Development and validation of a structured questionnaire for the diagnosis of oral allergy syndrome in subjects with seasonal allergic rhinitis during the UK birch pollen season

Comprehensive review of pollen-food allergy syndrome: Pathogenesis, epidemiology, and treatment approaches

Pollen-food allergy syndrome (PFAS) is caused by cross-reaction of a specific pollen antigen with the corresponding food allergen in sensitized individuals. The manifestations are usually limited to oral symptoms; however, sometimes, rhinitis, respiratory and skin symptoms, and anaphylactic shock may occur. In PFAS pathogenesis, when food containing protein antigens (pan-allergens) with high homology to pollen antigens is ingested, mast cells bound to pollen antigen-specific IgE distributed in the oral mucosa cross-react with the food antigen, causing a local type I allergic reaction. The prevalence of PFAS depends on the geographic conditions, such as the type and amount of pollen in the area. PFAS is prevalent in all regions owing to the wide variety of pollen antigens implicated in the disease, such as alder and grass pollen, even outside of the birch habitat area. Basic research on PFAS is expected to significantly contribute to elucidating the pathogenesis and development of therapeutic strategies for PFAS. Currently, effective treatment for patients with PFAS that allows safe consumption of raw foods is lacking, and avoiding the intake of causative foods is the basis of prevention. Furthermore, allergen immunotherapy for PFAS has not yet been established, but various attempts are underway to develop it into a novel treatment strategy. This review highlights the current research landscape on the pathophysiology, epidemiology, and clinical aspects of PFAS. We outline the research gaps that should be addressed to improve the outcomes of patients with PFAS.

Recombinant PreS-fusion protein vaccine for birch pollen and apple allergy

BACKGROUND

IgE cross-sensitization to major birch pollen allergen Bet v 1 and pathogenesis-related (PR10) plant food allergens is responsible for the pollen-food allergy syndrome.

METHODS

We designed a recombinant protein, AB-PreS, consisting of non-allergenic peptides derived from the IgE-binding sites of Bet v 1 and the cross-reactive apple allergen, Mal d 1, fused to the PreS domain of HBV surface protein as immunological carrier. AB-PreS was expressed in E. coli and purified by chromatography. The allergenic and inflammatory activity of AB-PreS was tested using basophils and PBMCs from birch pollen allergic patients. The ability of antibodies induced by immunization of rabbits with AB-PreS and birch pollen extract-based vaccines to inhibit allergic patients IgE binding to Bet v 1 and Mal d 1 was assessed by ELISA.

RESULTS

IgE-binding experiments and basophil activation test revealed the hypoallergenic nature of AB-PreS. AB-PreS induced lower T-cell activation and inflammatory cytokine production in cultured PBMCs from allergic patients. IgG antibodies induced by five injections with AB-PreS inhibited allergic patients' IgE binding to Bet v 1 and Mal d 1 better than did IgG induced by up to 30 injections of six licensed birch pollen allergen extract-based vaccines. Additionally, immunization with AB-PreS induced HBV-specific antibodies potentially protecting from infection with HBV.

CONCLUSION

The recombinant AB-PreS-based vaccine is hypoallergenic and superior over currently registered allergen extract-based vaccines regarding the induction of blocking antibodies to Bet v 1 and Mal d 1 in animals.

Diagnosis and Management of Pollen Food Allergy Syndrome to Nuts

Oral allergy syndrome or pollen food allergy syndrome (PFAS) represents a common clinical conundrum when the reported trigger food is a tree nut (usually almond or hazelnut) or peanut. The PFAS may give rise to uncertainty about the potential severity of the future reactions, indications for prescribing epinephrine, and the extent of the necessary dietary avoidance. As a food allergy, secondary to cross-reactivity with airborne pollen, PFAS usually manifests toward the end of the first decade of life as contact urticaria of the oropharyngeal mucous membranes. Molecular allergology facilitates diagnosis and risk stratification by establishing the profile of sensitization. Exclusive sensitization to pathogenesis-related proteins family 10 (PR10) and profilins indicates that signs and symptoms are due to PFAS, whereas sensitization to seed storage proteins with or without sensitization to PR10 and profilins may indicate a more severe primary nut allergy phenotype. Management relies on avoidance of the specific nut trigger, advice on the likelihood of more severe local or systemic symptoms, and treatment of reactions according to the severity. Future studies are needed to better delineate the risk of systemic reactions in individuals with nut PFAS and to establish the role of food or pollen allergen immunotherapy for the prevention or moderation of this condition.

Natural human Bet v 1-specific IgG antibodies recognize non-conformational epitopes whereas IgE reacts with conformational epitopes

BACKGROUND

The nature of epitopes on Bet v 1 recognized by natural IgG antibodies of birch pollen allergic patients and birch pollen-exposed but non-sensitized subjects has not been studied in detail.

OBJECTIVE

To investigate IgE and IgG recognition of Bet v 1 and to study the effects of natural Bet v 1-specific IgG antibodies on IgE recognition of Bet v 1 and Bet v 1-induced basophil activation.

METHODS

Sera from birch pollen allergic patients (BPA, n = 76), allergic patients without birch pollen allergy (NBPA, n = 40) and non-allergic individuals (NA, n = 48) were tested for IgE, IgG as well as IgG1 and IgG4 reactivity to folded recombinant Bet v 1, two unfolded recombinant Bet v 1 fragments comprising the N-terminal (F1) and C-terminal half of Bet v 1 (F2) and unfolded peptides spanning the corresponding sequences of Bet v 1 and the apple allergen Mal d 1 by ELISA or micro-array analysis. The ability of Bet v 1-specific serum antibodies from non-allergic subjects to inhibit allergic patients IgE or IgG binding to rBet v 1 or to unfolded Bet v 1-derivatives was assessed by competition ELISAs. Furthermore, the ability of serum antibodies from allergic and non-allergic subjects to modulate Bet v 1-induced basophil activation was investigated using rat basophilic leukaemia cells expressing the human FcεRI which had been loaded with IgE from BPA patients.

RESULTS

IgE antibodies from BPA patients react almost exclusively with conformational epitopes whereas IgG, IgG1 and IgG4 antibodies from BPA, NBPA and NA subjects recognize mainly unfolded and sequential epitopes. IgG competition studies show that IgG specific for unfolded/sequential Bet v 1 epitopes is not inhibited by folded Bet v 1 and hence the latter seem to represent cryptic epitopes. IgG reactivity to Bet v 1 peptides did not correlate with IgG reactivity to the corresponding Mal d 1 peptides and therefore does not seem to be a result of primary sensitization to PR10 allergen-containing food. Natural Bet v 1-specific IgG antibodies inhibited IgE binding to Bet v 1 only poorly and could even enhance Bet v 1-specific basophil activation.

CONCLUSION

IgE and IgG antibodies from BPA patients and birch pollen-exposed non-sensitized subjects recognize different epitopes. These findings explain why natural allergen-specific IgG do not protect against allergic symptoms and suggest that allergen-specific IgE and IgG have different clonal origin.

