Kiwi fruit is a significant allergen and is associated with differing patterns of reactivity in children and adults

The genus Actinidia Lindl. (Actinidiaceae): A comprehensive review on its ethnobotany, phytochemistry, and pharmacological properties

ETHNOPHARMACOLOGICAL RELEVANCE

Actinidia Lindl. belongs to the family Actinidiaceae. Plants of this genus are popularly known as kiwifruits and are traditionally used to treat a wide range of ailments associated with digestive disorders, rheumatism, kidney problems, cardiovascular system, cancers, dyspepsia, hemorrhoids, and diabetes among others.

AIM

This review discusses the ethnobotanical uses, phytochemical profile, and known pharmacological properties of Actinidia plants, to understand their connotations and provide the scientific basis for future studies.

MATERIALS AND METHODS

The data were obtained by surveying journal articles, books, and dissertations using various search engines such as Google Scholar, PubMed, Science Direct, Springer Link, and Web of Science. The online databases; World Flora Online, Plants of the World Online, International Plant Names Index, and Global Biodiversity Information Facility were used to confirm the distribution and validate scientific names of Actinidia plants. The isolated metabolites from these species were illustrated using ChemBio Draw ultra-version 14.0 software.

RESULTS

Ten (10) species of Actinidia genus have been reported as significant sources of traditional medicines utilized to remedy diverse illnesses. Our findings revealed that a total of 873 secondary metabolites belonging to different classes such as terpenoids, phenolic compounds, alcohols, ketones, organic acids, esters, hydrocarbons, and steroids have been isolated from different species of Actinidia. These compounds were mainly related to the exhibited antioxidant, antimicrobial, anti-inflammatory, antidiabetic, antiproliferative, anti-angiogenic, anticinoceptive, anti-tumor, and anticancer activities.

CONCLUSION

This study assessed the information related to the ethnobotanical uses, phytochemical compounds, and pharmacological properties of Actinidia species, which indicate that they possess diverse bioactive metabolites with interesting bioactivities. Actinidia plants have great potential for applications in folklore medicines and pharmaceuticals due to their wide ethnomedicinal uses and biological activities. Traditional uses of several Actinidia species are supported by scientific evidences, qualifying them as possible modern remedies for various ailments. Nonetheless, the currently available data has several gaps in understanding the herbal utilization of most Actinidia species. Thus, further research into their toxicity, mechanisms of actions of the isolated bioactive metabolites, as well as scientific connotations between the traditional medicinal uses and pharmacological properties is required to unravel their efficacy in therapeutic potential for safe clinical application.

Kiwifruit's Allergy in Children: What Do We Know?

Kiwifruit allergy is an emerging pathological condition in both general and pediatric populations with a wide range of symptoms linked to variable molecular patterns, justifying systemic and cross-reactions with other allergens (i.e., latex, pollen, and fruit). Skin prick test (SPT), specific serum IgE (Act d 1, Act d 2, Act d 5, Act d 8, and Act d 10) directed against five out of thirteen molecular allergens described in the literature, and oral test challenge with kiwifruit are available for defining diagnosis. The management is similar to that of other food allergies, mostly based on an elimination diet. Although kiwi allergy has been on the rise in recent years, few studies have evaluated the clinical characteristics and methods of investigating this form of allergy. Data collected so far show severe allergic reaction to be more frequent in children compared to adults. Therefore, the aim of this review is to collect the reported clinical features and the available association with specific molecular patterns of recognition to better understand how to manage these patients and improve daily clinical practice.

Application of Plant Proteases in Meat Tenderization: Recent Trends and Future Prospects

Papain, bromelain, and ficin are commonly used plant proteases used for meat tenderization. Other plant proteases explored for meat tenderization are actinidin, zingibain, and cucumin. The application of plant crude extracts or powders containing higher levels of compounds exerting tenderizing effects is also gaining popularity due to lower cost, improved sensory attributes of meat, and the presence of bioactive compounds exerting additional benefits in addition to tenderization, such as antioxidants and antimicrobial effects. The uncontrolled plant protease action could cause excessive tenderization (mushy texture) and poor quality due to an indiscriminate breakdown of proteins. The higher cost of separation and the purification of enzymes, unstable structure, and poor stability of these enzymes due to autolysis are some major challenges faced by the food industry. The meat industry is targeting the recycling of enzymes and improving their stability and shelf-life by immobilization, encapsulation, protein engineering, medium engineering, and stabilization during tenderization. The present review critically analyzed recent trends and the prospects of the application of plant proteases in meat tenderization.

