Transcript Omega_5_Gliadin - NHS Networks

f416 rTri a 19; Omega-5 Gliadin
- a risk marker for severe immediate or exercise-induced
reactions in patients with suspected wheat allergy
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Classification of wheat proteins
Albumin
Water/salt soluble
Globulin
Wheat
proteins
Water/salt insoluble
(Gluten 85%)
Gliadins
(α-,β-,γ-,ω-1,2,3,4,
ω-5)
Glutenins
(HMW*-, LMW-)
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What is on ImmunoCAP®
f416 rTri a 19; Omega-5 Gliadin?
 Tri a 19; Omega-5 Gliadin from wheat (Triticum aestivum).
 Omega-5 gliadin is a storage protein and a major allergen
among water/salt–insoluble proteins, with limited presence
on f4 Wheat ImmunoCAP.
 Omega-5 gliadin can be found to some extent on f79
Gluten and to a higher extent on f98 Gliadin ImmunoCAP.
 The immunodominant peptide epitopes of omega-5 gliadin
have been identified.
 A cDNA encoding a hydrophilic portion of Tri a 19,
containing major epitopes for IgE antibodies, has been
cloned and expressed in E. coli and the purified
recombinant product coupled to ImmunoCAP.
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Possible clinical utility of ImmunoCAP®
f416 rTri a 19; Omega-5 Gliadin
 Identify patients at risk of developing severe
immediate reactions to wheat.
 Identify patient at risk of developing anaphylaxis to
wheat in relation to exercise (WDEIA).
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Severe immediate reactions to wheat
 Are important to identify, especially in children.
 ~ 80% of patients with severe immediate reactions have
IgE antibodies to both omega-5 gliadin and wheat.
 The remaining 20% of patients have IgE antibodies to
other components in wheat and will thus be positive with
f4 Wheat ImmunoCAP.
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Doctors diagnosis of wheat allergy and levels of IgE ab
to omega-5 gliadin in 88 children sensitized to wheat
37/44 (84%)
> 0.35 kUA/l
100
12/44 (27%)
> 0.35 kUA/l
kUA /L
10
1
0.1
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No wheat allergy
n = 44
Wheat allergy
n = 44
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Reference: Ito K et al. Poster presented at AAAAI in San Diego 2007
Challenge outcome and levels of IgE ab to
omega-5 gliadin in children sensitized to wheat
p<0.001
100
kUA /L
10
1
0.1
Negative
Challenge/History
n = 44
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Mild
n=5
Moderate
n=8
Positive Challenge
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Reference: Ito K et al. Poster presented at AAAAI in San Diego 2007
Severe
n=8
Wheat-dependent, exerciseinduced anaphylaxis (WDEIA)
 Wheat allergy induced by physical exercise.
 Symptoms are typically generalized urticaria and
severe allergic reactions such as anaphylactic shock
or hypotension.
 Skin tests and in vitro IgE ab tests for wheat are not
always satisfactory.
 Challenge test + intense physical exercise is the gold
std for diagnosis, but is inconvenient and dangerous.
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Major allergens in WDEIA
 ~80% of patients with WDEIA have IgE ab to omega-5
gliadin.
 ~20% of patients with WDEIA have IgE ab to high
molecular weight glutenin (HMW-glutinin).
 30-50% of patient with WDEIA are, however, negative
with f4 Wheat ImmunoCAP, but a majority are positive
to omega-5 gliadin.
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IgE ab to different wheat
proteins in patients with WDEIA
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Wheat
Gluten
Peptide A
Peptide B
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Specific IgE (kUA /L)
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WDEIA patients reacting predominantly to peptide A (n=23)
WDEIA patients reacting predominantly to peptide B (n=6)
WDEIA patients not reacting to both peptide A and B (n=1)
Atopic dermatitis patients (n=25)
Normal controls (n=25)
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15
10
Peptide A = Omega-5 gliadin
5
0.35
Peptide B = HMW-glutinin
1
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Investigation of risk for severe immediate or exerciseinduced reactions in patients with suspected wheat allergy
Test with ImmunoCAP™Allergen:
f4 Wheat + f416 rTri a 19; Omega-5 Gliadin
Test results
f4 neg / f416 neg
Test results
f4 neg / f416 pos
Test results
f4 pos / f416 pos
Test results
f4 pos / f416 neg
Is there a history of
exercise-induced symptoms?
Yes
No
Conclusion
Conclusion
Conclusion
Conclusion
Conclusion
No sensitization to
wheat; symptoms are
probably caused by
another food or due to
a different mechanism
High risk for exerciseinduced reactions
due to wheat
High risk for severe
immediate reactions
due to wheat
High risk for severe
immediate or
exercise-induced
reactions due to wheat
Low risk for severe
immediate or
exercise-induced
reactions due to wheat
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Recommended test procedure in
patients with suspected wheat allergy
f4 Wheat + f415 rTri a 19; Omega-5 gliadin

The clinical relevance of a positive f4 Wheat test are sometimes difficult to interpret.

