Allergies to fruits and vegetables

Comprehensive Review on Banana Fruit Allergy: Pathogenesis, Diagnosis, Management, and Potential Modification of Allergens through Food Processing

The pulp of the banana fruit is rich in bioactive compounds like dietary fibers, low glycemic carbohydrates, natural sugars, vitamins, minerals and antioxidants. These beneficial compounds are responsible for the proper functioning of immune system and enhance prevention against various deadly diseases like cancer, diabetes and heart diseases. Despite having, positive effects, the fruit are recognized as an important source for causing allergy to 0.6% of people in general population and up to 67 and 46% for people with asthma or atopic dermatitis. Fruit allergy is one of the most common food allergies witnessed worldwide. Banana fruit allergy results from the abnormal immune response to the banana proteins soon after its consumption. Symptoms range from oral allergy syndrome (OAS) to the life-threatening anaphylaxis. IgE reactivity of banana is associated with different proteins of which six proteins have been identified as major allergens, viz., Mus a1 (Profilin-actin binding protein), Mus a 2 (Class 1 chitinase), Mus a 3 (Nonspecific lipid transfer protein), Mus a 4 (Thaumatin like protein), Mus a 5 (Beta 1,3 glucanase) and Mus a 6 (Ascorbate peroxidase). This review focuses on pathogenesis, clinical features, diagnosis, and different food processing methods to mitigate the allergenicity of banana fruit.

Fruit-Induced Anaphylaxis: Clinical Presentation and Management

BACKGROUND

Data are sparse regarding the clinical characteristics and management of fruit-induced anaphylaxis.

OBJECTIVE

To assess clinical characteristics and management of patients with fruit-induced anaphylaxis and determine factors associated with severe reactions and epinephrine use.

METHODS

Over 9 years, children and adults presenting with anaphylaxis to seven emergency departments in four Canadian provinces and patients requiring emergency medical services in Outaouais, Quebec were recruited as part of the Cross-Canada Anaphylaxis Registry. A standardized form documenting symptoms, triggers, and management was collected. Multivariate logistic regression was used to identify factors associated with severe reactions and epinephrine treatment in the pre-hospital setting.

RESULTS

We recruited 250 patients with fruit-induced anaphylaxis, median age 10.2 years (interquartile range, 3.6-23.4 years); 48.8% were male. The most common fruit triggers were kiwi (15.6%), banana (10.8%), and mango (9.2%). Twenty-three patients reported having eczema (9.3%). Epinephrine use was low in both the pre-hospital setting and the emergency department (28.4% and 40.8%, respectively). Severe reactions to fruit were more likely to occur in spring and among those with eczema (adjusted odds ratio [aOR] = 1.12, 95% confidence interval [CI], 1.03-1.23; and 1.17, 95% CI, 1.03-1.34, respectively). Patients with moderate and severe reactions (aOR = 1.23; 95% CI, 1.06-1.43) and those with a known food allergy (aOR = 1.38; 95% CI, 1.24-1.54) were more likely to be treated with epinephrine in the pre-hospital setting.

CONCLUSIONS

Severe anaphylaxis to fruit is more frequent in spring. Cross-reactivity to pollens is a potential explanation that should be evaluated further.

Banana anaphylaxis in Thailand: case series

Background

Banana fruit has been recognized as an important food allergen source. Nowadays banana hypersensitivity had been reported more frequently with various presentations from oral allergy syndrome to anaphylaxis.

Objective

This study aims to describe the pattern of banana hypersensitivity and the sensitivity of diagnostic test.

Methods

Six patients who experienced banana hypersensitivity were recruited from adult allergy clinic, Ramathibodi Hospital, Mahidol University between 2015–2018. Demographic data, pattern of banana allergy consisted of the onset of reaction, symptoms, severity, cross-reactivity to kiwi, avocado, latex including type and amount of banana were collected. Skin test, serum specific IgE to banana and open-label food challenge test had been applied.

Results

All patients experienced multiple episodes of banana anaphylaxis. Regarding the diagnostic investigation, prick-to-prick skin test had higher sensitivity (sensitivity, 100%; 95% confidence interval [CI], 54.07%–100%) than the commercial banana extract (sensitivity, 83.33%; 95% CI, 35.88%–99.58%) and serum specific IgE to banana (sensitivity, 50%; 95% CI, 11.81%–88.19%). The discordance between skin prick test using commercial banana extract and skin test was reported. The cross-reactivity between the species of banana, kiwi, the avocado was documented in all patients. Latex skin prick test and application test were applied with negative results. From the oral food challenge test, a case of banana anaphylaxis patient can tolerate heated banana.

