Immediate hypersensitivity to common food allergens: an investigation on food sensitization in respiratory allergic patients of calcutta, India

Safety evaluation of the food enzyme endo-polygalacturonase from the non-genetically modified Aspergillus tubingensis strain MUCL 55013

The food enzyme endo-polygalacturonase ((1→4)-α-d-galacturonan glycanohydrolase (endo-cleaving); EC 3.2.1.15)) is produced with the non-genetically modified Aspergillus tubingensis strain MUCL 55013 by Soufflet Biotechnologies. The food enzyme is free from viable cells of the production organism. It is intended to be used in 10 food manufacturing processes: processing of fruits and vegetables for the production of juices, other fruit and vegetable products, wine, distilled spirits from wine, alcoholic beverages other than grape wine; processing of plant-derived products for the production of refined and unrefined sugar, edible oils from plants, green coffee beans by demucilation, coffee extracts and tea and other herbal and fruit infusions. Since residual amounts of total organic solids (TOS) are removed in three processes, dietary exposure was calculated only for the remaining seven food manufacturing processes. Exposure was estimated to be up to 7.834 mg TOS/kg body weight (bw) per day in European populations. Genotoxicity tests did not indicate a safety concern. The systemic toxicity was assessed by a repeated dose 90-day oral toxicity study in rats. The Panel identified a no observed adverse effect level of 2,097 mg TOS/kg bw per day, the highest dose tested, resulting in a margin of exposure of at least 268. A search for the similarity of the amino acid sequence of the food enzyme to known allergens found 14 matches, one of which was to a food allergen. The Panel considered that the risk of allergic reactions upon dietary exposure to this food enzyme cannot be excluded, in particular for individuals sensitised to papaya, but that the risk will not exceed that of consumption of papaya. In addition, oral allergy reactions cannot be excluded in pollen-sensitised individuals. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns, under the intended conditions of use.

The Need for Culturally Appropriate Food Allergy Management Strategies: The Indian Milk Ladder

BACKGROUND

Cow's milk allergy (CMA) is one of the most common and complex food allergies affecting children worldwide and, with a few exceptions, presents in the first few months of life. Baked-milk-containing diets are well tolerated in the majority of milk-allergic children and allow dietary restrictions to be relaxed. In addition, the early introduction of tolerated forms of allergenic foods to an infant's diet in small amounts may enhance the outgrowth of their milk allergy through oral tolerance induction. The methods of milk introduction vary widely across the globe.

METHODS

We convened an expert group to develop a comprehensive milk ladder based on the calculated milk protein content of Indian foods. To validate the milk ladder, the foods chosen for the ladder were analyzed and the ladder was re-evaluated based on the cooked milk protein content.

RESULTS

Combining expert consensus and validation of milk protein content, we created the world's first milk ladder containing Indian foods. This is the first ladder that provides information on the timing and temperature of cooking, with validated milk protein content.

CONCLUSIONS

This is the first milk ladder based on the unique features of Indian food habits built by the consensus of Indian experts along with international collaboration with laboratory quantification of milk protein in each step. We believe the "The Indian Milk Ladder" will be a very helpful tool for pediatricians helping manage CMA in children as well as their parents and caregivers, not only in India, but in countries world-wide where these foods are commonly consumed.

Pattern of Food Allergen Sensitivity Amongst Adult Allergic Rhinitis Patients: A Four Year Central Indian Study

AIMS

Only limited Indian data is available regarding the food allergy pattern among allergic rhinitis patients in Indian population. This study aims to assess the pattern of food allergen sensitivity amongst allergic rhinitis patients in central India.

MATERIAL AND METHODS

A total of 218 subjects with allergic rhinitis were enrolled in the study (from May 2018 to August 2022). Skin prick test was done in all subjects with proper technique and precautions by using 125 common food allergens and 75 aero allergens. The test readings were noted after 20 minutes by comparing the wheals so formed with the negative control of Saline and positive control of Histamine. Any reaction with a wheal diameter of 3mm or greater was considered as positive.

RESULTS

While test results of both food and inhalant allergens were issued to individual patients, this study was restricted to detection and analysis of pattern of food allergens. Our study observed male preponderance with predominantly a third decade affliction. The most common food allergen in the study population was beetle nut (29.3%) followed by chilli powder and spinach (28.8% each).

CONCLUSION

Along with aeroallergens, food allergens are also important provocateurs of allergic rhinitis. Diagnosing the offending food allergens and its avoidance reduces patient morbidity, need for pharmaceutical agents and subsequently drug dependence and its side effects. Offering subjects a replacement diet with food items of similar taste and nutritive character helps in sustainable avoidance therapy.

