Oral allergy syndrome Presented by Amornrat Prasertcharoensuk, MD. August10, 2018

1. Oral allergy syndrome
(Pollen-food syndrome )
Amornrat Prasertcharoensuk, MD
10 August 2018

2. Outline
• Introduction (Definition, Epidemiology)
• Clinical manifestation
• Cross-reactivity allergen
• Diagnosis
• Treatment

3. Definition
• Oral allergy syndrome (OAS) was first proposed in 1987
• Oral symptoms to fruit and vegetables in pollen allergic patients
• In 1988, cluster of OAS symptoms (fruit and vegetable and
relationship between the onset of hay fever and pollen
sensitivity .
• OAS is considered a collection of symptoms, which may have
different etiologies including PFS, food allergy (FA) or latex-fruit
syndrome

4. Oral allergy syndrome
• OAS to describe food allergy due to secondary sensitization
to cross-reactive pollens
• Pollen food allergy syndrome (PFAS) - cross-reactivity
between pollen-specific IgE and homologous proteins found
in fruits and vegetables.
• Latex fruit syndrome
Constance Helen Katelaris , Current Opinion in Allergy and Clinical Immunology
2010, 10:246–251

5. Class2 food allergy
Allergology International. 2009;58:485-491

6. Oral Allergy syndrome
Allergology International. 2009;58:485-491
Progress to systemic(GI) in 8.7% of patients.
Anaphylactic shock in 1.7%.
Cross-reactive protein
Heat-labile → PR-10 protein
Partially labile → profilin
Relative heat stable → lipid transfer protein
Ann Allergy Asthma Immunol 2010;104:101-108

7. Epidemiology
• European data estimate that OAS occurs in 47–70% of
pollen-allergic adult patients, while American data estimate
the prevalence to be 8%
• Prevalence determinations are influenced by geographical
pollen distribution, dietary influences or habits, and regional
prevalence of atopic disease
Allergy Clin. Immunol. 2010; 10: 246–51
J. Allergy Clin.Immunol. 2003; 112: 784–8

8. Mechanisms of cross-reactivity
• sensitizing and cross-reacting proteins belong to the same family of
proteins and are easily recognizable by the similarity in their amino
acid
sequences
• share a discrete three-dimensional structure, or have similar overall
conformation which accounts for their cross-reactivity (e.g. Profilins
and PR-10 family)
• epitopes based on linear sequence homology as well as have
conformational similarity (e.g. PR-5 and seed storage proteins)
Rana S. Bondsa, A structural basis for food allergy: the role of cross-reactivity, Current Opinion in Allergy and ClinicalImmunology 2008, 8:82–86

9. Overview of the most important allergen super families and families
EAACI Molecular Allergology User’s Guide, Pediatric Allergy and Immunology 2016: 27: (suppl23): 1–250

10. Overview of the most important allergen superfamilies and families
Oral allergy syndrome
EAACI Molecular Allergology User’s Guide, Pediatric Allergy and Immunology 2016: 27: (suppl23): 1–250

11. Overview of the most important allergen superfamilies and families
Oral allergy syndrome
EAACI Molecular Allergology User’s Guide, Pediatric Allergy and Immunology 2016: 27: (suppl23): 1–250
Bet V 2

12. Profilin-like superfamily
• protein of 12–15 kDa
• Profilins from higher plants constitute a family of highly conserved
proteins that show sequence identities of at least 75% even between
members from distantly related organisms
• Profilins are prominent allergens in pollens of trees, grasses, and
weeds and are recognized by 20% of pollen-allergic patients
• Profilin is a monomeric, actin-binding protein that regulates the
organization of the actin fi laments to form the actin cytoskeleton
EAACI Molecular Allergology User’s Guide, Pediatric Allergy and Immunology 2016: 27: (suppl23): 1–250

13. Aln g 2 Bet v 2 Car b 2 Cor a2
profilins from different pollen sources (Fagales)
Fag s2 Que a 2
EAACI Molecular Allergology User’s Guide, Pediatric Allergy and Immunology 2016: 27: (suppl23): 1–250