Conclusion

The various phenotypes of banana hypersensitivity were identified. The prick-to-prick test showed the highest sensitivity for diagnosis of banana allergy. However, component resolved diagnostics might be needed for conclusive diagnosis.

Simultaneous detection of fruit allergen-coding genes in tomato, apple, peach and kiwi through multiplex PCR

Fruit allergies have become more common in recent years, and are now a serious health problem. In this study, a multiplex PCR assay was used to detect potential fruit allergens causing food allergy labeling in Korea. For the detection of these allergens, specific primer pairs were designed to amplify the allergen-coding genes Cyclophilin (tomato), Mdtl 1 (apple), Pru p 2.01A (peach) and Pectin methylesterase inhibitor (kiwi), and primer pair targeting the 18S ribosomal RNA gene was additionally used as an endogenous control. Primer specificity was assessed with 23 plant species. A mixture of DNA from the four fruits was serially diluted and used to determine the sensitivity of the multiplex PCR assay, which was approximately 0.08 ng. Eleven commercial fruit products were evaluated to verify the applicability of the multiplex PCR assay. This assay is expected to be a specific and efficient method for detecting fruit allergens in foods.

Subcutaneous Immunotherapy in Patients with Fagales Pollen-Induced Oral Allergy Syndrome

Oral allergy syndrome (OAS) is the most common food allergy-related condition in adults. This study aimed to investigate whether subcutaneous immunotherapy (SCIT) with Fagales pollen-containing extracts can improve the clinical symptoms of OAS in Korea. In total, 56 OAS patients were included: 19 subjects treated with SCIT, which included Fagales pollen extracts, and 37 not treated with immunotherapy (IT). We reviewed the patients' medical records and administered a telephone questionnaire at one point to assess baseline OAS features and changes in the patients' OAS and allergic rhinoconjunctivitis (ARC) symptoms after treatment. Only 12 patients who received SCIT and 15 patients that did not receive SCIT could report on changes in OAS symptoms after treatment because the other patients practiced strict avoidance of their culprit fruits and vegetables, and they could not respond to the status of OAS. SCIT reduced the severity of OAS (p=0.005). Nine of the 12 patients (75%) that received SCIT reported a more than 50% reduction in OAS symptoms. In contrast, only three of the 15 patients (20%) that did not receive IT reported more than a 50% reduction in OAS symptoms. SCIT also reduced the severity of ARC symptoms (p<0.001). The results indicate that SCIT with Fagales pollen-containing extracts is associated with improved OAS symptoms in Korea.

Food-dependent, exercise-induced anaphylaxis in a patient allergic to peach

Determining the single factor that triggered anaphylactic shock can be challenging. We present an interesting case of a 25-year-old female patient with recurrent anaphylactic reactions developing after eating various foods, particularly in presence of co-factors of allergic reactions. Symptoms occurred after consumption of various kinds of foods - peach, pancakes with cottage cheese and fruit, a meal from a Chinese restaurant - all eaten on other occasions without symptoms. During diagnosis, skin prick tests were negative for all tested allergen extracts (both inhalatory and food) from Allergopharma. Prick by prick tests were positive for the peach - wheal diameter - 6 mm, nectarine - 4 mm (histamine 4 mm, negative control 0 mm). Increased levels of asIgE were found for allergens of peach (0.55 kU/L).Open challenge test with one mid-size peach combined with the physical exercise challenge test was positive. ImmunoCAP ISAC test indicated increased levels of IgE specific for the lipid transfer protein (LTP) for walnut (nJug r 3), peach (Pru p 3), wheat (rTri a 14) and plane tree (rPla a 3). The patient was diagnosed with food-dependent, exercise-induced anaphylaxis associated with an allergy to lipid transport proteins (LTPs).