Food allergy across the globe

The prevalence of food allergy (FA) is increasing in some areas of the globe, highlighting the need for better strategies for prevention, diagnosis, and therapy. In the last few decades, we have made great strides in understanding the causes and mechanisms underlying FAs, prompting guideline updates. Earlier guidelines recommended avoidance of common food allergens during pregnancy and lactation and delaying the introduction of allergenic foods in children aged between 1 and 3 years. Recent guidelines for allergy prevention recommend consumption of a healthy and diverse diet without eliminating or increasing the consumption of allergenic foods during pregnancy or breast-feeding. Early introduction of allergenic foods is recommended by most guidelines for allergy prevention after a period of exclusive breast-feedng (6 months [World Health Organization] or 4 months [European Academy of Allergy and Clinical Immunology]). New diagnostics for FA have been developed with varied availability of these tests in different countries. Finally, the first oral immunotherapy drug for FA was approved by the US Food and Drug Administration and European Medicines Agency in 2020. In this review, we will address the global prevalence of FA, our current understanding of the causes of FA, and the latest guidelines for preventing, diagnosing, and treating FA. We will also discuss similarities and differences between FA guidelines.

A Comprehensive Review on Mustard-Induced Allergy and Implications for Human Health

Mustard is widely used in a variety of foods/food products to enhance the flavor and nutritional value that subsequently raise the risk of hypersensitivity reactions. Mustard allergy has been reported for many years and is increasing gradually especially in the areas where its consumption is comparatively higher, and it may be considered among the most important food allergies. A number of relevant clinical studies focused on mustard-induced allergic manifestations are summarized in the current review. In addition, the knowledge regarding the immunological as well as biochemical characteristics of mustard allergens that have been known till date and their cross-reactivity with other food allergens have also been discussed here. Notably, mustard may also be present as a hidden allergen in foods; therefore, it is important to recognize food products that may contain mustard as it may pose potential risk for the allergic individuals. Additionally, the better understanding of the underlying mechanism in mustard allergy is a prerequisite for the development of specific therapeutic procedures. Conclusively, mustard sensitivity should be routinely tested in patients with idiopathic anaphylaxis for the safety of the allergic patients.

The nutritional and health attributes of kiwifruit: a review

PURPOSE

To describe the nutritional and health attributes of kiwifruit and the benefits relating to improved nutritional status, digestive, immune and metabolic health. The review includes a brief history of green and gold varieties of kiwifruit from an ornamental curiosity from China in the 19th century to a crop of international economic importance in the 21st century; comparative data on their nutritional composition, particularly the high and distinctive amount of vitamin C; and an update on the latest available scientific evidence from well-designed and executed human studies on the multiple beneficial physiological effects. Of particular interest are the digestive benefits for healthy individuals as well as for those with constipation and other gastrointestinal disorders, including symptoms of irritable bowel syndrome. The mechanisms of action behind the gastrointestinal effects, such as changes in faecal (stool) consistency, decrease in transit time and reduction of abdominal discomfort, relate to the water retention capacity of kiwifruit fibre, favourable changes in the human colonic microbial community and primary metabolites, as well as the naturally present proteolytic enzyme actinidin, which aids protein digestion both in the stomach and the small intestine. The effects of kiwifruit on metabolic markers of cardiovascular disease and diabetes are also investigated, including studies on glucose and insulin balance, bodyweight maintenance and energy homeostasis.

CONCLUSIONS

The increased research data and growing consumer awareness of the health benefits of kiwifruit provide logical motivation for their regular consumption as part of a balanced diet. Kiwifruit should be considered as part of a natural and effective dietary strategy to tackle some of the major health and wellness concerns around the world.

High frequency of IgE sensitization towards kiwi seed storage proteins among peanut allergic individuals also reporting allergy to kiwi

Background

IgE sensitization to storage proteins from nuts and seed is often related to severe allergic symptoms. There is a risk of immunological IgE cross-reactivity between storage proteins from different species. The potential clinical implication of such cross-reactivity is that allergens other than the known sensitizer can cause allergic symptoms. Previous studies have suggested that kiwi seed storage proteins may constitute hidden food allergens causing cross-reactive IgE-binding with peanut and other tree nut homologs, thereby mediating a potential risk of causing allergy symptoms among peanut ant tree nut allergic individuals. The objective of this study was to investigate the degree of sensitization towards kiwi fruit seed storage proteins in a cohort of peanut allergic individuals.

Methods

A cohort of 59 adolescents and adults with peanut allergy was studied, and self reported allergies to a number of additional foods were collected. Quantitative IgE measurements to seed storage proteins from kiwi and peanut were performed.

Results

In the cohort, 23 out of the 59 individuals were reporting kiwi fruit allergy (39%). The frequency of IgE sensitization to kiwi fruit and to any kiwi seed storage protein was higher among peanut allergic individuals also reporting kiwi fruit allergy (P = 0.0001 and P = 0.01). A positive relationship was found between IgE levels to 11S globulin (r = 0.65) and 7S globulin (r = 0.48) allergens from kiwi and peanut, but IgE levels to 2S albumin homologs did not correlate. Patients reporting kiwi fruit allergy also reported allergy to hazelnut (P = 0.015), soy (P < 0.0001), pea (P = 0.0002) and almond (P = 0.016) to a higher extent than peanut allergic individuals without kiwi allergy.

