ANAPHYLAXIS CAMPAIGN
Challenges in Food Allergy
Professor Ian Kimber
University of Manchester
DEFINITION OF TERMS
ADVERSE REACTIONS TO FOOD
FOOD POISONING FOOD ALLERGY AND INTOLERANCE
IMMUNE MEDIATED
ALLERGY
NON IMMU...
THE IMMUNE SYSTEM
Friend or Foe?
SEVERE COMBINED IMMUNODEFICIENCY DISEASE
FOOD ALLERGY
ALLERGY - The adverse health effects that may
result from the stimulation of an immune
response.
FOOD ALLERGY...
MOST FOOD ALLERGY IS IgE ANTIBODY
MEDIATED
INCREASING PREVALENCE OF IgE ALLERGIES
Asthma prevalence in Europe
(children an...
ANTIBODY PRODUCTION
T
P
B
help
Differentiation
IgG antibody
IgE ANTIBODY PRODUCTION
P
P
T
B
help
Differentiation
IgG antibody
IgE antibody
MAST CELL DEGRANULATION
IgE ANTIBODY
PRODUCTION MAST CELL
SENSITISATION
LEUKOTRIENES
VASOACTIVE AMINES
and other inflammat...
WHAT FOODS CAUSE ALLERGY?
KIWI FRUIT ALLERGY
2
4
6
8
10
12
Allergypublications
kiwi fruit
introduced
to UK diet
first paper
published on
kiwi fruit
...
WHY HAS THERE BEEN AN INCREASE IN THE
PREVALENCE OF ATOPIC ALLERGY - INCLUDING
FOOD ALLERGY?
5-7% children, 2% adults
Chan...
WHAT FACTORS DETERMINE SUSCEPTIBILITY TO
FOOD ALLERGY
INHERENT
INDIVIDUAL
SUSCEPTIBILITY
Inherited
Acquired
Extrinsic Fact...
WHAT FACTORS DETERMINE SUSCEPTIBILITY TO
FOOD ALLERGY
INHERENT
INDIVIDUAL
SUSCEPTIBILITY
Inherited
Acquired
Extrinsic Fact...
INTRINSIC DIFFERENCES IN ALLERGENIC
PROPERTIES
Strongly/commonly
allergenic
Weakly/rarely
allergenic
PEANUT LETTUCEPOTENCY...
IMPORTANT INFLUENCES ON
ALLERGENIC ACTIVITY
• SIZE
• FUNCTION
• STABILITY
• SUGARS
• IMMUNOGENICITY
WHAT FACTORS DETERMINE SUSCEPTIBILITY TO
FOOD ALLERGY
INHERENT
INDIVIDUAL
SUSCEPTIBILITY
Inherited
Acquired
Extrinsic Fact...
DIETARY EXPOSURE – OR VIA THE SKIN?
• High levels of environmental exposure to peanut
promotes sensitisation (Fox et al., ...
COMMITTEE ON TOXICITY OF CHEMCIALS IN
FOOD CONSUMER PRODUCTS AND THE
ENVIRONMENT (COT) 1998
Mothers who are atopic (or whe...
THE BALANCE BETWEEN ALLERGY AND TOLERANCE
ALLERGY
TOLERANCE
Journal of Allergy and Clinical Immunology 122, 984-991, 2008.
A NOVEL HYPOTHESIS
•Early dietary exposure to potential allergenic foods
facilitates the development of immunological
tole...
LEAP (Learning Early About Peanut Allergies)
The primary aim of the LEAP
Study is to assess whether
oral administration of...
The primary aim of the EAT Study is
to assess whether the introduction
of allergenic foods from 3 months of
age, alongside...
WHAT FACTORS DETERMINE SUSCEPTIBILITY TO
FOOD ALLERGY
INHERENT
INDIVIDUAL
SUSCEPTIBILITY
Inherited
Acquired
Extrinsic Fact...
Objectives
• Establish a dose-distribution curve for
peanut threshold in a UK peanut
allergic population of adults
• Model...
THE BIG CHALLENGES/QUESTIONS
• What makes a protein an allergen?
• What drives inter-individual differences in
susceptibil...
Nächste SlideShare
Wird geladen in …5
×

Challenges in food allergy pr ian kimber

606 Aufrufe

Veröffentlicht am

Veröffentlicht in: Gesundheitswesen, Gesundheit & Medizin
  • Als Erste(r) kommentieren

  • Gehören Sie zu den Ersten, denen das gefällt!

Challenges in food allergy pr ian kimber

  1. 1. ANAPHYLAXIS CAMPAIGN Challenges in Food Allergy Professor Ian Kimber University of Manchester
  2. 2. DEFINITION OF TERMS ADVERSE REACTIONS TO FOOD FOOD POISONING FOOD ALLERGY AND INTOLERANCE IMMUNE MEDIATED ALLERGY NON IMMUNE MEDIATED INTOLERANCE
  3. 3. THE IMMUNE SYSTEM Friend or Foe? SEVERE COMBINED IMMUNODEFICIENCY DISEASE
  4. 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. 5. MOST FOOD ALLERGY IS IgE ANTIBODY MEDIATED INCREASING PREVALENCE OF IgE ALLERGIES Asthma prevalence in Europe (children and young adults)
  6. 6. ANTIBODY PRODUCTION T P B help Differentiation IgG antibody
  7. 7. IgE ANTIBODY PRODUCTION P P T B help Differentiation IgG antibody IgE antibody
  8. 8. MAST CELL DEGRANULATION IgE ANTIBODY PRODUCTION MAST CELL SENSITISATION LEUKOTRIENES VASOACTIVE AMINES and other inflammatory mediators within minutes of challenge
  9. 9. WHAT FOODS CAUSE ALLERGY?
  10. 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. 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. 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. 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. 14. INTRINSIC DIFFERENCES IN ALLERGENIC PROPERTIES Strongly/commonly allergenic Weakly/rarely allergenic PEANUT LETTUCEPOTENCY PERSISTENCE Commonly life-long Usually transient PEANUT COWS’ MILK
  15. 15. IMPORTANT INFLUENCES ON ALLERGENIC ACTIVITY • SIZE • FUNCTION • STABILITY • SUGARS • IMMUNOGENICITY
  16. 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. 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. 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. 19. THE BALANCE BETWEEN ALLERGY AND TOLERANCE ALLERGY TOLERANCE
  20. 20. Journal of Allergy and Clinical Immunology 122, 984-991, 2008.
  21. 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. 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. 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. 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. 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. 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?

×