Type IV chitinase quantification in four different grape cultivars (Vitis vinifera) in northeast of Iran by an indirect sandwich enzyme-linked immunosorbent assay

The incidence of grape (Vitis vinifera) allergy in the northeast of Iran is second to melon allergy. Type IV chitinase is one of the major grape allergens. The current study investigates the level of type IV chitinase in four grape variants for the first time in Khorasan Razavi Province using a highly sensitive sandwich enzyme-linked immunosorbent assay (ELISA). This assay was developed using a polyclonal antibody as a capture antibody and monoclonal antibody as a secondary one. Finally, the amount of type IV chitinase was measured by the validated ELISA test. The sensitivity of the developed sandwich ELISA is 16 ± 0.05 ng/ml, and its mean coefficients of intraday and interday variations are <5% and <15%, respectively. The recovery of the designed ELISA is 64 ± 0.9 %. The assessments showed that the highest level of type IV chitinase was 39.7 ± 2.3 μg/g in Peykani grape, whereas in the Sultana cultivar, it was 1.76 ± 0.1 μg/g. According to the data, the level of type IV chitinase is variable in different cultivars, and hence, it will be helpful for clinicians to recommend a less allergenic variety to the patient.

Sunflower seed allergy

Sunflower seeds are a rare source of allergy, but several cases of occupational allergies to sunflowers have been described. Sunflower allergens on the whole, however, still await precise and systematic description. We present an interesting case of a 40-year-old male patient, admitted to hospital due to shortness of breath and urticaria, both of which appeared shortly after the patient ingested sunflower seeds. Our laryngological examination revealed swelling of the pharynx with retention of saliva and swelling of the mouth and tongue. During diagnostics, 2 months later, we found that skin prick tests were positive to mugwort pollen (12/9 mm), oranges (6/6 mm), egg protein (3/3 mm), and hazelnuts (3/3 mm). A native prick by prick test with sunflower seeds was strongly positive (8/5 mm). Elevated concentrations of specific IgE against weed mix (inc. lenscale, mugwort, ragweed) allergens (1.04 IU/mL), Artemisia vulgaris (1.36 IU/mL), and Artemisia absinthium (0.49 IU/mL) were found. An ImmunoCap ISAC test found an average level of specific IgE against mugwort pollen allergen component Art v 1 - 5,7 ISU-E, indicating an allergy to mugwort pollen and low to medium levels of specific IgE against lipid transfer proteins (LTP) found in walnuts, peanuts, mugwort pollen, and hazelnuts. Through the ISAC inhibition test we proved that sunflower seed allergen extracts contain proteins cross-reactive with patients' IgE specific to Art v 1, Art v 3, and Jug r 3. Based on our results and the clinical pattern of the disease we confirmed that the patient is allergic to mugwort pollen and that he had an anaphylactic reaction as a result of ingesting sunflower seeds. We suspected that hypersensitivity to sunflower LTP and defensin-like proteins, both cross-reactive with mugwort pollen allergens, were the main cause of the patient's anaphylactic reaction.

AllergenOnline: A peer-reviewed, curated allergen database to assess novel food proteins for potential cross-reactivity

SCOPE

Increasingly regulators are demanding evaluation of potential allergenicity of foods prior to marketing. Primary risks are the transfer of allergens or potentially cross-reactive proteins into new foods. AllergenOnline was developed in 2005 as a peer-reviewed bioinformatics platform to evaluate risks of new dietary proteins in genetically modified organisms (GMO) and novel foods.

METHODS AND RESULTS

The process used to identify suspected allergens and evaluate the evidence of allergenicity was refined between 2010 and 2015. Candidate proteins are identified from the NCBI database using keyword searches, the WHO/IUIS nomenclature database and peer reviewed publications. Criteria to classify proteins as allergens are described. Characteristics of the protein, the source and human subjects, test methods and results are evaluated by our expert panel and archived. Food, inhalant, salivary, venom, and contact allergens are included. Users access allergen sequences through links to the NCBI database and relevant references are listed online. Version 16 includes 1956 sequences from 778 taxonomic-protein groups that are accepted with evidence of allergic serum IgE-binding and/or biological activity.

CONCLUSION

AllergenOnline provides a useful peer-reviewed tool for identifying the primary potential risks of allergy for GMOs and novel foods based on criteria described by the Codex Alimentarius Commission (2003).

Proposed new mechanism for food and exercise induced anaphylaxis based on case studies

We present two cases of food and exercise-induced anaphylaxis (FEIA) in patients with a diagnosis of oral allergy syndrome (OAS) to the implicated foods. Patient A had FEIA attributed to fresh coriander and tomato and Patient B to fresh celery. These food allergens have been implicated in OAS and have structural antigenic similarity to that of birch and/or grass. Both patients' allergies were confirmed by fresh skin prick tests. In both cases, strenuous exercise was antecedent to the systemic anaphylaxis reaction and subsequent ingestion without exercise produced only local symptoms of perioral pruritus. We review the current proposed mechanisms for food and exercise induced anaphylaxis to oral allergens and propose a novel and more biologically plausible mechanism. We hypothesize that the inhibitory effects of exercise on gastric acid secretion decreases the digestion of oral allergens and preserves structural integrity, thereby allowing continued systemic absorption of the allergen whether it be profilins, lipid transfer proteins, or other antigenic determinants.

