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Challenges in food allergy pr ian kimber
Challenges in food allergy pr ian kimber
Challenges in food allergy pr ian kimber
Challenges in food allergy pr ian kimber
Challenges in food allergy pr ian kimber
Challenges in food allergy pr ian kimber
Challenges in food allergy pr ian kimber
Challenges in food allergy pr ian kimber
Challenges in food allergy pr ian kimber
Challenges in food allergy pr ian kimber
Challenges in food allergy pr ian kimber
Challenges in food allergy pr ian kimber
Challenges in food allergy pr ian kimber
Challenges in food allergy pr ian kimber
Challenges in food allergy pr ian kimber
Challenges in food allergy pr ian kimber
Challenges in food allergy pr ian kimber
Challenges in food allergy pr ian kimber
Challenges in food allergy pr ian kimber
Challenges in food allergy pr ian kimber
Challenges in food allergy pr ian kimber
Challenges in food allergy pr ian kimber
Challenges in food allergy pr ian kimber
Challenges in food allergy pr ian kimber
Challenges in food allergy pr ian kimber
Challenges in food allergy pr ian kimber
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Challenges in food allergy pr ian kimber

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  • 1. ANAPHYLAXIS CAMPAIGN Challenges in Food Allergy Professor Ian Kimber University of Manchester
  • 2. DEFINITION OF TERMS ADVERSE REACTIONS TO FOOD FOOD POISONING FOOD ALLERGY AND INTOLERANCE IMMUNE MEDIATED ALLERGY NON IMMUNE MEDIATED INTOLERANCE
  • 3. THE IMMUNE SYSTEM Friend or Foe? SEVERE COMBINED IMMUNODEFICIENCY DISEASE
  • 4. FOOD ALLERGY ALLERGY - The adverse health effects that may result from the stimulation of an immune response. FOOD ALLERGY - Adverse health effects* that are caused by an allergic reaction to food proteins encountered in the diet. * rash, swelling, nausea, vomiting, asthma, anaphylaxis.
  • 5. MOST FOOD ALLERGY IS IgE ANTIBODY MEDIATED INCREASING PREVALENCE OF IgE ALLERGIES Asthma prevalence in Europe (children and young adults)
  • 6. ANTIBODY PRODUCTION T P B help Differentiation IgG antibody
  • 7. IgE ANTIBODY PRODUCTION P P T B help Differentiation IgG antibody IgE antibody
  • 8. MAST CELL DEGRANULATION IgE ANTIBODY PRODUCTION MAST CELL SENSITISATION LEUKOTRIENES VASOACTIVE AMINES and other inflammatory mediators within minutes of challenge
  • 9. WHAT FOODS CAUSE ALLERGY?
  • 10. KIWI FRUIT ALLERGY 2 4 6 8 10 12 Allergypublications kiwi fruit introduced to UK diet first paper published on kiwi fruit allergy kiwi fruit recognized as important allergen
  • 11. WHY HAS THERE BEEN AN INCREASE IN THE PREVALENCE OF ATOPIC ALLERGY - INCLUDING FOOD ALLERGY? 5-7% children, 2% adults Changes in the gene pool Altered patterns of exposure (chemicals, pollutants) The hygiene hypothesis
  • 12. WHAT FACTORS DETERMINE SUSCEPTIBILITY TO FOOD ALLERGY INHERENT INDIVIDUAL SUSCEPTIBILITY Inherited Acquired Extrinsic Factors CONDITIONS OF EXPOSURE Extent Frequency Route Age NATURE OF PROTEIN Intrinsic allergenic potential Stability ALLERGIC SENSITISATION
  • 13. WHAT FACTORS DETERMINE SUSCEPTIBILITY TO FOOD ALLERGY INHERENT INDIVIDUAL SUSCEPTIBILITY Inherited Acquired Extrinsic Factors CONDITIONS OF EXPOSURE Extent Frequency Route Age NATURE OF PROTEIN Intrinsic allergenic potential Stability ALLERGIC SENSITISATION
