Your SlideShare is downloading. ×
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Egg allergy: new allergens and molecular diagnosis
Upcoming SlideShare
Loading in...5
×

Thanks for flagging this SlideShare!

Oops! An error has occurred.

×
Saving this for later? Get the SlideShare app to save on your phone or tablet. Read anywhere, anytime – even offline.
Text the download link to your phone
Standard text messaging rates apply

Egg allergy: new allergens and molecular diagnosis

1,364

Published on

Egg allergy: new allergens and molecular diagnosis …

Egg allergy: new allergens and molecular diagnosis

Presented by Suparat Sirivimonpan, MD.

September7, 2012

Published in: Health & Medicine
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total Views
1,364
On Slideshare
0
From Embeds
0
Number of Embeds
2
Actions
Shares
0
Downloads
69
Comments
0
Likes
0
Embeds 0
No embeds

Report content
Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
No notes for slide
  • Gallus domesticusไก่บ้านImmunocapมี Gal d123 ใน egg white but egg yolk Gal d 5Most of the allergenic egg proteins are found in egg whiteThe main allergen in egg yolk, chicken serum albumin (also called alpha-livetin, Gal d 5), is thought to be involved in thepathogenesis of bird-egg syndrome
  • OVA : most abundant proteinOVM : dominant allergen OVM 28 kDa glycoprotein comprising 186 amino acids It comprises 3 protein domains, each stabilized by 3 intradomain disulfide bondsส่วน ovotransferrin , lysozymeมีบทบาทน้อยAllergo Sorbent Test (RAST) reported the order of allergenicity as ovomucoid > ovalbumin > ovotransferrin > lysozymeThe allergenicity of proteins depends mostly, but not exclusively, on their resistance to heat and digestive enzymes
  • Egg-yolk alpha-livetin, chicken serum albumin (CSA),All patients had positive skin tests and serum IgE against egg yolk, chicken serum, chicken meat, bird feathers, and chicken albumin. The presenceof airborne chicken albumin in the domestic environment was con®rmed.Speci®c bronchial challenge to chicken albumin elicited early asthmatic responses in six patients with asthma. An oral challenge with chicken albuminprovoked digestive and systemic allergic symptoms in the two patients challenged. IgE reactivity to chicken albumin was reduced by 88% after heatingat 90uC for 30 min. ELISA inhibition demonstrated only partial cross-reactivity between chicken albumin and conalbumin
  • ม่วงmixed
  • The sIgE to OVM showed higher PPVs
  • Transcript