Lipid transfer protein syndrome: clinical pattern, cofactor effect and profile of molecular sensitization to plant-foods and pollens

BACKGROUND

Multiple plant-food sensitizations with a complex pattern of clinical manifestations are a common feature of lipid transfer protein (LTP)-allergic patients. Component-resolved diagnosis permits the diagnosis of the allergen sensitization profile.

OBJECTIVE

We sought to clinically characterize and describe the plant-food and pollen molecular sensitization profile in patients with LTP syndrome.

METHODS

Forty-five subjects were recruited, after being diagnosed with multiple plant-food allergies sensitized to LTP, but not to any other plant-food allergen, according to the molecular allergen panel tested (Pru p 3 (LTP), Pru p 1 (Bet v 1-like), Pru p 4 (profilin) and those included in a commercial microarray of 103 allergenic components). IgE-mediated food-allergy symptoms and pollinosis were collected. Patients were skin prick tested with a plant-food and pollens panel, and specific IgE to Tri a 14 was evaluated.

RESULTS

A heterogeneous group of plant-foods was involved in local and systemic symptoms: oral allergy syndrome (75.6%), urticaria (66.7%), gastrointestinal disorders (55.6%) and anaphylaxis (75.6%), 32.4% of which were cofactor dependent (Non-Steroidal Anti-inflammatory Drugs, exercise). All tested subjects were positive to peach and Pru p 3, Tri a 14 and to some of the LTPs included in the microarray. Pollinosis was diagnosed in 75.6% of subjects, with a broad spectrum of pollen and pollen-allergen sensitization. Plane tree and mugwort were the statistically significant pollens associated with Pru p 3.

CONCLUSIONS AND CLINICAL RELEVANCE

Several plant-foods, taxonomically unrelated, independent of peach involvement, are implicated in LTP syndrome. Local symptoms should be evaluated as a risk marker for anaphylaxis because they are frequently associated with cofactor-dependent anaphylaxis. The association of these symptoms with pollinosis, especially plane tree pollinosis, could be part of this syndrome in our area.

Anaphylaxis and generalized urticaria from eating Chinese bayberry fruit

Chinese bayberry Myrica rubra is a very popular fruit in southeastern China. In spite of its wide consumption, no allergies to this fruit have been reported previously. Here we report on a 40-year-old woman suffering from anaphylaxis to Chinese bayberry fruit. Prick-prick skin tests revealed strong reactions to fresh Chinese bayberry fruits as well as to peach, and weaker reactions to some other fruits including apple, melon, and banana. ImmunoCAP analysis revealed identical titers of specific IgE (4.3 kU(A)/L) to peach extract and its lipid transfer protein (LTP, rPru p 3), which was confirmed by detection of a 9 kD band following immunoblotting. Immunoblot analysis with Chinese bayberry extract gave bands of 22, 45, and 90 kD, but no 9 kD band was recognized. There was also no evidence of LTP recognition for loquat (36 kD) or melon (24 kD). This first report of a severe allergic reaction to Chinese bayberry fruit in a patient with LTP-mediated peach allergy indicates that other as yet unidentified non-pollen related fruit allergens are involved in this new severe fruit allergy.

Detection of Phl p 1, Phl p 5, Phl p 7 and Phl p 12 specific IgE antibodies in the sera of children and adult patients allergic to Phleum pollen

BACKGROUND

Grasses belong to major sources of inhaled allergens. The knowledge of particular molecules responsible for hypersensitivity is of crucial importance for better understanding of individual differences among single allergic subjects and allergic populations living in various world-areas.

METHODS

Specific-IgE-antibodies against Phl p 1, Phl p 5, Phl p 7, Phl p 12 were detected in a group of 130 Phleum-allergic-subjects (82 children, 48 adults).