Pollen Food Allergy Syndrome in Japanese Children and Adolescents: Risk Factors and Pollen Sensitisation

Pollen food allergy syndrome (PFAS) is caused by cross-reactivity with pollen; however, not all-pollen-sensitised individuals develop PFAS, and studies on the characteristics of PFAS development are limited in Japan. We investigated the prevalence and risk factors for the development of PFAS in Japanese children and adolescents sensitised to pollen and their association with pollen-specific IgE levels. The characteristics of PFAS were investigated in patients with allergies aged 3-18 years who visited Dokkyo Medical University Hospital between January 2016 and December 2019. Specific IgE levels for alder, Japanese cedar, ragweed, and orchard grass were measured in patients sensitised to any of the pollens. Patients were categorised into preschool (G1), elementary school (G2), and middle-high school (G3) groups. Overall, 600 patients were enrolled. The prevalence of PFAS was 8.5% in G1, 20% in G2, and 36.3% in G3. Multivariate logistic regression analysis demonstrated strong associations between the risk of developing PFAS and older age (odds ratio (OR), 1.12; 95% confidence interval (CI), 1.06-1.19; P < 0.001), seasonal allergy rhinitis (OR, 6.93; 95% CI, 1.59-30.34; P = 0.010), and alder sensitisation (OR, 6.20; 95% CI, 2.66-14.49; P < 0.001). Spearman's correlation revealed statistically significant positive correlation between each pollen-specific IgE level; high pollen-specific IgE levels were also a risk factor. The OR for being sensitised to all four species was 36.83 (95% CI, 8.93-151.83, P < 0.001) when compared with Japanese cedar alone. Alder was most relevant, with an alder-specific IgE level cutoff value of 2.54 UA/mL. The sensitivity was 78.9%, and the specificity was 70.9%. In conclusion, preschool children develop PFAS with alder sensitisation, and higher pollen-specific IgE levels and increased number of pollen sensitisations are risk factors for developing PFAS.

Relationship among airborne pollen, sensitization, and pollen food allergy syndrome in Asian allergic children

Background

Causes of pediatric pollen food allergy syndrome (PFAS) differ depending on airborne pollen levels in a particular region. We aimed to analyze airborne pollen counts, IgE sensitization rates, and PFAS incidence among children with allergies in South Korea and Japan.

Methods

This cross-sectional study included children aged 5-17 years with allergies in 2017. Airborne pollen samples were collected from Busan in South Korea, and Fukuoka and Tochigi in Japan. Questionnaires were used to assess bronchial asthma, seasonal allergic rhinitis, atopic dermatitis, food allergy, and PFAS. The serum IgE specific to Dermatophagoides pteronyssinus, pollen, tomato, and peach were investigated.

Results

In total, 57, 56, and 20 patients from Busan, Fukuoka, and Tochigi, respectively, were enrolled. Airborne Japanese cedar and cypress pollen were predominant in Fukuoka and Tochigi, whereas pine and alder pollen were predominant in Busan. Children with allergies in Fukuoka and Tochigi had a significantly higher sensitization rate to Japanese cedar, cypress, juniper, orchard grass, ragweed, Japanese hop, and tomato compared with children in Busan. In Fukuoka and Tochigi, where Japanese cedar and cypress pollen were frequently scattered, high sensitizations among allergic children were observed. The sensitization rate was not affected by the pollen count in alder, grass, ragweed, and Japanese hop. In multivariable analysis, only alder sensitization was found to be associated with PFAS (odds ratio: 6.62, 95% confidence interval: 1.63-26.87, p = 0.008). In patients with PFAS in Busan and Tochigi, peach associated with birch allergen Bet v 1 was a causative food item for PFAS. Moreover, PFAS was associated with ragweed and Japanese hop pollen sensitization in Fukuoka.

Conclusion

Regardless of pollen counts, alder pollen sensitization was associated with PFAS in children. Ragweed and Japanese hop pollen sensitization were associated with PFAS, particularly among children in southern Japan.

Phenotypic characterization of childhood- and adult-onset food allergy among adults in the United States

Background

Food allergy (FA) affects ~10% of adults; however, little is known about the extent to which FA phenotypes and psychosocial burden vary depending on timing of allergy onset, whether in childhood or as an adult.

Objective

This study explored FA characteristics according to timing of FA onset in US adults.

Methods

Between 2015 and 2016, a cross-sectional survey was administered to 40,443 US adults. Complex survey-weighted results were tabulated across key demographic and clinical strata. Linear regression models explored covariate-adjusted variability in FA-related psychosocial burden across 3 groups: (1) adults solely with childhood-onset FA, (2) adults solely with adult-onset FA, and (3) adults with both childhood- and adult-onset FA.

Results

Adults with both childhood- and adult-onset FAs, compared to adults with solely childhood- or adult-onset FAs, are significantly more likely to have severe FAs (57.3%, 52.6%, 43.2%), physician-diagnosed FAs (54.2%, 52.4%, 33.0%), and multiple FAs (74.8%, 41.0%, 30.3%) (P < .001). Adults solely with childhood-onset FA, compared to adults solely with adult-onset FA, had significantly lower rates of environmental allergies (27.6% vs 39.2%; P < .001) and medication allergies (17.3% vs 25.9%; P < .001). Adults with both childhood- and adult-onset FAs reported highest rates of all comorbidities. Adults solely with adult-onset FA reported significantly lower FA-related psychosocial burden (P < .05).

Conclusion

Differences exist in reaction severity, health care utilization, atopic comorbidities, and psychosocial burden according to the timing of FA onset. Future research exploring the heterogeneity of phenotypic expressions of adult FA may inform underlying mechanisms.

BSACI guideline for the diagnosis and management of pollen food syndrome in the UK

Pollen food syndrome (PFS) is a highly prevalent food allergy affecting pollen-sensitized children and adults. Sufferers experience allergic symptoms when consuming raw plant foods, due to the homology between the pollen allergens and unstable proteins in these foods. The triggers involved can vary depending on the pollen sensitization, which in turn is affected by geographical location. The British Society of Allergy and Clinical Immunology (BSACI) Standards of Care Committee (SOCC) identified a need to develop a guideline for the diagnosis and management of PFS in the United Kingdom (UK). Guidelines produced by the BSACI use either the GRADE or SIGN methodology; due to a lack of high-quality evidence these recommendations were formulated using the SIGN guidelines, which is acknowledged to be less robust than the GRADE approach. The correct diagnosis of PFS ensures the avoidance of a misdiagnosis of a primary peanut or tree nut allergy or confusion with another plant food allergy to non-specific lipid transfer proteins. The characteristic foods involved, and rapid-onset oropharyngeal symptoms, mean PFS can often be diagnosed from the clinical history alone. However, reactions involving tree nuts, peanuts and soya milk or severe/atypical reactions to fruits and vegetables may require additional diagnostic tests. Management is through the exclusion of known trigger foods, which may appear to be simple, but is highly problematic if coupled with a pre-existing food allergy or for individuals following a vegetarian/vegan diet. Immunotherapy to pollens is not an effective treatment for PFS, and although oral or sublingual immunotherapy to foods seems more promising, large, controlled studies are needed. The typically mild symptoms of PFS can lead to an erroneous perception that this condition is always easily managed, but severe reactions can occur, and anxiety about the onset of symptoms to new foods can have a profound effect on quality of life.