    • 1. Egg Allergy 7/9/2012 Suparat Sirivimonpan,MD.
    • 2. Egg allergyIntroductionPrevalence Egg allergen : new allergen Diagnosis : molecular diagnosis
    • 3. Introduction• Egg allergy may be defined as an adverse reaction of immunologic nature induced by egg proteins – IgE ,non-IgE , mixed IgE-mediated disorders• hen’s egg allergy is the second most common food allergy in infants and young children• closely associated with atopic dermatitis• Increase risks of sensitization to aeroallergens and asthma in children with egg allergy Pediatr Clin N Am 2011;58:427–443
    • 4. Prevalence• estimated prevalence : varies depending on method of data collection or definition• A meta-analysis of the prevalence of egg allergy in children – Self-reported prevalence : up to 7% – challenge-confirmed egg allergy : up to 1.7% Allergy 2010; 65: 283–289
    • 5. PrevalenceIn Thailand• Santadusit S, et al. – Egg allergy : 1.52% J Med Assoc Thai 2005;88:S27-32• Unpublished data 2012, Chulalongkorn university – egg allergy : 1.1% (parent reported and physician diagnosis) in young children
    • 6. Egg allergen
    • 7. Egg allergens• 5 major allergenic proteins : Gal d 1 to Gal d 5 (Gallus domesticus) Curr Allergy Asthma Rep 2006;6(2):145–52
    • 8. Egg White allergen
    • 9. Egg white allergens Allergy 2010; 65: 283–289
    • 10. Ovomucoid• dominant allergen in egg• unique characteristics – relative stability against heat and digestion with proteinases – presence of strong disulfide bonds that stabilize protein• children with persistent egg allergy had significantly higher specific IgE levels to OVM than children who outgrew their egg allergy• A favorable prognosis was associated with the absence or a decline in OVM-specific IgE titers Allergy 2007; 62:758–765 Curr Opin Allergy Clin Immunol 2011, 11:210–215
    • 11. Ovalbumin• heat-labile and less allergenic• IgE-binding epitopes on OVA might be destroyed after heating : children who have specific IgE primarily to OVA are likely to tolerate heated egg Curr Opin Allergy Clin Immunol 2011, 11:210–215
    • 12. Ovalbumin• The Maillard reaction occurs between reducing sugars and proteins during thermal processing of foods• It produces chemically glycated proteins termed advanced glycation end products (AGEs)  T-cell immunogenicity of chemically glycated ovalbumin• The glycation structures of AGEs are suggested to function as pathogenesis-related immune epitopes in food allergy J Allergy Clin Immunol 2010;125:175-83.
    • 13. Newly identified egg white allergen Allergology International. 2010;59:175-183
    • 14. • Diluted egg white proteins were separated by 2-dimensional (2-D) gel electrophoresis 63 spots Allergology International. 2010;59:175-183
    • 15. • Immunolabeling was performed on individual patient sera • 19 child patients with egg white allergy • 11 negative control subjects19 patients 11 negative control subjects-Aged 2.2 ± 1.7 years -Aged 4.0 ± 3.7 years-Total IgE 434.1 ± 424.7 Iuml -no clinical history of any allergic-Diagnosis was based on clinical history symptomsand CAP-RAST results to hen’s eggwhite-Open food challenges : 9/19 patients Allergology International. 2010;59:175-183
    • 16. Allergology International. 2010;59:175-183
    • 17. 15/25• Spots of egg white proteins that bound to the patients’ IgE were identified by mass spectrometry-based proteomics 10/25 Allergology International. 2010;59:175-183
    • 18. Identification of IgE-reactive spots • spots were excised • digested in-gel with trypsin • The resulting peptide mixtures were analyzed by26% pt – LC-MS/MS (Liquid chromatographytandem mass16% pt spectrometry) L-PGDS – MALDI-TOF/MS (matrix assisted laser desorption(1 anaphylaxis) ionization time of flight mass spectrometry)53% pt Allergology International. 2010;59:175-183
    • 19. L-PGDS Cystatin • Reaction to LPGDS and cystatin was confirmed using each purified protein Allergology International. 2010;59:175-183
