Food allergy

Molecular mechanisms of portal vein tolerance

The liver has been considered as a tolerogenic organ in the sense that favors the induction of peripheral tolerance. The administration of antigens (Ags) via the portal vein causes tolerance, which is termed portal vein tolerance and can explain the occurrence of tolerogenic responses in the liver. Here we discuss the fundamental mechanisms accounting for portal vein tolerance. Antigen-presenting cells (APCs) in the liver, especially dendritic cells and sinusoidal endothelial cells, have limited the ability to produce pro-inflammatory cytokines upon stimulation with endotoxin, an effect that could be due to the continuous exposure to bacterial Ags derived from intestinal microflora. Ag presentation by liver APCs results in T cell tolerance through clonal deletion and selection of regulatory T cells. Thus, APCs with immunosuppressive functions are associated with the achievement of portal vein tolerance via the induction of clonal deletion and generation of regulatory T cells.

Lupin allergy in peanut-allergic children and teenagers

BACKGROUND

Lupin has now been introduced into food production in the UK. There is a concern that, on account of cross-reactivity, peanut-allergic children are at high risk for lupin allergy.

AIMS

To investigate the prevalence of lupin sensitization and allergy in children with peanut allergy compared with atopic controls.

METHODS

Children (<18 years) were recruited. Peanut-allergic subjects either had a convincing history of peanut allergy with diagnostic peanut skin prick test (SPT) or specific-immunoglobulin E (IgE) results or a positive food challenge. Control subjects were atopic but not peanut-allergic. All subjects had SPT to peanut and lupin. Sensitized subjects were offered a randomized, double-blind, placebo-controlled lupin challenge. Lupin allergy was defined as objective immediate hypersensitivity reaction at food challenge.

RESULTS

Forty-seven peanut-allergic children and 46 atopic controls were recruited. Sixteen peanut-allergic children were sensitized to lupin [34%, 95% confidence interval (CI): 21-49%]. Nine were challenged to lupin. Two reacted (itchy mouth and urticaria; itchy mouth and 20% drop in peak expiratory flow rate) giving a minimum prevalence of lupin allergy in peanut-allergic children of 4.0% (95% CI: 1-15%). Atopic controls were significantly (P = 0.001) less likely to be sensitized to lupin (4%, 95% CI: 1-15%) and had smaller wheals and serum-specific IgE results. None of the atopic controls reacted on lupin challenge, giving a rate of allergy in the atopic controls of 0% (95% CI: 0-8%).

CONCLUSIONS

A small but significant number of children with peanut allergy are allergic to lupin. Sensitization to lupin is much rarer in nonpeanut-allergic atopic subjects.

Anaphylaxis in patients with mastocytosis: a study on history, clinical features and risk factors in 120 patients

BACKGROUND

Excessive mast cell mediator release may lead to anaphylaxis in patients with mastocytosis. However, the incidence, clinical features and trigger factors have not yet been analyzed.

METHODS

To identify risk factors for anaphylaxis in mastocytosis, we determined cumulative incidence, severity, clinical characteristics, and trigger factors for anaphylaxis in 120 consecutive patients (53 male; 67 female, median age and range 24 years, 1 month to 73 years), and correlated these with disease severity of mastocytosis, skin involvement, basal total serum tryptase, and diaminooxidase concentrations.

RESULTS

The cumulative incidence of anaphylaxis in patients with mastocytosis was higher in adults (49%; P < 0.01) compared with that in children (9%). Only children with extensive skin involvement had experienced anaphylaxis. In adults, anaphylaxis was correlated to the absence of urticaria pigmentosa lesions (P < 0.03). Reactions occurred more frequently in adults with systemic (56%) when compared with cutaneous mastocytosis (13%; P < 0.02). In adults, 48% of reactions were severe, and 38% resulted in unconsciousness. Major perceived trigger factors for adults were hymenoptera stings (19%), foods (16%), and medication (9%); however, in 26% of reactions, only a combination of different triggers preceded anaphylaxis. Trigger factors remained unidentified in 67% of reactions in children compared with 13% in adults. Patients with anaphylaxis had higher basal tryptase values (60.2 +/- 55 ng/ml, P < 0.0001) in comparison with those without (21.2 +/- 33 ng/ml), but not diaminooxidase levels.

CONCLUSION

Adult patients and children with extensive skin disease with mastocytosis have an increased risk to develop severe anaphylaxis; thus, an emergency set of medication including epinephrine is recommended.

Diarrhea

Diarrheal diseases continue to contribute significant morbidity and mortality to pediatric populations in developed and developing countries around the world. The prevalence of diarrheal illness across cultures is inversely proportional to the availability of public sanitation, clean water supply, and adequate medical care. As such, it is not surprising that the incidence of diarrheal disease is much higher in developing societies and can approach 10 episodes per child per year in children under 5 years of age. In these areas, aggregate mortality can reach 3–5 million deaths per year. In the US and other developed nations, both the incidence (1–2 episodes per year) and mortality (approximately 400–500 deaths annually) are considerably decreased. Nonetheless, the burdens placed on Western healthcare systems by pediatric diarrheal disease are considerable and approximately 20% of all pediatric ambulatory visits and 10% of all inpatient hospital admissions in children under 3 years of age are for the evaluation and treatment of these disorders and their complications.

Modulation of mucosal immunity in a murine model of food-induced intestinal inflammation

BACKGROUND

Hypersensitivity or uncontrolled responses against dietary antigens can lead to inflammatory disorders like food allergy and current models reflect a variety of causes but do not reveal the detailed modulation of gut immunity in response to food antigens after breakdown in mucosal tolerance.

OBJECTIVE

To develop and characterize a murine model for food-induced intestinal inflammation and to demonstrate the modulation of gut immune response by dietary allergenic antigens.

METHODS

C57BL/6 mice were sensitized with peanut proteins, challenged with peanut seeds and their sera and gut segments were collected for subsequent analyses.

RESULTS

Sensitization and challenged with peanut seeds led to alterations in gut architecture with inflammatory response characterized by oedema in lamina propria and cell infiltrate composed mainly by eosinophils, mast cells, phagocytes, natural killer and plasma cells, together with low percentage of gammadelta+ and CD4+CD25+Foxp3+ cells in Peyer's patches. These animals also presented high levels of specific IgE and IgG1 in sera and modulation of mucosal immunity was mediated by increased expression of GATA-3, IL-4, IL-13 and TNF-alpha in contrast to low IFN-gamma in the gut.

