN) Survey

Background

Fruits and vegetables are rich in compounds with proposed antioxidant, anti-allergic and anti-inflammatory properties, which could contribute to reduce the prevalence of asthma and allergic diseases.

Objective

We investigated the association between asthma, and chronic rhino-sinusitis (CRS) with intake of fruits and vegetables in European adults.

Methods

A stratified random sample was drawn from the Global Allergy and Asthma Network of Excellence (GA²LEN) screening survey, in which 55,000 adults aged 15–75 answered a questionnaire on respiratory symptoms. Asthma score (derived from self-reported asthma symptoms) and CRS were the outcomes of interest. Dietary intake of 22 subgroups of fruits and vegetables was ascertained using the internationally validated GA²LEN Food Frequency Questionnaire. Adjusted associations were examined with negative binomial and multiple regressions. Simes procedure was used to control for multiple testing.

Results

A total of 3206 individuals had valid data on asthma and dietary exposures of interest. 22.8% reported having at least 1 asthma symptom (asthma score ≥1), whilst 19.5% had CRS. After adjustment for potential confounders, asthma score was negatively associated with intake of dried fruits (β-coefficient −2.34; 95% confidence interval [CI] −4.09, −0.59), whilst CRS was statistically negatively associated with total intake of fruits (OR 0.73; 95% CI 0.55, 0.97). Conversely, a positive association was observed between asthma score and alliums vegetables (adjusted β-coefficient 0.23; 95% CI 0.06, 0.40). None of these associations remained statistically significant after controlling for multiple testing.

Conclusion and clinical relevance

There was no consistent evidence for an association of asthma or CRS with fruit and vegetable intake in this representative sample of European adults.

Allergy Work-Up Including Component-Resolved Diagnosis: How to Make Allergen-Specific Immunotherapy More Specific

Symptoms are recorded by obtaining a clinical history. Allergen sensitization is demonstrated by skin prick test or allergen-specific IgE serology. IgE sensitizations to allergen sources can be identified knowing the relationship between major aeroallergens and homologous allergen families. Some develop allergic sensitization to pan-allergens. Allergen extracts do not allow definitive separation of the sources. IgE antibody analysis of the major allergenic molecules facilitates differentiation of sensitizing allergen sources. IgE sensitizations to inhalant allergens are only relevant in the case of corresponding symptoms. In questionable cases, conjunctival or nasal provocation tests help induce confirmatory symptoms and identify relevant allergens for immunotherapy.

EAACI Molecular Allergology User's Guide

The availability of allergen molecules ('components') from several protein families has advanced our understanding of immunoglobulin E (IgE)-mediated responses and enabled 'component-resolved diagnosis' (CRD). The European Academy of Allergy and Clinical Immunology (EAACI) Molecular Allergology User's Guide (MAUG) provides comprehensive information on important allergens and describes the diagnostic options using CRD. Part A of the EAACI MAUG introduces allergen molecules, families, composition of extracts, databases, and diagnostic IgE, skin, and basophil tests. Singleplex and multiplex IgE assays with components improve both sensitivity for low-abundance allergens and analytical specificity; IgE to individual allergens can yield information on clinical risks and distinguish cross-reactivity from true primary sensitization. Part B discusses the clinical and molecular aspects of IgE-mediated allergies to foods (including nuts, seeds, legumes, fruits, vegetables, cereal grains, milk, egg, meat, fish, and shellfish), inhalants (pollen, mold spores, mites, and animal dander), and Hymenoptera venom. Diagnostic algorithms and short case histories provide useful information for the clinical workup of allergic individuals targeted for CRD. Part C covers protein families containing ubiquitous, highly cross-reactive panallergens from plant (lipid transfer proteins, polcalcins, PR-10, profilins) and animal sources (lipocalins, parvalbumins, serum albumins, tropomyosins) and explains their diagnostic and clinical utility. Part D lists 100 important allergen molecules. In conclusion, IgE-mediated reactions and allergic diseases, including allergic rhinoconjunctivitis, asthma, food reactions, and insect sting reactions, are discussed from a novel molecular perspective. The EAACI MAUG documents the rapid progression of molecular allergology from basic research to its integration into clinical practice, a quantum leap in the management of allergic patients.