    • 20. Ch21 protein and L-PGDS• Ch21 protein and L-PGDS belong to the lipocalin Family• has been reported as allergenic• Ch21 protein and L-PGDS were minor allergens• However, the sera from patient (MT,HS), which reacted to spot no. 28 did not seem to react to the major spots, such as nos. 3, 4, 5, 48, or 49  not only the hidden allergen components, but there are some patients who are preferentially reacting to those minor egg allergens• minor allergen does not always mean that it is allergenically poor Allergology International. 2010;59:175-183
    • 21. Ch21 protein and L-PGDS• PGD2 synthesized by L-PGDS is related to allergic inflammation in vivo and that L-PGDS from chicken shows PGDS activity• These reports suggest that L-PGDS induces allergic reactions in addition to binding to IgE, and that PGD2 may exist in eggs Allergology International. 2010;59:175-183
    • 22. Cystatin• cysteine protease inhibitor• allergen in cats and dogs• considered to be a major allergen because it showed high reactivity to IgE from patients with egg allergy• 2 possible reasons for the lack of literature on cystatin as an allergen – similarity in molecular weight of cystatin and lysozyme, a major allergen, makes it difficult identify cystatin without using 2-D gel electrophoresis – presence of only a small amount of cystatin in eggs makes it difficult to identify without development of LC-MSMS Allergology International. 2010;59:175-183
    • 23. Egg yolk allergen
    • 24. Egg yolk allergens• alpha-livetin or chicken serum albumin (Gal d 5) is the major allergen and is involved in the bird-egg syndrome• Several other allergens have been identified in egg yolk – vitellenin (apovitellenin I) and – apoprotein B (apovitellenin VI) – roles in food allergy remain unclear Pediatr Clin N Am 2011;58:427–443
    • 25. Bird-egg syndrome• primary sensitization is to airborne bird allergens (feathers, droppings, serum) and there is secondary sensitization or cross- reactivity with albumin in egg yolk (Gal d 5)• respiratory symptoms such as rhinitis and/or asthma with bird exposure• allergic symptoms (respiratory and gastrointestinal symptoms) when egg is ingested• In children with allergy to birds and egg, egg allergy is usually more persistent• Sensitization to other aeroallergens is also greater in individuals with allergy to birds and egg Allergy 2001: 56: 754-762 Allergol et Immunopathol 2003;31(3):161-5
    • 26. J. Agric. Food Chem. 2010, 58, 7453–7457
    • 27. • Sera from 27 patients (ages 2-74 yrs) with egg allergy (clinical history and both positive-specific IgE and SPTs to egg)• sera from 2 non-allergic subjects as negative controls• The study was performed by – sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and – IgE-immunoblotting and – IgEimmunoblotting- inhibition assays• egg yolk extract was fractioned by reverse-phase high performance liquid chromatography (RP-HPLC) J. Agric. Food Chem. 2010, 58, 7453–7457
    • 28. • A new allergen with an apparent molecular weight around 35 kDa was identified from the yolk extract and enriched by RPHPLC (Figure 1A)• 5/27 patients studied (18%of patients) showed specific IgE binding to the allergen (Figure 1B) J. Agric. Food Chem. 2010, 58, 7453–7457
    • 29. J. Agric. Food Chem. 2010, 58, 7453–7457
    • 30. • new allergen detected was characterized by N-terminal amino acid analysis• revealed that allergen was the yolk glycoprotein 42 (YGP42) protein, a fragment of the vitellogenin-1 (VTG-1) precursor (positions 1628-1912)• The allergen has been designated Gal d 6.0101 by the World Health Organization (WHO)/International Union of Immunological Societies (IUIS) Allergen Nomenclature Subcommittee J. Agric. Food Chem. 2010, 58, 7453–7457
    • 31. • heat-resistant but digestible by pepsin J. Agric. Food Chem. 2010, 58, 7453–7457