CONCLUSION

A murine model for food-induced intestinal inflammation was characterized in which modulation of gut immunity occurs by peanut antigens in consequence of T-helper type 2 (Th2) allergic response and failure of regulatory mechanisms necessary for mucosa homeostasis, resembling food allergy. This work shed some light on the understanding of the pathogenesis of gastrointestinal disorders and intolerance in the gut and supports the development of therapies for food-related enteropathies like food allergy, focusing on gut-specific immune response.

Vicilin allergens of peanut and tree nuts (walnut, hazelnut and cashew nut) share structurally related IgE-binding epitopes

Surface-exposed IgE-binding epitopes of close overall conformation were characterized on the molecular surface of three-dimensional models built for the vicilin allergens of peanut (Ara h 1), walnut (Jug r 2), hazelnut (Cor a 11) and cashew nut (Ana o 1). They correspond to linear stretches of conserved amino acid sequences mainly located along the C-terminus of the polypeptide chains. A glyco-epitope corresponding to an exposed N-glycosylation site could also interfere with the IgE-binding epitopes. All these epitopic regions should participate in the IgE-binding cross-reactivity commonly reported between tree nuts or between peanut and some tree nuts in sensitized individuals. Owing to this epitopic community which constitutes a risk of cross-sensitization, the avoidance or a restricted consumption of other tree nuts should be recommended to peanut-sensitized individuals.

Two-dimensional grayscale ultrasound and spectral Doppler waveform evaluation of dogs with chronic enteropathies

Sonography is an important diagnostic tool to examine the gastrointestinal tract of dogs with chronic diarrhea. Two-dimensional grayscale ultrasound parameters to assess for various enteropathies primarily focus on wall thickness and layering. Mild, generalized thickening of the intestinal wall with maintenance of the wall layering is common in inflammatory bowel disease. Quantitative and semi-quantitative spectral Doppler arterial waveform analysis can be utilized for various enteropathies, including inflammatory bowel disease and food allergies. Dogs with inflammatory bowel disease have inadequate hemodynamic responses during digestion of food. Dogs with food allergies have prolonged vasodilation and lower resistive and pulsatility indices after eating allergen-inducing foods.

Psychological burden of food allergy

One fifth of the population report adverse reactions to food. Reasons for these symptoms are heterogeneous, varying from food allergy, food intolerance, irritable bowel syndrome to somatoform or other mental disorders. Literature reveals a large discrepancy between truly diagnosed food allergy and reports of food allergy symptoms by care seekers. In most studies currently available the characterization of patient groups is incomplete, because they did not distinguish between immunologic reactions and other kinds of food reactions. In analysing these adverse reactions, a thorough physical and psychological diagnostic approach is important. In our qualitative review, we present those diagnostic measures that are evidenced-based as well as clinically useful, and discuss the various psychological dimensions of adverse reactions to food. It is important to acknowledge the complex interplay between body and mind: Adults and children suffering from food allergy show impaired quality of life and a higher level of stress and anxiety. Pavlovian conditioning of adverse reactions plays an important role in maintaining symptoms. The role of personality, mood, or anxiety in food reactions is debatable. Somatoform disorders ought to be identified early to avoid lengthy and frustrating investigations. A future task will be to improve diagnostic algorithms, to describe psychological aspects in clearly characterised patient subgroups, and to develop strategies for an optimized management of the various types of adverse reactions to food.

Diagnostic accuracy of the atopy patch test in children with food allergy-related gastrointestinal symptoms

BACKGROUND

Little is known about the diagnostic accuracy of atopy patch tests (APT) in the clinical practice of pediatric gastroenterology. Moreover, APTs containing purified food extracts have recently become available, but their diagnostic accuracy is largely undefined.

PATIENTS AND METHODS

We evaluated the diagnostic accuracy of food challenge, skin prick test (SPT), serum specific IgE determination, and APT using fresh food and commercial food extracts in parallel in children referred for suspected food allergy-related gastrointestinal symptoms.

RESULTS

Eighty-nine food challenges were performed in 60 patients (38 boys, median age 23 months, range 3-48 months): 31 tested positive for cow's milk (CM), 19 for hen's egg (HE), and two for wheat. Specific immunoglobulin E (IgE) determination, and SPT, respectively, were positive in 7/31 and 14/31 of patients with cow's milk allergy (CMA), and in 7/19 and 7/19 with HE allergy. The results of APT with fresh food vs a commercial assay were (1) CM: sensitivity: 64.5%vs 6.4%, specificity 95.8%vs 95.6%, positive predictive value (PPV) 95.2%vs 66.6% and negative predictive value (NPV) 67.6%vs 43.1%; (2) HE: sensitivity 84.2%vs 5.2%, specificity 100%vs 100%, PPV 100%vs 100% and NPV 75.0%vs 33.3%.

CONCLUSIONS

Atopy patch test is a useful tool in the diagnostic work up of children with food-allergy-related gastrointestinal symptoms. The diagnostic accuracy of ATP was higher with fresh food than with commercial food extracts.

Relationship between Toxocara seropositivity and allergic rhinitis

BACKGROUND

Allergic rhinitis is the most common chronic disease in the upper respiratory tract, requiring better diagnostic methodology to counteract its onslaught. The purpose of this study was to investigate the association between Toxocara seropositivity and allergic rhinitis.

METHODS

Sixty-four consecutive patients with allergic rhinitis and 61 healthy volunteers in the control group were included in this study. The diagnosis of allergic rhinitis was defined by positive epicutaneous prick test. The diagnosis of toxocariasis was established by IgG and specific IgE antibodies against Toxocara by ELISA method. All cases were examined for intestinal parasites also. The seropositive cases with Toxocara were reevaluated for symptoms and signs of toxocariasis.

RESULTS

Higher toxocariasis seropositivity (ELISA IgG; 28.1%) rate was determined in the patients with allergic rhinitis and compared with the control groups (11.5%; p < 0.05). Specific IgE seropositivity (17.2%) was high for the patients with allergic rhinitis compared with the control group (3.3%; p < 0.05).

CONCLUSION

Our results show that there was a possible causal relationship between Toxocara infection and allergic rhinitis. Patients with allergic rhinitis from a region with high prevalence for this parasitic infection should be evaluated for Toxocara infection.

Assessment of childhood allergy for the primary care practitioner

PURPOSE

To update the primary care practitioner on the assessment of common childhood allergic illnesses.

DATA SOURCES

Relevant scientific literature and published clinical practice guidelines.

CONCLUSIONS

Atopic children often develop symptoms that occur in a predictable progression from atopic dermatitis to gastrointestinal disturbances, chronic serous otitis media, rhinitis, and asthma. Evaluation of allergic symptoms should be based on their chronicity, family history of atopy, and knowledge of how the information will change patient management. Both skin and blood testing are accurate and useful tools in establishing a diagnosis of allergic disease. Management includes avoidance/environmental control, medications, and, when necessary, referral to specialists.

