Food Allergy Module 1

Question 1

role of nutrition in disease = (3 Ps)

Answer 1

role of nutrition in disease = prevention + pathogenesis + prognosis

Question 2

how to prevent allergies in childhood?

Answer 2

early exposure

Question 3

role of nutrition in allergy: prevention

Answer 3

early introduction of allergenic foods to reduce development of food allergies, timing is critical!

Question 4

role of nutrition in allergy: pathogenesis

Answer 4

immune response to food trigger

Question 5

role of nutrition in allergy: prognosis

Answer 5

avoiding foods, allergy oral immunotherapy

Question 6

3 treatment options for allergy

Answer 6

1. Medical nutrition therapy (MNT): avoiding foods
2. Treating severe reactions when they happen
3. Allergy immunotherapy

Question 7

nutritional issues that impact immunity

Answer 7

1. alcohol
2. weight
3. poor diet
4. chronic disease
5. mental stress (cortisol)
6. lack of sleep
7. diet and lifestyle patterns

Question 8

food hypersensitivity =

Answer 8

food hypersensitivity = adverse reaction to foods

Question 9

is intolerance immune-mediated?

Answer 9

no

Question 10

immune mediated wheat hypersenstivity

Answer 10

1. allergy: wheat allergy
2. autoimmunity: CD and dermatitis herpetiformis
3. sensitivity (non-allergic/non-autoimmune): NCWS

Question 11

non-immune mediated wheat hypersensitivty

Answer 11

intolerance: FODMAP intolerance

Question 12

wheat allergy trigger

Answer 12

gluten and/or non-gluten proteins
GI tract, skin, respiratory

Question 13

wheat allergy symptoms

Answer 13

same as other allergies
rapid onset

Question 14

wheat allergy mechanism steps (6)

Answer 14

1. Presentation of allergen to and activation of T cells
2. T cell help to IgE-producing B cells
3. Production of IgE by B cells in response to an allergen (in predisposed individual)
4. Binding of IgE to mast cells (through Fc region), called sensitization
5. Antigen re-encounter and cross-linking of bound IgE by re-introduced antigen
6. Release of mast cell mediators (degranulation)

Question 15

wheat allergy:
degranulation releases __, __, and other __ which cause __ including __ and __ of __, and __

Answer 15

wheat allergy:
degranulation releases histamine, proteases, and other inflammatory mediators which cause inflammation including dilation and leakiness of blood capillaries, and tissue damage

Question 16

wheat allergy:
released cytokines recruit __ (__, __, and __) leading to symtpoms of __

Answer 16

wheat allergy:
released cytokines recruit leukocytes (neutrophils, eosinophils, and Th) leading to symtpoms of allergies

Question 17

allergy symptoms

Answer 17

1. sneezing
2. nasal irritation
3. itchiness

Question 18

anaphylaxis is the most severe form of __ caused by widespread and sudden __ cell __ in response to an __

Answer 18

anaphylaxis is the most severe form of hypersensitivity caused by widespread and sudden mast cell degranulation in response to an antigen

Question 19

anaphylaxis is associated with

Answer 19

dilation of blood vessels and sharp drop in blood pressure

Question 20

wheat allergy genetic marker

Answer 20

elevated levels of IgE antibody to gluten and non-gluten proteins
Commonly IgE to:
ω-gliadins
α-amylase/protease inhibitors (ATIs)

Question 21

wheat allergy testing

Answer 21

IgE antibody and skin prick tests

Question 22

wheat allergy treatment

Answer 22

wheat-free diet
anti-histamines
epinephrine

Question 23

some ppl with wheat allergy are cross reactive to

Answer 23

rye and barley

Question 24

celiac disease (CD) and dermatitis herpetiformis (DH) trigger

Answer 24

gluten in wheat and related cereals

Question 25

CD and DH target

Answer 25

small intestine in CD, skin in DH

Question 26

CD and DH symptoms

Answer 26

CD: diarrhea, pain, malnutrition DH: skin rash

Question 27

CD genetic component

Answer 27

strong genetic component linked to class II HLA genes (DQ2/DQ8)

