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Archive for category immune system


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How do peanut and nut-allergic consumers use information on the packaging to avoid allergens?

Reference:

Barnett J, Leftwich J, Muncer K, Grimshaw K, Shepherd R, Raats MM, Gowland MH, Lucas JS. How do peanut and nut-allergic consumers use information on the packaging to avoid allergens? Allergy. 2011 Feb 14. doi: 10.1111/j.1398-9995.2011.02563.x.


Abstract:

BACKGROUND: Recent legislation has sought to improve the information printed on packaged foods relevant to the safety of food allergic consumers. We aimed to understand the complex risk assessment decisions made by peanut and nut-allergic adults when purchasing food, with particular reference to use of printed package information.

METHODS: The behaviour and ‘thinking aloud’ of 32 participants were recorded during their normal food shop, followed by a semi-structured interview. During the interview they were given 13 potentially problematic packaged foods, and asked if they would purchase the product and what their reasons were. Transcribed data from the shop, interview and 13-product task were analysed to explore use of allergy advice boxes, ingredients lists and other packaging information.

RESULTS: Some participants used the ingredients list as their primary check for allergens, but most used the allergy advice box. Package-based information was generally considered reliable, but some supermarket and brand labels were trusted more than others. Images and product names were used to draw inferences about the presence of nuts. A number of improvements were suggested by participants, particularly a request for more ‘nut free’ labelling.

CONCLUSIONS: Food labels were used in conjunction with nonpacket-based strategies (e.g. previous experience) to make choices. External factors (e.g. trust of manufacturer) informed interpretation of and confidence in labels. Images and product names, not intended by manufacturers as an allergen risk assessment aid, were also used to inform choices.

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The challenges for nut-allergic consumers of eating out

Reference:

Leftwich J, Barnett J, Muncer K, Shepherd R, Raats MM, Hazel Gowland M, Lucas JS. The challenges for nut-allergic consumers of eating out. Clin Exp Allergy. 2011 Feb;41(2):243-9.


Abstract:

BACKGROUND: For individuals with a nut allergy, the avoidance of allergens is particularly challenging in situations where they are not preparing their own food. Many allergic reactions occur when eating outside the home.

OBJECTIVES: To identify and explore the challenges faced by nut-allergic individuals (NAIs) when they are eating in restaurants and other eating establishments.

METHODS: A qualitative interview study was conducted with 32 adults with a clinical history of allergy to peanuts and/or tree nuts.

RESULTS: The main strategies that participants adopted to manage the risk of allergic reactions when eating outside the home were avoidance and communication. They avoided types of restaurants, meal courses or particular foods. Seeking familiarity was a key strategy that enabled NAIs to reduce uncertainty and anxiety. Language differences were a major barrier to confident communication about food content. The need to check whether the food on offer may contain nuts was a source of social embarrassment for many participants and the desire to avoid this sometimes led to increased risk taking. Some did not disclose their allergy to restaurant staff as they feared a conservative reaction that would further constrain food choices. NAIs often have to plan where to eat out. The consequent lack of spontaneity was a source of regret to some.

CONCLUSION AND CLINICAL RELEVANCE: Communication patterns of nut-allergic adults are often grounded in legitimate everyday social considerations around embarrassment, choice and spontaneity. Education and training strategies are needed that recognize and take account of this. Focusing on communication deficits of NAIs may be unhelpful; responsibility for food safety must be shared with the food industry.

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Single-tree nut immunotherapy attenuates allergic reactions in mice with hypersensitivity to multiple tree nuts

Reference:

Kulis M, Li Y, Lane H, Pons L, Burks W. Single-tree nut immunotherapy attenuates allergic reactions in mice with hypersensitivity to multiple tree nuts. J Allergy Clin Immunol. 2011 Jan;127(1):81-8.


Abstract:

BACKGROUND: Allergic reactions to tree nuts are often severe and are outgrown in less than 10% of diagnosed patients.

OBJECTIVES: To determine whether treatment of underlying tree nut sensitization will prevent allergic reactions to cross-reacting tree nuts and to determine the effects of single-tree nut immunotherapy on true multi-tree nut sensitization.

METHODS: In the cross-reactivity model, cashew immunotherapy completely prevented allergic reactions on challenges with cashew or the cross-reactive pistachio. In the multisensitization model, mice with cashew plus walnut allergy were significantly protected from anaphylactic reactions on cashew challenge in both the cashew-alone and walnut-alone immunotherapy groups. Results from the walnut challenge demonstrated significantly decreased allergic responses in the walnut immunotherapy group, whereas mice in the cashew immunotherapy group experienced significantly lower symptoms. In the cross-reactivity model, immunotherapy effectively decreased IL-4 and IL-5 production and increased IL-12 relative to placebo while also inducing a 5-fold increase in specific IgG(1).