IMPLICATIONS FOR PRACTICE

As the incidence of allergic disease increases, the human and monetary costs associated with allergies place a major burden on our healthcare system. Early identification of allergies and appropriate intervention are important to prevent progression to more significant disease. The use of objective diagnostic testing aids in implementing appropriate evidence-based medical management.

Coping with Food Allergy: Exploring the Role of the Online Support Group

The aims of this study were to explore the reasons for participation in an online support group for individuals affected by food allergy, its perceived advantages and disadvantages as well as impact on the relationship with healthcare providers. A total of 32 members of the Food Allergy Survivors Together (F.A.S.T.) online support group completed an online structured interview and responses were analysed using thematic analysis. Group members identified a range of benefits, including accessibility, receipt of social support as well as guidance on coping strategies. The only disadvantages identified revolved around the accuracy and trust in information exchanged via the group bulletin board. Group participation did appear to impact on relationships with healthcare providers with several members reporting greater empowerment through decision-making, though in contrast some experienced difficulties in discussing their online support experiences and information obtained with their healthcare providers.

Mothers' views on feeding infants around the time of weaning

Objective

To describe women's views about aspects of infants' diets around the time of weaning, making comparisons with national guidelines.

Design

A survey of women with a 9-month-old child.

Setting

Adelaide, South Australia.

Subjects

Five hundred and five women who joined a longitudinal study during pregnancy.

Results

Sources of information varied, with written material most commonly used (37%). Cows' milk was considered suitable as the main drink for weaned infants by 14% of women. There were divergent views about the suitability of eggs, with many women concerned about allergy. The majority of women (84%) viewed fruit juice as suitable although many qualified their response, often by stating that fruit juice should be diluted. Almost all women considered the amount of sugar mattered, primarily because of tooth decay, and that salt mattered although the reason was often uncertain. It was widely believed (77%) that additives in food could cause health problems, in particular hyperactivity and allergies, and half of the women reported avoiding specific foods because of concerns about allergies. Many women thought that giving their child food that was high in fat would encourage a liking for ‘junk’ food or lead to fatness in adulthood.

Conclusions

There is considerable diversity in the views women express about aspects of infant feeding that have been the subject of guidelines. Further health promotion efforts are needed to achieve greater consistency with recommendations and to address other concerns women have. This will entail greater engagement with parents and shared development of responses.

Food allergy in gastroenterologic diseases: Review of literature

Food allergy is a common and increasing problem worldwide. The newly-found knowledge might provide novel experimental strategies, especially for laboratory diagnosis. Approximately 20% of the population alters their diet for a perceived adverse reaction to food, but the application of double-blind placebo-controlled oral food challenge, the “gold standard” for diagnosis of food allergy, shows that questionnaire-based studies overestimate the prevalence of food allergies. The clinical disorders determined by adverse reactions to food can be classified on the basis of immunologic or nonimmunologic mechanisms and the organ system or systems affected. Diagnosis of food allergy is based on clinical history, skin prick tests, and laboratory tests to detect serum-food specific IgE, elimination diets and challenges. The primary therapy for food allergy is to avoid the responsible food. Antihistamines might partially relieve oral allergy syndrome and IgE-mediated skin symptoms, but they do not block systemic reactions. Systemic corticosteroids are generally effective in treating chronic IgE-mediated disorders. Epinephrine is the mainstay of treatment for anaphylaxis. Experimental therapies for IgE-mediated food allergy have been evaluated, such as humanized IgG anti-IgE antibodies and allergen specific immunotherapy.

Epitope characterization of ovalbumin in BALB/c mice using different entry routes

Ovalbumin (OVA) is known as a major allergen in egg white. A number of studies have reported the partial T and B cell epitope mapping of OVA using murine models and allergic patients' sera. Recently, we have reported the IgE-binding regions of the entire OVA molecule using egg allergic patients' sera. However, the entire epitope mapping of OVA in a murine model has not been completed yet. In the present study, BALB/c mice were administered a solution of OVA using three different entry routes (oral, intraperitoneal and subcutaneous) with their respective adjuvant (cholera toxin, aluminum hydroxide and Freund's adjuvant). Two nitrocellulose membranes containing 188 overlapping synthetic peptides (with a length of 12 amino acids and an offset of two amino acids) covering the primary sequence of OVA, were probed with the three different BALB/c mice antisera. Antisera obtained from orally challenged mice identified eight IgE epitope regions, i.e. I53D60; V77R84; S103E108; G127T136; E275V280; G301F306; I323A332 and A375S384, while sera raised by intraperitoneal and subcutaneous injections exhibited two (K55D60 and K277L282) and five (K55R58; G127T136; K279L282; T303S308 and I323A332) IgE binding sequences, respectively. The residues critical for the epitope-paratope interactions were finely characterized using the oral immunization serum. Analysis of IgE binding epitopes in mice provides us with potential strategies for design of specific immunotherapy.

Gastro-Intestinal Exposure to Latex Antigens Induce Allergic Responses in Mice

BACKGROUND

Natural rubber latex (NRL) has emerged as a major cause of respiratory allergy among specific exposed groups of individuals. Since latex allergens are dispersed in the environment it is conceivable that latex proteins are both inhaled and ingested. The mechanism of latex allergy and the immune responses following reexposure of latex allergens by the intranasal route was studied in a murine model of latex allergy developed by intragastric sensitization with NRL.

METHODS

BALB/c mice were sensitized intragastrically ('ig'), intranasally ('in') or 'ig' followed by 'in' challenge with NRL allergens. The cellular and humoral immune responses, lung function and histological changes were determined.

RESULTS

Peripheral blood eosinophilia was observed in the 'ig' and 'ig/in'-NRL-sensitized animals in comparison to normal controls (p < 0.05). The 'ig' group showed a marked increase over control mice in serum total IgE, NRL-specific IgG and IgG subclasses (p < 0.05). Increased levels of IL-4, IL-5, IL-10, and IL-13 were detected in 'ig'-NRL-sensitized mice. Intranasal exposure with NRL after 'ig' sensitization further enhanced the cytokine levels. A tendency towards enhanced stimulation was determined in 'ig'-sensitized mice; a significant difference was shown in the 'ig/in'-group (p < 0.05). Increased airway hyperreactivity was found in 'ig'-NRL-sensitized-mice (15.1 +/- 2.5 vs. 8.9 +/- 1.7 cm H2O x ml(-1) x s, p < 0.05). Mucus secretion from jejunal epithelium and eosinophilic infiltration into the jejunal lamina propria were observed in the 'ig'-NRL-sensitized-mice.