Conclusions

Thirty-nine percent of the peanut allergic patients in this cohort also reported kiwi fruit allergy, they displayed a higher degree of sensitization to kiwi storage proteins from both kiwi and peanut, and they also reported a higher extent of allergy to other nuts and legumes. On the molecular level, there was a correlation between IgE levels to 11S and 7S storage proteins from kiwi and peanut. Taken together, reported symptoms and serological findings to kiwi in this cohort of patients with concurrent allergy to peanut and kiwi fruit, could be explained by a combination of cross-reactivity between the 11S and 7S globulins and co-sensitization to the 2S albumin Act d 13.

Is kiwifruit allergy a matter in kiwifruit-cultivating regions? A population-based study

BACKGROUND

Although kiwifruit is known as a common cause of food allergy, population-based studies concerning the prevalence of kiwifruit allergy do not exist. We aimed to determine the prevalence and clinical characteristics of IgE-mediated kiwifruit allergy in 6-18-year-old urban schoolchildren in a region where kiwifruit is widely cultivated.

METHODS

This cross-sectional study recruited 20,800 of the randomly selected 6-18-year-old urban schoolchildren from the Rize city in the eastern Black Sea region of Turkey during 2013. Following a self-administered questionnaire completed by the parents and the child, consenting children were invited for skin prick tests (SPTs) and oral food challenges (OFCs). Children with suspected IgE-mediated kiwifruit were skin prick tested with kiwifruit (commercial allergen and prick-to-prick test with fresh kiwifruit) and a pre-defined panel of allergens (banana, avocado, latex, sesame seed, birch, timothy, hazel, cat, Dermatophagoides pteronyssinus, and Dermatophagoides farinae). All children with a positive SPT to kiwifruit were invited for an open OFC. The prevalence of IgE-mediated kiwifruit allergy was established using open OFCs.

RESULTS

The response rate to the questionnaire was 75.9% (15783/20800). The estimated prevalence of parental-perceived IgE-mediated kiwifruit allergy was 0.5% (72/15783) (95% CI, 0.39-0.61%). Of the 72 children, 52 (72.2%) were skin tested, and 17 (32.7%) were found to be positive to kiwifruit with both commercial extract and kiwifruit. The most frequently reported symptoms in kiwifruit SPT-positive children were cutaneous (n = 10, 58.8%) followed by gastrointestinal (n = 6, 35.3%) and bronchial (n = 4, 23.5%). Oral symptoms were reported in six (35.3%) children. All children who were kiwifruit positive by SPT were found positive during the oral challenge. The confirmed prevalence of IgE-mediated kiwifruit allergy by means of open OFC in 6-18-year-old urban schoolchildren living in Rize city was 0.10% (95% CI, 0.06-0.16).

CONCLUSION

Prevalence of parental-perceived and clinically confirmed kiwifruit allergy is not consistent. In contrast to expectations, kiwifruit allergy prevalence was low in a city where it is cultivated and highly consumed.

Allergenicity assessment strategy for novel food proteins and protein sources

To solve the future food insecurity problem, alternative and sustainable protein sources (e.g. insects, rapeseed, fava bean and algae) are now being explored for the production of food and feed. To approve these novel protein sources for future food a comprehensive risk assessment is needed according to the European food legislation. Allergenicity risk assessment might pose some major difficulties, since detailed guidance on how to assess the allergenic potential of novel foods is not available. At present, the approach relies mostly on the guidance of allergenicity assessment for genetically modified (GM) plant foods. The most recent one was proposed by EFSA (2010 and 2011); "weight-of-evidence approach". However this guidance is difficult to interpret, not completely applicable or validated for novel foods and therefore needs some adjustments. In this paper we propose a conceptual strategy which is based on the "weight-of-evidence approach" for food derived from GM plants and other strategies that were previously published in the literature. This strategy will give more guidance on how to assess the allergenicity of novel food proteins and protein sources.

Kiwifruit Allergy in Children: Characterization of Main Allergens and Patterns of Recognition

Kiwifruit allergy has been described mostly in the adult population, but immunoglobulin (Ig)E-mediated allergic reactions to kiwifruit appear to be occurring more frequently in children. To date, 13 allergens from kiwifruit have been identified. Our aim was to identify kiwifruit allergens in a kiwifruit allergic-pediatric population, describing clinical manifestations and patterns of recognition. Twenty-four children were included. Diagnosis of kiwifruit allergy was based on compatible clinical manifestations and demonstration of specific IgE by skin prick test (SPT) and/or serum-specific IgE determination. SDS-PAGE and immunoblotting were performed with kiwifruit extract, and proteins of interest were further analyzed by mass spectrometry/mass spectrometry. For component-resolved in vitro diagnosis, sera of kiwifruit-allergic patients were analyzed by an allergen microarray assay. Act d 1 and Act d 2 were bound by IgE from 15 of 24 children. Two children with systemic manifestations recognized a protein of 15 kDa, homologous to Act d 5. Act d 1 was the allergen with the highest frequency of recognition on microarray chip, followed by Act d 2 and Act d 8. Kiwifruit allergic children develop systemic reactions most frequently following ingestion compared to adults. Act d 1 and Act d 2 are major allergens in the pediatric age group.

