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User:Puffysphere/Non-classical food allergies

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A food allergy is defined as an adverse health effect arising from a specific immune response that occurs reproducibly on exposure to a given food. Food allergy may be IgE or non-IgE mediated. [1] This article is about food allergies that have only recently been scientifically established. These include:

Symptoms

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NCGS symptoms include both gastrointestinal and non-intestinal symptoms, occurring within a few hours or days of gluten ingestion. Gastrointestinal symptoms include abdominal pain and bloating, diarrhea, constipation. Non-intestinal symptoms include mental confusion or a ‘foggy mind’, fatigue, skin rash, headache, joint and muscle pain, leg or arm numbness, depression and anxiety, and anemia. [4]

Gluten sensitivity may also have neurological and psychiatric symptoms. Gluten can cause ataxia, likely because antibodies to gluten attack the Purkinje cells in the cerebellum. Gluten ataxia may slowly improve with a gluten-free diet. [5]

Epidemiology

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The prevalence of non-IgE mediated food allergy is unknown. However, non-IgE mediated food allergy is thought to be more common than IgE mediated food allergy. [6] The prevalence of non-celiac gluten sensitivity is also unknown, but it may be estimated at 6%, since about 20% of people in Northern Europe have irritable bowel syndrome, and in studies, about 30% of people with irritable bowel syndrome have have non-celiac gluten sensitivity. [3]

Diagnosis

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There are no definitive lab tests for non-classical food allergies. The gold standard for diagnosis is:

Diagnosis of non-celiac gluten sensitivity (NCGS) is similar. In a study of wheat sensitivity, patients were put on an elimination diet that excluded wheat, cow’s milk, eggs, tomato, chocolate and any other food they felt they were hypersensitive to, for 4 weeks. Then they underwent DBPC food challenges. The challenges were performed with the reintroduction of a single food at a time. [8]

The lymphocyte stimulation test, which is a common method to estimate cellular immunity, may be an effective diagnostic test for cow's milk allergy, when a blood test for IgE antibodies to cow's milk is negative. [9]

Mechanisms

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The mechanism for FPIES is unknown. It has been postulated to be a T-cell-mediated disorder, with a major role of tumor necrosis factor alpha (TNF-α). [10] However, the food reaction develops in most cases within 3 hours after the food challenge. This response time is extremely short for a cell-mediated allergic reaction, which is known to require a time period longer than 24 hours, and indistinguishable from IgE-mediated immediate allergic reactions.[9] One study found that atopy patch tests with the specific allergen were positive in FPIES patients, and this supports a role for T cells.[11] Humoral immunity may also be involved in FPIES, since blood levels of specific IgA antibodies to the culprit food tend to be elevated, and blood levels of specific IgG4 antibodies tend to be lower in FPIES patients. IgG4 may protect against food allergy, so a lack of IgG4 may be part of the cause of FPIES. [10]

Blood tests for specific IgE are usually negative in FPIES. [10] However, IgE-mediated allergic reactions can occur in mucous membranes, even when skin and blood tests for IgE-mediated allergy are negative,[12] and some studies suggest that some non-classical food allergies, including FPIES, may be IgE-mediated allergies that are localized in the GI tract. [10] One study was on adults who had food allergy-related gastrointestinal symptoms such as diarrhea that were confirmed by double-blind placebo-controlled food challenges. Biopsy samples were taken from their small intestines, both while they were having food allergy symptoms and while they were symptom-free. The biopsy samples suggested that a localized IgE-mediated response caused their gastrointestinal symptoms. The biopsy results were similar between the patients had positive skin-prick tests/blood allergy tests for the food, and the patients who did not have positive SPT or blood allergy tests. The results were also similar between patients who had symptoms within an hour of ingesting the food, and patients whose food reactions were delayed for more than an hour. [13]

Antigen-specific T-cell responses in patients with non–IgE-mediated gastrointestinal food allergy are predominantly skewed to TH2. It remains unclear why antigen-specific IgE antibodies are not detected.[14]

The innate immune system plays an important role in non-celiac gluten sensitivity.[4] Other components of wheat besides gluten may be involved in NCGS. Amylase/trypsin inhibitors, which are non-gluten proteins in wheat, are strong activators of innate immune responses. [15] Wheat also has FODMAPS (fermentable, poorly absorbed, short-chain carbohydrates), and a study found that people with IBS who had improved on a gluten-free diet, also improved on a low-FODMAPS diet, and worsened when either gluten or whey protein was added to their diet. [16] However, gluten itself also seems to be important in NCGS. [17]