CONCLUSIONS

The results demonstrate that intragastric NRL sensitization did not induce specific tolerance, and additional intranasal exposure with latex allergens resulted in systemic allergic manifestations in the murine model.

Allergic reactions in the community: a questionnaire survey of members of the anaphylaxis campaign

BACKGROUND

Allergic reactions to food are well recognized in both children and adults, but because of their relative infrequency their typical features may not be readily recognized by patients and their medical care givers who are not allergists.

OBJECTIVE

We sought to investigate the circumstances and clinical characteristics of food allergies in adults and children in the community.

METHODS

Self-completed questionnaire responses over a 6-month period from 109 members of the Anaphylaxis Campaign, the major British patient resource group for people who have suffered severe allergic reactions.

RESULTS

One hundred and nine respondents reported 126 reactions during the study period. Seventy-five were children (under 16 years, median age 6 years at the time of reaction). Predictably more boys than girls were reported to have had reactions but more women reported reactions than men (P<0.05). Although the groups were equally aware of their food allergies the children had undergone diagnostic tests more often (P<0.001). Foods were implicated in 112 (89%) of reports. Restaurants were implicated less often (14%) than in other series, probably reflecting British eating habits. Children with asthma reported more severe reactions than those without asthma (P=0.008), although frequency or severity of recent asthma symptoms was not associated with severity of allergic reaction reported. When available, self-injectable adrenaline was used in 35% of severe reactions and 13% of non-severe reactions (P=0.01). A quarter of adults who received one dose of adrenaline also received a second dose.

CONCLUSION

The allergens implicated in this report reflect previous data from similar patient groups in North America. Asthmatic children suffer more severe reactions than non-asthmatic children. It appears that British adults need better access to expert care of their allergies. Even when it is prescribed and available self-injectable adrenaline appears under-used in severe reactions. The incidence of severe but non-fatal allergic reactions in the UK may have been underestimated in the past.

Health-related quality of life in food hypersensitive schoolchildren and their families: parents' perceptions

BACKGROUND

About 20% of schoolchildren and adolescents in Sweden suffer from perceived food hypersensitivity (e.g. allergy or intolerance). Our knowledge of how child food hypersensitivity affects parents HRQL and what aspects of the hypersensitivity condition relate to HRQL deterioration in the family is limited. Thus the aim of this study was to investigate the parent-reported HRQL in families with a schoolchild considered to be food hypersensitive. The allergy-associated parameters we operated with were number of offending food items, adverse food reactions, additional hypersensitivity, allergic diseases and additional family members with food hypersensitivity. These parameters, along with age and gender were assessed in relation to child, parent and family HRQL.

METHODS

In May 2004, a postal questionnaire was distributed to parents of 220 schoolchildren with parent-reported food hypersensitivity (response rate 74%). Two questionnaires were used: CHQ-PF28 and a study-specific questionnaire including questions on allergy-associated parameters. In order to find factors that predict impact on HRQL, stepwise multiple linear regression analyses were carried out.

RESULTS

An important predictor of low HRQL was allergic disease (i.e. asthma, eczema, rhino conjunctivitis) in addition to food hypersensitivity. The higher the number of allergic diseases, the lower the physical HRQL for the child, the lower the parental HRQL and the more disruption in family activities. Male gender predicted lower physical HRQL than female gender. If the child had sibling(s) with food hypersensitivity this predicted lower psychosocial HRQL for the child and lower parental HRQL. Food-induced gastro-intestinal symptoms predicted lower parental HRQL while food-induced breathing difficulties predicted higher psychosocial HRQL for the child and enhanced HRQL with regards to the family's ability to get along.

CONCLUSION

The variance in the child's physical HRQL was to a considerable extent explained by the presence of allergic disease. However, food hypersensitivity by itself was associated with deterioration of child's psychosocial HRQL, regardless of additional allergic disease. The results suggest that it is rather the risk of food reactions and measures to avoid them that are associated with lower HRQL than the clinical reactivity induced by food intake. Therefore, food hypersensitivity must be considered to have a strong psychosocial impact.

Is there a role of food allergy in irritable bowel syndrome and functional dyspepsia? A systematic review

A significant proportion of adults believe they suffer from food allergy, and 20-65% of patients with irritable bowel syndrome (IBS) attribute their symptoms to something in food that activates an abnormal response. This systematic review evaluates the role of food allergy in aetiology and management of these disorders. Activation of gastrointestinal mucosal immune system may be one of the causative factors in the pathogenesis of functional dyspepsia and IBS. This activation may result from effects of bacterial infection or other luminal factors including commensal microbial flora and food antigens. Some studies have reported on the role of food allergy in IBS; only one epidemiological study on functional dyspepsia and food allergy has been published. The mechanism by which food activates mucosal immune system is uncertain, but food specific IgE and IgG4 appeared to mediate the hypersensitivity reaction in a subgroup of IBS patients. Exclusion diets based on skin prick test, RAST for IgE or IgG4, hypoallergic diet and clinical trials with oral disodium cromoglycate have been conducted, and some success has been reported in a subset of IBS patients. Further well-controlled studies are needed to establish whether food allergy plays a role in the pathophysiology of functional dyspepsia and IBS.

Exposure to the fish parasite Anisakis causes allergic airway hyperreactivity and dermatitis

BACKGROUND

Several case reports show allergy and anaphylactic reactions to the fish parasite Anisakis in the domestic and occupational setting. Further research is needed on the prevalence and mechanisms of disease.

OBJECTIVE

To determine the prevalence of Anisakis sensitization and related symptoms among workers in 2 fish-processing factories, and to use gene-deficient mice to determine the working mechanisms of Anisakis allergy.

METHODS

A modified version of the European Community Respiratory Health Survey was used to interview 578 South African fish-processing workers. Sensitization to Anisakis, seafood, and common aeroallergens was determined by skin prick test. Lung function was measured by spirometry and methacholine challenge. Serum eicosapentaenoic acid levels were used as an index of seafood consumption. Sensitized wild-type, IL-4, or IL-4 receptor alpha-deficient mice were challenged orally with Anisakis extract. Allergic reactions, lung pathology, antibodies, cytokines, mast cell proteases, and histamine were evaluated.

RESULTS

The prevalence of sensitization to Anisakis was higher than the prevalence of sensitization to fish (8% vs 6%). Anisakis-specific IgE reactivity was associated with bronchial hyperreactivity and dermatitis, and significantly increased with fish consumption. In mice, Anisakis infective larvae (L3) induced a striking T(H)2/type 2 response. Food-allergic-type reactions induced by oral challenge with Anisakis extract were absent in IL-4 receptor alpha knockout mice.