The impact of telemonitoring on adherence to nasal corticosteroid treatment in children with seasonal allergic rhinoconjunctivitis

BACKGROUND

Adherence to controller therapy in allergic diseases is low. Telemonitoring has been proposed to improve adherence to treatment in chronic diseases. However, this strategy has never been tested in allergic rhinoconjunctivitis.

OBJECTIVE

To test whether Internet-based telemonitoring during the grass-pollen season of children with allergic rhinoconjunctivitis may enhance adherence to treatment.

METHODS

Children and adolescents, 5-18 years old, with moderate-to-severe seasonal allergic rhinoconjunctivitis to grass pollen requiring daily administration of nasal corticosteroid (NCS) (mometasone) were recruited (April 2013) in a paediatric allergy practice. Participants were randomized to Internet-based monitoring (AllergyMonitor(™) , AM) or to usual care (no diary at all, controls) and followed from 13 May (T0) to 15 June 2013 (T2). An intermediate visit (T1) was performed between 31 May and 2 June. Optimal adherence to therapy was expressed as the use of at least 0.190 g/day of mometasone, corresponding to 1 puff/nostril/day, and it was measured by canister weights during (T1) and at the end (T2) of the study period. Main secondary outcomes included the reported disease severity (validated self-questionnaire) and quality of life (AdoIRQLQ questionnaire), disease knowledge (multiple-choice questionnaire), nasal flow and resistance at baseline and at T2.

RESULTS

The use of mometasone, expressed as both optimal adherence rate (48.4% vs. 12.5%; P = 0.002) and average daily use (0.20 ± 0.12 g/day vs. 0.15 ± 0.07 g/day; P = 0.037), was higher in the AM group (n = 31) than among controls (n = 32). Disease knowledge improved among the patients using AM (83.3% vs. 68.3%; P < 0.001) but not among controls (68.2% vs. 67.7% right answers; P > 0.05). No differences were observed in the reported severity of disease, nasal flow and resistance and quality of life both at baseline and at follow-up visits.

CONCLUSIONS

Internet-based telemonitoring improves adherence to NCS treatment and disease knowledge among children and adolescents with seasonal allergic rhinoconjunctivitis.

Pilot study on the short-term prediction of symptoms in children with hay fever monitored with e-Health technology

Forecasting symptoms of pollen-related allergic rhinoconjunctivitis at the level of individual patients would be useful to improve disease control and plan pharmacological intervention. Information Technology nowadays facilitates a more efficient and easier monitoring of patients with chronic diseases. We aimed this study at testing the efficiency of a model to short-term forecast symptoms of pollen-AR at the "individual" patient level. We analysed the data prospectively acquired from a group of 21 Italian children affected by pollen-related allergic rhinoconjunctivitis and recorded their symptoms and medication "Average Combined Score" (ACS) on a daily basis during April-June 2010-2011 through an informatics platform (Allergymonitor™). The dataset used for prediction included 15 variables in four categories: (A) date, (B) meteo-climatic, (C) atmospheric concentration of 5 pollen taxa, and (D) intensity of the patient's IgE sensitization. A Partial Least Squares Discriminant Analysis approach was used in order to predict ACS values above a fixed threshold value (0.5). The best performing predicting model correctly classified 77.8% ± 10.3% and 75.5% ± 13.2% of the recorded days in the model and test years, respectively. In this model, 9/21 patients showed ≥ 80% correct classification of the recorded days in both years. A better performance was associated with a higher degree of patient's atopic sensitization and a time lag > 1. Symptom forecasts of seasonal allergic rhinitis are possible in highly polysensitised patients in areas with complex pollen exposure. However, only predictive models tailored to the individual patient's allergic susceptibility are accurate enough. Multicenter studies in large population samples adopting the same acquisition data system on smart phones are now needed to confirm this encouraging outcome.

Parental hay fever reinforces IgE to pollen as pre-clinical biomarker of hay fever in childhood

BACKGROUND

An early IgE response to grass or birch pollen can anticipate seasonal allergic rhinitis to pollen later in life or remain clinically silent.