    • 32. J Allergy Clin Immunol 2004;113:805-19• Conformational epitopes can be destroyed with heating or partial hydrolysis• Egg-specific IgE molecules that identify sequential or conformational epitopes of OVM and OVA can distinguish different clinical phenotypes of egg allergy – patient with IgE antibodies reacting against sequential epitopes tend to have persistent allergy – IgE antibodies primarily to conformational epitopes tend to have transient allergy Pediatr Clin N Am 2011;58:427–443
    • 33. Diagnosis
    • 34. Diagnosis• Double-blind, placebo-controlled food challenge : gold standard• open food challenges (OFCs) – Less resource-intensive – are generally considered sufficient in clinical practice Curr Opin Allergy Clin Immunol2009;9:244–250
    • 35. Diagnosis• detailed history and physical examination• in vitro and/or in vivo allergy tests – used to support diagnosis – food-specific IgE antibodies – skin prick tests – diagnostic elimination diet – OFC Pediatr Clin N Am 2011;58:427–443
    • 36. Skin prick tests• used in screening for egg-specific IgE and should be performed by trained personnel• diagnostic accuracy is dependent on quality of the extract, which should be standardized• SPT shows a good sensitivity and NPV, but poor specificity and PPV – negative test essentially excludes an IgE-mediated egg allergy – positive test does not predict clinical reactivity accurately Allergy 2010; 65: 283–289
    • 37. Skin prick test for diagnosisReferences Year Age group (yr) Method Numbers of PPV SPT Wheal of Dx patients diameter (mm)Sampson and 1997 Children and DBC 100 85 ≥3*Ho1 adolescentsSporik et al2 2000 <2 OC 39 100 ≥ 5 EW >2 82 ≥ 7 EWBoyano- 2001 <2 OC 81 93 ≥ 3 EW,EYMartinez et al 3Monti et al4 2002 <19 mo (mean 16 mo) OC 107 100 ≥ 5 EW, EYHill et al5 2004 <2 OC 30 100 ≥5*Verstege et al6 2005 All(3 mo-14.5yr) DBC/OC 160 95 ≥ 13 fresh mixed EW&EY <1 26 ≥ 11.2 >1 134 ≥ 13.3 1JAllergy Clin Immunol 1997;100(4):444–51 4Clin Exp Allergy 2002; : – 2Clin Exp Allergy 2000;30(11):1540–6 5Pediatr AllergyImmunol 2004;15(5):435–41 3Clin Exp Allergy 2001;31(9):1464–9 6Clin Exp Allergy ; ( ): –
    • 38. Serum specific IgEReferences Year Age group (yr) Method Numbers of PPV Egg-specific IgE of Dx patients (kUA/L)Sampson and 1997 Children and DBC 100 95 6*Ho1 adolescentsSampson2 2001 3 mo-14 yrs DBC 75 98 7* (median 3.8yr)Boyano- 2002 11-24 mo OC 58 95 2 EW (mean 16 mo)Martinez et al3Osterballe and 2003 0.5-4.9 yr OC 56 95 1.5 EWBindslev-Jensen4 (median2.2yr)Celik-Bilgili et 2005 0.1-16.1 yr OC All 277 95 12.6 *al5 (median13mo) ≤ 1 yr 41 10.9 > 1 yr 186 13.2 1J Allergy Clin Immunol 1997;100(4):444–51 4 J Allergy Clin Immunol 2003; 112:196–201 2J Allergy Clin Immunol 2001;107:891-6 5Clin Exp Allergy 2005; 35:268–73 3 J Allergy Clin Immunol 2002;110(2):304–9
    • 39. Serum specific IgE (cont.)References Year Age group (yr) Method Numbers of PPV Egg-specific IgE of Dx patients (kUA/L)Komata et 2007 0.2-14.6 yr OC 764 95 ALL ≥ 25.5al6 (median2.2yr) ≤ 1 : 13 1-2 : 23 ≥ 2 : 30Benhamou 2008 16 mo – 11.9yr OC/DBC 35 95 7*et al7 (median 3.9 yr)Ando et al 8 2008 14 mo – 13yr DBC 108 95 (raw EW EW 7.38 (median 34.5 mo) allergy) OVA 9.84 OVM 5.21 84-88 (heated EW 30.7 EW allergy) OVA 29.3 OVM 10.8 6J Allergy Clin Immunol 2007; 119:1272–4 7Pediatr Allergy Immunol 2008; 19:173–9 8J Allergy Clin Immunol 2008; 122:583–8
    • 40. MOLECULAR DIAGNOSIS IN FOOD ALLERGY• specific responses at the level of individual allergenic proteins : component-resolved diagnosis [CRD]or• IgE-binding epitopes of allergens : epitope mapping or profiling Immunol Allergy Clin N Am 2012;32:97–109
    • 41. Microarray-based component-resolved diagnosis• ImmunoCAP-ISAC or Immuno Solid phase Allergen Chip (VBC Genomics-Vienna, Austria; Phadia, Uppsala, Sweden)• It currently has 112 native/recombinant component allergens from 51 allergenic sources• two main advantages: – assesses simultaneously specific IgE to different components and requires small amounts of serum(relevant in children) – cost-efficient approach, as it delivers results for over 100 components Curr Opin Allergy Clin Immunol 2011;11:210–215 Immunol Allergy Clin N Am 2012;32:97–109