RESULTS: In the cross-reactivity model, cashew immunotherapy completely prevented allergic reactions on challenges with cashew or the cross-reactive pistachio. In the multisensitization model, mice with cashew plus walnut allergy were significantly protected from anaphylactic reactions on cashew challenge in both the cashew-alone and walnut-alone immunotherapy groups. Results from the walnut challenge demonstrated significantly decreased allergic responses in the walnut immunotherapy group, whereas mice in the cashew immunotherapy group experienced significantly lower symptoms. In the cross-reactivity model, immunotherapy effectively decreased IL-4 and IL-5 production and increased IL-12 relative to placebo while also inducing a 5-fold increase in specific IgG(1).

CONCLUSIONS: Single-tree nut immunotherapy can effectively decrease allergic responses in both the cross-reactivity and multisensitization mouse models. Further studies are needed to determine which single-tree nut immunotherapies will be most effective for specific multi-tree nut allergy profiles.

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Characterizing the relationship between sesame, coconut, and nut allergy in children

Reference:

Stutius LM, Sheehan WJ, Rangsithienchai P, Bharmanee A, Scott JE, Young MC, Dioun AF, Schneider LC, Phipatanakul W. Characterizing the relationship between sesame, coconut, and nut allergy in children. Pediatr Allergy Immunol. 2010 Dec;21(8):1114-8


Abstract:

Sesame and coconut are emerging food allergens in the United States. We sought to examine whether children allergic to peanuts and tree nuts are at increased risk of having an allergy to sesame or coconut. We performed a retrospective chart review of children who underwent skin prick testing (SPT) to sesame and coconut and identified 191 children who underwent SPT to sesame and 40 to coconut. Sensitization to sesame was more likely in children with positive SPT to peanuts (odds ratio [OR] = 6.7, 95% confidence interval [CI] [2.7-16.8], p < 0.001) and tree nuts (OR = 10.5, 95% CI [4.0-27.7], p < 0.001). Children with histories of both peanut and tree nut reaction were more likely to have a history of sesame reaction (OR = 10.2, 95% CI [2.7-38.7], p < 0.001). Children with sensitization or allergy to peanuts or tree nuts were not more likely to be sensitized or allergic to coconut. In conclusion, children with peanut or tree nut sensitization were more likely to be sensitized to sesame but not coconut. Children with clinical histories of both peanut and tree nut allergy were more likely to be allergic to sesame.

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How do we know when peanut and tree nut allergy have resolved, and how do we keep it resolved?

Reference:

Byrne AM, Malka-Rais J, Burks AW, Fleischer DM. How do we know when peanut and tree nut allergy have resolved, and how do we keep it resolved? Clin Exp Allergy. 2010 Sep;40(9):1303-11.


Abstract:

Over the last two decades, the prevalence of peanut and tree nut allergy has increased throughout the western world. Adverse reactions to these foods account for over 50% of all deaths resulting from food-related anaphylaxis. Until recently, evidence suggested that all peanut and tree nut allergy were permanent. It is now known that about 20% and 10%, respectively, of young patients outgrow peanut and tree nut allergies. Achieving tolerance is associated with increasing circulating T regulatory cells and reduced production of allergen-specific IgE. Reliable predictors of resolution are not yet available. A direct correlation between skin test weal size and allergen-specific IgE, at the time of diagnosis and likelihood of resolution, has been reported. Resolution of peanut or tree nut allergy cannot be determined conclusively by either allergen-specific IgE analysis or by skin prick testing. Oral food challenge is the gold standard for determining resolution of food allergy. Food challenges should only be undertaken in a clinical setting fully equipped to deal with a potential severe adverse reaction. Approximately 8% of patients who outgrow peanut allergy may suffer a recurrence, but recurrent tree nut allergy has not been reported to date. Infrequent ingestion of peanut may be related to the re-emergence of allergy. Induction of tolerance through oral immunotherapy or sublingual immunotherapy is now being actively studied, but remains experimental. Studies have reported short-term desensitization to peanut, but ongoing follow-up will determine whether tolerance is achieved long term.

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A population-based questionnaire survey on the prevalence of peanut, tree nut, and shellfish allergy in 2 Asian populations

Reference:

Shek LP, Cabrera-Morales EA, Soh SE, Gerez I, Ng PZ, Yi FC, Ma S, Lee BW. A population-based questionnaire survey on the prevalence of peanut, tree nut, and shellfish allergy in 2 Asian populations. J Allergy Clin Immunol. 2010 Aug;126(2):324-331.e7.


Abstract:

BACKGROUND: There has been a substantial increase in the prevalence of peanut and tree nut allergy in Western populations in the last 2 decades. However, there is an impression that peanut and tree nut allergy is relatively uncommon in Asia.

OBJECTIVE: To evaluate the prevalence of peanut, tree nut, and shellfish allergy in schoolchildren in 2 Asian countries (Singapore and Philippines).

METHODS: A structured written questionnaire was administered to local and expatriate Singapore (4-6 and 14-16 years old) and Philippine (14-16 years old) schoolchildren.