Contact urticaria on eczematous skin by kiwifruit allergy. In vivo component-resolved diagnosis

BACKGROUND

Kiwifruit allergy has been responsible for a variety of clinical manifestations, ranging from mild reactions, such as localised oral symptoms, to severe systemic symptoms, such as anaphylaxis. No cases of isolated contact urticaria (ICU) due to IgE-mediated allergy to kiwifruit have been reported in the literature so far. Here we describe the first three cases of ICU due to kiwi and we hypothesise about a kiwifruit allergen not described yet.

METHODS

Using the available in vivo allergy tests, we performed a component-resolved diagnosis to detect the allergen involved. All the patients underwent prick-by-prick with raw and boiled kiwi pulp and latex glove, skin prick test with commercial extracts of kiwifruit, birch, latex, palm profilin and peach lipid transfer protein, rub test with raw and boiled kiwi and oral food challenges with the raw fruit.

RESULTS

We found that, in our patients, the kiwifruit allergen responsible for ICU is thermolabile, gastrosensitive, and it does not show any of the most common kiwi-attributed cross-reactivity (latex, birch, profiling and lipid transfer protein). None of the 13 kiwifruit allergens already known shows all these features.

CONCLUSIONS

Kiwifruit allergy can also occur with ICU, probably due to a native protein that is not yet identified. In this case the elimination diet is not required.

Food processing and allergenicity

Food processing can have many beneficial effects. However, processing may also alter the allergenic properties of food proteins. A wide variety of processing methods is available and their use depends largely on the food to be processed. In this review the impact of processing (heat and non-heat treatment) on the allergenic potential of proteins, and on the antigenic (IgG-binding) and allergenic (IgE-binding) properties of proteins has been considered. A variety of allergenic foods (peanuts, tree nuts, cows' milk, hens' eggs, soy, wheat and mustard) have been reviewed. The overall conclusion drawn is that processing does not completely abolish the allergenic potential of allergens. Currently, only fermentation and hydrolysis may have potential to reduce allergenicity to such an extent that symptoms will not be elicited, while other methods might be promising but need more data. Literature on the effect of processing on allergenic potential and the ability to induce sensitisation is scarce. This is an important issue since processing may impact on the ability of proteins to cause the acquisition of allergic sensitisation, and the subject should be a focus of future research. Also, there remains a need to develop robust and integrated methods for the risk assessment of food allergenicity.

Molecular characterization of allergens in raw and processed kiwifruit

BACKGROUND

The prevalence of allergy to kiwifruit is increasing in Europe since the last two decades. Different proteins have been identified as kiwifruit allergens; even though with geographic differences, Act d 1, a cysteine protease protein of 30 kDa, and Act d 2, a thaumatin-like protein of 24 kDa, are normally considered the most important. The aim of this study was (i) to identify at molecular level the sensitization pattern in a group of well-characterized patients allergic to kiwifruit and (ii) to assess the role of technological treatments on kiwifruit allergenic potential.

METHODS

The differences in the pattern of antigenicity between fresh and processed kiwifruit were evaluated by both immunoelectrophoretic techniques and clinical tests.

RESULTS

In the group of patients included in this study, three proteins were identified as major allergens in fresh kiwifruit, as the specific sensitization was present in ≥50% of the subjects. These proteins corresponded to actinidin (Act d 1), pectin methyl aldolase (Act d 6), and thaumatin-like protein (Act d 2). Kiwellin (Act d 5) and proteins of Bet v 1 family (Act d 8/act d 11) were also recognized as minor allergens. Immunoreactivity was totally eliminated by industrial treatments used for the production of kiwifruit strained derivative.

CONCLUSIONS

In this group of allergic children, the technological treatments used in the production of kiwifruit strained product reduced drastically the allergenic potential of kiwifruit.

Food hypersensitivity is common in Swedish schoolchildren, especially oral reactions to fruit and gastrointestinal reactions to milk

AIM

This study examined the prevalence, symptom expression and risk factors for food hypersensitivity among Swedish schoolchildren.

METHODS

Parents of 2585 (96% of invited) children aged 7-8 years completed a questionnaire regarding food hypersensitivity and allergic diseases. A random sample of 1700 children (90% of invited) also participated in skin prick testing with ten airborne allergens.

