Pollen-related Food Allergy Research Articles

The effect of subcutaneous and sublingual birch pollen immunotherapy on birch pollen-related food allergy: a systematic review.

Birch pollen-related food allergy (BPFA) is the most common type of food allergy in birch-endemic areas such as Western and Central Europe. Currently, there is no treatment available for BPFA. Due to the cross-reactivity between birch pollen and a range of implicated plant foods, birch pollen allergen immunotherapy (AIT) may be effective in the treatment of BPFA. In this study, we systematically evaluate the effectiveness of birch pollen-specific subcutaneous or sublingual immunotherapy in treating BPFA. A search was performed in the PubMed, Embase, and Cochrane libraries. Studies were independently screened by two reviewers against predefined eligibility criteria. The outcomes of interest were changes in (1) severity of symptoms during food challenge, (2) eliciting dose (ED), and (3) food allergy quality of life (FA-QoL). The validity of the selected articles was assessed using the revised Cochrane risk of bias tool. We focused on studies with the lowest risk of bias and considered studies with a high risk of bias as supportive. Data were descriptively summarized. Ten studies were selected that included 475 patients in total. Seven studies were categorized into "high risk of bias" and three into "moderate risk of bias." The three moderate risk of bias studies, with a total of 98 patients, reported on severity of symptoms during challenge and on the ED. All three studies had a control group. Compared to the control group, improvement in severity of symptoms was observed during challenge in two out of the three studies and on the eliciting dose in one out of three. Only one study investigated the effect of birch pollen AIT on FA-QoL, showing that there was no significant difference between patients receiving subcutaneous immunotherapy or a placebo. Of the seven supportive studies, four had a control group and of those, three showed improvement on both severity of symptoms and ED. None of the supportive studies investigated the effect of the therapy on FA-QoL. This systematic review shows that there is not enough evidence to draw firm conclusions about the effect of AIT on BPFA. Future research is warranted that uses robust clinical studies that include long-term effects, QoL, and multiple BPFA-related foods.

Assessment of Co-Sensitization between Pollen and Food Allergen Sources among Bengali Population, West Bengal, India

Introduction: Secondary food allergies due to cross-reactivity between pollen and food allergens are a significant health burden in India. Prevalence of cross-reactivity varies by region, and particularly in West Bengal, it remains unexplored. The present study investigated sensitivities of pollen-related food allergy (PFA) patients of West Bengal by empirically determining co-sensitization patterns. Methods: The present study retrospectively analysed 1,310 pollen-allergic (PA) patients from the Allergy and Asthma Research Centre, West Bengal. A questionnaire survey was performed to record patients’ demographic and clinical features and categorized into seasonal and perennial ones. All patients were subjected to the skin prick test and specific IgE for evaluation of sensitivity against 16 pollen and 16 food allergens. Co-relation and principal component analysis (PCA) was performed to determine co-sensitivity. Results: Seasonal allergic patients were comparatively higher than perennial ones. PFA patients were mostly sensitive to eggplant (n = 387), while Azadirachta indica (n = 341) was predominant sensitizer among pollen allergen sources. Cynodon dactylon showed maximum significant positive correlation with banana, orange, peanut, pineapple, cucumber, eggplant, potato, tomato, and wheat. In the seasonal group, Cynodon dactylon-specific IgE in PFA patients (median = 4.60 kU/L) was significantly higher from that of PA ones (median = 3.44 kU/L). Among 32 allergens tested, 27 were placed in first two dimensions of the PCA biplot. Conclusion: The present study established that co-sensitivity between pollen and food allergen sources were predominant in allergic patients of West Bengal. The co-sensitization patterns among unrelated allergen sources may be due to possible expression of biologic cross-reactivity to similar allergens.

Birch Pollen Allergens.

Birch belongs to the order Fagales and the family Betulaceae. Birch pollen is one of the most important airborne inhaled allergens in the north temperate zone, leading to allergic rhinitis, asthma and pollen-related food allergy. The sensitization rate to birch pollen is about 8-16% in the general population and 7-57% in patients seen at various allergy centers. Seven birch pollen allergens have been recognized by the International Allergen Nomenclature Sub-committee, with Bet v 1 as the sole major allergen. Component-resolved diagnostics can help to discriminate broad cross-reactivity and false-positive diagnoses of pollen allergy caused by specific IgE to pan-allergens such as Bet v 2, 4 or Bet v 7 from true birch allergy represented by the major allergen Bet v 1-specific IgE. Patients with allergic symptoms to birch pollen showed significantly higher serum anti-Bet v 1 IgE concentrations than asymptomatic individuals with birch sensitization. A higher level of IgE to Bet v 1 also predicted oral allergy syndrome after the ingestion of Rosaceae fruits, nuts, or Apiaceae vegetables, which have cross-reactive homologous allergens with birch allergens. Bet v 1 is one of the first allergens developed using recombinant technology. Many forms of genetically modified Bet v 1 hypo-allergens have been developed and have shown benefit in animal models or even clinical trials of allergen immunotherapy.