A multi-disciplinary approach to the diagnosis and management of allergic diseases: An EAACI Task Force

BACKGROUND

Guidelines for management of patients with allergic conditions are available, but the added value of nurses, allied healthcare professionals (AHPs), and general practitioners (GPs), in the management of allergic disease, has not been fully clarified. The European Academy of Allergy and Clinical Immunology (EAACI) appointed a task force to explore this issue.

AIM

To investigate the added value of nurses, AHPs, and GPs in management of allergic diseases, in an integrated model of care.

METHODS

A search was made of peer-reviewed literature published between 2010 and December 2020 (Cochrane Library, PubMed, and CINAHL) on the involvement of the various specific healthcare providers (HCPs) in the management of allergic diseases.

RESULTS

Facilitative models of care for patients with allergies can be achieved if HCP collaborates in the diagnosis and management. Working in multi-disciplinary teams (MDT) can increase patients' understanding of the disease, adherence to treatment, self-care capabilities, and ultimately improve quality of life. The MDT competencies and procedures can be improved and enhanced in a climate of mutual respect and shared values, and with inclusion of patients in the planning of care. Patient-centered communication among HCPs and emphasis on the added value of each profession can create an effective integrated model of care for patients with allergic diseases.

CONCLUSION

Nurses, AHPs, and GPs, both individually and in collaboration, can contribute to the improvement of the management of patients with allergic disease. The interaction between the HCPs and the patients themselves can ensure maximum support for people with allergies.

The Challenges of Managing Multiple Food Allergies and Consequent Food Aversions

The allergic march can often result in children with one food allergy phenotype developing other allergic manifestations as they grow older. In this grand round, we describe the case of a child with a diagnosis of eosinophilic esophagitis at an early age, who subsequently developed IgE-mediated allergy to milk and egg. Because of the onset of allergic rhinitis, an additional complication of the teenage years was the development of pollen food syndrome, which further affected the already complex dietary management. These multiple allergies had a consequent effect on nutritional status and provoked considerable psychosocial issues, which greatly affected the patient's relationship with food. This case illustrates that for complex patients, a cohesive approach and shared decision-making are essential for diagnosis and management. Working with the patient and also the whole family, and considering how best to support them, necessitates a flexible approach. Regular follow-up is important to address changing psychosocial and dietary needs and monitor the resolution of allergies and response to pharmacotherapy. Complex patients need the input of a comprehensive multidisciplinary team, with good access to dietetic and psychological support, to optimize quality of life for these individuals and their families.

Heterogeneity of pollen food allergy syndrome in seven Southern European countries: The @IT.2020 multicenter study

BACKGROUND

Pollen food allergy syndrome (PFAS) is a frequently underdiagnosed disease due to diverse triggers, clinical presentations, and test results. This is especially relevant in geographic areas with a broad spectrum of pollen sensitization, such as Southern Europe.

OBJECTIVES

To elucidate similarities and differences of PFAS in nine Southern European centers and identify associated characteristics and unique markers of PFAS.

METHODS

As part of the @IT.2020 Multicenter Study, 815 patients with seasonal allergic rhinitis (SAR), aged 10-60 years, were recruited in seven countries. They completed questionnaires regarding SAR, comorbidities, family history, and PFAS, and underwent skin prick testing (SPT) and serum IgE testing.

RESULTS

Of the 815 patients, 167 (20.5%) reported PFAS reactions. Most commonly, eliciting foods were kiwi (58, 34.7%), peach (43, 25.7%), and melon (26, 15.6%). Reported reactions were mostly local (216/319, 67.7%), occurring within 5 min of contact with elicitors (209/319, 65.5%). Associated characteristics included positive IgE to at least one panallergen (profilin, PR-10, or nsLTP) (p = 0.007), maternal PFAS (OR: 3.716, p = 0.026), and asthma (OR: 1.752, p = 0.073). Between centers, heterogeneity in prevalence (Marseille: 7.5% vs. Rome: 41.4%, p < 0.001) and of clinical characteristics was apparent. Cypress played a limited role, with only 1/22 SPT mono-sensitized patients reporting a food reaction (p < 0.073).

CONCLUSIONS

PFAS is a frequent comorbidity in Southern European SAR patients. Significant heterogeneity of clinical characteristics in PFAS patients among the centers was observed and may be related to the different pollen sensitization patterns in each geographic area. IgE to panallergen(s), maternal PFAS, and asthma could be PFAS-associated characteristics.

Update on pollen-food allergy syndrome

INTRODUCTION

Allergies affect 20-30% of the population and respiratory allergies are mostly due to pollen grains from anemophilous plants. One to 5% of people suffer from food allergies and clinicians report increasing numbers of pollen-food allergy syndrome (PFAS), such that the symptoms have broadened from respiratory to gastrointestinal, and even to anaphylactic shock in the presence of cofactors. Thirty to 60% of food allergies are associated with pollen allergy while the percentage of pollen allergies associated to food allergy varies according to local environment and dietary habits.

AREAS COVERED

Articles published in peer-reviewed journals, covered by PubMed databank, clinical data are discussed including symptoms, diagnosis, and management. A chapter emphasizes the role of six well-known allergen families involved in PFAS: PR10 proteins, profilins, lipid transfer proteins, thaumatin-like proteins, isoflavone reductases, and β-1,3 glucanases. The relevance in PFAS of three supplementary allergen families is presented: oleosins, polygalacturonases, and gibberellin-regulated proteins. To support the discussion a few original relevant results were added.

EXPERT OPINION

Both allergenic sources, pollen and food, are submitted to the same stressful environmental changes resulting in an increase of pathogenesis-related proteins in which numerous allergens are found. This might be responsible for the potential increase of PFAS.

Can patients with oral allergy syndrome be at risk of anaphylaxis?

PURPOSE OF REVIEW

Oral allergy syndrome, also known as pollen-food syndrome (PFS), is a condition usually associated with adults and characterized by mild transient oropharyngeal symptoms. The purpose of this review is to determine whether systemic or anaphylactic reactions do occur and if so, who is affected and what are the triggers.

RECENT FINDINGS

An increasing number of studies demonstrate that PFS occurs all age groups, and a significant number of affected adults do experience systemic and anaphylactic reactions. The upsurge in the adoption of vegan lifestyles, increase in consumption of fruits and vegetables including smoothies and juices, and use of plant foods in nutritional or body-building supplements, could exacerbate this. Changes in pollen and pollution levels, cofactors and sensitization to other plant food allergens may also be involved.

SUMMARY

While the majority of those with PFS will continue to experience mild symptoms, all individuals should be properly advised regarding the dangers of concentrated or unusual forms of plant food allergens such as smoothies, juices, soy/nut milks and nutritional supplements. Further well characterized studies are needed to determine risk factors for severe reactions, and sensitization patterns to pollens and plant food allergens.