    • 42. • infants and children ,suspected IgE-mediated food (CM or HE) – Skin (42%), respiratory (6%), GI (16%), combination of skin, RS,GI (32%), anaphylactic shock (4%) – Only atopic eczema were excluded• all patients SPT, sIgE (ImmunoCAP and microarray) and open food challenge test were performed• Total 104 patients (62 males and 42 females), median age of 4.9 yrs (range 0.7–15.1)• hen’s egg allergy 46 patient Clinical & Experimental Allergy, 2010 (40) 1561–1570
    • 43. • FCT resulted positive in 22/46 (48%) patients with suspected HE allergy Clinical & Experimental Allergy, 2010 (40) 1561–1570
    • 44. 95% predicted probability (CDP)of a positive FCT Clinical & Experimental Allergy, 2010 (40) 1561–1570
    • 45. Clinical & Experimental Allergy, 2010 (40) 1561–1570
    • 46. ↓FCT≈15% ↓FCT≈37% Sequential use of the two tests did not lead to a further improvement in clinical performance False negative remains relatively high  FCT should still be performed Clinical & Experimental Allergy, 2010 (40) 1561–1570
    • 47. • 68 children (47 male, 69.1%),• Age 1 - 11 years (median 4.1 years)• suspected HE allergy based on – reported history of reactions like asthma, rhinitis, conjunctivitis, urticaria, worsening of eczema, vomiting, other gastro-intestinal tract symptoms, anaphylaxis, after ingestion or contact with HE, – and positive SPT or IgE to HE white extracts• 42/68 (62%) reported atopic dermatitis as the main allergic complain Clinical & Experimental Allergy 2012 :42;441-451
    • 48. • Skin prick test – Commercial extracts (Allergopharma, Reinbek, Germany) and fresh eggs using the prick-prick technique – Fresh: white and yolk from both raw and processed boiled HE – Positive : wheal greater than 7 mm2• Total and specific IgE – HE white and yolk : ImmunoCAP (Phadia AB, Uppsala, Sweden) – Specific IgE detection for Gal d 1, Gal d 2, Gal d 3 and Gal d5 : ISAC 103 microarray test (PMD, Vienna, Austria)• Double- blind, placebo-controlled food challenge (DBPCFC) – First : boiled egg (totol HE protein 6 g) – Patients tolerating boiled HE were then challenged with raw HE – patients with positive response to boiled HE challenge were considered likely to be allergic to both boiled and raw eggs Clinical & Experimental Allergy 2012 :42;441-451
    • 49. No significant differences significant differences, P<0.01 significant differences Clinical & Experimental Allergy 2012 :42;441-451
    • 50. ImmunoCAP Clinical & Experimental Allergy 2012 :42;441-451
    • 51. ISAC 20 of 21 Gal d 1 positive patients (95%) reacted to raw egg. 44/47 Gal d 1 negative patients (94%) could tolerate boiled egg Clinical & Experimental Allergy 2012 :42;441-451
    • 52. Clinical & Experimental Allergy 2012 :42;441-451
    • 53. ISAC – Other sensitization• 13 patients had no additional IgE detectable sensitizations on ISAC (103 microarray system) – 10 were in ST group – 3 in PT group – none in A group• 54 subjects : positive for at least one non-HE allergen – higher sensitization prevalence to other food and nonfood allergens in group A Clinical & Experimental Allergy 2012 :42;441-451
    • 54. A PT STAllerrgen group sensitizationLTP: Cor a 8, Pru p 3Parvalbumin: Cyp c 1, Gad c 1PR-10: Act d 11, Api g 1, Ara h 8, Bet v 1, Cor a 1.0101, Cora1.0401, Dau c 1, Mald 1, Pru p 1, Gly m 4Profilin: Bet v 2, Hev b 8, Mer a 1, Ole e 2, Phl p 12Tropomyosin: Der p 10, Ani s 3, Pen a 1,Pen i 1, Pen m 1; Clinical & Experimental Allergy 2012 :42;441-451
    • 55. statistically significant differencesAnisakis: Ani s 1Kiwi: Act d 1, Act d 2,Act d 5Cow’s milk: Bos d 4, Bos d 5, Bos d 8Seeds: Ana o 2, Ara h1, Ara h 2, Ara h 3, Ber e 1, Cor a 9, Gly m 5,Gly m 6, Ses i 1;Wheat: Tri a 18, Tri a 19, Tri a Gliadin Clinical & Experimental Allergy 2012 :42;441-451