Microarray Analysis Confirms ImmunoCAP-Fluorescence Enzyme Immunoassay Results on Specific IgE in Patients with Atopic Dermatitis and Suspected Birch Pollen-Related Food Allergy

Background: Previous studies demonstrated that birch pollen-related foods can cause late eczematous responses in birch pollen-sensitized patients with atopic dermatitis (AD). However, suitable markers to predict birch pollen-related food allergy in patients with AD are still lacking. Objective: We evaluated the correlation of the results from ImmunoCAP® fluorescence enzyme immunoassay (FEIA) singleplex and ImmunoCAP® immuno solid-phase allergen chip (ISAC) multiplex system in AD patients and investigated the diagnostic validity of allergen microarray analysis, measuring specific IgE (sIgE) with ImmunoCAP® ISAC to predict birch pollen-related food allergy in patients with AD. Methods: A total of 19 children and adults with AD, existing IgE-mediated birch pollen sensitization, and suspected birch pollen-related food allergy underwent a double-blind placebo-controlled food challenge (DBPCFC) in the clinical routine. Total and sIgE levels to birch pollen, Bet v 1, Bet v 2, and birch pollen-related foods (apple, carrot, celery, and hazelnut) were determined prior to the DBPCFC by ImmunoCAP®-FEIA. Additionally, allergen microarray ImmunoCAP® ISAC analysis was performed. Data were analyzed retrospectively. Results: Twelve out of 19 patients (63% responders) experienced an allergic reaction upon DBPCFC. Overall, 7 patients (37%) developed a significant deterioration of AD with a median increase of 12.4 points in the scoring of atopic dermatitis (SCORAD) index (range 10.0–15.7). Oral allergy syndrome was the predominant immediate-type symptom (n = 11/12 responders). There were no differences in sensitization frequencies regarding allergens of the pathogenesis-related protein family 10 between responders and non-responders. In all patients, correlation of IgE levels determined with ImmunoCAP® ISAC and ImmunoCAP®-FEIA, respectively, was significant with high correlation coefficients regarding birch pollen allergen extract, rBet v 1, and rBet v 2 (r_s > 0.8, p < 0.001) and lower but also significant correlation coefficients regarding food allergens (r_s < 0.8, p < 0.05–<0.001). Conclusion: ImmunoCAP® ISAC microarray allows displaying a differentiated sensitization profile in birch pollen-sensitized patients with AD. However, IgE-mediated sensitization against birch pollen-related allergens revealed by the allergen multiplex system does not predict late eczematous reactions upon DBPCFC with birch pollen-related foods.

NMR resonance assignments of the PR-10 allergens Act c 8 and Act d 8 from golden and green kiwifruit

Kiwifruits have become one of the most common food sources triggering allergic reactions. In patients suffering from birch pollen related food allergy, reactions result from initial sensitization to the birch (Betula verrucosa) pollen allergen Bet v 1, followed by immunological cross-reactivity to structurally homologous proteins in kiwifruit. Clinical symptoms range from scratching and itching of the oral cavity to more severe immunological reactions such as rhino conjunctivitis. In this work we assigned backbone and side chain 1H, 13C and 15N chemical shifts of the 17 kDa PR-10 allergens Act c 8.0101 and Act d 8.0101 from golden (Actinidia chinesis) and green (Actinidia deliciosa) kiwifruit by solution NMR spectroscopy. The chemical shift data confirm the characteristic Bet v 1 fold for both proteins, consisting of a seven-stranded antiparallel β-sheet interrupted by two short α-helices, along with a long C-terminal α-helix. Our data provide the basis for determining the three-dimensional solution structures of these proteins and characterizing their immunological cross-reactivity on a structural basis.

