Peter Vadas MD PhD Consultant in Allergy and Clinical Immunology

Research Highlights


While I have published close to 200 peer-reviewed studies, the following studies have had the highest impact in advancing the fields of anaphylaxis, peanut allergy, mast cell disorders, food and drug allergy.

Mechanisms of Anaphylaxis

  1. Platelet activating factor (PAF) is a major determinant of severity of near-fatal and fatal anaphylaxis.              New Engl J Med 2008
  2. PAF acetylhydrolase is a biomarker of severe anaphylaxis in children.  Allergy 2022
  3. Platelet activating factor is inactivated by an enzyme PAF acetylhydrolase (PAF-AH).  PAF-AH circulates as a complex bound to low density lipoprotein (LDL-cholesterol).  Medications that lower LDL-cholesterol also lower PAF-AH levels, thereby increasing the activity of PAF and the severity of anaphylaxis.  Allergy Asthma Clin Immunol 2014
  4. Epinephrine (adrenaline) inactivates the receptor for PAF and prevents PAF initiated signaling leading to anaphylaxis.  J Allergy Clin Immunol 2012
  5. PAF is a more sensitive marker of severe anaphylaxis than either histamine or tryptase.  J Allergy Clin Immunol 2013
  6. Lipid lowering drugs (eg statins) increase severity of Hymenoptera venom anaphylaxis.   Annals Allergy Asthma Immunol 2024
  7. Anaphylactic reactions follow stereotypic sequences when caused by the same trigger.  J Allergy Clin Immunol Pract 2022
  8. Methylene blue for the treatment of anaphylaxis refractory to epinephrine.  Am J Emerg Med 2013

           Peanut Allergy

  1. Chocolate bars imported from eastern Europe have high levels of undeclared peanut protein.  As a result of our study, the CFIA promulgated new legislation to regulate labelling of imported chocolates to enhance safety of peanut allergic consumers.  J Food Prot 2003
  2. Peanut protein is secreted in breast milk of lactating women.  JAMA 2001
  3. Peanut protein is secreted in saliva after ingestion and is present in spite of  thorough brushing and rinsing.  J Allergy Clin Immunol 2006
  4. Activated charcoal binds to and neutralizes peanut protein.   J Allergy Clin Immunol 2003
Systemic Mastocytosis, Hereditary Alpha Tryptasemia and Monoclonal Mast Cell Activation Syndrome
13. Prevalence of autoantibodies in patients with hereditary alpha tryptasemia.
Int Arch Allergy Immunol 2024
14. Hereditary alpha tryptasemia and complete deletion of exon 8 of the c-kit gene in patients with mast cell activation syndrome.    Leukemia Lymphoma 2023
15. Efficacy of omalizumab in indolent systemic mastocytosis.  Case Reports Hematol 2019
16. Omalizumab prevents recurrent anaphylaxis in a patient with monoclonal mast cell activation syndrome.  Ann Allergy Asthma Immunol 2014

Food and Drug-Induced Anaphylaxis

17. Characterization of salivary proteins from non-medicinal North American leech causing anaphylaxis.  Pediatric Allergy Immunol 2025
18. Systemic capillary leak syndrome caused by hydrochlorothiazide.   Amer J Emerg Med 2020
19. Adult-onset food protein induced enterocolitis syndrome (FPIES).                                 Ann Allergy Asthma Immunol 2018;  Ann Allergy Asthma Immunol 2021
20. Severe and near-fatal anaphylaxis triggered by chlorhexidine-coated central venous catheters in patients undergoing renal allograft surgery.    Can J Anaesth 2019
21. Anaphylaxis to blood-feeding leech.   Characterization of allergenic salivary proteins in non-medicinal North American leech causing anaphylaxis and cross-reactivity with venom of white face hornet.   Pediatric Allergy Immunol 2025

Systemic Mastocytosis, Hereditary Alpha Tryptasemia and Monoclonal Mast Cell Activation Syndrome

  1. Prevalence of autoantibodies in patients with hereditary alpha tryptasemia.  Int Arch Allergy Immunol 2024
  2. Hereditary alpha tryptasemia and complete deletion of exon 8 of the c-kit gene in patients with mast cell activation syndrome.    Leukemia Lymphoma 2023
  3. Efficacy of omalizumab in indolent systemic mastocytosis.  Case Reports Hematol 2019
  4. Omalizumab prevents recurrent anaphylaxis in a patient with monoclonal mast cell activation syndrome.  Ann Allergy Asthma Immunol 2014

 

           Food and Drug-Induced Anaphylaxis

 

  1. Characterization of salivary proteins from non-medicinal North American leech causing anaphylaxis. Pediatric Allergy Immunol 2025
  2. Systemic capillary leak syndrome caused by hydrochlorothiazide.   Amer J Emerg Med 2020
  3. Adult-onset food protein induced enterocolitis syndrome (FPIES).                                 Ann Allergy Asthma Immunol 2018;  Ann Allergy Asthma Immunol 2021
  4. Severe and near-fatal anaphylaxis triggered by chlorhexidine-coated central venous catheters in patients undergoing renal allograft surgery.    Can J Anaesth 2019