OBJECTIVE

To identify risk factors early in life that allow discriminating pathogenic from non-pathogenic IgE responses and contribute to the development of seasonal allergic rhinitis to grass pollen.

METHODS

The German Multicentre Allergy Study examined a birth cohort born in 1990. A questionnaire was yearly administered and blood samples collected at age 1,2,3,5,6,7,10,13 yr. The definition of the primary outcome grass- and birch-pollen-related seasonal allergic rhinitis (SARg, SARb) was based on nasal symptoms in June/July and April, respectively. Serum IgE antibodies to Phleum pratense and Betula verrucosae extracts were monitored with immune-enzymatic singleplex assays.

RESULTS

Of the 820 examined children, 177 and 148 developed SARg and SARb, respectively. Among healthy children aged 3 or more years, IgE to grass pollen was the strongest risk factor of SARg (OR 10.39, 95%CI 6.1-17.6, p < 0.001), while parental hay fever was the only risk factor in early childhood independently associated with future SARg (1 parent: OR 2.56, 95%CI 1.4-4.5, p < 0.001; 2 parents: OR 4.17, 95%CI 1.7-10.1) and SARb (1 parent OR: 5.21, 95%CI 2.20-12.4, p < 0.001; 2 parents: OR 8.02, 95%CI 2.0-32.9, p < 0.001). Parental hay fever was associated with an increase of the concentration of pollen-specific IgE in seropositive subjects, after the age of 6 and was also a hallmark of molecularly more complex specific IgE responses to grass or birch pollen at age 6 or older.

CONCLUSIONS

Parental hay fever and specific IgE to grass and/or birch pollen are strong pre-clinical determinants and potentially good predictors of seasonal allergic rhinitis.

Immunoglobulin G in IgE-mediated allergy and allergen-specific immunotherapy

Allergen-specific IgG antibodies play a significant role in allergen-specific tolerance, either naturally induced or generated by specific immunotherapy. Nevertheless, the underlying mechanisms are still debated, and allergen-specific IgG determinations are not recommended as a diagnostic tool in IgE-mediated allergy. This review summarizes the latest findings on the immunological and diagnostic role of IgG antibodies in respiratory and food allergies, and during allergen-specific immunotherapy.

Testing children for allergies: why, how, who and when: an updated statement of the European Academy of Allergy and Clinical Immunology (EAACI) Section on Pediatrics and the EAACI-Clemens von Pirquet Foundation

Allergic diseases are common in childhood and can cause a significant morbidity and impaired quality-of-life of the children and their families. Adequate allergy testing is the prerequisite for optimal care, including allergen avoidance, pharmacotherapy and immunotherapy. Children with persisting or recurrent or severe symptoms suggestive for allergy should undergo an appropriate diagnostic work-up, irrespective of their age. Adequate allergy testing may also allow defining allergic trigger in common symptoms. We provide here evidence-based guidance on when and how to test for allergy in children based on common presenting symptoms suggestive of allergic diseases.

Perspectives on allergen-specific immunotherapy in childhood: an EAACI position statement

This article is the result of consensus reached by a working group of clinical experts in paediatric allergology as well as representatives from an ethical committee and the European Medicine Agency (EMA). The manuscript covers clinical, scientific, regulatory and ethical perspectives on allergen-specific immunotherapy in childhood. Unmet needs are identified. To fill the gaps and to bridge the different points of view, recommendations are made to researchers, to scientific and patient organizations and to regulators and ethical committees. Working together for the benefit of the community is essential. The European Academy of Allergy and Clinical Immunology (EAACI) serves as the platform of such cooperation.

Prospective validation of 'Allergy-Control-SCORE(TM)': a novel symptom-medication score for clinical trials

BACKGROUND

Combined symptom and medication scores (SMS) are recommended as primary endpoints in clinical trials. Several SMS have been created, but none has been formally validated.

OBJECTIVE

To evaluate the validity of the 'Allergy-Control-SCORE© (ACS)', a novel instrument to assess patient's allergy severity by recording symptoms and rescue medication.