RESULTS

The overall prevalence of reported food hypersensitivity to milk, egg, fish, wheat, soya, fruits and, or, nuts was 21%, with symptoms caused by milk (9%) being the most common. The most frequently reported symptoms were oral symptoms (47.4%), mainly caused by fruit, and gastrointestinal symptoms (45.7%), mainly caused by milk. Factors associated with any food hypersensitivity were female sex, allergic heredity and a positive skin prick test. Eczema was consistently associated with symptoms caused by milk, egg, fish, wheat, soya, fruits and nuts. Rhinitis was associated to the same foods, except milk.

CONCLUSION

Reported food hypersensitivity was common among Swedish schoolchildren. The most frequent symptom expressions were oral symptoms triggered by fruits and gastrointestinal symptoms triggered by milk. The high prevalence of reported symptoms should be validated by clinical examinations to provide a diagnosis.

The effect of kiwifruit (Actinidia deliciosa) cysteine protease actinidin on the occludin tight junction network in T84 intestinal epithelial cells

Actinidin, a kiwifruit cysteine protease, is a marker allergen for genuine sensitization to this food allergen source. Inhalatory cysteine proteases have the capacity for disruption of tight junctions (TJs) enhancing the permeability of the bronchial epithelium. No such properties have been reported for allergenic food proteases so far. The aim was to determine the effect of actinidin on the integrity of T84 monolayers by evaluating its action on the TJ protein occludin. Immunoblot and immunofluorescence were employed for the detection of occludin protein alterations. Gene expression was evaluated by RT-PCR. Breach of occludin network was assessed by measuring transepithelial resistance, blue dextran leakage and passage of allergens from the apical to basolateral compartment. Actinidin exerted direct proteolytic cleavage of occludin; no alteration of occludin gene expression was detected. There was a reduction of occludin staining upon actinidin treatment as a consequence of its degradation and dispersion within the membrane. There was an increase in permeability of the T84 monolayer resulting in reduced transepithelial resistance, blue dextran leakage and passage of allergens actinidin and thaumatin-like protein from the apical to basolateral compartment. Opening of TJs by actinidin may increase intestinal permeability and contribute to the process of sensitization in kiwifruit allergy.

Characterization of the allergenic potential of proteins: an assessment of the kiwifruit allergen actinidin

Assessment of the potential allergenicity (IgE-inducing properties) of novel proteins is an important challenge in the overall safety assessment of foods. Resistance to digestion with pepsin is commonly measured to characterize allergenicity, although the association is not absolute. We have previously shown that specific IgE antibody production induced by systemic [intraperitoneal (i.p.)] exposure of BALB/c strain mice to a range of proteins correlates with allergenic potential for known allergens. The purpose of the present study was to explore further the utility of these approaches using the food allergen, actinidin. Recently, kiwifruit has become an important allergenic foodstuff, coincident with its increased consumption, particularly as a weaning food. The ability of the kiwifruit allergen actinidin to stimulate antibody responses has been compared with the reference allergen ovalbumin, and with the non-allergen bovine haemoglobin. Haemoglobin was rapidly digested by pepsin whereas actinidin was resistant unless subjected to prior chemical reduction (reflecting intracellular digestion conditions). Haemoglobin stimulated detectable IgG antibody production at relatively high doses (10%), but failed to provoke detectable IgE. In contrast, actinidin was both immunogenic and allergenic at relatively low doses (0.25% to 1%). Vigorous IgG and IgG1 antibody and high titre IgE antibody responses were recorded, similar to those provoked by ovalbumin. Thus, actinidin displays a marked ability to provoke IgE, consistent with allergenic potential. These data provide further encouragement that in tandem with analysis of pepsin stability, the induction of IgE after systemic exposure of BALB/c strain mice provides a useful approach for the prospective identification of protein allergens.

Kiwifruit: our daily prescription for health

Kiwifruit are unequalled, compared with other commonly consumed fruit, for their nutrient density, health benefits, and consumer appeal. Research into their health benefits has focussed on the cultivars Actinidia deliciosa 'Hayward' (green kiwifruit) and Actinidia chinensis 'Hort 16A', ZESPRI(®) (gold kiwifruit). Compared with other commonly consumed fruit, both green and gold kiwifruit are exceptionally high in vitamins C, E, K, folate, carotenoids, potassium, fibre, and phytochemicals acting in synergy to achieve multiple health benefits. Kiwifruit, as part of a healthy diet, may increase high-density lipoprotein cholesterol, and decrease triglycerides, platelet aggregation, and elevated blood pressure. Consuming gold kiwifruit with iron-rich meals improves poor iron status, and green kiwifruit aids digestion and laxation. As a rich source of antioxidants, they may protect the body from endogenous oxidative damage. Kiwifruit may support immune function and reduce the incidence and severity of cold or flu-like illness in at-risk groups such as older adults and children. However, kiwifruit are allergenic, and although symptoms in most susceptible individuals are mild, severe reactions have been reported. While many research gaps remain, kiwifruit with their multiple health benefits have the potential to become part of our "daily prescription for health."