IgE-reactivity profiles to allergen molecules in Russian children with and without symptoms of allergy revealed by micro-array analysis

BACKGROUND

The analysis of longitudinal birth cohorts with micro-arrayed allergen molecules has provided interesting information about the evolution of IgE sensitization in children. However, so far no cross-sectional study has been performed comparing IgE sensitization profiles in children with and without symptoms of allergy. Furthermore, no data are available regarding molecular IgE sensitization profiles in children from Russia.

METHODS

We recruited two groups of age- and gender-matched children, one (Group 1: n = 103; 12.24 ± 2.23 years; male/female: 58/45) with symptoms and a second (Group 2: n = 97; 12.78 ± 2.23 years; male/female: 53/44), without symptoms of allergy according to international ISAAC questionnaire. Children were further studied regarding symptoms of allergy (rhinitis, asthma, atopic dermatitis) according to international guidelines, and skin prick testing with a panel of aeroallergen extracts was performed before sera were analyzed in an investigator-blinded manner for IgE specific to more than 160 micro-arrayed allergen molecules using ImmunoCAP ISAC technology.

RESULTS

IgE sensitization = or >0.3 ISU to at least one of the micro-arrayed allergen molecules was found in 100% of the symptomatic children and in 36% of the asymptomatic children. Symptomatic and asymptomatic children showed a comparable IgE sensitization profile; however, frequencies of IgE sensitization and IgE levels to the individual allergen molecules were higher in the symptomatic children. Aeroallergen sensitization was dominated by sensitization to major birch pollen allergen, Bet v 1, and major cat allergen, Fel d 1. Food allergen sensitization was due to cross-sensitization to PR10 pollen and food allergens whereas genuine peanut sensitization was absent.

CONCLUSION

This is the first study analyzing molecular IgE sensitization profiles to more than 160 allergen molecules in children with and without symptoms of allergy. It detects similar molecular IgE sensitization profiles in symptomatic and asymptomatic children and identifies Bet v 1 and Fel d 1 as the predominant respiratory allergen molecules and PR10 proteins as the major food allergens and absence of genuine peanut allergy in Moscow region (Russia).

The prevalence of oral symptoms caused by Rosaceae fruits and soybean consumption in children; a Japanese population-based survey

BACKGROUND

Pollen food Syndrome (PFS) to Rosaceae fruits and soybean, related to Bet v 1 homologue sensitization has been reported increasingly throughout Japan, possibly due to the wide distribution of alder.

METHODS

In 2015, we conducted a school-based questionnaire survey among two age groups; students in primary school (Years 1-2) and secondary school (Years 8-9) from each of the 47 prefectures of Japan. We analyzed the prevalence, demographic and clinical characteristics of children with oral symptoms to Rosaceae fruits/soybean; defined as oral symptoms occurring shortly after ingesting apple, peach, cherry or soybean. Additionally, we assessed the correlation between the prevalence and external data on alder sensitization rates by prefecture.

RESULTS

Responses from 41,264 primary and 35,302 secondary school students were analyzed. The prevalence of oral symptoms to Rosaceae fruits/soybean was 0.99%, 95%CI: 0.89-1.09% and 2.75%, 95%CI: 2.59-2.93% among each age group, respectively. Children with oral symptoms were more likely to have parental and personal history of allergic disease compared to those without symptoms. Oral symptoms were experienced more often in children with severe spring allergic rhinitis or have both allergic rhinitis and wheeze. There was a strong correlation between the prevalence of oral symptoms and alder sensitization rates by prefecture among both age groups (r = 0.63, p < 0.001 and r = 0.76, p < 0.001, respectively).

CONCLUSIONS

Oral symptoms to Rosaceae fruits/soybean, which is suggestive of PFS was reported by 1-3% Japanese school children. It was associated with the geographic alder sensitization rate, supporting the underlying sensitization to Bet v 1.

The Effect of Birch Pollen Immunotherapy on Apple and rMal d 1 Challenges in Adults with Apple Allergy

Background: A proportion of patients allergic to birch pollen are also allergic to pit fruit. The objective of this study was to investigate the effect of immunotherapy with birch pollen on birch-pollen-related apple allergy. Method: Patients with birch pollen immunotherapy underwent a skin-prick test with birch pollen, apple and rMal d 1, global assessments and nasal challenges with birch pollen, open food challenge with apple and a double-blind, placebo-controlled test with rMal d 1 at the start of and during the immunotherapy. Measurements of specific IgE in response to Bet v 1 and rMal d 1 and IgG4 in response to Bet v 1 and rMal d 1 took place. Results: Six of eight patients demonstrated an improvement of nasal challenge test results and all patients improved on global assessment during the immunotherapy. The median oral dose of apple required to elicit a reaction increased but was not statistically significant. The patients showed a decrease in skin-prick test values in response to birch pollen (1.05 to 0.36), apple (0.78 to 0.25) and rMal d 1 (0.51 to 0.10) with p-values of 0.04, 0.03 and 0.06, respectively and a decrease of specific IgE in response to Bet v 1 (10.66 kU/L to 5.19 kU/L) and rMal d 1 (0.99 to 0.61 kU/L) with p-values of 0.01 and 0.05, respectively. Only the median specific IgG4 value to Bet v 1 increased from 0.05 to 1.85 mg/L (p-value of 0.02) and not to IgG4 rMal d 1 (0.07 to 0.08 kU/L). Conclusion: The beneficial effects of immunotherapy for birch pollen were accompanied by a limited effect on apple allergy.

Pollen-Food Allergy Syndrome: A not so Rare Disease in Childhood

Seasonal allergic rhinoconjunctivitis (SAR) affects millions of people worldwide, particularly in childhood and adolescence. Pollen food allergy syndrome (PFAS) is a common adverse reaction occurring few minutes after the consumption of vegetable foods in patients with pollen-induced SAR. PFAS has rarely been investigated in the pediatric population, as it has been mainly examined as an adult disease. Recent studies suggested that PFAS might be more frequent in childhood than previously recognized. The present review aims to give an overview of the epidemiology, pathophysiology, diagnosis, management and prognosis of PFAS in children with SAR-induced by pollens.

Lipid Transfer Protein allergy in the United Kingdom: Characterization and comparison with a matched Italian cohort

BACKGROUND

Although pollen-related food allergy occurs in all European populations, lipid transfer protein (LTP) allergy is considered to manifest mainly in Mediterranean countries. We aimed to characterize adults presenting with LTP allergy in a northern European country.

METHOD

The clinical history and sensitization patterns of subjects born and residing in the United Kingdom (UK), with a prior diagnosis of LTP allergy and sensitization to the peach LTP allergen Pru p 3, were compared to UK subjects with pollen food syndrome (PFS). The sensitization patterns were also evaluated against a matched cohort of Italian subjects diagnosed with LTP allergy.

RESULTS

None of the 15 UK PFS subjects had a positive SPT to LTP-enriched peach reagent, compared to 91% of the 35 UK LTP subjects. The UK LTP cohort were also more likely to have positive skin prick tests to cabbage, lettuce and mustard and sensitization to the LTP allergens in peach, walnut, mugwort and plane tree These sensitization patterns to individual allergens were not significantly different to those obtained from the Italian LTP subjects, with significant correlations between Pru p 3 and the LTP allergens in peanuts, walnuts, plane tree and mugwort in both groups.