Safety evaluation of the food enzyme endo-polygalacturonase from the genetically modified Aspergillus niger strain EPG

The food enzyme endo-polygalacturonase ((1-4)-α-d-galacturonan glycanohydrolase; EC 3.2.1.15) is produced with the genetically modified Aspergillus niger strain EPG by DSM Food Specialties B.V. The genetic modifications do not give rise to safety concerns. The food enzyme is free from viable cells of the production organism and its DNA. It is intended to be used in fruit and vegetable processing for juice production. The dietary exposure to the food enzyme-total organic solids (TOS) was estimated to be up to 0.122 mg TOS/kg body weight (bw) per day in European populations. Genotoxicity tests did not indicate a safety concern. The systemic toxicity was assessed by means of a repeated dose 90-day oral toxicity study in rats. The Panel identified a no observed adverse effect level of 1,014 mg TOS/kg bw per day, the highest dose tested, which, when compared with the estimated dietary exposure, resulted in a margin of exposure at least 8,311. A search for the similarity of the amino acid sequence of the food enzyme to known allergens was made and 38 matches were found, two of which are food allergens. The Panel considered that, under the intended conditions of use, the risk of allergic reactions upon dietary exposure to this food enzyme cannot be excluded, in particular for individuals sensitised to papaya or maize, but that the risk will not exceed that of consumption of papaya or maize. In addition, oral allergy reactions cannot be excluded in pollen-sensitised individuals. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns, under the intended conditions of use.

Prevalence of Food Allergy and Common Food Allergen Among Saudi Adults in Makkah Region, Saudi Arabia

Introduction

The prevalence of food allergy (FA) in the Makkah region has received little attention, so we conducted this study to estimate the prevalence of FA in adults.

Methods

This descriptive, cross-sectional, survey-based study was conducted online among 531 participants with or without a prior diagnosis of FA. The collected data related to socio-demographics (age and gender), whether the participant had been medically diagnosed with any food allergens, and assessing the prevalence of different food allergens.

Results

Only 93 (17.5%) of the 531 people screened positive for FA; females (65.6%) predominated, with 37.6% aged 40-59. The type of food for allergy was: eggs (47%), seafood (44%), fruits (40%), nuts and legumes (37%), milk and dairy products (25%), vegetables (17%), sesame (11%), wheat (9%), soy (8%), 2% to chili peppers, and only 1% honey and chocolate.

Conclusion

Both genders were allergic to eggs, followed by seafood, fruits, nuts, and legumes, and milk and dairy products, respectively.

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.

Food allergy in children with asthma and its correlation with level of asthma control

Background

There is paucity of regional data regarding food allergy among children with asthma.

Objectives

To estimate the proportion of children with asthma who have food‐related respiratory symptoms and to correlate it with (a) skin prick test (SPT) results and (b) level of asthma control.

Methodology

This cross‐sectional study involved children with asthma, aged ≥6 years attending the childhood asthma clinic in a tertiary care hospital, in the southern part of India from July 2017 to July 2019. Basic demography and clinical details were recorded. In subjects with a history of food allergy, skin prick test (SPT) was done using AllergoSPT according to guidelines recommended by British Society of Allergy and Clinical Immunology (BSACI). Asthma control was assessed using asthma control test (ACT) and childhood ACT questionnaires.

Results

Of the total 305 children included, the most commonly reported allergen was banana (45%, n = 137). The predominant symptom reported was wheezing (54%). SPT was positive in 76 children (24.9%). Level of asthma control (P value < .01), family history of atopy (P value < .01), and age at introduction of complementary foods (P value < .01) were significantly associated with food allergy.

Conclusion

Presumed food allergy is seen in one‐fourth of children with asthma and significantly affects symptom control in them.

Cloning and immunobiochemical analyses on recombinant chymopapain allergen Cari p 2 showing pollen-fruit cross-reaction

Papaya is reported to trigger food and respiratory allergy. Here, we identified chymopapain Cari p 2 as an allergen that can sensitize atopic individuals through fruit consumption followed by respiratory hazards through pollen exposure. Recombinant Cari p 2 displayed IgE-reactivity with 78% of papaya allergic sera. rCari p 2 also displayed allergenic activity through basophil degranulation. rCari p 2 is correctly folded and showed irreversible denaturation in the melting curve. rCari p 2 displayed IgE-cross-reactivity with homologous cysteine proteases from kiwi and pineapple. Cari p 2 transcript was also detected in papaya pulps. rCari p 2 was resistant to pepsin digestion and retained IgE-reactivity after 60 minutes of pepsin digestion. In mouse model, rCari p 2 was found to elicit inflammatory responses in the lung and gastrointestinal epithelium. Hence, Cari p 2 is a newly characterized allergen with diagnostic and immunotherapeutic potential for managing allergic disorders in papaya sensitized individuals.