Kiwifruit allergies

While kiwifruit has a high nutritive and health value, a small proportion of the world's population appears to be allergic to the fruit. IgE-mediated kiwifruit allergy is often associated with birch and grass pollinosis as well as with latex allergy. Isolated allergy to kiwifruit is also relatively common and often severe. Eleven green kiwifruit (Actinidia deliciosa cv. Hayward) allergens recognized to date are termed as Act d 1 through Act d 11. Bet v 1 homologue (Act d 8) and profilin (Act d 9) are important allergens in polysensitized subjects, whereas actinidin (Act d 1) is important in kiwifruit monosensitized subjects. Differences in allergenicity have been found among kiwifruit cultivars. Allergy sufferers might benefit from the selection and breeding of low-allergenic kiwifruit cultivars.

Differential immunogenicity and allergenicity of native and recombinant human lactoferrins: role of glycosylation

Human native milk lactoferrin (LF) and recombinant forms of lactoferrin (rLF) are available with identical aa sequences, but different glycosylation patterns. Native lactoferrin (NLF) possesses the intrinsic ability to stimulate vigorous IgG and IgE antibody responses in BALB/c mice, whereas recombinant forms (Aspergillus or rice) are 40-fold less immunogenic and 200-fold less allergenic. Such differences are independent of endotoxin or iron content and the glycans do not contribute to epitope formation. A complex glycoprofile is observed for NLF, including sialic acid, fucose, mannose, and Lewis (Le)(x) structures, whereas both rLF species display a simpler glycoprofile rich in mannose. Although Le(x) type sugars play a Th2-type adjuvant role, endogenous expression of Le(x) on NLF did not completely account for the more vigorous IgE responses it provoked. Furthermore, coadminstration of rLF downregulated IgE and upregulated IgG2a antibody responses provoked by NLF, but was without effect on responses to unrelated peanut and chicken egg allergens. These results suggest glycans on rLF impact the induction phase to selectively inhibit IgE responses and that differential glycosylation patterns may impact on antigen uptake, processing and/or presentation, and the balance between Th1 and Th2 responses.

Kiwifruit allergy across Europe: clinical manifestation and IgE recognition patterns to kiwifruit allergens

BACKGROUND

Kiwifruit is a common cause of food allergy. Symptoms range from mild to anaphylactic reactions.

OBJECTIVE

We sought to elucidate geographic differences across Europe regarding clinical patterns and sensitization to kiwifruit allergens. Factors associated with the severity of kiwifruit allergy were identified, and the diagnostic performance of specific kiwifruit allergens was investigated.

METHODS

This study was part of EuroPrevall, a multicenter European study investigating several aspects of food allergy. Three hundred eleven patients with kiwifruit allergy from 12 countries representing 4 climatic regions were included. Specific IgE to 6 allergens (Act d 1, Act d 2, Act d 5, Act d 8, Act d 9, and Act d 10) and kiwifruit extract were tested by using ImmunoCAP.

RESULTS

Patients from Iceland were mainly sensitized to Act d 1 (32%), those from western/central and eastern Europe were mainly sensitized to Act d 8 (pathogenesis-related class 10 protein, 58% and 44%, respectively), and those from southern Europe were mainly sensitized to Act d 9 (profilin, 31%) and Act d 10 (nonspecific lipid transfer protein, 22%). Sensitization to Act d 1 and living in Iceland were independently and significantly associated with severe kiwifruit allergy (odds ratio, 3.98 [P = .003] and 5.60 [P < .001], respectively). Using a panel of 6 kiwifruit allergens in ImmunoCAP increased the diagnostic sensitivity to 65% compared with 20% for skin prick tests and 46% ImmunoCAP using kiwi extract.

CONCLUSION

Kiwifruit allergen sensitization patterns differ across Europe. The use of specific kiwifruit allergens improved the diagnostic performance compared with kiwifruit extract. Sensitization to Act d 1 and living in Iceland are strong risk factors for severe kiwifruit allergy.

Developments in the field of allergy in 2010 through the eyes of Clinical and Experimental Allergy