CONCLUSION

Anisakis sensitization in fish-processing workers is associated with allergic symptoms and correlates with high levels of fish consumption. Anisakis proteins induce allergic reactions in sensitized mice by IL-4/IL-13-mediated mechanisms.

CLINICAL IMPLICATIONS

Anisakis allergy should be considered in fish-processing workers with allergic symptoms.

Molecularly defined adult-type hypolactasia in school-aged children with a previous history of cow’s milk allergy

AIM: To assess the role of lactase non-persistence/persistence in school-aged children and their milk-related symptoms.

METHODS: The genotypes for the C/T_-13910 variant associated with lactase non-persistence/ persistence were determined using PCR-minisequencing in a group of 172 children with a mean age of 8.6 years (SE = 0.02, 93 boys) participating in a follow-up study for cow’s milk allergy. The parents were asked to assess their children’s milk consumption and abdominal symptoms.

RESULTS: The presence of allergy to cow’s milk was not associated with the C/C_-13910 genotype related with a decline of lactase enzyme activity during childhood (lactase non-persistence). The frequency of the C/C_-13910 genotype (16%) was similar to published figures for the prevalence of adult-type hypolactasia in Finland. The majority of the children (90%) in this series consumed milk but 26% of their families suspected that their children had milk-related symptoms. Forty-eight percent of the children with the C/C_-13910 genotype did not drink milk at all or consumed a low lactose containing diet prior to the genotyping (P < 0.004 when compared to the other genotypes).

CONCLUSION: Analysis of the C/T_-13910 polymorphism is an easy and reliable method for excluding adult-type hypolactasia in children with milk-related symptoms. Genotyping for this variant can be used to advise diets for children with a previous history of cow’s milk allergy.

Cow's milk allergy: a complex disorder

Cow's milk allergy (CMA) is a complex disorder. Numerous milk proteins have been implicated in allergic responses and most of these have been shown to contain multiple allergenic epitopes. There is considerable heterogeneity amongst allergic individuals for the particular proteins and epitopes to which they react, and to further complicate matters, allergic reactions to cow's milk are driven by more than one immunological mechanism. Finally, the incidence and dominant allergic mechanisms change with age, with IgE-mediated reactions common in infancy and non-IgE-mediated reactions dominating in adults. The complexity of CMA has lead to many public misconceptions about this disorder, including confusion with lactose intolerance and frequent self-misdiagnosis. Indeed, the prevalence of self-diagnosed CMA in the community is 10-fold higher than the clinically proven incidence, suggesting a sizable population is unnecessarily eschewing dairy products. Avoidance of dairy foods, whether for true or perceived CMA, carries with it nutritional consequences and the provision of appropriate nutritional advice is important. In this review, the epidemiology and natural course of CMA is discussed along with our current understanding of its triggers and immunological mechanisms. We examine current strategies for the primary and secondary prevention of allergic sensitization and the ongoing search for effective therapies to ultimately cure CMA.

Adverse reactions to foods

Food allergy encompasses a variety of immune-mediated adverse reactions to foods. IgE-mediated, cell-mediated, and mixed-mechanism food allergy disorders are recognized. Over the past 2 decades, the prevalence of food allergy doubled and its phenotypic expression increased in Westernized societies. Major food allergens have been identified for many common foods. Laboratory diagnosis of food allergy relies heavily on the detection of food-specific IgE antibodies, but novel approaches include tests for T-cell-mediated disorders and tests for prediction of tolerance. OFC remains the diagnostic standard for food allergy. Management of food allergy focuses on avoidance of the offending foods, nutritional support, and prompt recognition and treatment of acute food allergic reactions. Anti-IgE monoclonal antibody is the first potential therapy for food allergy that is under-going testing in clinical trials.

Genetically modified plants and food hypersensitivity diseases: usage and implications of experimental models for risk assessment

The recent advances in biotechnology in the plant industry have led to increasing crop production and yield that in turn has increased the usage of genetically modified (GM) food in the human food chain. The usage of GM foods for human consumption has raised a number of fundamental questions including the ability of GM foods to elicit potentially harmful immunological responses, including allergic hypersensitivity. To assess the safety of foods derived from GM plants including allergenic potential, the US FDA, Food and Agriculture Organization of the United Nations (FAO)/World Health Organization (WHO), and the EU have developed approaches for evaluation assessment. One assessment approach that has been a very active area of research and debate is the development and usage of animal models to assess the potential allergenicity of GM foods. A number of specific animal models employing rodents, pigs, and dogs have been developed for allergenicity assessment. However, validation of these models is needed and consideration of the criteria for an appropriate animal model for the assessment of allergenicity in GM plants is required. We have recently employed a BALB/c mouse model to assess the potential allergenicity of GM plants. We have been able to demonstrate that this model is able to detect differences in antigenicity and identify aspects of protein post-translational modifications that can alter antigenicity. Furthermore, this model has also enabled us to examine the usage of GM plants as a therapeutic approach for the treatment of allergic diseases. This review discusses the current approaches to assess the allergenic potential of GM food and particularly focusing on the usage of animal models to determine the potential allergenicity of GM foods and gives an overview of our recent findings and implications of these studies.

The development and progression of allergy to multiple nuts at different ages

The aims of this study were to define the development of sensitization and clinical allergy to multiple nut types by age, and to identify associations. This observational cross- sectional study was carried out in a tertiary level allergy clinic. Seven hundred and eighty four nut-allergic children, prospectively enrolled on first attendance with history of a type-1 allergic reaction shortly after definite nut ingestion with evidence of sensitization (presence of nut-specific IgE) by skin prick test (SPT) to peanut, Brazil, almond, hazel and walnut (positive > or = 3 mm). Details of exposure (tolerance or allergy) to each nut were obtained. The main outcome measures were mono or multi-sensitization (specific IgE to one or more than one nut type, demonstrated by SPT); mono or multi-allergy (clinical allergy to one or more than one nut type). By 2 yr of age at least 19% were multi-sensitized, and 2% multi-allergic. Increasing proportions were exposed to multiple nut types with increasing age (23% at 2 yr to 73% by 10 yr) and greater proportions were multi-sensitized (19% at 2 yr to 86% at 5-14 yr) and multi-allergic (2% at 2 yr to 47% at 14 yr). This study is the first to define the natural history of multiple nut allergies in childhood. New findings are that a large proportion of those aged 0-1 yr with nut allergy are already sensitized (have specific IgE) to multiple nut types, implying in utero or early life sensitization; those who present later in childhood are increasingly likely to be sensitized and clinically allergic to multiple nuts. This is related to increased duration of allergy and exposure to multiple nut types with age. Children with nut allergy should avoid all nut types from the onset.

