1) IgG-mediated food intolerance involves an immune response to certain foods through IgG antibody production rather than IgE. It can cause a variety of symptoms through chronic inflammation.
2) A food print IgG test measures levels of food-specific IgG antibodies to identify foods an individual may be intolerant to. High antibody levels indicate foods that should be eliminated from the diet.
3) Eliminating foods identified on a food print test often significantly improves symptoms for those with conditions like irritable bowel syndrome, Crohn's disease, and celiac disease.
2. FOOD PRINT
Terminology
Reaction to food
A-Non Immune-mediated reaction.
Enzymatic insufficiency
a-Lactose intolerance
b-Histamine intolerance
B-Immune mediated
a-Type l immediate hypersensitivity reaction : IgE antibody-mediated
b-type lll immune complex mediated hypersensitivity reaction: IgG antibody-mediated
- Epidemiology
- Pathophisiology
- Symptomatology
- CLINICAL SIGNIFICANCE OF ESTIMATION OF SERUM IgG ANTIBODY TITRE TO FOOD
ANTIGENTS
- Food print IgG antibody test
- Antibody Levels
- Special considerations about application of food print results
- IMPORTANCE OF IgG FOOD PRINT IN iRRETABLE BOWEL SYNDROME
- A-Crohn's disease
- B-Celiac Disease.
3. Terminology
• The terms:
• (food allergy), (food hypersensitivity) &
(food intolerance) are often used
interchangeably & are often confused, but
essentially they all ,mean an abnormal
reaction to certain foods, which can manifest
them selves in many ways.
• They may be immunogenic mediated or
non-immunogenic mediated.
5. NON-IMMUNE-MEDIATED REACTIONS
• Reaction that don't produce an immune response
and are often referred as “food intolerances” .
• They can be caused by sensitivities to certain
chemicals or additives found in food, or more
commonly due to enzyme deficiency.
6. Enzymatic insufficiency(1)
• Lactose intolerance:
• caused by: a deficiency of “lactase” an enzyme that
breaks down lactose(a complex sugar)
• foods that contain lactose: diary products (milk,
yoghurts, cheese)
• Symptoms :bloating ,diarrhea and flatulence.
7. Enzymatic insufficiency(2)
• Histamine intolerance:
• Caused by an elevated histamine level due to
deficiency or inhibition of diamine oxidase (DAO);
an enzyme that breaks down histamine.
• Aggregated by foods high in histamine; including:
red wine , cheese and tuna fish.
• Symptoms include: migraine , dizziness, gastric
discomfort, rhinitis, depression and skin irritation.
9. A-Type l immediate hypersensitivity
reaction IgE ab-mediated
These reactions are characterized by the production
of IgE abs and histamine release, upon exposure to
an allergen (e.g. peanuts).
They are responsible for immediate-onset of
symptoms that often associated with a classical
allergic response: rash ,sneezing ,difficulty in
breathing & anaphylactic shock.
10. B-type III immune complex mediated
hypersensitivity reaction:
• Also known as : IgG-mediated Food hypersensitivity
reaction.
• Which is characterized by :
• the production of IgG antibodies and the gradual
formation of antigen-antibody complexes which are
deposited tissues , causing chronic inflammation &
delayed onset of symptoms which can occur several
hours to days after foods are ingested.
11. Epidemiology:(1)
The prevalence of IgG mediated-food food
intolerance is believed to be 5-20% of general
population.
The distribution of food-specific IgG levels
varied as a function of demographic
subgroups(sex, region & age).
12. Epidemiology:(2)
• Women had higher concentrations of food-specific
IgGs against the most common world wide tested
foods ;including : beef, chicken ,codfish ,pork ,rice,
wheat ,soy, tomato, cow's milk..etc) than men.
• In childhood , boys suffer from asthma , urticaria,
anaphylaxis & food allergy to eggplant & peanuts
more frequently than girls, while the sex difference
is reversed after puberty.
13. Epidemiology:(3)
• studies suggest that some female sex
steroids are pro-inflammatory & increase
the susceptibility of atopy, while
testosterone is a powerful inhibitor of
histamine and known to inhibit mast cell
degranulation
14. Pathophisiology
• It is believed to be caused by increased gut
permeability, which permits food substances to gain
access to the circulation and trigger food specific
IgG antibodies production.