In 2010 over 200 articles were published in Clinical and Experimental Allergy including editorials, reviews, opinion articles, letters, book reviews and of course at the heart of the journal, papers containing original data which have moved the field of allergy forward on a number of fronts. For the third year running the editors felt it would be of value to summarize the key messages contained in these papers as a snapshot of where the cutting edge of research into allergic disease is leading. We have broadly followed the sections of the journal, although this year the mechanistic articles are grouped together and the studies involving experimental models of disease are discussed throughout the paper. In the field of asthma and rhinitis phenotypes and biomarkers continue to a major pre-occupation of our authors. There is continued interest in mechanisms of inflammation and disordered lung function with the mouse model of asthma continuing to offer new insights. There is also a steady flow of papers investigating new therapies, including those derived from plants and herbs, although many are mechanistic with too few high quality clinical trials. The mechanisms involved in allergic disease are well covered with many strong papers using clinical material to ask relevant questions. Pro-pre and snybiotics continue to be of major interest to our authors and this remains a controversial and complicated field. The discipline of epidemiology has retained its interest in risk factors for the development of allergic disease with a view to refining and debating the reasons for the allergy epidemic. There is continued interest in the relationship between helminthic disease and allergy with a new twist in 2010 involving studies using infection with helminths as a potential treatment. The genetics of allergic disease continues to be very productive, although the field has moved on from only investigating single nucleotide polymorphisms of candidate genes to Genome Wide Association Studies and an increasing and welcome emphasis on gene-environment interactions. In the field of clinical allergy there is steady flow of papers describing patterns of drug allergy with renewed interest in reactions to contrast media, but food allergy is the major area of interest in this section of the journal. Lastly in the field of allergens there is a growing interest in the role of component resolved diagnosis in improving the diagnosis and management of allergic disease. Another excellent year, full of fascinating and high quality work, which the journal has been proud to bring to the allergy community.

Evaluation of IgE reactivity of active and thermally inactivated actinidin, a biomarker of kiwifruit allergy

Actinidin, an abundant cysteine protease from kiwifruit, is a specific biomarker of isolated allergy to kiwifruit. This study evaluates the IgE-binding properties of biologically active and thermally inactivated actinidin. Employing two different activity assays (caseinolytic assay and zymogram with gelatin) we showed that actinidin obtained from kiwifruit extract under native conditions represents a mixture of inactive and active enzyme. The structural integrity of actinidin was confirmed by SDS-PAGE, Edman degradation, mass fingerprint and Western blot with polyclonal antibodies. Although it was capable of inducing positive skin prick test reactions, we failed to detect IgE reactivity of active actinidin in Western blot with patient sera. Thermally inactivated actinidin exhibited IgE reactivity both in vivo and in vitro, indicating that heat processed kiwifruit products may induce clinical reactivity. These findings imply that apart from the allergenic epitopes on its surface, actinidin also contains hidden epitopes inside the protein which become accessible to IgE upon thermal treatment.

Risk factors for severe pediatric food anaphylaxis in Italy

BACKGROUND

Little is known about the cause of food-induced anaphylaxis in children or about the factors that might affect its clinical severity.

OBJECTIVE

The aim of this study was to investigate the cause of food-induced anaphylaxis in children in Italy and to identify factors that could influence the appearance of symptoms and the severity of anaphylaxis.

METHODS

One hundred and sixty-three children with anaphylaxis consecutively attending 29 outpatient allergy clinics throughout Italy were enrolled in this prospective study. Information about past anaphylaxis episodes was collected with a standardized questionnaire. Food sensitization was evaluated by skin-prick test.

RESULTS

A clinical history of asthma increased the risk of wheezing [odds ratio (OR) 2.2; 95% confidence interval (CI) 1.1-4.5] and respiratory arrest (OR 6.9; 95% CI 1.4-34.2). A clinical history of chronic/relapsing gastrointestinal symptoms increased the risk of vomiting (OR 2.1; 95% CI 0.9-4.3), hypotension (OR 7.9; 95% CI 1.9-32.0), and bradycardia/cardiac arrest (OR 9.2; 95% CI 0.9-91.3). The severity of present and previous episodes was similar only in patients with mild or moderate anaphylaxis. Peanut and egg were the most frequent causes of severe anaphylaxis.

CONCLUSIONS

A clinical history of asthma and chronic/relapsing gastrointestinal symptoms (probably linked to food allergy) may predict the development of respiratory and gastrointestinal symptoms and the severity of anaphylaxis.

Japan food allergen labeling regulation--history and evaluation

According to a national survey of food allergy cases, the food-labeling system for specific allergenic ingredients (i.e., egg, milk, wheat, buckwheat, and peanut) in Japan was mandated under law on April 1, 2002. By Japanese law, labeling of allergens is designated as mandatory or recommended based on the number of cases of actual illness and the degree of seriousness. Mandatory labeling is enforced by the ministerial ordinance, and the ministerial notification recommends that foods containing walnut and soybean be labeled with subspecific allergenic ingredients. Additional labeling of shrimp/prawn and crab has also become mandatory since 2008. To monitor the validity of the labeling system, the Japanese government announced the official methods for detection of allergens in a November 2002 ministry notification. These official methods, including two kinds of enzyme-linked immunosorbent assay kits for screening, Western blotting analyses for egg and milk, and polymerase chain reaction analyses for wheat, buckwheat, peanut, shrimp/prawn and crab as confirmation tests, have provided a means to monitor the labeling system. To standardize the official methods, the Japanese government described the validation protocol criteria in the 2006 official guidelines. The guidelines stipulate that any food containing allergen proteins at greater than 10mg/kg must be labeled under the Law. This review covers the selection of the specific allergenic ingredients by the Japanese government, the implementation of regulatory action levels and the detection methods to support them, and the assessment of the effectiveness of this approach.