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Notes

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  1. ^ NIAID-Sponsored Expert Panel (December 2010). "Guidelines for the Diagnosis and Management of Food Allergy in the United States: Report of the NIAID-Sponsored Expert Panel". The Journal of Allergy and Clinical Immunology. 126 (6, supplement): S1–S58. PMID 21134576. {{cite journal}}: Unknown parameter |displayauthors= ignored (|display-authors= suggested) (help)
  2. ^ Jyonouchi, Harumi (2012). "Non-IgE Mediated Food Allergy – Update of Recent Progress in Mucosal Immunity" (PDF). Inflammation & Allergy - Drug Targets (11): 382–396. PMID 22680623. {{cite journal}}: line feed character in |title= at position 69 (help)
  3. ^ a b Fasano, Alessio; Catassi, Carlo (2013). "Non-Celiac Gluten Sensitivity: The New Frontier of Gluten Related Disorders". Nutrients (5): 3839–3853. PMID 24077239. {{cite journal}}: Unknown parameter |displayauthors= ignored (|display-authors= suggested) (help)
  4. ^ a b Volta, Umberto; Caio, Giacomo; Tovoli, Francesco; De Giorgio, Roberto (2013). "Non-celiac gluten sensitivity: questions still to be answered despite increasing awareness". Cellular & Molecular Immunology. 10: 383–392. PMID 23934026.
  5. ^ Jackson, Jessica R.; Fasano, Alessio; Eaton, William W. (2012 Mar). "Neurologic and Psychiatric Manifestations of Celiac Disease and Gluten Sensitivity". Psychiatric Quarterly. 83 (1): 91–102. PMID 21877216. {{cite journal}}: Check date values in: |date= (help); Unknown parameter |displayauthors= ignored (|display-authors= suggested) (help)
  6. ^ "Food Allergy in Children and Young People: Diagnosis and Assessment of Food Allergy in Children and Young People in Primary Care and Community Settings". National Institute for Health and Clinical Excellence. February 2011. Retrieved 29 October 2013.
  7. ^ Sampson, Hugh A.; van Wijk,, Roy Gerth (2012). "Standardizing double-blind, placebo-controlled oral food challenges: American Academy of Allergy, Asthma & Immunology–European Academy of Allergy and Clinical Immunology" (PDF). Journal of Allergy and Clinical Immunology. 130 (6): 1260–74. PMID 23195525. {{cite journal}}: Unknown parameter |displayauthors= ignored (|display-authors= suggested) (help)CS1 maint: extra punctuation (link)
  8. ^ Carroccio, Antonio; Mansueto, Pasquale (2012 Dec). "Non-Celiac Wheat Sensitivity Diagnosed by Double-Blind Placebo-Controlled Challenge: Exploring a New Clinical Entity" (PDF). American Journal of Gastroenterology. 107 (12): 1898–906. PMID 22825366. {{cite journal}}: Check date values in: |date= (help); Unknown parameter |displayauthors= ignored (|display-authors= suggested) (help)
  9. ^ a b Kimura, Mitsuaki; Oh, Shigeharu; Narabayashi, Shigeyuki; Taguchi, Tomohide (2012). "Usefulness of lymphocyte stimulation test for the diagnosis of intestinal cow's milk allergy in infants". International Archives of Allergy and Immunology. 157 (1): 58–64. PMID 21912174. {{cite journal}}: Unknown parameter |displayauthors= ignored (|display-authors= suggested) (help)
  10. ^ a b c d Caubet, Jean-Christoph; Nowak-Węgrzyn, Anna (2011). "Current understanding of the immune mechanisms of food protein-induced enterocolitis syndrome". Expert Rev. Clin. Immunol. 7 (3): 317–327. PMID 21595598.
  11. ^ Fogg, Matthew I.; Brown-Whitehorn, Terri A.; Pawlowski, Nicholas A.; Spergel, Jonathan M. (August 2006). "Atopy patch test for the diagnosis of food protein-induced enterocolitis syndrome". Pediatric Allergy and Immunology. 17 (5): 351–355. PMID 16846453.
  12. ^ Powe, DG; Bonnin, AJ; Jones, NS (2010 Jul). "'Entopy': local allergy paradigm". Clinical & Experimental Allergy. 40 (7): 987–97. PMID 20642577. {{cite journal}}: Check date values in: |date= (help)
  13. ^ Lin, Xiao Ping; Magnusson,, Jenny (2002 May). "Local allergic reaction in food-hypersensitive adults despite a lack of systemic food-specific IgE" (PDF). Journal of Allergy and Clinical Immunology. 109 (5): 879–87. PMID 11994715. {{cite journal}}: Check date values in: |date= (help); Unknown parameter |displayauthors= ignored (|display-authors= suggested) (help)CS1 maint: extra punctuation (link)
  14. ^ Morita, Hideaki; Nomura, Ichiro; Orihara, Kanami. "Antigen-specific T-cell responses in patients with non–IgE-mediated gastrointestinal food allergy are predominantly skewed to TH2". The Journal of Allergy and Clinical Immunology. 131 (2): 590–592. PMID 23083674. {{cite journal}}: Unknown parameter |displayauthors= ignored (|display-authors= suggested) (help)
  15. ^ Junker, Yvonne; Zeissig, Sebastian; Kim, Seong-Jun (2012 Dec 17). "Wheat amylase trypsin inhibitors drive intestinal inflammation via activation of toll-like receptor 4". Journal of Experimental Medicine. 209 (13): 2395–408. PMID 23209313. {{cite journal}}: Check date values in: |date= (help); Unknown parameter |displayauthors= ignored (|display-authors= suggested) (help)
  16. ^ Biesiekierski, Jessica R.; Gibson, Peter R.; Peters, Simone L. (August 2013). "No Effects of Gluten in Patients With Self-Reported Non-Celiac Gluten Sensitivity After Dietary Reduction of Fermentable, Poorly Absorbed, Short-Chain Carbohydrates". Gastroenterology. 145 (2): 320–328. PMID 23648697. {{cite journal}}: Unknown parameter |displayauthors= ignored (|display-authors= suggested) (help)
  17. ^ Biesiekierski, Jessica R; Gibson, Peter R; Newnham, Evan D (11 January 2011). "Gluten Causes Gastrointestinal Symptoms in Subjects Without Celiac Disease: A Double-Blind Randomized Placebo-Controlled Trial". American Journal of Gastroenterology. 106 (3): 508–14. PMID 21224837. {{cite journal}}: Unknown parameter |displayauthors= ignored (|display-authors= suggested) (help)
  18. ^ {{cite journal}}: Empty citation (help)