Oral birch pollen immunotherapy with apples: Results of a phase II clinical pilot study

BackgroundSeventy percent of patients suffering from birch pollen allergy (BPA) develop a pollen‐related food allergy (prFA), especially to apples, due to a clinically relevant cross‐reactivity between the major allergen in birch Bet v 1 and Mal d 1 in apples. Therefore allergen‐specific immunotherapy with fresh apples (AITA) could be a promising natural treatment of both BPA and prFA.ObjectiveTo assess the clinical efficacy of immunotherapy by daily apple consumption for patients with BPA and prFA.MethodsA daily defined increasing amount of selected cultivars (Red Moon®, Pink Lady®, Topaz, Golden Delicious) was continuously consumed by 16 patients (12 female; median age; 50; range, 23–68 years), leading to increased intake of allergen over a period of at least 8 months. Specific IgE and IgG4 to Bet v 1 and Mal d 1, conjunctival and oral provocation tests, skin reactivity, and the average daily rhinoconjunctivitis combined symptom and medication score (CSMS) were measured during the peak birch pollen season.ResultsAfter 8 months of therapy, patients showed increased tolerance to apples (p < .001) and a decreased skin reactivity to apples. Oral allergy syndrome to other birch prFA than apple also decreased (p < .05). Moreover, daily rhinoconjunctivitis CSMS declined by 34% (p < .001), as did conjunctival reactivity to birch pollen extract by 27% (p < .01), while specific IgG4 to Mal d 1 and Bet v 1 increased (p < .01).

Pollen-related food allergy in children with seasonal allergic rhinitis.

IntroductionSeasonal allergic rhinitis (SAR) and bronchial asthma are typical manifestations of pollen-food sensitization in adults. There is limited information regarding the sensitization patterns of pollen-food allergy in children.AimTo evaluate the prevalence of SAR in children with pollen-food sensitization and assess the impact of food allergens on nasal symptoms.Material and methodsForty-three children with pollen-food sensitization aged 2–14 years were evaluated for evidence of SAR. The inclusion criteria was IgE-mediated sensitization to pollen and homologous food allergens. The control group consisted of 19 children with SAR caused by pollen without sensitization to homologous food allergens.ResultsAllergic rhinitis was the main symptom in 65.1% of children; in 25.6% an association between ingestion of pollen-related foods and nasal symptoms was observed. The simultaneous sensitization to animal origin food allergens was stated in 63.3% of children with SAR. In 25.6% anaphylactic reactions to foods were registered. 37.2% of children were asymptomatic to pollen origin foods despite pollen-food sensitization. The statistically significant differences between values were noticed in comparison to the control group.ConclusionsAllergic rhinitis is a common manifestation of pollen-food sensitization in children and this type of immunological hyperreactivity should be taken into account regardless of age. The lack of association of symptoms with plant origin foods in the majority of cases and the asymptomatic course of food sensitization in more than one third of patients indicates the need for follow-up and being careful in routine recommending the avoidance diet.

Characteristics of pollen-related food allergy based on individual pollen allergy profiles in the Chinese population

BackgroundPatients with pollinosis are often multi-sensitized to diverse pollen allergens. However, little is known about pollen allergy types among Chinese pollinosis patients. This study is aimed to characterize clinical manifestations of food allergy among patients with different types of pollen allergy. MethodsWe retrospectively analyzed 402 pollinosis patients from an outpatient allergy department of the Peking Union Medical College Hospital who had been diagnosed by experienced allergists. All included patients who answered a questionnaire regarding seasonal pollinosis and clinical symptoms after ingestion of food and underwent intradermal skin tests. Total IgE and specific IgE levels were quantified by ImmunoCAP, using 0.35 kUA/L as a threshold for positivity. ResultsThe patients were divided into 3 groups, based on the season during which they experienced symptoms and the 2 peaks of Chinese airborne pollen: spring-tree pollen symptoms group (SG), autumn-weed pollen symptoms group (AG), and a combined spring and autumn pollen symptoms group (CG). Birch pollen (83%) and ash pollen (74%) were common allergens among patients with spring symptoms, while mugwort pollen (87%) was a common allergen among patients with autumn symptoms. In total, 30% of the study population experienced pollen-related food allergy. Pollen-related food allergies were more prevalent among the single-season symptom groups (68% and 50% for the SG and AG, respectively) than among the CG (20%). All patients with pollen-related food-induced anaphylaxis exhibited autumn weed pollen symptoms. Except for 2 patients, all patients with food-induced anaphylaxis were allergic to mugwort pollen. In the SG, all patients with food allergy were sensitive to birch pollen, with birch and Bet v 1-specific IgE levels higher in this group than in the group without food allergy (p < 0.001). In the AG, Art v 3 was more prevalent among patients with pollen-related food allergy than without food allergy (79% vs. 33%, p < 0.001), a proportion similar to the one in the CG (67% vs. 48%, p = 0.01). Meanwhile, the Art v 3-specific IgE levels among patients with pollen-related food allergy were higher than among tolerant patients in the AG (p < 0.001) and CG (p = 0.02). Unexpectedly, the Art v 3-specific IgE levels were higher in patients with food-induced anaphylaxis than with oral allergy syndrome only in the CG. ConclusionsBet v 1 (a Pathogenesis-related 10 protein) and Art v 3 (a non-specific lipid transfer protein; nsLTP) are candidate molecular biomarkers for the diagnosis of food allergies in patients with season-specific pollen-related allergies. Measuring pollen allergen component-specific IgE levels might be an effective tool for the management of pollinosis in clinical practice in China.