A Review of Food Allergy and Nutritional Considerations in the Food-Allergic Adult

In the United States, the prevalence of adults with food allergies is approximately 2% to 3%. Theoretically, any food can cause an allergic reaction; however, some foods are clearly more allergenic than others. In adults, peanuts, tree nuts, finned fish, crustaceans, fruit, and vegetables account for 85% of the food-allergic reactions. Currently, the only ways to manage food allergies are to avoid the allergen and initiate therapy for an allergic reaction if ingestion does occur. The presence of homologous proteins among animal or plant foods and between foods and certain airborne allergens may account for cross-sensitization that may be clinically relevant. For inpatients or outpatients with food allergies, nutrient and fluid requirements are the same as for individuals without food allergies. Since patients with adverse reactions to food may self-restrict intake or have been counseled on food avoidance, it is particularly important to determine dietary adequacy and to provide patients with appropriate food substitutions to provide nutrients that may be missing from a patient’s diet. This is of particular concern for individuals with multiple food allergies. Eating away from home and traveling also pose special problems for those with food allergies.

The psychosocial impact of food allergy and food hypersensitivity in children, adolescents and their families: a review

Food allergy affects 6% of children but there is no cure, and strict avoidance of index allergens along with immediate access to rescue medication is the current best management. With specialist care, morbidity from food allergy in children is generally low, and mortality is very rare. However, there is strong evidence that food allergy and food hypersensitivity has an impact on psychological distress and on the quality of life (QoL) of children and adolescents, as well as their families. Until recently, the measurement of QoL in allergic children has proved difficult because of the lack of investigative tools available. New instruments for assessing QoL in food allergic children have recently been developed and validated, which should provide further insights into the problems these children encounter and will enable us to measure the effects of interventions in patients. This review examines the published impact of food allergy on affected children, adolescents and their families. It considers influences such as gender, age, disease severity, co-existing allergies and external influences, and examines how these may impact on allergy-related QoL and psychological distress including anxiety and depression. Implications of the impact are considered alongside avenues for future research.

The management of the allergic child at school: EAACI/GA2LEN Task Force on the allergic child at school

Allergy affects at least one-quarter of European schoolchildren, it reduces quality of life and may impair school performance; there is a risk of severe reactions and, in rare cases, death. Allergy is a multi-system disorder, and children often have several co-existing diseases, i.e. allergic rhinitis, asthma, eczema and food allergy. Severe food allergy reactions may occur for the first time at school, and overall 20% of food allergy reactions occur in schools. Up to two-thirds of schools have at least one child at risk of anaphylaxis but many are poorly prepared. A cooperative partnership between doctors, community and school nurses, school staff, parents and the child is necessary to ensure allergic children are protected. Schools and doctors should adopt a comprehensive approach to allergy training, ensuring that all staff can prevent, recognize and initiate treatment of allergic reactions.

Component-resolved diagnosis of kiwifruit allergy with purified natural and recombinant kiwifruit allergens

BACKGROUND

Kiwifruit is one of the most common causes of food allergic reactions. Component-resolved diagnostics may enable significantly improved detection of sensitization to kiwifruit.

OBJECTIVE

To evaluate the use of individual allergens for component-resolved in vitro diagnosis of kiwifruit allergy.

METHODS

Thirty patients with a positive double-blind placebo-controlled food challenge to kiwifruit, 10 atopic subjects with negative open provocation to kiwifruit, and 5 nonatopic subjects were enrolled in the study. Specific IgE to 7 individual allergens (nAct d 1-5 and rAct d 8-9) and allergen extracts was measured by ImmunoCAP.

RESULTS

The diagnostic sensitivities of the commercial extract and of the sum of single allergens were 17% and 77%, respectively, whereas diagnostic specificities were 100% and 30%. A combination of the kiwi allergens Act d 1, Act d 2, Act d 4, and Act d 5 gave a diagnostic sensitivity of 40%, whereas diagnostic specificity remained high (90%). Exclusion of the Bet v 1 homolog recombinant (r) Act d 8 and profilin rAct d 9 from this allergen panel reduced sensitivity to 50% but increased specificity to 40%. Kiwifruit-monosensitized patients reacted more frequently (P < .001) with Act d 1 than polysensitized patients, whereas the latter group reacted more frequently with rAct d 8 (P = .004).

CONCLUSION

Use of single kiwifruit allergen ImmunoCAP increases the quantitative test performance and diagnostic sensitivity compared with the commercial extract. Bet v 1 homolog and profilin are important allergens in pollen-related kiwifruit allergy, whereas actinidin is important in monoallergy to kiwifruit, in which symptoms are often more severe.