Prevalence of food allergy and its relationship to asthma and allergic rhinitis in schoolchildren

BACKGROUND

Food allergy (FA) is an important health problem. However, epidemiological studies at the population level are scarce. We assessed the prevalence of FA and its associations with respiratory manifestations among schoolchildren.

METHODS

A total of 6672 schoolchildren aged 9-11 years recruited from 108 randomly chosen schools in six French cities underwent a clinical examination including skin prick test (SPT) to common food and aeroallergens and the standardized protocol of the run test to assess exercise-induced bronchial hyper-responsiveness (EIB). Asthma, allergic rhinitis (AR) and clinical symptoms of FA were determined using a standardized questionnaire completed by parents.

RESULTS

About 2.1% of the children reported symptoms of FA, 1.9% were sensitized to food allergens, and 0.1% had SP-tested FA. The AR was more prevalent than asthma (20.0% lifetime, 11.9% past year vs 9.8%, 8.7% respectively). Reported FA, food sensitization and SP-tested FA were all positively associated with asthma and AR (P < 0.001). These associations persisted also for FA not manifesting as respiratory symptoms (P < 0.001). Asthma and AR remained significantly associated with reported symptoms of FA and allergic sensitization to food allergens after adjustment for confounders as well as for sensitization to aeroallergens. No relationship existed between EIB (9.0%) and FA.

CONCLUSION

The relationships between FA and asthma and AR could be totally explained neither by the existence of respiratory manifestations of FA nor by sensitization to aeroallergens. The FA might intervene differently in asthma and AR.

Improving the management of atopic disease

Asthma, wheeze, eczema, and, to a certain extent, rhinitis are very common conditions among children. The prevalence of allergic disease in the general population has increased alarmingly over the past 25 years, particularly in Western industrialised countries. However, it is important to remember that the symptoms often associated with allergy can have other aetiologies. Evidence suggests that in most circumstances, only 30-40% of chronic allergic-type symptoms are due to allergy. Accurate diagnosis of the presence of allergy is therefore an important issue, particularly given the interventions that such a diagnosis may initiate. In this review, we examine management options for allergy, provide the evidence as to what proportions of patients with common allergic-type symptoms are actually allergic, and list other causes of such symptoms. The importance of allergy testing and the options available are described, particularly with reference to the role of the non-allergist.

A framework for measuring costs to society of IgE-mediated food allergy

Both immunoglobulin E (IgE)-mediated food allergy and food intolerance can lead to many changes in personal behaviour and health care resource use which have important economic consequences. These costs will impact directly, indirectly and intangibly on both individuals and society in general. It is important to measure the cost of illness (COI) of food allergy as a first step in developing and evaluating measures to reduce and control the burden of illness. This paper outlines a framework for assessing COI of food allergy from different viewpoints. It offers a structure for identifying the different cost impacts on allergic and nonallergic consumers, food producers and society as a whole, and for scoping, measurement and valuation of relevant costs. Within this structure, the existing literature is reviewed. This review illustrates the lack of information and clear methodology for assessing costs of food allergy. The paper concludes that there is a need for a more structured research programme to generate data essential for future evaluations of procedures and technologies for the diagnosis, treatment and management of food allergy.

Epsilon germ-line and IL-4 transcripts are expressed in human intestinal mucosa and enhanced in patients with food allergy

BACKGROUND

The mechanisms of gastrointestinal (GI) food allergy (FA) are poorly understood. Immunoglobulin E (IgE) is increased in stools from patients with FA, as well as the number of cells carrying IgE in intestinal mucosa, but the origin of IgE production remains unknown. To investigate a local production of IgE in intestine, we analysed the levels of transcripts for epsilon germ-line (epsilonGT), and potential regulators of IgE production, IL-4, IL-13, IFN-gamma, IL-4Ralpha, STAT6 and FcepsilonRIalpha in intestinal mucosa of adult patients with FA.

METHODS

Endoscopic biopsies were obtained from the caecum of 25 patients with FA and 14 control patients. The levels of epsilonGT, IL-4, IL-13, IFN-gamma, IL-4Ralpha, STAT6 and FcepsilonRIalpha mRNA were analysed by real-time RT-PCR and compared with unpaired nonparametric Mann-Whitney test.

RESULTS

The mean epsilonGT transcript level in caecum was increased in FA patients compared with control patients (P < 0.05). IL-4 mRNA expression was also increased in FA patients (P < 0.05), whereas mRNA expression for IL-13, IFN-gamma, IL-4Ralpha, STAT6 and FcepsilonRIalpha mRNA expression was not altered. However, the ratio of IL-4 mRNA/IFN-gamma mRNA was significantly increased in FA patients (P < 0.05). No correlation was observed between epsilonGT transcripts expression in intestinal mucosa and total IgE levels in serum.

CONCLUSIONS

This study shows that (i) epsilonGT transcripts are expressed in human intestinal mucosa; (ii) epsilonGT and IL-4 transcripts are increased in caecal mucosa from patients with FA. These results suggest local production of IgE in intestine that might be of importance for inflammatory reactions in the GI tract.

Nasal IL-12p70 DNA Prevents and Treats Intestinal Allergic Diarrhea

OVA-induced allergic diarrhea occurs as a consequence of over-expression of Th1 inhibitory IL-12p40 monomers and homodimers in the large intestine, establishing a dominant Th2-type environment. In this study, we demonstrate that intranasally administered murine IL-12p70 naked DNA expression plasmids resulted in the synthesis of corresponding cytokine in the large intestinal CD11c(+) dendritic cells, leading to the inhibition of Ag-specific Th2-type response for the prevention of allergic diarrhea and the suppression of clinical symptoms including OVA-specific IgE Ab synthesis. The nasal IL-12p70 DNA treatment proved effective even after the establishment of allergic diarrhea. These results suggest that the mucosal administration of naked IL-12p70 DNA plasmid should be considered as a possible preventive and therapeutic treatment for Th2 cell-mediated food allergic diseases in the intestinal tract.

Allergy-like conditions and health-care contacts among children with exclusion diets at school

AIM

To find out whether children with exclusion diet at school had allergy-like conditions that could explain their food avoidance, the objective of this study was to describe health-care contacts and diagnostic testing among schoolchildren with exclusion diet and compare the magnitude of allergy-like conditions between those children who had vs. had not consulted health-care professionals. Telephone interviews were conducted with the parents of 230 schoolchildren, aged 6-18 years, with certificates for exclusion diets at school.