IgE-blocking antibodies following SLIT with recombinant Mal d 1 accord with improved apple allergy

We recently reported that 16 weeks of sublingual immunotherapy (SLIT) with recombinant (r) Mal d 1, but not rBet v 1, significantly improved birch pollen-related apple allergy. Allergen-specific IgE-blocking IgG antibodies have been associated with clinical efficacy. We compared the quantity, quality, and IgE-blocking bioactivity of SLIT-induced Mal d 1-specific IgG antibodies in both treatment groups. Pre- and post-SLIT sera were assessed for rMal d 1-specific IgG antibodies in ELISA and for their ability to inhibit apple allergen-induced upregulation of CD63 on basophils from nontreated individuals with birch pollen-related apple allergy. Post-SLIT sera depleted of IgG1 or IgG4 were compared for their IgE-blocking activity. IgG1 binding to rMal d 1 was competed with rMal d 1 and rBet v 1 in ELISA. SLIT with rMal d 1 and rBet v 1 induced comparable levels of rMal d 1-specific IgG1, IgG2, IgG3, and IgG4 antibodies. Only post-rMal d 1 SLIT sera displayed IgE-blocking activity, which was significantly reduced by depletion of IgG1 and less so by IgG4 depletion. In competition ELISA, IgG1 binding to Mal d 1 in post-rMal d 1 SLIT sera was fully inhibited with rMal d 1 but not with rBet v 1. Correspondingly, Bet v 1 was the more potent competitor for IgG1 binding to Mal d 1 in post-rBet v 1 SLIT sera. rMal d 1 SLIT for 16 weeks induced functional, primarily Mal d 1-specific IgE-blocking antibodies, whereas rBet v 1 SLIT induced Bet v 1-specific, Mal d 1-cross-reactive IgG antibodies with limited cross-blocking activity. These results provide a possible explanation for the limited effectiveness of birch pollen immunotherapy in birch pollen-related food allergy and indicate a dominant protective role of functional IgE-blocking IgG1 antibodies in the early phase of allergy treatment.

Allergen-specific immunotherapy with apples: selected cultivars could be a promising tool for birch pollen allergy.

BackgroundMost birch pollen‐allergic patients develop allergic cross‐reactions to the major allergen found in apples Mal d1, known as pollen‐related food allergy (prFA). This is due to a strong clinically relevant homology between the major allergen in birch Bet v 1 and Mal d 1. Daily apple consumption induces oral tolerance in prFA, but its effect on the inhalational allergy has not been investigated.ObjectivesAs continuous apple consumption might also mitigate the inhalational allergy, this study aimed to uncover apple cultivars suitable for treatment of birch pollen rhinoconjunctivitis and apple allergy in a controlled and established dosage.MethodsPatients (n = 52) with birch pollen allergy and prFA to apples were subjected to a prick‐to‐prick test (SPT) with 23 cultivars (red‐fleshed, old traditional and new commercial). By SPT, the apple parts flesh, peel equatorial and peel apical near the stalk were compared for their reactivity. One apple cultivar of each allergenicity class (low, middle and high) was subsequently tested in an oral provocation test (OPT).ResultsAccording to the SPTs, we provide a ranking of all 23 cultivars. Red‐fleshed apples displayed the lowest reactivity, followed by old and new cultivars. Four cultivars showed disagreement from their allergenicity class: Santana and Pink Lady®, new cultivars that provoked only low to moderate. In contrast, White Rosemary and Goldparmäne, two old cultivars, induced strong reactions. Skin reactivity increased from flesh to peel to stalk, and SPT results could predict the severity of prFA of each allergenicity class.ConclusionsHerein, we propose a treatment protocol for allergen immunotherapy to birch pollen and prFA with daily apple consumption. Red‐fleshed, old and the new cultivars Santana and Pink Lady® provoke less allergic reactions and are suitable for initial induction. After a controlled and well‐tolerated increase of intake, also moderate and finally high allergenic apple cultivars should be integrated into treatment of birch pollen allergenic patients.