Omega-5 gliadin is found to be a risk marker for severe immediate reactions including
WDEIA (80% pos).

30-50% of patients with WDEIA have no IgE abs to wheat (f4).

f4 neg & f416 neg tests: no sensitization to wheat is found; another food or mechanism
is probably the cause.

f4 neg & f416 pos tests: high risk for severe immediate reactions including WDEIA due
to wheat.

f4 pos & f416 pos tests: high risk for severe immediate reactions including WDEIA due to
wheat.

f4 pos & f416 neg tests: low risk for severe immediate reactions including WDEIA due to
wheat. However, many of these patients will have immediate type reactions such as skin
and gastrointestinal symptoms.
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A case report
 Age: 57
 Gender: Male
 Race group: White
 Country of birth: Zambia
 Living in: South Africa
 Occupation: Engineer, Project Manager (often very stressful)
 Activities: Camping, Cycling, Scuba diving, Hiking
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Anamnesis
 Onset three years ago, June 2003.
 15 adverse reactions between June -03 and Feb -06.
 Reaction one hour after eating with extreme itching from
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hairline to armpits, buttocks and groin where hives break out.
Steadily increasing hart rate (180 beats vs. 80 normally).
Tight chest with labored breathing.
Loss of conscious ones with cardiac arrest.
Mild reactions on a few occasions that were stopped with 3
antihistamine tablets.
Many hospital visits with intravenous adrenaline and
cortisone.
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What is the offending allergen (s)?
- ImmunoCAP® tested in South Africa
13 Nov 2003
 Total IgE 1601 kU/l
 Phadiatop positive
 Cat 1.09 kUA/l
 Mixed Cockroach 0.56
kUA/l
 Negative test results*:
Dog, mites, trees,
weeds, timothy grass,
mould, egg, milk, soy,
peanut, wheat, fish and
shrimp
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31 March 2004
 Total IgE 1818 kU/l
 Phadiatop positive
 Milk 0.58 kUA/l
 Negative test results*:
soy, peanut, wheat, fish,
shrimp, cheese
* Negative < 0.35 kU /l
A
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What is the offending allergen (s)?
- ImmunoCAP® tested in South Africa
11 March 2006
 Total IgE 2315 kU/l
 Mixed cockroach 0.81 kUA/l (tropomyosin)
 Avocado & pear negative* (Chitinase)
 Pineapple negative* (Profilin)
 Sunflower seed negative* (2S albumin)
 Peach negative* (LTP)
 Strawberry negative* (Bet v 1)
 Salmon negative* (Calcium binding protein/Polcalcin)
 Yeast negative* (Enolase)
 Bell pepper/paprika negative* (Thaumatin protein)
* Negative < 0.35 kUA/l
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What is the offending allergen (s)?
- ImmunoCAP® tested at Phadia in Sweden
Fall 2006
 Phadiatop 0.47 PAU/l
 Pork 0.81 kUA/l
 Mushroom 0.1 kUA/l
 Sesame 0.19 kUA/l
 Black pepper 0.13 kUA/l
 Olive 0.15 kUA/l
 Casein 0.19 kUA/l
 Bovine lactoferrin 0.64 kUA/l
 Beef 1 kUA/l
 Anisakis 0.15 kUA/l
 Echinococcus 0.91 kUA/l
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 Wheat 3.3 kUA/l
 Gluten 4.4 kUA/l
 Gliadin 30.5 kUA/l
 Omega-5 Gliadin 30.5 kUA/l
 Negative test results*: tomato,
Gly m 4, Ara h 8, onion, grape,
mustard, alfa-lactalbumin,
beta-lactoglobuline, CCD; MUXF3
* Negative < 0.1 kUA/l
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Summary case report
 Omega-5 gliadin from wheat was finally found to be the
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offending allergen.
Since wheat was tested negative already in South Africa it
was not at once retested at Phadia.
To test for gluten (f79) was a last try to find the offending
allergen.
The positive gluten result (4.4 kUA/L) led into testing with
gliadin (AGf98) but also omega-5 gliadin (f416) that was
under development.
When omega-5 gliadin was tested positive (30.5 kUA/L) the