Association of HLA-DQ and IL13 gene variants with challenge-proven shrimp allergy in West Bengal, India

Little is known about genetic factors and mechanisms underlying shrimp allergy. Genome-wide association studies identified HLA class-II and IL13 genes as highly plausible candidates for shrimp allergy. The present study was designed to investigate potential associations of HLA-DQ rs9275596, IL13 rs20541, and IL13 rs1800925 polymorphisms with challenge-proven shrimp allergy using the data from 532 people of West Bengal, India; selected on basis of positive skin prick test, elevated specific IgE and medical history. Risk genotypes, i.e., HLA-DQ rs9275596 CC, IL13 rs20541 AA, and IL13 rs1800925 TT, were found to be significantly associated with challenge positive shrimp allergy (P = 0.04, 0.01, and 0.03, respectively). Distribution of genotypes for HLA-DQ and IL13 polymorphisms in allergic and control subjects showed significant difference between younger (20-40 years) and older (> 40 years) age group (P = 0.006). Risk genotypes significantly associated with elevated shrimp-specific IgE. IL13 TA haplotype significantly associated with shrimp allergy and elevated specific IgE (P = 0.02). Synergistic effect of IL13 TA haplotype-HLA-DQ rs9275596 CC genotype interaction significantly elevated specific IgE (P = 0.03). The present study suggests that HLA-DQ and IL13 polymorphisms pose major risk for shrimp allergic patients in West Bengal, India and thus could be helpful for early target-specific therapeutic intervention in near future.

Sensitization to Local Seafood Allergens in Adult Patients with Atopic Dermatitis in Malaysia

BACKGROUND

Seafood is an important source of nutrition in Asia. However, it was believed to cause or aggravate atopic dermatitis (AD).

OBJECTIVES

We aim to determine relevant seafood sensitization among adults with AD and investigate cross-sensitization to aeroallergens.

METHODS

One hundred thirty-two adults with AD who were subjected to skin prick test (SPT) with 7 common local seafood allergens (anchovy, tuna, mackerel, squid, giant freshwater prawn, shrimp, and crab), house dust mites (HDMs), and cockroach were analyzed retrospectively.

RESULTS

The median age of the study subjects was 32 years (range 17-77 years) with a male to female ratio of 1:3. The mean duration of AD was 16 years. Eighty-two patients (62.2%) had other atopic conditions. Using SCORAD, 44.7% had mild, 42.4% moderate, and 12.9% severe disease. Eighty-six patients (65.2%) self-reported to have seafood allergy, with the main symptoms of transient pruritus and erythema within 2 h of ingestion. SPT revealed 51.5% of the patients were sensitized to at least 1 of the 7 seafood allergens. The relevant sensitization rate was 45.1%. Interestingly, 46% of those without a history of seafood allergy developed at least 1 positive reaction in the SPT. Prawn, shrimp, and crab were the 3 most frequently sensitized allergens. Nearly all patients (98.3%) who were sensitized to crustaceans were also sensitized to HDMs and/or cockroach. There was no significant correlation between a positive SPT to seafood with age, age of onset of AD, duration, and severity of AD, and the presence of other atopic diatheses.

CONCLUSION

The relevant sensitization rate of local seafood among adults with AD was 45.1%.

An appraisal of allergic disorders in India and an urgent call for action

India is the second most populous country in the world with a population of nearly 1.3 billion, comprising 20% of the global population. There are an estimated 37.5 million cases of asthma in India, and recent studies have reported a rise in prevalence of allergic rhinitis and asthma. Overall, 40-50% of paediatric asthma cases in India are uncontrolled or severe. Treatment of allergic rhinitis and asthma is sub-optimal in a significant proportion of cases due to multiple factors relating to unaffordability to buy medications, low national gross domestic product, religious beliefs, myths and stigma regarding chronic ailment, illiteracy, lack of allergy specialists, and lack of access to allergen-specific immunotherapy for allergic rhinitis and biologics for severe asthma. High quality allergen extracts for skin tests and adrenaline auto-injectors are currently not available in India. Higher postgraduate specialist training programmes in Allergy and Immunology are also not available. Another major challenge for the vast majority of the Indian population is an unacceptably high level of exposure to particulate matter (PM)_2.5 generated from traffic pollution and use of fossil fuel and biomass fuel and burning of incense sticks and mosquito coils. This review provides an overview of the burden of allergic disorders in India. It appraises current evidence and justifies an urgent need for a strategic multipronged approach to enhance quality of care for allergic disorders. This may include creating an infrastructure for education and training of healthcare professionals and patients and involving regulatory authorities for making essential treatments accessible at subsidised prices. It calls for research into better phenotypic characterisation of allergic disorders, as evidence generated from high income western countries are not directly applicable to India, due to important confounders such as ethnicity, air pollution, high rates of parasitic infestation, and other infections.