CONCLUSION

Native UK subjects with LTP allergy are not dissimilar to those with LTP allergy in southern Europe. Testing to LTP-enriched peach SPT reagent and/or LTP allergens in peach, walnut, mugwort and plane tree may enhance diagnostic accuracy.

Food-Induced Anaphylaxis: Role of Hidden Allergens and Cofactors

Food anaphylaxis is on the increase, with those who have an allergy to peanuts, tree nuts, milk, and seafood at the highest risk of developing such a reaction. However, the diet in many societies is increasingly varied, much of the food consumed is prepared outside the home, and meals are often composed of many different ingredients. Anaphylaxis may occur to a composite food, and it may be unclear whether the reaction is due to contamination or to a culprit allergen present in an added ingredient. Composite foods can contain many allergic proteins present in small amounts, which do not always have to be labeled, unless they feature in European or US labeling regulations. These "hidden" allergens include mustard, celery, spices, lupine, pea, natural food colourings, and preservatives, but can occasionally include allergenic material from contaminants such as cereal mites. Hidden allergens can provoke severe reactions to seemingly unconnected foods which might then lead to a diagnosis of idiopathic anaphylaxis. The same problem can arise with two well-known types of food allergy; wheat-dependant exercise induced anaphylaxis and allergy to non-specific Lipid Transfer Protein allergens, both of which might only manifest when linked to a cofactor such as exercise. Many of these risk factors for food anaphylaxis have a common link; the public's engagement with popular concepts of health and fitness. This includes the development of a food and exercise culture involving the promotion and marketing of foods for their health-giving properties i.e., meat substitutes, wheat substitutes, supplements and alternative, or "natural" remedies for common ailments. Some of these foods have been reported as the cause of severe allergic reactions, but because they are often viewed as benign unlikely causes of severe allergic reactions, could be considered to be hidden allergens. The best resource to elicit the likelihood of a hidden allergen provoking an allergic reaction is to take a detailed history of the allergic reaction, presence of co-factors, foods suspected, type of food and where it was consumed. A good knowledge of commonly used ingredients, and list of potential hidden allergen suspects are essential tools for the food allergy detective.

POLLEN–FOOD ALLERGY SYNDROME AMONG CHILDREN WITH SENSITIZED TO SPRING TREES

It is known that among 40–70 % of patients pollinosis can run in conjunction with pollen-food allergy syndrome (PFS), while development of PFS is associated with the consumption of fresh fruits, vegetables, nuts and spices. Clinical course and severity of the disease depend on the sensitization profile, which can be represented by proteins-panallergens (PR-10, profilins, nsLTPs). However, there is little information about the sensitization profiles of patients with pollinosis caused by pollen of spring trees in Ukraine. Aim. To study the profiles of sensitization of children with spring pollinosis. Methods. We examined 61 children (aged 4-17 years) with spring seasonal allergic rhinitis/rhinoconjunctivitis (SAR). To establish the diagnosis, all children were given questionnaires, skin prick tests (SPTs) with commercial pollen extracts, and prick to prick tests with fresh fruits, vegetables and nuts. Component resolved diagnosis (CRD) were detected using an ImmunoCAP system. (Phadia, 100). Results. It has been found that in 43 children (70.5 %) had polinosis in combination with PFS, the main clinical manifestation of which was an oral allergic syndrome in 43 children (100 %). Among the causal food allergens that caused the manifestations of PFS were more apples, peaches, carrots and hazelnuts (consumption of which led to 11.6 % of children before the development of anaphylaxis). All of the examined children (100 %) had a positive IgE response to rBet v 1 at significant concentrations. In 9.3 % of children, panallergens were found at once from several botanical groups. Such panallergens: rBet v 2, rBet v 4, rPhl p 7, rPhl p 12, rArt v 3 are generally not defined in the control group children. Conclusions. Birch related PFS are common in Ukrainian pollen-allergic children with nuts and fruits predominantly implicated. Sensitization profile of children with Birch-pollen syndrome is complex and associated with sensitization to panalergens. Clinicians should be worried of PFS in patients with a high degree of sensitization to birch pollen and even young children if they have birch sensitization.

Mugwort Pollen-Related Food Allergy: Lipid Transfer Protein Sensitization and Correlation With the Severity of Allergic Reactions in a Chinese Population

PURPOSE

Little is known about the importance of lipid transfer protein (LTP) sensitization in China. In this study, we investigated the relationship between LTP sensitization and the severity of clinical symptoms in a population of patients with mugwort pollen-related food allergy.

METHODS

Food-induced symptoms were evaluated in 148 patients with mugwort pollen allergy by a standardized questionnaire. Specific immunoglobulin E (IgE) to Art v 1, Art v 3, Pru p 3, Ara h 9 and Cor a 8 were quantified by ImmunoCAP. Immunoblotting of peach extracts were performed with sera from peach-allergic patients.

RESULTS

In total, 72% (107/148) of the study population experienced food allergy. Forty-eight percent (51/107) of patients with mugwort pollen-related food allergy experienced at least 1 episode of food-induced anaphylaxis. Food allergy correlated with IgE reactivity to Art v 3, but not to Art v 1. Sensitization to Pru p 3, Ara h 9 or Cor a 8 was prevalent (80%, 69 or 63%, respectively) among individuals with food allergy. Food allergic patients with systemic reactions (SR) had higher values for Pru p 3, Ara h 9 and Cor a 8 than patients with oral allergy syndrome (OAS). Furthermore, the strong IgE reactivity detected in immunoblots of peach extracts indicated that Pru p 3 was the major allergen and was more prevalent in patients with SR than in patients with OAS (100% vs. 55%).

CONCLUSIONS

LTPs are major food allergens for mugwort pollen-related food allergy in China, and may contribute to SR.

Promoting and achieving excellence in the delivery of Integrated Allergy Care: the European Academy of Allergy & Clinical Immunology competencies for allied health professionals working in allergy

The multi-disciplinary team approach is an effective model for patient care. Allied health professionals (AHPs) are an important part of such teams, bringing specific knowledge and skills related to the target patient population. The AHPs most often involved in allergy care are nurses and dietitians. Nurses are often involved in the care of patients with all types of allergy and also with asthma, whilst allergy-specialist dietitians provide vital nutritional and dietary support for the diagnosis and management of food allergy. There are many other AHPs who have a role to play in allergy care, including physiotherapists, psychologists, pharmacists and speech therapists, and their involvement is likely to develop as allergy care becomes more rooted in the community. With the development of multi-professional teams comes the requirement for disease-specific knowledge and skill sets, with all allergy team members required to have baseline knowledge and competency of the condition being managed. Whilst some competencies for AHPs practising in other disease states have been published, none are available for allergic disease against which AHPs can be benchmarked. The European Academy of Allergy & Clinical Immunology (EAACI) recognised this need, and supported the establishment of a Task Force to develop allergy-focussed competencies for AHPs. The varied skills, expertise and professional background of the Task Force members enabled the creation of a set of allergy competencies relevant to all AHPs working in allergy. It is recognised that the training and allergy expertise of AHPs, and their role within the allergy setting, will vary considerably depending on the country. However, it is important for patient care, that all AHP involved in allergy services have access to training, of a sufficiently high enough level to be aspirational and enable the continued growth and development of a wide range of allergy services, given the increasing need. The EAACI competencies will provide an important benchmark for allergy knowledge and skills against which education and training can be designed and health care professionals can subsequently be measured. However, more importantly, the EAACI AHP allergy competencies will enable the development and reach of specialist allergy services, with allergy-specialist AHPs undertaking key roles, especially in the community care setting.

