Food Allergy
A Practice
Parameter
Update 2014
Part II
Suda Sibunruang, M.D.
Commins S. and Platts-Mills T. J Allergy Clin Immunol 2009;124:652-7Tripathi A. et.al. J Allergy Clin Immunol Pract 2014;2:259-65
α-gal oligosaccharide • Major blood group substance of non-primate mammals• Present on glycolipids and glycoproteins in meat
and organs of a wide range of mammals• Target of IgG antibodies, which are present in the serum
of all immunocompetent individuals
Commins S. and Platts-Mills T. J Allergy Clin Immunol 2009;124:652-7
N-acetylglucosamine GalactoseFucose
Comparison of mammalian blood group-related oligosaccharides
O’Neil B.et.al. J Clin Oncol 2007;25:3644-8
Picture from www.ephotopix.comAccess December 16, 2014
Chung C. et.al. N Engl J Med 2008;358:1109-17
Chung C. et.al. N Engl J Med 2008;358:1109-17
Chung C. et.al. N Engl J Med 2008;358:1109-17
In most subjects who had a hypersensitivity reaction to cetuximab, IgE antibodies against cetuximab were present in serum before therapy.
The antibodies were specific for galactose-α-1,3-galactose
Tripathi A. et al. J Allergy Clin Immunol Pract 2014;2:259-65
Whether there were allergic diseases associated with IgE antibodies to alpha-gal ?
Identified a group of patients who had episodes of generalized urticaria, angioedema, or
recurrent anaphylaxis
Several patients had delayed anaphylaxis to red meat
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Delay anaphylaxis to red meat
• Delay symptoms for at least 2 hours
(most cases, 3 – 5 hours)
• All patients reported meat consumption before the onset of syndrome
• Many patients > 60 years old
(reported cases in children 5 years old)
Tripathi A. et al. J Allergy Clin Immunol Pract 2014;2:259-65
Differential diagnosis
Tripathi A. et al. J Allergy Clin Immunol Pract 2014;2:259-65
Cat- pork syndrome
Commins S. and Platts-Mills T. Curr Allergy Asthma Rep 2013;13:72–7
Differential diagnosis
• Reactions are rapid
(occur within 1 hr)
• Only after ingestion of pork
Tripathi A. et al. J Allergy Clin Immunol Pract 2014;2:259-65
Cat- pork syndrome
Investigations
• Specific IgE to -gal, beef, pork, lamb and milk
(lack of IgE to chicken, turkey, and fish)
• Skin tests
Tripathi A. et al. J Allergy Clin Immunol Pract 2014;2:259-65
Kennedy J. et.al. Pediatrics 2013;131:1545–52
Correlations of IgE to a-Gal and specific allergens
Commins S. et.al. J Allergy Clin Immunol 2009;123:426-33
SPT and ID test in patients with IgE antibodies to α-gal
SPT- commercially reagents1:20 wt/vol
ID - commercially reagents1:100 dilution (ie, 1:2000 wt/vol)
Commins S. et.al. J Allergy Clin Immunol 2009;123:426-33
SPTs with commercially available reagents (Lt) and fresh meat extract (Rt)
Picture from www.healthunit.orgAccess December 16, 2014
Relevance of tick bites
Commins S. et.al. J Allergy Clin Immunol 2011;127:1286-93
States where anaphylactic reactions to cetuximab were reported in 2006
Commins S. et.al. J Allergy Clin Immunol 2011;127:1286-93
Reported prevalence of Rocky Mountain spotted fever
Tripathi A. et al. J Allergy Clin Immunol Pract 2014;2:259-65Data are from the Centers for Disease Control and PreventionWeb site (http://www.cdc.gov/
ticks/geographic_distribution.html#lone-star)
Commins S. et.al. J Allergy Clin Immunol 2011;127:1286-93
Patients with delayed anaphylaxis to red meat whose serum contained IgE antibodies to alpha-gal
Access from www.jamestownri.govDecember 16, 2014
These bites characteristically itch for 10 days or more !
Wolver S. et.al. J Gen Intern Med 2012;28:322–5
Commins S. and Platts-Mills T. Curr Opin Allergy Clin Immunol 2013;13:354–9
Why is there delay in response ?
• The only coherent explanation is that the oligosaccharide is absorbed in some form that enters the circulation slowly
Tripathi A. et al. J Allergy Clin Immunol Pract 2014;2:259-65
Management
• Avoidance of “red meat”
• Avoiding tick bites
• Management of episodes
Tripathi A. et al. J Allergy Clin Immunol Pract 2014;2:259-65
Avoidance of “red meat”
• Avoiding not only beef, pork, and lamb but also horse, goat, rabbit, and squirrel,includes organs from mammalian sources such as liver, intestine, heart, and kidney
• In addition, other mammalian products include lard, suet, gelatin, pork rinds, and dairy products
Tripathi A. et al. J Allergy Clin Immunol Pract 2014;2:259-65
Management
• Avoidance of “red meat”
• Avoiding tick bites
• Management of episodes
Tripathi A. et al. J Allergy Clin Immunol Pract 2014;2:259-65
Unknown aspects
• Why the tick bites induce such high levels of IgE antibody and why the response is specific for this oligosaccharide
• The basis for the delay in symptoms is not clear
Tripathi A. et al. J Allergy Clin Immunol Pract 2014;2:259-65
Summary Statement 5
• Test for IgE antibodies specific for the immunogenic oligosaccharide galactose-alpha-1, 3-galactose (alpha-gal) in patients who report a delayed systemic reaction to red meat or unexplained anaphylaxis, particularly if they have a history of previous tick bites[Moderate; C Evidence]
Summary Statement 6
• Avoid all mammalian meats in patients with alpha-gal allergy because this oligosaccharide antigen is widely expressed in mammalian tissues[Moderate; C Evidence]
Thank you for your attention