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

BackgroundAlthough 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.MethodThe 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.ResultsNone 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.ConclusionNative 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.

The Occurrence of Food Hypersensitivity Reactions and the Relation to the Sensitization to Grass and Trees in Atopic Dermatitis Patients 14 Years of Age and Older.

Background:Although epidemiologic data are scarce, there is no doubt that the increase in pollen allergies is going to be followed by an increase in the so-called pollen-related food allergies. The aim of this study was the evaluation of the food hypersensitivity reactions in atopic dermatitis patients and the relation to the sensitization to grass and trees.Methods:The complete dermatological and allergological examinations were performed in all included patients; the occurrence of food hypersensitivity reactions was recorded and the sensitization to inhalant allergens (grass and trees) was examined (skin prick test, and specific IgE). The statistical evaluation of the relation between the sensitization to these inhalant allergens and the occurrence of food hypersensitivity reactions was performed.Results:A total of 321 patients were included, with an average age of 26.7 years (±9.2 years) and with an average SCORAD of 33.2 (±13.3) points. The significant relation was recorded between the patients suffering from sensitization to grass and the reactions to peanuts, celery and walnuts; another significant relation was demonstrated between the patients suffering from sensitization to trees and reactions to apple, peanuts, and walnuts. In patients suffering from sensitization to grass and trees, the occurrence of food hypersensitivity reactions to tomatoes, kiwi, spices, oranges, capsicum, tangerines, and carrot was higher also, but the relation was not significant.Conclusion:The significant relation was found between the reactions to peanuts and walnuts and sensitization to grass and trees, another significant relation was found between the sensitization to grass and celery and between the sensitization to trees and apple.

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

PurposeLittle 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.MethodsFood-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.ResultsIn 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%).ConclusionsLTPs are major food allergens for mugwort pollen-related food allergy in China, and may contribute to SR.

Clinical utility of basophil activation test in diagnosis and predicting severity of mugwort pollen-related peach allergy

BackgroundCross-reactivity between pollen and plant foods results in low specificity of food-IgE and skin prick testing, which may cause over-diagnosis. A test that can accurately diagnose pollen-related food allergy and identify patients at risk of developing severe reactions is needed. This study evaluates basophil CD63 expression as a biomarker for diagnosis and predicting severity of mugwort pollen-related peach allergy. MethodsBased on their allergic reactions to peach, an oral allergy symptom group (OAS, n ​= ​15), a systemic reaction group (SR, n ​= ​23), a peach-sensitized but tolerant group (PST, n ​= ​21) and a non-peach-sensitized nonallergic group (NSE, n ​= ​10) were identified among mugwort pollen allergic patients. Measurements of specific IgE to peach and its components, and basophil activation test (BAT) were performed. ResultsUpon stimulation with peach extract, BAT in peach-allergic patients (OAS and SR groups) showed a significant dose-dependent upregulation of CD63 compared with PST patients, but showed no difference between SR and OAS groups. BAT to Pru p 3 could discriminate not only between sensitization and clinical allergy, but also between OAS and systemic reactions. BAT to Pru p 3 revealed 92% sensitivity, 95% specificity, 92% positive predictive value, and 92% negative predictive value. Receiver operating characteristic curves showed that BAT to Pru p 3 had the largest area under the curve. ConclusionsIn the diagnosis of mugwort pollen-related peach allergy, BAT to Pru p 3 is superior to testing for IgE specific for peach and its components. Additionally, basophil activation can predict clinical severity.

Allergen immunotherapy for oral allergy syndrome: what is the evidence for efficacy?

Background The vast majority of IgE-mediated food allergies in adults are based on sensitization to pollen and subsequent cross-reactions to structurally related allergens in fruit, vegetables, and spices. The effect of allergen immunotherapy (AIT) against pollen on pollen-related food allergy has not been conclusively elucidated.