Question 28

CD involes which 2 immune responses

Answer 28

innate and adaptive

Question 29

CD involves immune response to (3)

Answer 29

1. Anti-gluten antibody 2. Anti-deamidated gluten antibody 3. Anti-transglutaminase 2 antibody

Question 30

CD testing: 3 options

Answer 30

1. Blood tests: most sensitive and specific marker: IgA to tissue transglutaminase (tTG or TG2)/IgA anti-endomysial antibody 2. IgG to deamidated gluten (“DGP”) useful in cases of IgA deficiency. 3. Genetic testing (HLA-DQ2/8) useful in equivocal cases and children Useful in difficult cases, low positive predictive value bc a lot of people have this gene *Antibodies to native gluten (gliadin) no longer used in context of celiac disease.

Question 31

what type of testing is no longer used in CD

Answer 31

Antibodies to native gluten (gliadin) no longer used in context of celiac disease

Question 32

CD diagnostic algorithm

Answer 32

1. suspicion of CD 2. serologic tests (IgA anti-TG2) 3. intestinal biopsy 4. provisional diagnosis of CD 5. GFD 6. definitive diagnosis if GFD causes improvement

Question 33

CD treatment

Answer 33

lifelong GFD

Question 34

NCWS definition

Answer 34

- Onset of symptoms in response to ingestion of wheat, rye, and barley - Resolution of symptoms on removal of those foods from diet - In patients in whom celiac disease and wheat allergy have been ruled out

Question 35

NCWS symptoms

Answer 35

intestinal: abdominal pain, diarrhea, bloating extra-intestinal: fatigue, headache, cognitive difficulties

Question 36

speed of symptom response: WA, CD, NCWS

Answer 36

WA < NCWS < CD

Question 37

triggers of NCWS

Answer 37

wheat, gluten fructans ATIs

Question 38

NCWS as a subset of IBS

Answer 38

some ppl with IBS appear to have NCWS wheat-free diet reduces IBS symptoms in patients with anti-gluten antibody

Question 39

is NCWS immune mediated

Answer 39

in substantial proportion

Question 40

3 types of markers of NCWS

Answer 40

1. elevated response to wheat gluten (IgG2, IgG4, IgM) 2. systemic innate immune activation in response to microbial translocation (LBP, sCD14) 3. intestinal cell damage (FABP2)

Question 41

proposed mechanism for NCWS

Answer 41

data point to microbial translocation across intestinal barrier

Question 42

ATIs

Answer 42

α-amylase/protease inhibitors (ATIs or APIs) of wheat shown to be strong activators of innate immune response through the engagement of the TLR4-MD2-CD14 complex

Question 43

NCWS treatment

Answer 43

GFD

Question 44

potential downsides of GFD

Answer 44

Processed gluten-free products may contain ingredients inferior to their gluten-containing counterparts in nutritional value. Avoiding wheat products may result in lower fiber intake (affecting cardiovascular risk). Gluten-free breads and cereals less likely to be fortified. Heavy metal concentrations higher in gluten-free foods (attributed to rice content) and in blood/urine of gluten-free people. BUT: Poorer health outcome not linked to gluten-free diet in vast majority

Question 45

GF food is usually but not always wheat-free food is usually but not always

Answer 45

GF food is usually but not always wheat-free wheat-free food is usually but not always GF

Question 46

FDA definition of gluten-free

Answer 46

A) The food is inherently gluten-free (e.g., corn, potato, etc.) B) Does not contain an ingredient that is: 1) a gluten-containing grain (e.g., wheat, rye, barley, spelt, etc.) 2) derived from a gluten-containing grain but processed to remove gluten (e.g., wheat flour) to below a concentration of 20 ppm. C) Any unavoidable presence of gluten in the food must be less than 20 ppm.

Question 47

how was FDA's 20 ppm limit decided upon?

Answer 47

The FDA recommendation of 20 ppm for the “gluten-free label” was based on the fact that it was the lowest level to be reliably detected in foods using established analytical tools (consistent with the clinical recommendation). It was NOT based on data suggesting 20 ppm as the safe level.