wheat test was repeated and now found positive (3.3 kUA/L).
Similar levels of IgE ab to gliadin (AGf98) and omega-5
gliadin (f416), indicate that the amount of omega-5 gliadin is
fairly good represented on gliadin ImmunoCAP AGf98.
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Information material available
New Horizon 1/2007; article & clinical leaflet, product leaflet and test chart
See more info in Marketing Info No. 6 & 7/2007
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References
1. Matsuo H, Kohno K, Morita E.
Molecular cloning, recombinant expression and IgE-binding epitope of
w-5 gliadin, a major allergen in wheat-dependent exercise-induced
anaphylaxis.
FEBS Journal 2005;272:4431-8
9. Palosuo K, Varjonen E, Nurkkala J, Kalkkinen N, Harvima R, Reunala T,
Alenius H.
Transglutaminase-mediated cross-linking of a peptic fraction of w-5 gliadin
enhances IgE reactivity in wheat-dependent, exercise-induced anaphylaxis.
J Allergy Clin Immunol 2003;111(6):1386-92
2. Morita E, Matsuo H, Mihara S, Morimoto K, Savage AW, Tatham AS.
Fast w-gliadin is a major allergen in wheat-dependent exercise-induced
anaphylaxis.
J Dermatol Sci 2003;33(2):99-104
10. Varjonen E, Vainio E, Kalimo K.
Life threatening anaphylaxis caused by allergy to gliadin and exercise.
Clin Exp Allergy 1997;27:162-6
11. Lehto M, Palosuo K, Varjonen E, Majuri ML, Andersson U, Reunala T, Alenius H.
Humoral and cellular responses to gliadin in wheat-dependent, exercise-induced
anaphylaxis.
Clin Exp Allergy 2003;33(1):90-5
3. Palosuo K, Alenius H, Varjonen E, Kalkkinen N, Reunala T.
Rye g-70 and g-35 secalins and barley g-3 hordein cross-react with w-5
gliadin, a major allergen in wheat-dependent, exercise-induced anaphylaxis.
Clin Exp Allergy 2001;31(3):466-73
12. Morita E, Kameyoshi Y, Mihara S, Hiragun T, Yamamoto S.
g-Gliadin: a presumptive allergen causing wheat-dependent exercise-induced
anaphylaxis. [Letter]
Br J Dermatol 2001;145(1):182-4
4. Matsuo H, Morita E, Tatham AS, Morimoto K, Horikawa T, Osuna H,
Ikezawa Z, Kaneko S, Kohno K, Dekio S.
Identification of the IgE-binding epitope in w-5 gliadin, a major allergen in
wheat-dependent exercise-induced anaphylaxis.
J Biol Chem 2004;279(13):12135-40
13. Morita E, Yamamura Y, Mihara S, Kameyoshi Y, Yamamoto S.
Food-dependent exercise-induced anaphylaxis: a report of two cases and
determination of wheat-g-gliadin as the presumptive allergen.
Br J Dermatol 2000;143(5):1059-63
5. Tanabe S, Arai S, Yanagihara Y, Mita H, Takahashi K, Watanabe M.
A major wheat allergen has a Gln-Gln-Gln-Pro-Pro motif identified as an
IgE-binding epitope.
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14. Gall H, Steinert M, Peter RU.
Exercise-induced anaphylaxis to wheat flour.
Allergy 2000;55(11):1096-7
6. Battais F, Pineau F, Popineau Y, Aparicio C, Kanny G, Guerin L, MoneretVautrin DA, Denery-Papini S.
Food allergy to wheat: identification of immunogloglin E and immunoglobulin Gbinding proteins with sequential extracts and purified proteins from wheat flour.
Clin Exp Allergy 2003;33(7):962-70
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Wheat w-5 gliadin is a major allergen in children with immediate allergy to
ingested wheat.
J Allergy Clin Immunol 2001;108(4):634-8
7. Palosuo K, Alenius H, Varjonen E, Koivuluhta M, et al.
A novel wheat gliadin as a cause of exercise-induced anaphylaxis.
J Allergy Clin Immunol 1999;103(5 Pt 1):912-7
16. Daengsuwan T, Palosuo K, Phankingthongkum S, Visitsunthorn N,
Jirapongsananuruk O, Alenius H, Vichyanond P, Reunala T.
IgE antibodies to w-5 gliadin in children with wheat-induced anaphylaxis.
Allergy 2005;60:506-9
8. Maruyama N, Ichise K, Katsube T, Kishimoto T, Kawase S, Matsumura Y,
Takeuchi Y, Sawada T, Utsumi S.
Identification of major wheat allergens by means of the Escherichia coli
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