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Published on: June 29, 2021
Platelet-activating factor, histamine, and tryptase levels in human anaphylaxis
Peter Vadas1, Boris Perelman, Gary Liss
1Division of Allergy and Clinical Immunology, Department of Medicine, St Michael's Hospital, University of Toronto, Toronto, Ontario, Canada. vadasp@smh.ca
Platelet-activating factor (PAF) levels strongly correlate with allergic reaction severity, unlike histamine or tryptase. PAF was elevated in all severe anaphylaxis cases, highlighting its key role in allergic responses.
Area of Science:
- Immunology
- Allergy and Immunology
- Pharmacology
Background:
- Platelet-activating factor (PAF) is recognized as a significant mediator in anaphylaxis.
- The correlation of PAF with anaphylaxis severity compared to histamine or tryptase remains unclear.
Purpose of the Study:
- To evaluate platelet-activating factor (PAF), histamine, and tryptase levels in relation to the severity of acute allergic reactions.
Main Methods:
- Blood samples were collected from 41 patients experiencing acute allergic reactions and 23 healthy volunteers.
- Serum levels of PAF, histamine, and tryptase were quantified.
- Allergic reactions were categorized into three severity grades (1-3).
Main Results:
- Platelet-activating factor (PAF) levels showed a statistically significant increase with rising allergic reaction severity (P < .0001).
- Elevated PAF levels were detected in 20% of grade 1, 66.7% of grade 2, and 100% of grade 3 reactions.
- While histamine and tryptase levels also increased with severity, the correlations were not as significant as those observed for PAF.
Conclusions:
- PAF levels are significantly elevated in proportion to the severity of acute allergic reactions.
- PAF was elevated in all patients with severe anaphylaxis, a finding not observed for histamine or tryptase.
- These results suggest a pivotal role for PAF as a mediator in anaphylaxis, with a stronger correlation to severity than histamine or tryptase.
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