• Increased production of food specific IgG antibodies
coupled with decreased production of anti-
inflammatory cytokines such as IL-10 & TGFbeta1
have been implicated in irritable bowel
syndrome(IBS).
15. Symptomatology(1)
• IgG-mediated food intolerance has been associated
with a wide range of specific & non specific
symptoms; which include:
• A-symptoms associated with allergy:
• rash, utricaria & asthma
• B-Gastrointestinal symptoms suggestive of irritable
bowel syndrome including :
• abdominal cramps , diahorrea, constipation.
18. CLINICAL SIGNIFICANCE OF FOOD PRINT(1)
• Prohibition & elimination of
incriminating foods that patients
were intolerant resulted in significant
improvement in symptom scores.
19. CLINICAL SIGNIFICANCE OF FOOD PRINT(2)
Patient clinically presenting with allergic
symptoms are usually investigated for the
presence of specific IgE antibodies that
may not be present among a sub-group
of patients presenting with allergic
symptoms to due to food intolerance.
20. CLINICAL SIGNIFICANCE OF FOOD PRINT(3)
• These symptoms, however, take time to manifest
since the formation IgGs takes days to months.
• As a result ; this group of patients may not only
remain undiagnosed , but also suffer from
significant preventable morbidity associated with
considerable financial burden on both patient &
heath care resources
21. Food print IgG antibody test
• Measures type III IgG immune mediated to food with a
report lists the numbers of foods that the patient / person
is sensitive or not tolerated.
• Two different types of test reports are provided:
• A-food groups : foods are listed alphabetically within there
respective food group.
• B-order of reactivity : foods are listed according to the
strength of antibody reaction.
• IgG abs are measured by ELIZA
22. Antibody Levels
• A numerical value is also displayed in a colored box
adjacent to each food this represents the
concentration of IgG abs detected in(U/ml) for each
food and the higher the value assigned, the
stronger the immune response to that particular
food.
• Depending upon the antibody level detected, foods
are categorized as :
• 1-Elevated
• 2-Border line
• 3-Normal
23. NORMAL
BORDER LINE
ELEVATED
Indicates that no
significant reaction
was detected
Indicates that a
moderate antibody
reaction was detected
Indicates that a high
antibody reaction was
detected
These foods can be
eaten without
restriction, unless
they have previously
caused an adverse
reaction.
These are a moderate
“problem foods”,
which should be
reduced from diet for
at least 3 months to
avoid increase
intolerance.
These are the primary
“problem foods”,
which should be
eliminated from diet
for at least 3 months.
24. • If patent is experiencing adverse symptoms and the food print
test identified ELEVATED or BORDERLINE IgG antibody levels,
this may indicate an intolerance to those specific foods.
• Removing them from diet usually results in an improvement
of symptoms
25. Special considerations about application of food
print results (1):
• 1-If the food print IgG test has not identified any
elevated foods, but the patient has experienced any
symptoms associated with food intolerance , it is
recommended that borderline foods be avoided for
3 months.
• 2-It can be difficult to eliminate multiple foods at
the same time. It is easier to:
• a-completely avoid the top 4 or 5 foods showing the
highest antibody concentrations.
• b-reduce or rotate the remaining foods showing the
moderate antibody concentrations.
26. • 3 - It is normal for patient to feel worse for few days after
eliminating specific foods & changing his diet. The body
needs time to overcome the withdrawal symptoms it is
experienced, so his should be prepared to persevere.
Improvement may only become apparent after a few
weeks.
• 4 -To" rotate foods" patient should eat them no more than
once every 4-5 days. For example, to rotate wheat :
• -eat wheat bread on day 1
• -oat cakes on day 2
• -corn cakes on day 3
• rye crisp-bread on day 4…. etc.
Special considerations about application of
food print results(2):
27. • 5-If elevated foods are to be eliminated from diet (e.g.
milk), it is essential that nutrients found in this food
group (e.g. calcium) should be sourced from other
foods.
• 6-Do not eliminate foods and then substitute them
solely with other foods from the same group , as this is
likely to create another intolerance. For example, if
wheat is being eliminated from diet , but is regularly
consumed for break fast (e.g. toast) , don't substitute it
for porridge oats for every day. It is advisable to eat &
rotate a wide variety of foods from the same age group.
