Metabolic Disturbances due to Food Allergies Flashcards
Are food allergies more prevalent in children or adults?
Children (6-8% vs 3.7%)
The leading causes of fatal and near-fatal food allergic reactions
Tree nuts and peanuts
Over a period of 2 years, what are the chances that an individual has an allergic reaction?
50%
What are the most common allergies in adults?
Seafood allergies
Food allergies are the most frequent precipitators of emergency room visits to treat
Anaphylaxis (32-54%)
The least abundant immunoglobin
-found only in mammals
IgE
IgE is found in the mucous membranes of
Lungs, intestines, and skin
IgE provides protection against
Parasites (helminths)
Plays a major role in allergies
IgE
Binds to basophils (mast cells) on the FCeRI
IgE
What are the two stages of food allergy progression?
Sensitization and elicitation
The majority of food allergens are
Proteins
What is the protein that causes peanut allergies?
-seed storage protein
Ara h 1-8
What is the protein that causes shellfish allergy?
-muscle protein
Tropomyosin
What is the protein that causes allergy to cow’s milk?
-functions in lactose biosynthesis
Lactalbumin
Allergens contain one or more epitopes (fragments) that bind
IgE
Structural similarity between allergens, such as that seen in the birch pollen (Bet v 1 ) and apple (Mal d 2) allergens may drive
Cross-reactivity
A very atypical food allergy
Celiac disease
A proline/glutamine rich polypeptide found in wheat
Gliadin
Gliadin binds strongly to
HLA type DQ2
Gliadin binding strongly to HLA type DQ2 drives an
Immune response
HLA-DQ2 binding is made more potent by activation of peptides by tissue
Transglutaminase
Transglutaminase can crosslink with gliadin peptides, resulting in formation of antibodies against peptide-bound complex, leading to a stronger
Autoimmune reaction
The proline rich sequence of gliadin makes it resistant to
Protease digestion
This increases gliadin’s concentration in the small intestine where it can be absorbed and drive an
Immune response
Inhibits digestion of dietary proteins and causes food allergy
Antacid medication
Antacid medications can cause
Food allergies
Interferes with denaturation and proteolysis of food antigens in the stomach
Gastric acid suppression
Drugs that elevate gastric pH may allow epitopes that are normally destroyed in the stomach to be preserved and recognized by the
Immune system
Mice fed Bifidobacterium breve and fructo + galacto oligosaccharides were less likely to be sensitized to
Whey proteins
How many human milk oligosaccharides (HMOs) that do not nourish infants but support growth of certain beneficial gut bacteria like Bifidobacterium infantis
200
Also prevent the growth of harmful bacteria like Campylobacter jejuni by blocking their binding to the intestinal mucosa
HMOs
Human milk contains several lactic acid bacteria that secrete
-kills harmful pathogens
Hydrogen peroxide
Gastric acid suppression during pregnancy can lead to
Childhood asthma (or other allergies)
The use of maternal acid-suppressive medication is associated with an increased odds ratio for the development of
Childhood asthma
Environmentally induced alterations in the commensal microbiota have been implicated in the increasing prevalence of
Food allergies
Sensitization to a food allergen is increased in mice that have been treated with
Antibiotics
By selectively colonizing gnotobiotic mice, we demonstrate that the allergy protective capacity is conferred by a
Clostridia-containing microbiota
Microarray analysis of intestinal epithelial cells from gnotobiotic mice revealed a previously unidentified mechanism by which Clostridia regulate
Innate lymphoid cell function
A method to elevate IgG and Treg levels and reduce allergies
Sublingual immunotherapy (SLIT)
SLIT results in lower
IgE levels
mABs against IgE or FceRI broadly reduce sensitivity to a range of
Antigens
Allosteric binding to IgE heavy chain domains can dissociate
IgE from the receptor
