Christmas candy maker's asthma. IgG4-mediated pectin allergy

Citrin: a novel food allergen in citrus seeds and citrus-derived pectin that shows cross-reactivity with cashew and pistachio

BACKGROUND

Patients exquisitely sensitive to cashew/pistachio are at risk for allergic reactions to citrus seeds and pectin.

OBJECTIVE

In this study, we sought to evaluate whether pectin is contaminated with citrus seeds, to identify a culprit antigen in citrus seeds, and to assess for cross-reactivity among allergens in citrus seeds, citrus pectin, and cashew or pistachio.

METHODS

Proteins from orange seed coats, orange seed endosperms, lemon seeds, grapefruit seeds, citrus pectin, apple pectin, and grapefruit pectin were extracted. Protein concentrations in all extracts were determined and visualized using sodium dodecyl sulfate-polyacrylamide gel electrophoresis technique. Immunoglobulin E-binding capacity was determined with Western blot analyses and tandem mass spectrometry for the identification of the culprit allergen in citrus seeds and pectin.

RESULTS

In subjects with citrus seed, pectin, and cashew allergies, there was strong immunoglobulin E-reactivity to bands between 17 to 28 kDa and 28 to 38 kDa. The tandem mass spectrometry analysis of these bands indicated the presence of citrin as the culprit allergen. Citrin and Ana o 2 are both 11S globulins belonging to the cupin superfamily, and significant homology was found between these proteins.

CONCLUSION

Citrus pectin may be contaminated with citrus seeds. Citrin, a newly identified allergen in citrus seeds, seems to be the culprit antigen in citrus seeds and contaminated citrus pectin. Citrin is highly homologous with Ana o 2 in cashew and Pis v 2 in pistachio, suggesting potential for cross-reactivity and providing an explanation for co-allergenicity of cashew or pistachio, citrus seeds, and citrus pectin.

Hidden and Rare Food Allergens in Pediatric Age

In food allergy management, the avoidance of the allergen that caused the reaction plays a fundamental role. Nevertheless, that can be thwarted in case of accidental exposure to a rare or hidden allergen, causing the adoption of a monotonous diet and a consequent reduction in the quality of life of the patient and their family. The identification of a rare and hidden allergen is an important diagnostic challenge, taking into account that a significant proportion of all food reactions is in reality due to them. The aim of the present review is to provide the pediatric allergist an overview of the possible sources of rare and hidden food allergens, taking into consideration the routes of exposure to these potential allergens with the main examples published in the scientific literature and the distinction between types of direct or cross-contamination. The identification of the allergen responsible for the reaction and the provision of a dietary advice customized for the specific individual’s dietary habits is essential to improve quality of life of the familiar nucleus and to reduce the risk of further allergic reactions.

The Dietary Fiber Pectin: Health Benefits and Potential for the Treatment of Allergies by Modulation of Gut Microbiota

Purpose of Review

The incidence of allergies is increasing and has been associated with several environmental factors including westernized diets. Changes in environment and nutrition can result in dysbiosis of the skin, gut, and lung microbiota altering the production of microbial metabolites, which may in turn generate epigenetic modifications. The present review addresses studies on pectin-mediated effects on allergies, including the immune modulating mechanisms by bacterial metabolites.

Recent Findings

Recently, microbiota have gained attention as target for allergy intervention, especially with prebiotics, that are able to stimulate the growth and activity of certain microorganisms. Dietary fibers, which cannot be digested in the gastrointestinal tract, can alter the gut microbiota and lead to increased local and systemic concentrations of gut microbiota-derived short chain fatty acids (SCFAs). These can promote the generation of peripheral regulatory T cells (T_reg) by epigenetic modulation and suppress the inflammatory function of dendritic cells (DCs) by transcriptional modulation.

The dietary fiber pectin (a plant-derived polysaccharide commonly used as gelling agent and dietary supplement) can alter the ratio of Firmicutes to Bacteroidetes in gut and lung microbiota, increasing the concentrations of SCFAs in feces and sera, and reducing the development of airway inflammation by suppressing DC function.