RESULTS

Phl p 1 antibodies were detected in most pediatric and adult patients, however, the children were associated with higher RAST classes more often. Anti-Phl p 5-antibodies were found more frequently in adults. An increase was observed in the number of pediatric patients reacting to Phl p 7 and Phl p 12. There were no differences in concentrations of specific-IgE against Phl p 5, Phl p 7 and Phl p 12 depending on age. Almost 10% of allergic children produced antibodies directed exclusively against minor allergens or did not produce specific-IgE-antibodies against tested molecules. Part of the patients reacted to profilin and calcium-binding protein originating from only one source (Phl p 12/Bet v 2 and Phl p 7/Bet v 4).

CONCLUSIONS

Antibodies against Phl p 1 and Phl p 5 can be used as a marker of allergy to grasses in adult patients. Children reacted exclusively to minor allergens more frequently than adults. Prolonged allergen exposure is evidently necessary to induce sensitization to Phl p 5. A high level of homology between profilins and calcium-binding proteins enables only one allergen to be used for diagnostic purposes but a possibility of a reaction to species-bound epitopes should be taken into account.

Generation and characterization of anti-chitinase monoclonal antibodies

Class IV chitinase, an allergenic protein of Vitis vinifera (grape), was purified by anion exchange chromatography and used for immunization of Balb/c mice. Monoclonal antibodies (MAbs) were raised by hybridoma technology using Sp2/0 myeloma cells. Finally after three limiting dilutions, six stable clones were generated. Antibody isotyping showed that IgG(2a), IgG(2b), and IgM were produced by one, two, and three of the clones, respectively. All of the MAbs had kappa light chain. The affinities were in the range of 3 × 10(8) to 1.2 × 10(9) M(-1). The MAbs were specific for grape chitinase as confirmed by Western blotting. In conclusion, we successfully produced several MAbs against grape class IV chitinase, which could be used for assessment of this allergen in different grape cultivars.

Airborne pollen of ornamental tree species in the NW of Spain

This study analyzed airborne pollen counts for the tree taxa most widely used for ornamental purposes in the northwestern Iberian Peninsula (Platanus, Cupressaceae, Olea, Myrtaceae, Cedrus, and Casuarina) at four sites (Vigo, Ourense, Santiago, and Lugo), using aerobiological data recorded over a long period (1993-2007). The abundance and the temporal and spatial distribution of these pollen types were analyzed, and the influence of weather-related factors on airborne pollen counts was assessed. Platanus (in Ourense) and Olea (in Vigo) were the taxa contributing most to pollen counts. In general terms, the results may be taken as indicators of potential risk for pollen-allergy sufferers and therefore used in planning future green areas.

Food allergy and oral allergy or pollen-food syndrome

PURPOSE OF REVIEW

This paper reviews current concepts in our understanding of oral allergy or pollen-food syndrome. As technology has improved, much more accurate profiling of food allergic individuals is now possible, resulting in more precise diagnosis, elucidation of cross reactivity patterns and more helpful prediction of risk of anaphylaxis.

RECENT FINDINGS

The identification and characterization of various ubiquitous plant proteins have led to greater understanding of food cross reactive reactions. Newer diagnostic techniques utilizing purified and recombinant allergens are available for more precise diagnosis and clinical profiling of patients presenting with food allergy.

SUMMARY

In-vitro screening of food allergic patients with large panels of allergens will change the accuracy of diagnosis resulting in better management. Allergens are now available for use in the allergist's office to improve diagnostic accuracy of skin tests in patients presenting with plant-food allergy. Knowledge of the specific sensitization of individual patients has consequences for both risk assessment and dietary management.

Component-resolved allergy diagnosis by microarray: potential, pitfalls, and prospects

Diagnosis of IgE-mediated allergies is not always straightforward, as traditional tests can yield equivocal or negative results and provocation tests are hampered by several practical and ethical limitations. During the last decades two new in vitro techniques have entered the field of allergy diagnosis, that is, flow-assisted analysis of allergen-specific activated basophils and component-resolved diagnosis (CRD). This review focuses on component-resolved allergy diagnosis by microarray that has evolved from recent advances in molecular allergology and biochip technology. The technique allows a comprehensive analysis of individual sensitization profiles with multiplexed purified and recombinant allergens within a single run using only a minute amount of serum, providing information that largely exceeds the output from current sIgE capturing tools. Actually, multiplexing allows identification of diagnostic patterns that may facilitate the formulation of diagnostic algorithms. Although CRD by microarray sounds promising, the diagnostic performance requires further intensive assessment before it can enter mainstream application. In our opinion, the technique should currently be considered a complementary diagnostic tool rather than a first-line choice.