Association of the STAT6 rs3024974 (C/T) Polymorphism with IgE-Mediated Food Sensitization among West Bengal Population in India

INTRODUCTION

Genetic polymorphisms associated with IgE-mediated food sensitization have been a robust area of research for decades. A genome-wide search for susceptible loci regulating the IgE response (atopy) identified the candidate gene STAT6, which is important in the context of food allergic manifestations.

OBJECTIVE

The present study was designed to investigate the sensitization of West Bengal population against some common allergenic food items and to study the role of the STAT6 gene polymorphism in elevating food-specific IgE levels among sensitized individuals.

METHODS

Skin prick test was performed for 6 food items among 501 patients (126 children, 85 adolescents, and 290 adults)from West Bengal, India. Among them, 165 patients were selected for measurement of total IgE and food-specific IgE levels along with 165 controls. Finally, the STAT6 (rs3024974 (C/T) polymorphism was genotyped in 139 cases and control subjects.

RESULTS

Shrimp was identified as a dominant food allergen in adolescents and adults, whereas milk sensitization was highest in children. Food-sensitized patients with onset during childhood had significantly higher total IgE levels compared to patients with onset during adulthood (p < 0.00001). The frequency of the rs3024974 CC genotype in both cases and control subjects (55.40 and 46.76%, respectively) was higher than that of CT or TT. Patients with childhood onset bearing the CC genotype had significantly higher specific IgE levels in comparison to those with adult onset (p = 0.001).

CONCLUSION

Food sensitization has a genetic background and the rs3024974 polymorphism is associated with susceptibility and reaction severity in food-sensitized patients in West Bengal population in India.

Cari p 1, a Novel Polygalacturonase Allergen From Papaya Acting as Respiratory and Food Sensitizer

Papaya has been reported to elicit IgE-mediated hypersensitivity via pollen inhalation and fruit consumption. Certain papaya sensitive patients with food allergy were found to experience recurrent respiratory distresses even after quitting the consumption of fruits. This observation prompted us to investigate the allergens commonly present in fruits and pollen grains of papaya. A discovery approach consisting of immunoproteomic detection followed by molecular characterization led to the identification of a novel papaya allergen designated as Cari p 1. This allergen was detected as a 56 kDa IgE-reactive protein from pollen as well as fruit proteome through serological analysis. The protein was identified as an endopolygalacturonase by tandem mass spectrometry. Full length Cari p 1 cDNA was isolated from papaya pollen, cloned in expression vector, and purified as recombinant allergen. The recombinant protein was monomeric and displayed pectinolytic activity. Recombinant Cari p 1 reacted with IgE-antibodies of all the papaya sensitized patient sera. In addition to IgE-reactivity, rCari p 1 displayed allergenic activity by stimulating histamine release from IgE-sensitized granulocytes. CD-spectroscopy of rCari p 1 revealed the presence of predominantly β-sheet characters. The melting curve of the allergen showed partial refolding from a fully denatured state indicating the possible presence of conformational IgE-epitopes characteristic of inhalant allergens in addition to the linear IgE-epitopes of food allergens. The expression of this allergen in papaya fruits was detected by immunoblot with anti-Cari p 1 rabbit IgG and reconfirmed by PCR. In an in vivo mouse model, rCari p 1 exhibited a comparable level of inflammatory responses in the lung and duodenum tissues explaining the dual role of Cari p 1 allergen in respiratory sensitization via pollen inhalation and sensitization of gut mucosa via fruit consumption. Purified rCari p 1 can be used a marker allergen for component-resolved molecular diagnosis. Further immunological studies on Cari p 1 are warranted to design immunotherapeutic vaccine for the clinical management of papaya allergy.