  • 14. INTRINSIC DIFFERENCES IN ALLERGENIC PROPERTIES Strongly/commonly allergenic Weakly/rarely allergenic PEANUT LETTUCEPOTENCY PERSISTENCE Commonly life-long Usually transient PEANUT COWS’ MILK
  • 15. IMPORTANT INFLUENCES ON ALLERGENIC ACTIVITY • SIZE • FUNCTION • STABILITY • SUGARS • IMMUNOGENICITY
  • 16. WHAT FACTORS DETERMINE SUSCEPTIBILITY TO FOOD ALLERGY INHERENT INDIVIDUAL SUSCEPTIBILITY Inherited Acquired Extrinsic Factors CONDITIONS OF EXPOSURE Extent Frequency Route Age NATURE OF PROTEIN Intrinsic allergenic potential Stability ALLERGIC SENSITISATION
  • 17. DIETARY EXPOSURE – OR VIA THE SKIN? • High levels of environmental exposure to peanut promotes sensitisation (Fox et al., 2008) • Impaired skin barrier function is associated with peanut allergy (Brown et al., 2011) • Skin homing lymphocytes predominate in peanut allergy (Chan et al., 2012) • Peanut protein spreads easily throughout the home and is resistant to cleaning (Brough et al., 2013a) • Household peanut dust is immunologically active (Brough et al., 2013b)
  • 18. COMMITTEE ON TOXICITY OF CHEMCIALS IN FOOD CONSUMER PRODUCTS AND THE ENVIRONMENT (COT) 1998 Mothers who are atopic (or where there is an atopic background) may wish to avoid eating peanuts or peanut products during pregnancy and lactation
  • 19. THE BALANCE BETWEEN ALLERGY AND TOLERANCE ALLERGY TOLERANCE
  • 20. Journal of Allergy and Clinical Immunology 122, 984-991, 2008.
  • 21. A NOVEL HYPOTHESIS •Early dietary exposure to potential allergenic foods facilitates the development of immunological tolerance •Skin exposure to allergenic food proteins promotes the development of sensitisation
  • 22. LEAP (Learning Early About Peanut Allergies) The primary aim of the LEAP Study is to assess whether oral administration of a peanut-containing snack can induce tolerance in children at high risk for peanut allergy. The LEAP Study Team: Monica Basting, Charlotte Stedman, Muhsinah Adam, Richard Cleaver, Louise Coverdale, Amy Nixon, George du Toit, Catherine Clarke, Una O’Dwyer-Leeson and Alicia Parr.
  • 23. The primary aim of the EAT Study is to assess whether the introduction of allergenic foods from 3 months of age, alongside continued breastfeeding, results in a reduced prevalence of IgE-mediated food allergy by 3 years of age. EAT (Enquiring About Tolerance) Michael Perkin, Gideon Lack and Kirsty Logan
  • 24. WHAT FACTORS DETERMINE SUSCEPTIBILITY TO FOOD ALLERGY INHERENT INDIVIDUAL SUSCEPTIBILITY Inherited Acquired Extrinsic Factors CONDITIONS OF EXPOSURE Extent Frequency Route Age NATURE OF PROTEIN Intrinsic allergenic potential Stability ALLERGIC SENSITISATION
  • 25. Objectives • Establish a dose-distribution curve for peanut threshold in a UK peanut allergic population of adults • Model the variability of challenge thresholds over time within individuals, as a result of repeat challenges • Examine how these extrinsic factors shift the dose response curve: – Exercise – Stress through sleep deprivation
  • 26. THE BIG CHALLENGES/QUESTIONS • What makes a protein an allergen? • What drives inter-individual differences in susceptibility to food allergy? • What routes of exposure are relevant for the acquisition of sensitisation? • What factors influence the severity of food allergic reactions? • Why do some adults develop allergy to foods that they have tolerated for years?

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