Immunology and Allergy
Update
Greg Rex
Department of Pediatrics, Division of Allergy
IWK Health Centre
CFPC CoI Templates: Slide 1
Faculty/Presenter Disclosure
• Faculty: Gregory Rex, MD, FRCPC
• Relationships with commercial interests:
• Speakers Bureau/Honoraria: Takeda, Merck
CFPC CoI Templates: Slide 2
Disclosure of Commercial Support
• None
CFPC CoI Templates: Slide 3
Mitigating Potential Bias
• Today I will discuss topics unrelated to the companies mentioned in the previous
slide.
Objectives
• Review current recommendations for food/allergen exposure in
infancy
• Review recent advances in peanut allergy prevention
• Discuss which “at risk” infants would be appropriate for specialist
referral.
Peanut (PN) Allergy
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PN allergy prevalence: 1.4% to 3% in Western countries;
quadrupled in past 13 yrs
Leading cause of anaphylaxis and death due to food allergy
Significant psychosocial/economic burdens on
patients/families
Develops early in life and is not commonly outgrown
“Becoming Allergic – Immunology 101”
• Need exposure to sensitize (placenta, breast milk, infant diet)
• ? Immature gut
• ? Immature immune system
AAP Guidelines
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“Solid foods should not be
introduced into the diet of high-risk
infants until 6 months of age, with
dairy products delayed until 1 year,
eggs until 2 years, and peanuts,
nuts, and fish until 3 years of age.”
-AAP Statement 2000
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Based on infant feeding
trials
Made “immunologic sense”
Some data fradulent
AAP Guidelines
“Although solid foods should not
be introduced before 4 to 6
months of age, there is no current
convincing evidence that delaying
their introduction beyond this
period has a significant protective
effect on the development of
atopic disease.”
-AAP Statement 2008
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Rates of PN allergy and
atopy continued to rise
Data becoming “better” and
showing no benefit to
delaying introduction
Observational Data
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Koplin et al, JACI 2010
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2589 children followed and skin tested / challenged with egg
at 1 year; comparing introduction at 4-6 months vs later
Much higher (OR of 3.4) risk of egg allergy with delayed egg
introduction
Early consumption of peanuts in infancy is associated
with a low prevalence of peanut allergy
Methods
Du Toit G et al. J Allergy Clin Immunol 2008; 122: 984-91.

5171 Jewish school children
in UK and 5615 Jewish
school children in Israel
were compared for food
allergies and atopy.

Questionnaire based
assessment of peanut
allergy validated by
challenges.
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Infant weaning for peanut
and other foods was
determined in infants using
a validated FFQ.
Early consumption of peanuts in infancy is
associated with a low prevalence of peanut allergy
2
% PA Prevalence
1.8
1.6
Prevalence of Peanut Allergy in Children 418yrs
1.85%
1.4
p < 0.001
1.2
1
0.8
0.6
0.17%
0.4
0.2
Median gms of peanut protein / week
0
United Kingdom
8
Israel
7.1 g/week
Peanut Protein Consumption 8-14 month
7
6
5
p < 0.001
4
3
2
1
0 g/week
0
United Kingdom
Israel
Du Toit G et al. J Allergy Clin Immunol 2008; 122: 984-91.
United Kingdom
5171
Israel
5615
Canadian Position Statement
Joint statement of CSACI and CPS
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Do not delay the introduction of any specific
solid food beyond six months of age. Later
introduction of peanut, fish or egg does not
prevent, and may even increase, the risk of
developing food allergy. (Evidence II-2B)
Chan E and Cummings C, Paediatr Child Health 2013;18(10):545-9
LEAP Study
Learning Early About Peanut allergies
Learning Early About Peanut Allergy (LEAP Study)
Screening
Intervention group
Peanut consumed 3 times per week(n≈320)
Randomisation/
Stratification
4-11 month old
children
eczema and/or
egg allergy
Control Group
Peanut avoidance (n≈320)
4-11 months
V -1
1 yr
V0
5 yr♦
2.5 yr
V 12
V 30
V 60
Issues
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What about SPT > 4 mm?
Does it need to be 6 g of PN protein per week?
What if gaps in regular consumption?
What about general population?
What about other foods…milk, eggs, tree nuts?
EAT Study - Early Weaning Trial
Infants exclusively
breastfed (EBF) at 3
months of age
Early introduction
(4 months of age) of
allergenic foods &
breastfeeding
1302
subjects
1 and 3 yr
assessment
Food allergy
Eczema
Randomization (3 months)
6 months EBF (UK infant
feeding guidelines)
Atopic wheeze
Cumulative
allergy
Moving forward
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Well done study: randomized, prospective, controlled
Results clearly show that in this “at risk” group, early
introduction of PN dramatically decreases the risk of
development of PN allergy (70-80%)
Guideline changes are “in the works”
What does this mean to MDs?
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Need for GPs and pediatricians to recognize these “at risk”
children and refer them ASAP
Need for allergists to find a way to see these infants in a
timely manner, so not to delay introduction
Need to change mindset of population towards early
introduction.
Need to get the message out
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Statements and guidelines coming
Thank You