Dietary Interventions in Pollen-Related Food Allergy.

In practice, it remains unclear what the best dietary approach is in subjects with pollen-related food allergy (PRFA). Our objective was to evaluate the effect of (1) dietary avoidance advice, (2) oral immunotherapy (OIT), (3) (heat) processing, and (4) consumption of hypoallergenic cultivars on frequency, severity, and eliciting dose of pollen-related food allergic reactions. A systematic search was conducted in PubMed, Embase, and Cochrane. All studies performing an in vivo investigation of one of the four interventions in adults with PRFA were included. Each study was assessed for quality and validity. Available data on frequency, severity, and eliciting dose of allergic reactions were extracted. Ten studies matched the eligibility criteria. No studies were retrieved on dietary avoidance advice. Two studies (N = 92) on apple OIT reported that tolerance was induced in 63% and 81% of subjects. Four studies (total N = 116) focused on heat processing. Heating was found to completely eradicate symptoms in 15–71% of hazelnut allergic and 46% of celery allergic individuals. Four studies (N = 60) comparing low to high allergenic apple cultivars revealed that Santana (and possibly Elise) apples seemed to cause milder reactions than Golden Delicious. In the awareness that overall level of evidence was low, we conclude that OIT, heat processing, and hypoallergenic cultivars may diminish or completely prevent allergic reactions in some but not all subjects with PRFA.

Birch pollen-related foods can cause late eczematous reactions in patients with atopic dermatitis.

Previous studies have indicated that in patients with atopic dermatitis (AD) and birch pollen allergy pollen-related foods are able to cause late eczematous response. However, the relevance of AD worsening by ingestion of birch pollen-related foods is still a matter of debate. The purpose of this retrospective study was to determine how frequently birch pollen-related foods induce a deterioration of eczema. Additionally, the diagnostic value of specific IgE (sIgE) determination was evaluated. A total of 182 children and adults with AD and suspected birch pollen-related food allergy underwent 261 double-blind placebo-controlled food challenges (DBPCFC). Total and sIgE levels were determined prior to DBPCFC. Sixty-five patients developed allergic reactions (responders) upon DBPCFC with birch pollen-related foods (n=103 DBPCFC). Of these, 32 patients exhibited significant deterioration of AD defined as a median increase of 15.4 severity scoring of atopic dermatitis index points (95% CI 12.4-16.3) from baseline making up 37% of all positive reactions. Responders showed significantly higher sIgE levels to birch pollen and apple as well as a higher prevalence of allergic rhinoconjunctivitis compared to nonresponders (P<.05). However, patients with late eczematous response could not be differentiated from those with isolated immediate-type reactions by sIgE levels. In a subpopulation of patients with AD and birch pollen sensitization, related foods should be considered as a trigger for an aggravation of eczema. As sufficient markers for prediction of late eczematous reactions are still lacking, DBPCFC cannot be replaced in diagnosis of birch pollen-related foods in patients with AD. In patients with AD and birch pollen allergy, birch pollen-related foods should be considered as a provocation factor for an aggravation of disease signs and symptoms.

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

BackgroundOral 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.MethodsWe 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.ResultsOf 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.ConclusionOAS 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.

NMR resonance assignments of a hypoallergenic isoform of the major birch pollen allergen Bet v 1

In Northern America and Europe a great number of people are suffering from birch pollen allergy and pollen related food allergies. The trigger for these immunological reactions is the 17.5 kDa major birch pollen allergen Bet v 1, which belongs to the family of PR-10 (pathogenesis-related) proteins. In nature, Bet v 1 occurs as a mixture of various isoforms that possess different immunological properties despite their high sequence identities. Bet v 1.0102 (Bet v 1d), which is investigated here, is a hypoallergenic isoform of Bet v 1 and a potential candidate for allergen-specific immunotherapy. We assigned the backbone and side chain 1H, 13C and 15N resonances of this protein and predicted its secondary structure. The NMR-chemical shift data indicate that Bet v 1.0102 is composed of three α-helices and a seven stranded β-sheet, in agreement with the known structure of the hyperallergenic isoform Bet v 1.0101 (Bet v 1a). Our resonance assignments create the foundation for detailed characterization of the dynamic properties of Bet v 1 isoforms by NMR relaxation measurements.

What Is Oral Allergy Syndrome?

What Is Oral Allergy Syndrome?