Summary

Pectin has shown immunomodulatory effects on allergies, although the underlying mechanisms still need to be elucidated. It has been suggested that the different types of pectin may exert direct and/or indirect immunomodulatory effects through different mechanisms. However, little is known about the relation of certain pectin structures to allergies.

Re-evaluation of pectin (E 440i) and amidated pectin (E 440ii) as food additives

Following a request from the European Commission, the EFSA Panel on Food Additives and Nutrient sources added to Food (ANS) was asked to deliver a scientific opinion on the re-evaluation of pectin (E 440i) and amidated pectin (E 440ii) as food additives. An acceptable daily intake (ADI) 'not specified' was allocated by the Scientific Committee for Food (SCF) for E 440i and E 440ii. Pectin and amidated pectin would not be absorbed intact, but extensively fermented by intestinal microbiota in animals and humans; products formed from pectins in the gastrointestinal tract are similar to manufactured pectin-derived acidic oligosaccharides (pAOS). There is no indication of genotoxicity for pectin and amidated pectin, although the available data were limited. No adverse effects were reported in a chronic toxicity study in rats at levels up to 5,000 mg pectin/kg bw per day, the highest dose tested. No treatment-related effects were observed in a dietary one-generation reproductive toxicity study with pAOS in rats at up to 6,200 mg/kg body weight (bw) per day, the highest dose tested. The Panel did not consider E 440i and E 440ii as having allergenic potential. A dose of 36 g/day (equivalent to 515 mg/kg bw per day) for 6 weeks in humans was without adverse effects. Exposure to pectins from their use as food additives ranged up to 442 mg/kg bw per day for toddlers at the 95th percentile (brand-loyal scenario). The Panel concluded that there is no safety concern for the use of pectin (E 440i) and amidated pectin (E 440ii) as food additives for the general population and that there is no need for a numerical ADI.

Allergic and immunologic reactions to food additives

For centuries, food additives have been used for flavouring, colouring and extension of the useful shelf life of food, as well as the promotion of food safety. During the last 20 years, the studies implicating the additives contained in foods and medicine as a causative factor of allergic reactions have been proliferated considerably. In this review, we aimed to overview all of the food additives which were approved to consume in EU and find out how common and serious allergic reactions come into existence following the consuming of food additives.

Development of hypoallergenic galacto-oligosaccharides on the basis of allergen analysis

Galacto-oligosaccharides (GOSs) are recognized as prebiotics beneficial to human health through their abilities to modulate gut microbiota. On the other hand, it has been reported that immediate allergic reactions are caused by a GOS product (Bc-GOS) produced by treating lactose with β-galactosidase derived from Bacillus circulans. The objective of this study was to create a safer GOS product that is less likely to cause GOS-induced allergy (GOS-AL). First, we identified two derivatives of tetrasaccharide sugar chains in Bc-GOS as the factors responsible for GOS-AL by histamine release test (HRT) using blood samples obtained from two GOS-AL patients. Through our search for non-allergic GOS, we developed a new GOS product, SK-GOS, which was produced by catalyzing lactose with β-galactosidase derived from Sporobolomyces singularis and Kluyveromyces lactis. We regard it as a hypoallergic and safe GOS product that does not cause GOS-AL.

Gum arabic as a cause of occupational allergy

Background. Gum arabic is a potential sensitizer in food industry. Methods. We examined 11 candy factory workers referred to examinations due to respiratory and skin symptoms paying attention to exposure and sensitization to gum arabic. Skin tests, pulmonary function tests, and respiratory provocation tests were carried out as indicated by the symptoms and findings. Results. Occupational asthma, caused by gum arabic was diagnosed in 4/11 candy factory workers and two of them had also occupational contact urticaria and one had occupational rhinitis. One of them had oral symptoms associated with ingestion of products containing gum arabic. Conclusions. Airborne exposure to gum arabic may cause sensitization leading to allergic rhinitis, asthma, and urticaria.