RESULTS: A total of 25,692 schoolchildren responded to the survey (response rate, 74.2%). Of these, 23,425 responses fell within the study protocol’s 4 to 6 and 14 to 16 year age groups and were included in the analysis. The prevalence of convincing peanut and tree nut allergy were similar in both local Singapore (4-6 years, 0.64%, 0.28%; 14-16 years, 0.47%, 0.3%, respectively) and Philippine (14-16, 0.43%, 0.33%, respectively) schoolchildren, but was higher in the Singapore expatriates (4-6 years, 1.29%, 1.12%; 14-16 years, both 1.21%, respectively; 4-6 years, expatriates vs local Singaporeans: peanut, P = .019; tree nut, P = .0017; 14-16 years, P > .05). Conversely, shellfish allergy was more common in the local Singapore (4-6 years, 1.19%; 14-16 years, 5.23%) and Philippine (14-16 years, 5.12%) schoolchildren compared with expatriate children (4-6 years, 0.55%; 14-16 years, 0.96%; P < .001). When data were pooled, respondents born in Western countries were at higher risk of peanut (adjusted odds ratios [95% CIs]: 4-6 years, 3.47 [1.35-8.93]; 14-16 years, 5.56 [1.74-17.76]) and tree nut allergy (adjusted odds ratios [95% CIs]: 4-6 years, 10.40 [1.61-67.36]; 14-16 years, 3.53 [1.00-12.43]) compared with those born in Asia. CONCLUSIONS: This study substantiates the notion that peanut and tree nut allergy is relatively low in Asian children, and instead shellfish allergy predominates. Environmental factors that are yet to be defined are likely to contribute to these differences.

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Management of nut allergy influences quality of life and anxiety in children and their mothers

Reference:

Cummings AJ, Knibb RC, Erlewyn-Lajeunesse M, King RM, Roberts G, Lucas JS. Management of nut allergy influences quality of life and anxiety in children and their mothers. Pediatr Allergy Immunol. 2010 Jun;21(4 Pt 1):586-94


Abstract:

Nut allergy is known to impact on the quality of life (QoL) and anxiety of both the allergic child and their parents, but little is known about how the management of food allergy is associated with these variables. To investigate the impact of nut allergy on QoL and anxiety in mothers and children with nut allergy in order to identify management strategies that may influence these factors. Forty-one nut allergic children (age 6-16 yrs) and their mothers completed questionnaires to assess maternal and children’s QoL (PedsQL, WHOQOL-BREF, FAQL-PB), anxiety (SCAS, STAI) and perceived stress scale (PSS). Children also completed a nut allergy specific QoL questionnaire. Demographic data, details of previous reactions, test results and management plans were collected using parent-report questionnaires and hospital notes. Children with nut allergy had poorer emotional (p = 0.004), social (p = 0.043), and psychological (p = 0.006) QoL compared to healthy normative data. Maternal and child QoL and anxiety were not influenced by the severity of previous reactions. Mother and child reported lower anxiety (p = 0.043 and p < 0.001 respectively) when the child was prescribed an epinephrine auto-injector. Anxiety was not associated with whether the child carried the auto-injector or whether they strictly avoided traces of nuts in foods. Prescribing auto-injectors is associated with reduced anxiety for food allergic children and their mothers, but is not associated with improved adherence with medical management or reduced risk-taking behavior.

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US prevalence of self-reported peanut, tree nut, and sesame allergy: 11-year follow-up

Reference:

Sicherer SH, Muñoz-Furlong A, Godbold JH, Sampson HA. US prevalence of self-reported peanut, tree nut, and sesame allergy: 11-year follow-up. J Allergy Clin Immunol. 2010 Jun;125(6):1322-6.


Abstract:

BACKGROUND: Allergy to peanuts and tree nuts (TNs) is the leading cause of fatal allergic reactions in the United States, and the prevalence appears to be increasing.

OBJECTIVES: We sought to determine the US prevalence of self-reported peanut, TN, and sesame allergy in 2008 and compare results with comparable surveys conducted in 1997 and 2002.

METHODS: A nationwide, cross-sectional, random telephone survey for peanut and TN allergy was conducted with a previously used questionnaire, with additional questions about sesame.

RESULTS: A total of 5,300 households (13,534 subjects) were surveyed (participation rate, 42% vs 52% in 2002 and 67% in 1997). Peanut allergy, TN allergy, or both was reported by 1.4% of subjects (95% CI, 1.2% to 1.6%) compared with 1.2% in 2002 and 1.4% in 1997. For adults, the prevalence was 1.3% (95% CI, 1.1% to 1.6%), which was not significantly different from prior surveys. However, the prevalence of peanut or TN allergy for children younger than 18 years was 2.1% (95% CI, 1.6% to 2.7%) compared with 1.2% in 2002 (P = .007) and 0.6% in 1997 (P < .001). The prevalence of peanut allergy in children in 2008 was 1.4% (95% CI, 1.0% to 1.9%) compared with 0.8% in 2002 (P = not significant) and 0.4% in 1997 (P < .0001). The prevalence of childhood TN allergy increased significantly across the survey waves (1.1% in 2008, 0.5% in 2002, and 0.2% in 1997). Sesame allergy was reported by 0.1% (95% CI, 0.0% to 0.2%). CONCLUSIONS: Although caution is required in comparing surveys, peanut allergy, TN allergy, or both continue to be reported by more than 1% of the US population (eg, >3 million subjects) and appear to be increasingly reported among children over the past decade. Sesame allergy is reported much less commonly.

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