RESULTS

The majority of the schoolchildren (85%) had consulted health-care professionals for food-related problems, and 68% were doctor-diagnosed as having food hypersensitivity. Those who had consulted health-care professionals specifically for their food-related problems had more complex and severe problems compared with those who had not consulted health-care professionals. Breathing difficulties (27/196) and anaphylaxis (9/196) related to intake of food were reported only for those who had sought health-care professionals (n = 196). Regardless of whether the children had consulted the health-care professionals, their food-related problems were consistent with food hypersensitivity. Schoolchildren avoided food items known to be associated with food hypersensitivity such as tree nuts, fruit, egg, peanut, lactose and fish. Furthermore, 83% of the 230 children also had allergic diseases (i.e. asthma, eczema or hay fever) or were hypersensitive to other substances besides food, and 83% had at least one sibling or parent with hypersensitivity to foods or other substances.

CONCLUSIONS AND IMPLICATIONS FOR THE SCHOOL NURSE

Schoolchildren with food certificates for exclusion diets, based on parents' statements, have food-related and allergy-like problems that may well motivate exclusion diets at school. The school nurses can rely on the parents' information as to what foods their children should avoid, even when doctor diagnoses have not been made or health-care consultations have not been carried out.

Pattern recognition and feature extraction of canine celiac and cranial mesenteric arterial waveforms: normal versus chronic enteropathy--a pilot study

In this pilot study, we hypothesize that waveform patterns of the celiac and cranial mesenteric arteries differ pre- and post-prandially in normal dogs compared to those with chronic enteropathy. We further suggest that it is possible to classify these findings according to the type of disease present. Eleven dogs with chronic enteropathy and eight normal dogs were examined. Doppler examinations were performed at times 0 (fasted), and at 20, 40, 60 and 90 min post-prandially. The waveform shapes were described and the following features were extracted: resistive and pulsatility index, mean maximum velocity, mean diastolic velocity, peak systolic velocity, early diastolic notch ratio and the deceleration time interval. Dogs with inflammatory bowel disease had either lower or absent flow at fasting in early diastole compared to the other groups. Resistive and pulsatility indices decreased during digestion in all groups except those with protein losing enteropathy. The increase in mean diastolic flow during digestion in affected dogs was either lacking (protein-losing enteropathy) or significantly lower (inflammatory bowel disease, P<0.05) compared to normal dogs. Dogs with chronic enteropathies had abnormal arterial waveform shapes and suboptimal increases in diastolic blood flow during digestion and these findings worsened with the severity of the histological lesions present. Doppler ultrasound of the celiac and mesenteric arteries has great potential to enhance our understanding of intestinal disease in conscious dogs.

Gastrointestinal food allergy: new insights into pathophysiology and clinical perspectives

Adverse reactions to food that result in gastrointestinal symptoms are common in the general population; while only a minority of such individuals will have symptoms due to immunologic reactions to foods, gastrointestinal food allergies do exist in both children and adults. These immune reactions are mediated by immunoglobulin E-dependent and -independent mechanisms involving mast cells, eosinophils, and other immune cells, but the complexity of the underlying mechanisms of pathogenesis have yet to be fully defined. Knowledge of the spectrum of adverse reactions to foods that affect the digestive system, including gastrointestinal food allergy, is essential to correctly diagnose and manage the subset of patients with immunologically mediated adverse reactions to foods. Potentially fatal reactions to food necessitate careful instruction and monitoring on the part of health care workers involved in the care of individuals at risk of anaphylaxis. New methods of diagnosis and novel strategies for treatment, including immunologic modulation and the development of hypoallergenic foods, are exciting developments in the field of food allergy.

Food hypersensitivity in patients with seasonal rhinitis in Ankara

BACKGROUND

Food hypersensitivity (FH) affects 1-2 % of the adult population and is more common in atopic individuals. The aim of this study was to determine the frequency of FH and risk factors for its development in patients with seasonal rhinitis (SR) in our allergy clinic.

METHODS

We performed a retrospective study based on the medical records of 774 patients out of 955 patients diagnosed with SR in an adult allergy clinic between 1 January 1991 and 31 December 2003.

RESULTS

The mean age of the patients was 29.1 +/- 9.29 and 62.7 % were females. The most common major complaints were due to nasal symptoms in 82.3 %. The mean duration of SR was 6.8 +/- 6.8 years. Patients were symptomatic for a mean of 3.5 +/- 1.7 months per year. Skin prick tests (SPT) with common aeroallergens were positive in 685 patients (90.3 %), and the most common sensitivity was against timothy (85.1 %). The most common accompanying allergic disease was FH in 14 %. FH according to history and the results of SPT performed with food allergens were discordant. The most common clinical manifestations of FH were oral allergy (49.1 %) and cutaneous symptoms (38.9 %). Risk factors for the development of FH in patients with SR were dermatological symptoms, rhinitis duration > 5 years, symptom duration > 3 months per year, SPT reactivity to Artemisia vulgaris, tree pollen allergens (Corylus avellena, Betula verrucosa), and bee allergy.

CONCLUSION

FH was the most common (14 %) accompanying allergic disease in patients with SR. SPT with food allergens have limited diagnostic value for food allergy and/or intolerance. Risk factors for developing FH in patients with SR in Turkey were dermatological symptoms, duration of rhinitis > 5 years, duration of rhinitis symptoms > 3 months per year, and SPT reactivity to Corylus avellena.

RETRACTED: Promising treatments in development for food allergies

Up to 6% of young children and 2% of adults suffer from food allergy. Among them many have IgE-mediated food allergy, a condition with potentially fatal allergic reactions. The only proven treatment is avoidance of the offending food, which can be identified using standardised allergic tests. However, several studies have addressed possible definite treatment options for food allergy. Immunotherapy, administered orally or by systemic injections, shows promising preliminary results, but these therapeutics are based on studies with insufficient scientific support, or are associated with a high risk of severe side effects. At present, no studies can support pharmacotherapy. However, promising results were recently published with anti-IgE antibodies in a human trial, and various approaches in a mouse model of food allergy (chinese herbal medicine, specific modulation of the T-cell response). Rapidly evolving findings might provide hope for a cure for food allergy in the near future.

Identification of allergens responsible for canine cutaneous adverse food reactions to lamb, beef and cow's milk

Lamb, beef and cow's milk are common causes of cutaneous adverse food reactions in dogs. The aim of this study was to identify the proteins responsible for cutaneous adverse reactions to these foods. Ten dogs with allergen-specific serum immunoglobulin (Ig)E to lamb, beef and cow's milk were included in the study. These dogs had been diagnosed with cutaneous adverse food reactions by convincing clinical history and food-elimination diet trials followed by challenge exposure. Sera were analysed by enzyme-linked immunosorbent assay with bovine proteins and SDS-PAGE immunoblots with lamb, beef and cow's milk extracts. All the dogs had specific IgE against bovine IgG, and it was the only protein in the cow's milk extract that bound IgE from the sera studied. In the lamb and beef extracts, the major allergens recognized by the specific IgE of most sera had molecular masses between 51 and 58 kDa, which were identified as phosphoglucomutase and the IgG heavy chain. Other IgE-binding proteins with molecular masses of 27, 31, 33, 37 and 42 kDa were also detected with some sera. Our results indicate that bovine IgG is a major allergen in cow's milk and hence it appears to be a source of cross-reactivity with beef and probably with lamb because of the high homology with ovine immunoglobulins. These results are similar to those found for meat allergy in humans. However, this is the first time that phosphoglucomutase has been identified as an important allergen involved in allergic reactions to lamb and beef.