Oral Allergy Syndrome in Birch Pollen-Sensitized Patients from a Korean University Hospital

BACKGROUND

Oral allergy syndrome (OAS) is a type of allergic reaction that mainly occurs on oral contact with raw fruit, vegetables, or nuts. The most common type of OAS is birch pollen-related food allergy. Although OAS is a common food allergy in adults, only few epidemiologic studies have been reported in Korea. Here we investigate the prevalence and triggers of birch pollen-related food allergy.

METHODS

We conducted a retrospective chart review of 1,427 patients who underwent a skin prick test for inhalant allergens at the Asthma and Allergy Clinic in Seoul National University Bundang Hospital from January 2011 to December 2016.

RESULTS

Of 1,427 patients, 125 (8.7%) were sensitized to birch pollen. Among them, 20.0% developed OAS, which was the most common food allergy (96.2%). The prevalence of OAS was higher in females, and was 18.2% in birch pollen-sensitized allergic rhinoconjunctivitis patients. Further, 72.0% OAS patients had rhinoconjunctivitis, 20.0% had asthma, and 12.0% had chronic urticaria. Apple (68.0%), peach (56.0%), nuts (36.0%), kiwi (20.0%), persimmon (20.0%), plum (16.0%), and cherry (16.0%) were frequent triggers; however, Chinese yam, kudzu vine, bellflower root, codonopsis, and ginseng were also revealed as triggers. Patients (60.0%) showed OAS with ≥ 3 foods at the same time. Only 3 patients showed mono-sensitivity to birch pollen, while others were multi-sensitized to trees, grasses, weed, or house dust mite allergens.

CONCLUSION

OAS was the most common food allergy in birch pollen-sensitized patients. This study revealed the unique triggers of OAS in Korea in addition to well-known triggers.

The concordance between component tests and clinical history in British adults with suspected pollen-food syndrome to peanut and hazelnut

BACKGROUND

Mild oropharyngeal symptoms to peanut/hazelnut occur in ~30% of patients with pollen-food syndrome (PFS). Component tests are considered a useful adjunct to the diagnosis and may help differentiate PFS from those at a risk of anaphylaxis due to storage protein/lipid transfer protein (LTP) sensitisation.

AIMS

To assess concordance between component tests and clinical history in suspected PFS to peanut/hazelnut in a specialist clinic.

METHODS

Adult patients were classified into PFS (group 1, n=69) and PFS with mild systemic symptoms (group 2, n=45) based on clinical history. Specific IgE (sIgE) of ≥0.35 kUA/L was considered positive as per manufacturers' recommendation. Kappa (κ) inter-rater agreement was calculated for concordance between clinical classification and test profiles.

RESULTS

Group 1 hazelnut: 85% monosensitised to Cor a1, 12% to storage protein/s or LTP and 3% negative to all components. Group 1 peanut: 41% monosensitised to Ara h8, 44% to storage protein/s or ±LTP and 15% negative to all components. Group 2 hazelnut: 67% monosensitised to Cor a1, 16% sensitised to storage protein/s and 17% negative to all components. Group 2 peanut: 19% monosensitised to Ara h8, 62% sensitised to storage protein/s and/or LTP and 19% negative to all components.SIgE to Ara h8 and Cor a1 were greater in group 1 versus group 2: (median (IQR) kUA/L; hazelnut: 12.1 (7.8-25.2) vs 2.4 (0.36-6.3), p<0.001; peanut: 2.4 (0.10-21.1) vs 0.3 (0-3), p<0.01)).

CONCLUSION

Concordance between component tests and clinical history for adults with PFS was good for hazelnut (κ=0.63) but poor for peanut (κ=-0.12). Food challenges are warranted in discordant cases for an accurate diagnosis.

Multi-morbidities of allergic rhinitis in adults: European Academy of Allergy and Clinical Immunology Task Force Report

This report has been prepared by the European Academy of Allergy and Clinical Immunology Task Force on Allergic Rhinitis (AR) comorbidities. The aim of this multidisciplinary European consensus document is to highlight the role of multimorbidities in the definition, classification, mechanisms, recommendations for diagnosis and treatment of AR, and to define the needs in this neglected area by a literature review. AR is a systemic allergic disease and is generally associated with numerous multi-morbid disorders, including asthma, eczema, food allergies, eosinophilic oesophagitis (EoE), conjunctivitis, chronic middle ear effusions, rhinosinusitis, adenoid hypertrophy, olfaction disorders, obstructive sleep apnea, disordered sleep and consequent behavioural and educational effects. This report provides up-to-date usable information to: (1) improve the knowledge and skills of allergists, so as to ultimately improve the overall quality of patient care; (2) to increase interest in this area; and (3) to present a unique contribution to the field of upper inflammatory disease.

Exploratory analysis of CD63 and CD203c expression in basophils from hazelnut sensitized and allergic individuals

Background

Sensitization to hazelnut (HN) is frequent and requires clarification to determine whether this sensitization is clinically relevant. The aim of this study was to investigate basophil activation profiles in HN-sensitized and allergic subjects.

Methods

Basophil activation was determined by flow cytometric analyses of CD63 and CD203c expression using several HN allergen concentrations. Depending on their clinical reaction pattern, an oral allergy symptom group (OAS, n = 20), a systemic reaction group (n = 12) and a sensitized group without clinical symptoms (n = 20) were identified. Additionally, 10 non-allergic and non-sensitized individuals served as controls.

Results

CD63 and CD203c expression differed between allergic (OAS and systemic group) and sensitized subjects. The HN concentration required to activate 30% of CD203c⁺ basophils [effective concentration (EC)30] was significantly higher in sensitized versus the allergic group (p = 0.0089). This was more pronounced when the basophil allergen threshold sensitivity (CD-sens) was calculated (CD63: p = 0.018; CD203c: p = 0.009).

Conclusion

Our data indicate that the basophil activation test may provide information to better distinguish between sensitized and allergic subjects if several allergen concentrations are considered. CD203c expression displayed a better discrimination compared to CD63; therefore, its diagnostic value might be superior compared with CD63.

Electronic supplementary material

The online version of this article (doi:10.1186/s13601-016-0134-7) contains supplementary material, which is available to authorized users.

Endotypes of pollen-food syndrome in children with seasonal allergic rhinoconjunctivitis: a molecular classification

BACKGROUND

Pollen-food syndrome (PFS) is heterogeneous with regard to triggers, severity, natural history, comorbidities, and response to treatment. Our study aimed to classify different endotypes of PFS based on IgE sensitization to panallergens.