    • 56. Cat: Fel d 1,Cypress: Cry j 1, Cup a 1;Dog: Can f 1, Can f 3Grasses: Phl p 1, Phl p 2, Phl p 4, Phl p 5, Phl p 6, Phl p 11Mites: Der p 1, Der p 2, Der f 1, Der f 2, Eur m 2Olive: Ole e 1 Clinical & Experimental Allergy 2012 :42;441-451
    • 57. • IgE detection to Gal d 1 on the ISAC microarray system useful tool to predict oral tolerance to boiled eggs• DBPCFC in egg allergic children should be performed first with boiled eggs to introduce at least well cooked eggs in HE allergic children’s diet• Outgrowing clinical allergy leads to negativity of tests later on, and ISAC IgE detection reaches such condition before all other tests – majority of the subjects tested negative for HE allergens on ISAC were in the PT and ST groups Clinical & Experimental Allergy 2012 :42;441-451
    • 58. • Patients without previous egg exposure were recruited between January 2005 and October 2011• examined to determine their sIgE titers (mostly because of atopic dermatitis, other food allergies, or family history)• n= 100, males/females = 69/31• Median age of 17 months (range 12-23 months) J Allergy Clin Immunol 2012:129(6);168132
    • 59. • sIgE titers to EW (n = 100) and OVM (n = 80, males/females = 55/25) : ImmunoCAP System (Phadia AB, Uppsala, Sweden)• OVM was not determined in 20 patients because of inadequate sample volume or cost of the testing• 2 children were sIgE-negative to EW, but they had previously tested positive to EW or had a positive skin prick test result J Allergy Clin Immunol 2012:129(6);168132
    • 60. • open OFCs using boiled EW• Each child ate EW, boiled for more than 20 minutes, in increasing amounts (trace, 1, 2, 5, and 10 g) at 20-minute intervals• total amount : half a large egg, containing 2.0 g of EW protein• OFC was not conducted in patients with extremely high sIgE titers to EW and OVM (50 kUA/L or higher [n = 17]) to decrease the risk of inducing reactions J Allergy Clin Immunol 2012:129(6);168132
    • 61. • Positive challenges 33 patients – dermal (n = 31), RS (n = 8), and GI (n = 4) symptoms – sIgE to OVM was examined in 27 patients• Multisystem reactions : 12 patients• 3 required intramuscular epinephrine injection• The median cumulative EW dose required to provoke allergic symptoms was 10.6 g (range, 1.0-18.5 g), containing approximately 1.7 g of EW protein J Allergy Clin Immunol 2012:129(6);168132
    • 62. • The median concentration of sIgE against EW was – 15.6 kUA/L (range, 1.58-51.3 kUA/L) in challenge-positive patients, (significantly higher, P <0.01) – 4.34 kUA/L (range, 0.35-51.5 kUA/L) in challenge-negative patients• A similar difference was observed for OVM (P < 0.01) – 8.12 kUA/L (range, 0.35-48.8 kUA/L) – 1.00 kUA/L (range, 0.35-32.0 kUA/L; P < .01) J Allergy Clin Immunol 2012:129(6);168132
    • 63. sIgE to EW 10 kUA/L: 30% PPV 30 kUA/L:65% PPVThe calculated sIgEtiter that indicated a95% PPV was sIgE to OVM61.8 kUA/L for EW 10 kUA/L: 54% PPV26.6 kUA/L for OVM 30 kUA/L:97% PPV J Allergy Clin Immunol 2012:129(6);168132
    • 64. Patients with undetectable sIgE against OVM (<0.35 kUA/L; n = 24), regardless of the sIgE titer to EW (range, 0.35-27.5 kUA/L), showed 88% (21 of 24) likelihood of a negative challenge 3 individuals demonstrating a positive OFC showed only mild cutaneous symptomsindicate the advantage of using sIgE titers against OVM to identifypatients who can safely consume boiled egg products J Allergy Clin Immunol 2012:129(6);168132
    • 65. • OVM IgE : new predictive marker• sIgE titer against OVM has a better predictive value than does a titer against EW• But for safety, we recommend an office challenge to introduce egg products to the sensitized children, even if sIgE to OVM is negative J Allergy Clin Immunol 2012:129(6);168132
    • 66. Treatment• Standard therapy for egg allergy is strict avoidance Or a l i mmu n o t h e r a p y (O I T ) o r s p e c i f i c o r a l
    • 67. Thank you

    ×