Prevalence and main characteristics of schoolchildren diagnosed withfood allergies in France

BACKGROUND

A cross-sectional, descriptive, questionnaire-based survey was conducted in Toulouse schools to determine the prevalence of food allergies among schoolchildren.

OBJECTIVES

The first goal of the survey was to estimate the prevalence of food allergies. The second goal was to determine the main characteristics of the allergies.

METHODS

The questionnaires (3500) were distributed in 150 classes in eight schools. The return rate was 77.6% (2716).

RESULTS

Of the 192 (7.0%) questionnaires with a 'Yes' response (report of a food allergy), 182 were retained as reporting true food allergies (6.7%). The cumulative and point prevalences were 6.7% [95% confidence interval (CI) 5.8-7.6] and 4.7% [95% CI 3.9-5.5], respectively. The point prevalences were 4.0% for the children aged 2-5 years, 6.8% for the children aged 6-10 years, and 3.4% for the children aged 11-14 years. The main foods reported as causing adverse reactions were cow milk (n = 29, 11.9%), eggs (n = 23, 9.4%), kiwis (n = 22, 9.0%), peanuts (n = 20, 8.2%), fish (n = 19, 7.8%), tree nuts (n = 19, 7.8%), and shrimp (n = 13, 5.3%). The average age at which the allergies were detected was 3.4+/-2.8 years (with a range of 0.1-12 years). The clinical signs of the food allergies were cutaneous (n=153, 62.7%), digestive (n = 74, 30.3%), respiratory (n = 17, 6.9%), and anaphylactic shock (n = 12, 4.9%).

CONCLUSION

While well aware of the biases inherent in this type of study, we estimated the cumulative and point prevalences of food allergies in a population of school-age children in Toulouse at 6.7% and 4.7%, respectively. Cow milk, eggs, and peanuts were the main foods reported as causing allergies. Exotic fruits, shellfish, and tree nuts appeared to be relatively new allergens.

Health-related quality of life among adolescents with allergy-like conditions - with emphasis on food hypersensitivity

BACKGROUND

It is known that there is an increase in the prevalence of allergy and that allergic diseases have a negative impact on individuals' health-related quality of life (HRQL). However, research in this field is mainly focused on individuals with verified allergy, i.e. leaving out those with self-reported allergy-like conditions but with no doctor-diagnosis. Furthermore, studies on food hypersensitivity and quality of life are scarce. In order to receive information about the extent to which adolescent females and males experience allergy-like conditions and the impact of these conditions on their everyday life, the present study aimed to investigate the magnitude of self-reported allergy-like conditions in adolescence and to evaluate their HRQL. Special focus was put on food hypersensitivity as a specific allergy-like condition and on gender differences.

METHODS

In connection with lessons completed at the children's school, a study-specific questionnaire and the generic instrument SF-36 were distributed to 1488 adolescents, 13-21 years old (response rate 97%).

RESULTS

Sixty-four per cent of the respondents reported some kind of allergy-like condition: 46% reported hypersensitivity to defined substances and 51% reported allergic diseases (i.e. asthma/wheezing, eczema/rash, rhino-conjunctivitis). A total of 19% reported food hypersensitivity. Females more often reported allergy-like conditions compared with males (p < 0.001). The adolescents with allergy-like conditions reported significantly lower HRQL (p < 0.001) in seven of the eight SF-36 health scales compared with adolescents without such conditions, regardless of whether the condition had been doctor-diagnosed or not. Most adolescents suffered from complex allergy-like conditions.

CONCLUSIONS

The results indicate a need to consider the psychosocial impact of allergy-like conditions during school age. Further research is needed to elucidate the gender differences in this area. A team approach addressing better understanding of how allergy-like conditions impair the HRQL may improve the management of the adolescent's health problems, both in health-care services and in schools.

Recurrent abdominal pain in school children revisited: fitting adverse food reactions into the puzzle

The diagnostic work-up of children seeking health care because of recurrent abdominal pain is a clinical challenge. Food hypersensitivity might be one of the aetiologies behind this symptom. Neither the understanding of possible immune mechanisms nor endoscopic or histological findings have yet contributed to reliable diagnostic tests.

CONCLUSION

The possibility of adverse food reactions should be evaluated among other abnormalities behind recurrent abdominal pain in children. Still, the diagnosis of immunemediated food reactions depends on open or blinded food challenge.

Adoptive transfer of dendritic cells from allergic mice induces specific immunoglobulin E antibody in naïve recipients in absence of antigen challenge without altering the T helper 1/T helper 2 balance

Dendritic cells (DCs) are important in the regulation of immune responses and it has been proposed that these cells play an important role in asthma; however, their role in food allergy is still largely unknown. Our aim was to study specific immunoglobulin E (IgE) and immunoglobulin G (IgG) responses in naïve recipients following adoptive transfer of myeloid DCs from allergic and control mice. The phenotypic features and lymphokine production of DCs were also investigated. CD11c+/hi B220- DCs isolated from spleen and Peyer's patches (PP) of cow's milk (CM) allergic and control mice were transferred intravenously (i.v.) into naïve syngeneic recipients, and IgE- and IgG-specific responses were evaluated. Experiments were also carried out to determine the levels of interferon-gamma (IFN-gamma) and interleukin (IL)-4 produced by splenocytes from naïve recipients following the adoptive transfer, and CD40 ligand (CD40L)-mediated IL-10 production by DCs from allergic and control mice. DCs isolated from spleen and PP of allergic mice, but not control groups, induced CM-specific IgG and IgE antibody production in naïve recipients in the absence of previous immunization, but did not modify the T helper 1 (Th1) and T helper 2 (Th2) balance. Furthermore, although no difference was observed in the expression of canonical DC surface markers, PP DCs from allergic mice produced less IL-10 than DCs from controls. We interpret these data as showing that DCs play a pivotal role in allergen-specific IgE responses and that a Th2-skewed response may not be involved in the early phase of allergic responses. The identification of the mechanisms underlying these events may help to design novel strategies of therapeutic intervention in food allergy.