METHODS

We examined 1271 Italian children (age 4-18 years) with seasonal allergic rhinoconjunctivitis (SAR). Foods triggering PFS were acquired by questionnaire. Skin prick tests were performed with commercial pollen extracts. IgE to panallergens Phl p 12 (profilin), Bet v 1 (PR-10), and Pru p 3 (nsLTP) were tested by ImmunoCAP FEIA. An unsupervised hierarchical agglomerative clustering method was applied within PFS population.

RESULTS

PFS was observed in 300/1271 children (24%). Cluster analysis identified five PFS endotypes linked to panallergen IgE sensitization: (i) cosensitization to ≥2 panallergens ('multi-panallergen PFS'); (ii-iv) sensitization to either profilin, or nsLTP, or PR-10 ('mono-panallergen PFS'); (v) no sensitization to panallergens ('no-panallergen PFS'). These endotypes showed peculiar characteristics: (i) 'multi-panallergen PFS': severe disease with frequent allergic comorbidities and multiple offending foods; (ii) 'profilin PFS': oral allergy syndrome (OAS) triggered by Cucurbitaceae; (iii) 'LTP PFS': living in Southern Italy, OAS triggered by hazelnut and peanut; (iv) 'PR-10 PFS': OAS triggered by Rosaceae; and (v) 'no-panallergen PFS': mild disease and OAS triggered by kiwifruit.

CONCLUSIONS

In a Mediterranean country characterized by multiple pollen exposures, PFS is a complex and frequent complication of childhood SAR, with five distinct endotypes marked by peculiar profiles of IgE sensitization to panallergens. Prospective studies in cohorts of patients with PFS are now required to test whether this novel classification may be useful for diagnostic and therapeutic purposes in the clinical practice.

Pollen food syndrome amongst children with seasonal allergic rhinitis attending allergy clinic

BACKGROUND

There is limited information regarding the onset and sensitization patterns of pollen food syndrome (PFS) in children. The aim was to explore this within children referred to a specialist allergy clinic at a London Tertiary Hospital.

METHODS

A total of 54 patients with seasonal allergic rhinitis (SAR) were enrolled in equal numbers in three age groups; 0-5, 6-10, 11-15 years. Families completed a questionnaire on rhinitis, food symptoms and quality of life. Children underwent skin prick testing (SPT) to fresh fruits, nuts and a blood test for microarray analysis.

RESULTS

Clinical diagnosis of PFS was made in 26/54 (48%), increasing with age (group 1 = 3 (17%), group 2 = 9 (50%), group 3 = 14 (78%) (p = 0.03)). Microarray demonstrates children aged 2.8 years sensitized to pan-allergens and 4.5 years symptomatic to pan-allergens. Peach, cherry, carrot and strawberry SPT had the highest sensitivity and NPV at 100%. The sensitivity of PR10 molecules on microarray was 92%, PPV 62% and NPV 87%. Microarray confirmed 69% of allergens on clinical history compared to 61% by SPT. Microarray and SPT had a 19% false-negative rate. The quality-of-life data showed moderate impact across all domains, and patients with PFS were significantly more likely to have increased anxiety over time spent preparing food (p = 0.029).

CONCLUSIONS

We demonstrate that SAR occurs in children from 1.4 years and PFS from 4.5 years with a changing pattern of pan-allergen sensitization. Microarray and SPT have moderate concordance in confirming allergens. PFS impacts negatively on quality of life and should be assessed in all paediatric allergy patients.

The development of a standardised diet history tool to support the diagnosis of food allergy

The disparity between reported and diagnosed food allergy makes robust diagnosis imperative. The allergy-focussed history is an important starting point, but published literature on its efficacy is sparse. Using a structured approach to connect symptoms, suspected foods and dietary intake, a multi-disciplinary task force of the European Academy of Allergy and Clinical Immunology developed paediatric and adult diet history tools. Both tools are divided into stages using traffic light labelling (red, amber and green). The red stage requires the practitioner to gather relevant information on symptoms, atopic history, food triggers, foods eaten and nutritional issues. The amber stage facilitates interpretation of the responses to the red-stage questions, thus enabling the practitioner to prepare to move forward. The final green stage provides a summary template and test algorithm to support continuation down the diagnostic pathway. These tools will provide a standardised, practical approach to support food allergy diagnosis, ensuring that all relevant information is captured and interpreted in a robust manner. Future work is required to validate their use in diverse age groups, disease entities and in different countries, in order to account for differences in health care systems, food availability and dietary norms.

IgE, IgG4 and IgA specific to Bet v 1-related food allergens do not predict oral allergy syndrome

BACKGROUND

Birch pollen-associated plant food allergy is caused by Bet v 1-specific IgE, but presence of cross-reactive IgE to related allergens does not predict food allergy. The role of other immunoglobulin isotypes in the birch pollen-plant food syndrome has not been investigated in detail.

METHODS

Bet v 1-sensitized birch pollen-allergic patients (n = 35) were diagnosed for food allergy by standardized interviews, skin prick tests, prick-to-prick tests and ImmunoCAP. Concentrations of allergen-specific IgE, IgG1, IgG4 and IgA to seven Bet v 1-related food allergens were determined by ELISA.

RESULTS

Bet v 1, Cor a 1, Mal d 1 and Pru p 1 bound IgE from all and IgG4 and IgA from the majority of sera. Immunoglobulins to Gly m 4, Vig r 1 and Api g 1.01 were detected in <65% of the sera. No significant correlation was observed between plant food allergy and increased or reduced levels of IgE, IgG1, IgG4 or IgA specific to most Bet v 1-related allergens. Api g 1-specific IgE was significantly (P = 0.01) elevated in celeriac-allergic compared with celeriac-tolerant patients. Likewise, frequencies of IgE (71% vs 15%; P = 0.01) and IgA (86% vs 38%; P = 0.04) binding to Api g 1.01 were increased.

CONCLUSION

Measurements of allergen-specific immunoglobulins are not suitable for diagnosing Bet v 1-mediated plant food allergy to hazelnut and Rosaceae fruits. In contrast, IgE and IgA to the distantly related allergen Api g 1 correlate with allergy to celeriac.

Review article: the diagnosis and management of food allergy and food intolerances

BACKGROUND

Adverse reactions to food include immune mediated food allergies and non-immune mediated food intolerances. Food allergies and intolerances are often confused by health professionals, patients and the public.

AIM

To critically review the data relating to diagnosis and management of food allergy and food intolerance in adults and children.

METHODS

MEDLINE, EMBASE and the Cochrane Database were searched up until May 2014, using search terms related to food allergy and intolerance.

RESULTS

An estimated one-fifth of the population believe that they have adverse reactions to food. Estimates of true IgE-mediated food allergy vary, but in some countries it may be as prevalent as 4-7% of preschool children. The most common food allergens are cow's milk, egg, peanut, tree nuts, soy, shellfish and finned fish. Reactions vary from urticaria to anaphylaxis and death. Tolerance for many foods including milk and egg develops with age, but is far less likely with peanut allergy. Estimates of IgE-mediated food allergy in adults are closer to 1-2%. Non-IgE-mediated food allergies such as Food Protein-Induced Enterocolitis Syndrome are rarer and predominantly recognised in childhood. Eosinophilic gastrointestinal disorders including eosinophilic oesophagitis are mixed IgE- and non-IgE-mediated food allergic conditions, and are improved by dietary exclusions. By contrast food intolerances are nonspecific, and the resultant symptoms resemble other common medically unexplained complaints, often overlapping with symptoms found in functional disorders such as irritable bowel syndrome. Improved dietary treatments for the irritable bowel syndrome have recently been described.