Identification of parvalbumin and two new thermolabile major allergens of Thunnus tonggol using a proteomics approach

BACKGROUND

The longtail tuna (Thunnus tonggol) is widely consumed in Asia. Parvalbumin, the main major allergen of fish, has been well identified in multiple fish species, yet little is known about the allergenic proteins in T. tonggol. Thus, the aim of this study was to characterize the major allergens of T. tonggol using a proteomics approach.

METHODS

Raw and boiled extracts of the fish were prepared. Fish proteins were separated by means of SDS-PAGE and two-dimensional (2-DE) electrophoresis. 1-DE immunoblotting of raw extract was performed with sera from fish-allergic patients. Ten sera were further analysed by 2-DE immunoblotting. Selected major allergenic protein spots were excised, trypsin digested and analysed by means of mass spectrometry.

RESULTS

SDS-PAGE of raw extract revealed 26 protein fractions, while boiled extract demonstrated fewer bands. The 2-DE gel profile of the raw extract further fractionated the protein bands to more than 100 distinct protein spots. 1-DE immunoblotting of raw extract exhibited two thermolabile protein fractions of 42 and 51 kDa as the major allergens, while the boiled extract only revealed a single IgE-binding band at 151 kDa. 2-DE immunoblotting of raw extract further detected numerous major IgE-reactive spots of 11-13, 42 and 51 kDa. Mass spectrometry analysis of the peptides generated from the 12, 42 and 51 kDa digested spots indicated that these spots were parvalbumin, creatine kinase and enolase, respectively.

CONCLUSIONS

In addition to parvalbumin, two new thermolabile allergens were identified as major allergenic proteins of T. tonggol. This study proved that both thermostable and thermolabile proteins are important in local tuna allergy and should be included in diagnostic strategies.

Evaluation of banana hypersensitivity among a group of atopic egyptian children: relation to parental/self reports

Purpose

To evaluate the frequency of banana sensitization and allergy among a group of atopic Egyptian children in relation to parental/self reports.

Methods

This is a case-control study included 2 groups of allergic children with and without history of banana allergy, each included 40 patients. They were subjected to skin prick test (SPT) using commercial banana allergen extract and prick-prick test (PPT) using raw banana, in addition to measuring the serum banana-specific IgE. Oral banana challenge was performed in suspected cases.

Results

Banana allergy was diagnosed in 3 (7.5%) patients based on positive history of allergy on exposure to banana, positive SPT/PPT and elevated banana-specific IgE. The 3 patients had bronchial asthma with exacerbation upon banana exposure. The PPT results conform with those of SPT both in diagnosis of banana allergy and in the skin reactivity to banana. Serum banana-specific IgE was detectable in the whole studied sample with higher serum level among those without history of banana allergy (P=0.005). Oral banana challenge was negative for 20 patients with history of banana allergy and positive serum banana-specific IgE but negative SPT and PPT.

Conclusions

Self/parental reports of banana allergy is high while the actual banana allergy is uncommon. The PPT seems as reliable as SPT in diagnosis of banana allergy unlike specific IgE which reflects sensitization rather than allergy. Oral food challenge remains the most helpful tool for diagnosis of food allergy in suspected cases.

Clinico-Immunological Analysis of Eggplant (Solanum melongena) Allergy Indicates Preponderance of Allergens in the Peel

Background

Eggplant (Solanum melongena L.) is known to cause food allergy in some Asian countries but detailed studies on eggplant allergy are lacking.

Objective

The objective is to investigate sensitization to different parts of eggplant fruit, and detection of the allergens.

Methods

Six eggplant-allergic subjects were assessed for sensitization to eggplant (peel/pulp, and raw/cooked) by skin prick test, allergen-specific IgE, and immunoblots. Allergens were analyzed for glycoprotein nature by staining/lectinoblots, and in vitro stability in simulated gastric fluid.

Results

All the eggplant-sensitized subjects showed positive skin prick test with peel, pulp, raw, and cooked eggplant extracts; allergen-specific IgE to all these was positive. Raw eggplant contains 5 allergens in the range 36-71 kD. Most allergens are localized in the eggplant peel (9 allergens; 26-71 kD range) than the pulp (3 allergens; 52-71 kD); among these, the 26, 28, 36, and 71 kD allergens seem to be heat-stable. The 43, 45, 64, and 71 kD allergens are detected as glycoproteins; the 26, 64, and 71 kD allergens are stable displaying retention of IgE-binding ability in simulated gastric fluid digestion.

Conclusions

Eggplant is a multiallergenic vegetable in the context of presence of allergens in all edible parts of eggplant having preponderance in the peel.