Special considerations about application of food
print results(3):
28. • 7-Many people experience the greatest
improvement when they completely eliminate
"problem " foods. However , no worry if these foods
cannot be completely eliminated or it is needed to
break diet occasionally- the patient should start
again as soon as it is convenient.
• 8-If particular food has not been consumed within
last 3months, the food print test is likely to produce
a NORMAL reaction due to low IgG antibody levels.
Special considerations about application of food
print results(4):
29. • 9-If symptoms have not improved after 2-3 months,
despite eliminating the ELEVATED foods identified in
the food print test, this could indicate that IgG-
mediated food intolerance is not the cause of the
abnormal symptoms.
• 10-Gliadin is a protein fraction of gluten and is found in
gains of wheat , barely & rye. Due to nature of the food
print IgG antibody test , gliadin is tested separately to
these grains. If the test shows an elevated response to
gliadin, it is advisable to avoid any foods containing
wheat, barely or rye, even if these grains are listed as
NORMAL in the test report of the patient.
Special considerations about application of food
print results(5):
30. Special considerations about application
of food print results(6):
• 11-FoodPrint Test is measured by U/Ml:
• Which stands for “Unit per millitre”, it is a measure of
concentration. The result for each food listed in the test
report is expressed in U/Ml, shows the concentration of
food IgG antibodies detected in the blood sample
provided.
• 12-some foods may cause a classic allergic reaction
involving the production of IgE abs(Type1 allergy).
These will not be detected by the Food Print test as it
detects IgG abs. there are many foods that can cause a
reaction in the body without involving the immune
system, but produce symptoms similar to IgG reactions:
amines found in choclate , cheese & red wine may
cause migraines.
31. Special considerations about
application of food print results(7):
• 13- food print test is suitable for testing children,
but the recommended is a minimum age limit of 2
years.
• 14-if a certain food has been avoided for more than
3 months, it is likely that IgG antibody levels will be
insufficient to be detected by the test and may give
a normal result
• 15-To test intolerance to a certain food , it should
be included in the daily diet , for at least 4-6 weeks
before testing.
33. • a clinically significant improvement in IBS was
observed in patient eliminating foods according to
IgG food print test.
• Many patients with IBS prefer a diary solution to
their problem rather than having to take
medication.
34. Crhon's disease
• According some recent studies; it have been shown
that IgG abs against food antigens are elevated in
patients with Crhon's disease.
• A clinically significant improvement in IBS
symptoms was observed in patients eliminating
foods to which they were found to exhibit
sensitivity.
• INF gamma secretion by T-cells was increased after
specific diet.
35. Celiac Disease(1)
• Small intestinal villous atrophy in celiac disease is most likely
induced by an abnormal immune response to gluten.
• IgG antibodies may be of pathogenic importance in addition
to activated T lymphocytes and various cytokines.
• IgG is extravascularly distributed , its intestinal concentration
being at least half of that in serum.
• Both locally produced and circulating IgG with complement
activating prosperities and specificy for gluten & other
luminal antigens are thus available for mucosal immune
reactions.
• In adult celiac disease , the IgG fraction of mucosal
immunoglobulin producing cells was found to be most
markedly increased in relative terms.
36. Celiac Disease(2)
• More over in children with celiac disease, an inverse
linear relationship was noted between time to
clinical relapse after gluten challenge and mucosal
IgG cell number.
• A raised serum IgG activity to gluten & other dietary
antigens was found in most patients with untreated
celiac disease(
37. Celiac Disease(3)
• Celiac disease patients showed significantly higher
serum IgG levels against variety of foods compared
to both ulcerative colitis.
• It is suggested that detection of IgG against
combined food antigens is a beneficial method for
diagnosing Celiac disease.
38. REFERANCES
1- Prevalence of IgG-mediated food intolerance among patients with
allergic symptoms : Zahid Shakoor et al :2016.
2-Serum IgG subclass antibodies to variety of food antigens in patients
with celiac disease; M Hvatum et al :1992.
3-Variable food-specific IgG antibody level in healthy and symptomatic
Chinese adults :Qiang Zeng et al
4-Food elimination based on IgG antibodies in Irritable bowel syndrome
W.Akinson et al :2004.
5-Clinical Relevance of IgG Antibodies against food Antigens in Crohn's
disease. S.Bentz et al:2010.
6-Effectiveness of serum iGg antibody against food antigens as a
diagnostic marker of Crohn's disease ; Kawaguchi T et al :2010