CONCLUSIONS

Food allergies are more common in children, can be life-threatening and are distinct from food intolerances. Food intolerances may pose little risk but since functional disorders are so prevalent, greater efforts to understand adverse effects of foods in functional disorders are warranted.

Intestinal allergic inflammation in birch pollen allergic patients in relation to pollen season, IgE sensitization profile and gastrointestinal symptoms

BACKGROUND

Birch pollen allergic patients frequently experience gastrointestinal upset accompanied by a local allergic inflammation in the small intestine especially during the pollen season. However, it is not known if the GI pathology is connected to the subjective symptoms of the patient. The objective of this study was to evaluate the immune pathology of the duodenal mucosa and the serum IgE antibody profiles in birch pollen allergic patients in relation to their gastrointestinal symptoms, during and outside the birch pollen season.

METHODS

Thirty-two patients with birch pollen allergy and sixteen healthy controls were enrolled in the study. Twenty allergic patients had gastrointestinal symptoms and twelve did not. All participants underwent an allergy investigation and gastroscopy with duodenal biopsy. The duodenal biopsies were retrieved during the pollen season (May-June) and off-season (November-March). The biopsies were immunostained for mast cells (IgE and tryptase), eosinophils, T cells (CD3), and dendritic cells (CD11c). Pollen-specific IgE antibodies were determined by ImmunoCAP and component microarray (ISAC).

RESULTS

Patients in both pollen allergic groups showed similar degree of intestinal allergic inflammation during the pollen season regardless of gastrointestinal symptoms. The eosinophils, mast cells and dendritic cells were increased in the mucosa. Patients with gastrointestinal symptoms had significantly elevated IgE antibodies to birch (rBet v 1), hazelnut (rCor a 1), and apple (rMal d1) during the pollen season.

CONCLUSIONS

Patients allergic to birch pollen have clear signs of an ongoing allergic inflammation in their intestinal mucosa, which is aggravated during the pollen season. The magnitude of the allergic intestinal inflammation is not associated with subjective gastrointestinal symptoms of the individual patient.

Imbalance of serum IL-10 and TGF-β in patients with pollen food syndrome

BACKGROUND

Pollen food syndrome is one of the main causes of food allergies in adults. However, the intrinsic immunological mechanisms remain unclear.

METHODS

Forty pollinosis sufferers [23 with a food allergy (PSFA) and 17 without a food allergy (PS)] and 17 non-atopic healthy controls were included in this study. The PSFA group was subdivided into an oral allergy syndrome group, a systemic reaction group, and an anaphylactic reaction group according to their symptoms after eating the suspected foods. Serum IL-10 and TGF-β levels of all participants were determined by ELISA. Clinical characteristics of the patients were also evaluated.

RESULTS

There were no significant differences in age, sex, pollen-associated symptoms, duration of respiratory disease, and positive parental history of atopy between the PSFA and PS groups. Compared to healthy controls, serum IL-10 levels of both the PSFA group and PS group were significantly lower (p≤0.01), but TGF β levels were significantly higher in the PSFA group (35.3±5.6ng/ml vs. 31.2±6.6ng/ml, respectively; p=0.037). Within the PSFA group, IL-10 levels in the anaphylactic reaction subgroup were significantly lower compared to oral allergy syndrome subgroup (1.87±0.47pg/ml vs. 1.40±0.30pg/ml, respectively; p=0.027). More severe food allergy symptoms were associated with lower serum IL-10 levels. In contrast, the highest serum levels of TGF-β were found in patients from the anaphylactic reaction subgroup.

CONCLUSIONS

With the exception of a defect in regulatory cells represented by the reduction of IL-10, other potential immunological mechanisms (e.g., Th17 or IL-23 together with TGF-β) may be involved in the development of pollen food syndrome.

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.

Developments in the field of allergy in 2011 through the eyes of Clinical and Experimental Allergy

As in previous years, we felt it would be of value to our readership to summarize the new information provided by the authors who have published in Clinical and Experimental Allergy in 2011 and set this in the context of recent advances in our understanding of the pathogenesis and management of allergic disease in all its many manifestations. In 2011, about 210 articles were published in Clinical and Experimental Allergy including editorials, reviews, opinion articles, guidelines, letters, book reviews and of course at the heart of the journal, papers containing original data. As before, this review is divided into sections based on the way the journal is structured, although this year we have grouped together all the papers dealing with mechanisms of allergic disease, whether they involve patients (clinical mechanisms), pure in vitro studies (basic mechanisms) or animal models (experimental models), as we felt this was a more coherent way to deal with the subject. In the field of asthma and rhinitis, the relationship between airway inflammation and airway dysfunction was of perennial interest to investigators, as were phenotypes and biomarkers. Aspirin hypersensitivity appeared in studies in several papers and there was new interest in asthma in the elderly. The mechanisms involved in allergic disease describe advances in our understanding of T cell responses, the relationship between inflammation and disease, mast cell and basophil activation, steroid resistance and novel therapies. In the section dealing with epidemiology, studies seeking to identify risk factors for allergic disease including vitamin D are prominent, as once again are studies investigating gene-environment interactions. The clinical allergy section focuses on drug allergy, food allergy and immunotherapy. The area of oral immunotherapy for food allergy is well covered and we were grateful to Stephen Durham for guest editing an outstanding special issue on immunotherapy in the centenary year of Leonard Noon's pioneering work. Lastly, in the field of allergens, the interest in component-resolved diagnosis continues to grow and there are also articles describing important novel cultivars and the effect of food processing on the allergenic properties of foods. Another terrific year, full of important and high-quality work,which the journal has been proud to bring to the allergy community.

Innate immunostimulatory properties of allergens and their relevance to food allergy

Food allergy is an increasingly prevalent disease of immune dysregulation directed to a small subset of proteins. Shared structural and functional features of allergens, such as glycosylation, lipid-binding and protease activity may provide insight into the mechanisms involved in the induction of primary Th2 immune responses. We review the literature of innate Th2-type immune activation as a context for better understanding the properties of allergens that contribute to the induction of Th2-biased immune responses in at least a subset of individuals. Th2-priming signals have been largely identified in the context of parasite immunity and wound healing. Some of the features of parasite antigens and the innate immune responses to them are now understood to play a role in allergic inflammation as well. These include both exogenous and endogenous activators of innate immunity and subsequent release of key cytokine mediators such as thymic stromal lymphopoietin (TSLP), interleukin (IL)-25 and IL-33. Moreover, numerous innate immune cells including epithelium, dendritic cells, basophils, innate lymphoid cells and others all interact to shape the adaptive Th2 immune response. Progress toward understanding Th2-inducing innate immune signals more completely may lead to novel strategies for primary prevention and therapy of respiratory and food allergies.