Lung disease in flavoring and food production: learning from butter flavoring

Workers in the food industry are exposed to multiple respiratory hazards that include irritants, allergens, and substances capable of causing destruction and scarring of the lungs. Cases of constrictive bronchiolitis obliterans, a severe potentially disabling lung disease, have been identified in workers exposed to flavorings. Workplace engineering controls, work practices, and respiratory protection can minimize potential exposures. Medical surveillance of workers exposed to known respiratory hazards will help to identify disease early, facilitate the prompt removal of workers from the causative exposure(s), and prevent further worsening and/or permanence of disease. When companies or employees suspect occupational respiratory disease, they can involve public health agencies to investigate any excess risk of lung disease, risk factors among processes and exposures, and effectiveness of interventions, if needed.

Pectin anaphylaxis and possible association with cashew allergy

BACKGROUND

Inhalation of pectin has been identified as a cause of occupational asthma. However, allergic reactions to orally ingested pectin have not been reported.

OBJECTIVES

To describe a child with pectin-induced food anaphylaxis and to discuss its possible relationship to cashew allergy.

METHODS

A 3 1/2-year-old boy developed anaphylaxis once after eating cashews and later after eating a pectin-containing fruit "smoothie." He also has a history of generalized pruritus after eating grapefruit. Skin tests or radioallergosorbent tests (RASTs) were performed to pectin and other suspected food allergens.

RESULTS

The child had a positive skin prick test reaction to pectin and a high RAST reaction to cashew and pistachio. He had a low-level positive RAST reaction to grapefruit. Results of allergy tests for the other potential food allergens were negative. The pectin in the smoothie was confirmed to be of citrus origin. Review of previous case reports of pectin-induced occupational asthma revealed several patients with allergies to and cross-reactivity with cashew.

CONCLUSIONS

Ingestion, not only inhalation, of pectin can cause hypersensitivity reactions. Cashew, and possibly pistachio, allergy may be associated with pectin allergy, and the possibility of pectin allergy should be considered in cashew- or pistachio-allergic patients who have unexplained allergic reactions.

IgG4 response to fur animal allergens among fur workers

OBJECTIVE

The aim of this study was to determine whether IgG(4) antibodies to allergens in urine extracts from fur animals associated with positive prick tests to the same allergens and with the occurrence of respiratory symptoms among fur workers, especially among highly exposed fur farmers.

METHODS

Among the fur workers and among their referents, IgG(4) antibodies to mink and silver fox urine were analysed in three groups; all workers with a positive skin prick test to any fur animal allergen (n=50), all workers who had reported shortness of breath or rhinitis or eye symptoms (n=159), and to a random sample of asymptomatic persons (n=178). In the two last groups none of the workers had a positive skin test to any fur animal allergen.

RESULTS

The fur farmers had higher level of IgG(4) values than other groups and also had positive IgG(4) antibodies to urine extract more frequently than the other groups. Among the exposed subjects, there was a distinct overlapping of a positive skin prick test to fur urine allergens and positive IgG(4) antibodies to responding allergens. Among the fur farmers the IgG(4) levels were associated with symptoms.

CONCLUSIONS

IgG(4) antibodies were shown to be a good indicator of exposure. Because of an overlapping of positive skin prick tests and IgG(4) response to the same allergens, and an association between symptoms and IgG(4) response, it is recommended that the potential role of IgG(4) antibodies as an indicator of alternative sensitisation should be further examined in prospective studies.

Asian pear pectin administration during presensitization inhibits allergic response to ovalbumin in BALB/c mice

OBJECTIVE

A type of respiratory disorder resembling some aspects of human allergic asthma can be induced in mice using ovalbumin. The factors that influence the etiology of asthma are poorly understood even though cytokines are known to play a pivotal role. The purpose of this study was to test the hypothesis whether an administration of Asian pear pectin during presensitization could suppress allergic response to ovalbumin in BALB/c mice.