14. profilins from different pollen sources
Ole e2Fra e 2
EAACI Molecular Allergology User’s Guide, Pediatric Allergy and Immunology 2016: 27: (suppl23): 1–250

15. Phl p 12
profilins from different glass sources
EAACI Molecular Allergology User’s Guide, Pediatric Allergy and Immunology 2016: 27: (suppl23): 1–250

16. Art v4Amb a2
profilins from different weed polen sources
EAACI Molecular Allergology User’s Guide, Pediatric Allergy and Immunology 2016: 27: (suppl23): 1–250

17. Mer a 1 Par j 3
profilins from different weed pollen sources
EAACI Molecular Allergology User’s Guide, Pediatric Allergy and Immunology 2016: 27: (suppl23): 1–250

18. EAACI Molecular Allergology User’s Guide, Pediatric Allergy and Immunology 2016: 27: (suppl23): 1–250
profilins from some plant foods

19. Clinical
• Plant – food allergen in about 50% of sensitized subjects
• Profilin-induced food allergy (certain foods- melon, water-
melon, citrus fruits, banana, pineapple, persimmon, zucchini,
tomato)
• Patients tolerate processed foods
• Profilin and natural rubber latex allergy (Hev b 8)
EAACI Molecular Allergology User’s Guide, Pediatric Allergy and Immunology 2016: 27: (suppl23): 1–250

20. Overview of the most important allergen superfamilies and families
Oral allergy syndrome
EAACI Molecular Allergology User’s Guide, Pediatric Allergy and Immunology 2016: 27: (suppl23): 1–250

21. Bet v 1-like superfamily
• Bet v 1-like superfamily currently harbors 14,065 proteins
from 1,452 species with sequences related to the major birch
(Betula verrucosa) pollen allergen Bet v 1.
EAACI Molecular Allergology User’s Guide, Pediatric Allergy and Immunology 2016: 27: (suppl23): 1–250

22. Pathogenesis-related protein subfamily 10 (PR-10)
• the PR-10 proteins are actually one of the 11 subfamilies of the
Bet v 1 family.
EAACI Molecular Allergology User’s Guide, Pediatric Allergy and Immunology 2016: 27: (suppl23): 1–250

23. Aln g 1 Bet v 1 Car b 1 Cas s 1
Fag s1 Que a 1
PR-10 from different pollen sources (Fagales)

24. PR-10 from some plant foods
EAACI Molecular Allergology User’s Guide, Pediatric Allergy and Immunology 2016: 27: (suppl23): 1–250

25. Diagnosis algorithm in case tree pollen related food
allergy to raw plant
EAACI Molecular Allergology User’s Guide, Pediatric Allergy and Immunology 2016: 27: (suppl23): 1–250

26. Overview of the most important allergen superfamilies and families
Oral allergy syndrome
EAACI Molecular Allergology User’s Guide, Pediatric Allergy and Immunology 2016: 27: (suppl23): 1–250

27. Non-specific lipid transfer proteins (nsLTPs)
• mediate the transfer of phospholipids between vesicles and membranes
• nsLTPs play a role in plant defense against fungi and bacteria.
• Allergenic nsLTPs are a large group of proteins that are resistant to heat
and digestion
• Pru p 3, the major allergen of peach
• the nsLTPs have been classified as type 14 pathogenesis-related proteins
EAACI Molecular Allergology User’s Guide, Pediatric Allergy and Immunology 2016: 27: (suppl23): 1–250

28. nsLTPs from some plant foods
EAACI Molecular Allergology User’s Guide, Pediatric Allergy and Immunology 2016: 27: (suppl23): 1–250