METHODS

One hundred and twenty-one consenting subjects (age 18-65 year), including 81 patients with allergic rhino-conjunctivitis and/or asthma and 40 healthy controls, participated in the study. They recorded daily nasal, eye, and lung symptoms using a 4-point scale (none, mild, moderate, and severe) and use of anti-symptomatic medication. Pollen counts were monitored during the study period. Symptom and medication scores values were compared to global allergy severity, quality of life, and allergy-related medical consultations. Feasibility was tested through a questionnaire on comprehensibility, easiness of use, and completeness. Retest reliability was assessed by testing consistency, in relation to pollen exposure, and for values recorded during each of 2 consecutive weeks.

RESULTS

Convergent reliability analysis indicated a highly significant correlation between ACS© and global allergy severity (P < 0.0001), quality of life (P < 0.0001), and allergy-related medical consultations (P < 0.0001). Scores were highly related to pollen counts. Allergy-Control-SCORE© showed a good retest reliability (r = 0.81; P < 0.0001) and discriminated extremely well between patients with allergy and healthy controls (6.1 ± 4.8 vs 0.2 ± 0.5; t = 10.82; P < 0.0001) with a sensitivity of 97% and a specificity of 87%. Study participants evaluated the feasibility of the SMS as excellent.

CONCLUSIONS

Allergy-Control-SCORE© is a valid and reliable instrument to assess allergy severity in clinical trials and observational studies of respiratory allergic diseases.

99th Dahlem conference on infection, inflammation and chronic inflammatory disorders: controversial aspects of the 'hygiene hypothesis'

The 'hygiene hypothesis' proposes that the epidemic of allergic and autoimmune diseases is due to changes in the interactions between humans and the microbes of their ecosystem. This theory apparently does not explain (i) why allergic asthma is rising in 'unhygienic' American inner cities; (ii) why allergic diseases are less prevalent among migrants' children living in European big cities; (iii) why infections with airborne viruses do not 'protect' from allergic sensitization; (iv) why the inverse association between some infections (e.g. hepatitis A virus) and allergic diseases has been reproduced in some populations, but not in others; and (v) why probiotics are not effective in the prevention and therapy of allergic diseases. These challenging questions are useful starting points to improve our understanding of the hypothesis, and to identify among the infectious agents those really responsible for a protective influence against atopic and autoimmune diseases.

Dynamic evolution of serum immunoglobulin E to airborne allergens throughout childhood: results from the Multi-Centre Allergy Study birth cohort

BACKGROUND

Allergic rhinoconjunctivitis and asthma evolve dynamically throughout childhood. Yet, data on the evolution of serum levels of IgE antibodies against airborne allergens throughout the first decade of life are scarce.

OBJECTIVE

To describe the patterns of new and persistent sensitization against airborne allergens including remission from birth to 10 years of age and the long-term clinical outcomes up to the age of 13 years.

METHODS

In 273 children from the Multi-Centre Allergy Study, a German birth cohort, IgE levels were determined against airborne allergens (Dermatophagoides pteronyssinus, cat and dog dander, birch and grass species pollens) at 2, 5, 7, and 10 years of age (ImmunoCAP, Phadia); allergic rhino-conjunctivitis and asthma were ascertained at the 13 years of age through a standardized questionnaire (International Study of Asthma and Allergies in Childhood).

RESULTS

The prevalence of sensitization to each allergen increased steadily throughout childhood, and a hierarchy of sensitization prevalence (grass>birch>mites>cat>dog) was maintained from 5 years of age onwards. A mono-sensitization state was relatively short (measurable half-life=3 years) as additional sensitizations were acquired frequently, and relatively soon after the first one. Remission of weak sensitization (UNICAP classes 1-2) was also quite frequent, especially before 5 years of age. By contrast, stronger IgE responses (>3.5 kU/L) were invariably persistent. Early sensitization was associated with a higher tendency for poly-sensitization at 10 years of age and allergic rhino-conjunctivitis and/or asthma at 13 years of age.

CONCLUSIONS

IgE responses against airborne allergens undergo dynamic changes throughout childhood, with a high frequency of new sensitization or remission. The long-term persistence and the clinical impact of IgE responses are affected by the intensity of IgE sensitization and the age of its onset.