DESIGN

High-dose (100 microg) of pectin-sol was used and values were compared to those from the control. Ovalbumin and aluminum hydroxide were utilized for sensitization while ovalbumin aerosol was used for provocation 2 weeks later. The bronchoalveolar lavage (BAL) and assessment of tracheal smooth muscle responsiveness to electrical field stimulation or acetylcholine were performed 1 day after ovalbumin provocation. Two main cytokines of interferon (IFN)-gamma and interleukin (IL)-5, and serum immunoglobulin E (IgE) were assayed.

SETTINGS

Laboratory of the Chosun University Medical School

SUBJECT

Male BALB/c mice

RESULTS

Antigen dose of 5 microg for sensitization generated TH1 type cytokines in the lungs with a high level of IFN-gamma and a low level of IL-5. In contrast, TH2 type cytokines were produced in splenocytes including a high level of IL-5 and a low level of IFN-gamma. Asian pear pectin-sol administration during presensitization significantly inhibited (p < 0.05) sensitivity of airway smooth muscle to electrical field stimulation and acetylcholine. Further, IFN-gamma production significantly decreased (p < 0.05) in BAL fluids while it significantly increased (p < 0.05) in splenic cells. On the other hand, IL-5 production significantly increased (p < 0.05) in BAL fluids while it was a significant decrease (p < 0.05) in splenic cells. For the histopathologic changes in the lung, pear pectin-sol recovered ovalbumin (OVA)-induced abnormal signs to an almost normal state. As a correlate, IgE production significantly decreased (p < 0.05) in pectin-sol-treated animals compared to the control.

CONCLUSIONS

It is possible from these data that BALB/c mice have different susceptibilities to different doses of OVA regulated by pulmonary TH1 and TH2 type cytokines, independent of splenic TH1 and TH2 type cytokines production. These results also indicate that administration of Asian pear pectin-sol in presensitized mice suppresses allergic asthmatic reaction.

Occupational asthma due to freeze-dried raspberry

OBJECTIVE

To investigate the possibility that inhalation of raspberry powder at work can cause occupational asthma.

METHODS

We report the case of a 35-year-old, nonsmoking woman who complained of hay fever symptoms, wheezing, and shortness of breath two or three times a month exclusively in association with coating chewing gum with raspberry powder. Prick test extracts with the five types of fruit powder were produced. Peak expiratory flow rate monitoring five times daily was performed for an 8-week period while the patient was at work. Specific IgE and histamine release tests for raspberry powder were performed. Breathing zone dust measurements were taken.

RESULTS

Baseline lung function and histamine provocation test results were normal. During the 8-week monitoring period, 5 episodes of reduced peak expiratory flow rate were demonstrated. Each period was directly related to working with raspberry powder. A 9-mm prick test result positive for raspberry powder was seen (histamine control, 9 mm). In addition, the result of a radioallergosorbent test for raspberry was positive (0.84 kUA/L). The result of a histamine release test with raspberry powder from work was negative. Breathing zone total dust measurement was 5.9 mg/m3.

CONCLUSIONS

To our knowledge, this is the first description of occupational asthma due to the inhalation of raspberry powder. The symptoms of the patient described herein disappeared after she was moved to another part of the factory. Hygienic improvements were performed at the workplace to reduce the sensitization risk of other workers.

[Occupational asthma caused by organic substances]

Occupational asthma (OA) to organic substances is frequently related to IgE-dependent hypersensitivity. New etiological agents are latex and vegetal gums, in health care personnel as in carpet-making manufactures. Bakers are exposed to numerous allergens: wheat and cereal flours, sesame and other seed proteins, alpha-amylase and other enzymes. Alpha-amylase extracted from Aspergillus orizae is a potent allergen. Plant derived materials have been identified as allergens in the floral industry (Ficus, Ginseng, Gypsophila, etc). The accurate diagnosis relies upon a thorough history, completed by measurements of peak expiratory flows during the work. Sensitization can be confirmed by prick tests and immuno assays for IgE antibodies. Bronchial provocation tests documenting OA are advisable. The early detection of OA might be evaluated by skin tests to occupational allergens repeated yearly. The prevention of OA relies on air sampling technologies controlling the allergenic density of the atmosphere and removing asthmatics from exposed areas. There are no scientific grounds for discarding atopics from occupations at risk for OA.