29. Conclusion : Allergen class 2 food allergens
Allergology International. 2009;58:485-491

30. Allergology International. 2009;58:485-491
Conclusion : Allergen class 2 food allergens

31. Middleton 8th
Class 2 food allergens

32. Middleton 8th
Class 2 food allergens

33. Latex-fruit/vegetable syndrome
EAACI Molecular Allergology User’s Guide, Pediatric Allergy and Immunology 2016: 27: (suppl23): 1–250
30–70% of patients with
a latex allergy
associated food
allergies
particularly to banana,
avocado,
chestnut, kiwifruit

34. J ALLERGY CLIN IMMUNOL FEBRUARY 2003

35. European journal of allergy and clinical immunology, 2015

36. M. Egger, Pollen-food syndromes associated with weed pollinosis: an update from the molecular point of view, Allergy 2006: 61: 461–476
Art V1 and
Art v4
Art V 3 and Pru p3 → nsLTP

37. Current Opinion in Allergy and Clinical Immunology 2008, 8:82–86
Cross reactive carbohydrate determinants
shows an N-glycan containing a1,3-fucose and b1,2-
xylose. These are key structures for IgE binding and
are highlighted in purple and blue, respectively
M. Egger, Pollen-food syndromes associated with weed pollinosis: an update from the molecular point of
view, Allergy 2006: 61: 461–476

38. • Classic type 1 food allergy
• Eosinophilic oesophagitis
• Non IgE-mediated reactions
Differential diagnosis
Katelaris, Current Opinion in Allergy and Clinical Immunology 2010, 10:246–251

39. Diagnosis
• History and symptom
• Skin prick test ( Fresh foods vs commercial plant food extract)
• In vitro tests – specific IgE directed to single proteins (molecular or
component-resolved diagnosis)
• Oral provocation tests

40. Example of allergen source
EAACI Molecular Allergology User’s Guide, Pediatric Allergy and Immunology 2016: 27: (suppl23): 1–250

41. EAACI Molecular Allergology User’s Guide, Pediatric Allergy and Immunology 2016: 27: (suppl23): 1–250
evaluate a diagnosis algorithms that can be used to
potential nsLTP-mediated allergy

42. CRD: help to diagnosis primary VS secondary
European journal of allergy and clinical immunology, 2015

43. EAACI Molecular Allergology User’s Guide, Pediatric Allergy and Immunology 2016: 27: (suppl23): 1–250

44. Management
• Avoidance
• Symtomatic therapy ( antihistamine, corticosteroid, epinephrine)
• Allergen Immunotherapy
(immunotherapy with birch pollen extract significant reduction of
apple allergy. showed a negative skin test and tolerance 30 months
after the immunotherapy course)

45. Season Spring Summer Late-summer-
Fall
Fall
Pollen in the
oral cross-
reactivity
reaction with
foods
Birch Timothy and
orchard grass
Ragweed Mug wort
Apple
Apricot
Cherry
Peach
Pear
Plum
www.aaaai.org

46. Season Spring Summer Late-summer-
Fall
Fall
Pollen in the oral
cross-reactivity
reaction with
foods
Birch Timothy and
orchard grass
Ragweed Mug wort
Cantaloupe
Honeydew
Watermelon
Banana
Kiwi
Orange
Tomato
www.aaaai.org

47. Season Spring Summer Late-summer-
Fall
Fall
Pollen in the oral
cross-reactivity
reaction with
foods
Birch Timothy and
orchard grass
Ragweed Mug wort
Bell pepper
Broccoli
Cabbage
Carrot
Cauliflower
Celery
Chard www.aaaai.org

48. Season Spring Summer Late-summer-
Fall
Fall
Pollen in the oral
cross-reactivity
reaction with
foods
Birch Timothy and
orchard grass
Ragweed Mug wort
Cucumber
Garlic
Onion
Parsley
White potato
Zucchini
www.aaaai.org

49. Season Spring Summer Late-summer-
Fall
Fall
Pollen in the oral
cross-reactivity
reaction with
foods
Birch Timothy and
orchard grass
Ragweed Mug wort
Aniseed
Caraway
Coriander
Fennel
Black pepper
www.aaaai.org