Longitudinal trends of total and allergen-specific IgE throughout childhood

BACKGROUND

The development and the quantitative relationship between allergen-specific IgE (S-IgE) responses and total IgE (T-IgE), during childhood and adolescence have not been described and understood in detail. The objective of this study was to describe and compare the longitudinal trends of serum levels of S-IgE and T-IgE during childhood.

METHODS

We analysed data from participants in the MAS birth cohort study at 2, 5, 7 and 10 years of age (n = 273) and at 1, 3, 5, 6, 7, 10 and 13 years (n = 84). Total-IgE and the overall level of specific-IgE against nine locally relevant airborne and food allergens were determined by FEIA (ImmunoCAP). Allergic rhino-conjunctivitis and asthma were ascertained by questionnaires.

RESULTS

Longitudinal patterns of T-IgE levels from age 1 to 13 years were highly heterogeneous (declining, flat or increasing with different profiles). From 5 years of age, logarithmic (log(10)) transformed values of T-IgE and of S-IgE levels tend to follow a parallel trend, so that their relation remained constant throughout school age. A flat trend of T-IgE vs a constantly increasing trend of T-IgE was associated with a low or, respectively, high rate of wheezing at 13 years of age.

CONCLUSIONS

Beginning at the age of 5 years, total serum IgE levels in children from an industrialized country evolved in parallel with overall S-IgE levels. Therefore, variations in T-IgE levels at school age closely reflect variations in overall S-IgE levels. Further studies are required to strengthen the biological and clinical implication of this novel finding.

New visions for basic research and primary prevention of pediatric allergy: an iPAC summary and future trends

Hydrolyzed formula feeding, delayed introduction of solid food, indoor allergen avoidance, smoke and pollutants avoidance have been applied for several decades as primary preventive measures for allergic diseases. Unfortunately, some of these strategies have had no or modest success. Therefore, resources need to be focused on better understanding of the early allergic events and on interventional studies to investigate new strategies of primary and secondary prevention. Accordingly, this review summarizes the state-of-the-art of genetic, immunological and clinical aspects of primary prevention of allergic diseases. Studies investigating gene-by-gene and gene-by-environment interactions suggest that prevention of allergic diseases must be tailored to the individual genetic susceptibilities ('gene profiling') and environmental exposures. The expanding knowledge on new T cell populations (Th17, TSLP (thymic stromal derived lymphopoietin)-dependent 'inflammatory Th2 cells') is also inspiring new concepts on the origins of allergic diseases. The old concept of 'blocking immunoglobulin G antibodies' has been re-appraised and it is likely to generate novel preventive and therapeutic strategies. The major task for future clinical research is to clearly define the timing of optimal exposure to potential allergens. In addition, the role of microbial products such as certain bacteria, or their components, and of helminths or their larvae at different times in early life, alone or with potential allergens, definitely need to be further investigated. The benefit of efficient allergy prevention, based on focusing resources on novel and promising research lines, will be of prime importance to both affluent countries and other parts of the world where allergy is only currently emerging.

Wheezing in childhood: incidence, longitudinal patterns and factors predicting persistence

Childhood asthma is frequently perceived as a disease with uniform clinical pathways. This perception might be an oversimplification. The aim of the present study was to investigate the incidence and natural course of wheeze over the first 13 yrs of life and analyse the risk factors predicting wheeze at 11-13 yrs of age. The Multicentre Allergy Study, a German birth cohort, recruited 1,314 children in 1990. Physical examinations, interviews on atopic diseases, immunoglobulin (Ig)E and lung function tests were performed up to 13 yrs of age. Complete data on the course of wheeze were available for 441 children. It was found that incidence of wheezing declined with age. The first wheezing episode was reported by 29, 9 and 9% of participants at < or = 3 (early wheezers), 3-6 (late wheezers), and > 6 yrs (very late wheezers) of age, respectively. Wheezing at the age of 13 yrs was associated with parental atopy, and with IgE sensitisation to common allergens, elevated total IgE and exposure to high levels of indoor allergens in early life. All these associations were remarkably stronger among early wheezers than among early nonwheezers. In conclusion, the relevance of an early expression of atopy as a predictor of wheezing at age 13 yrs declines with increasing age of wheezing onset.