Platelet-activating factor acetylhydrolase is a biomarker of severe anaphylaxis in children

Julia E M Upton; Jennifer A Hoang; Matilde Leon-Ponte; Yaron Finkelstein; Yue Jennifer Du; Khosrow Adeli; Thomas Eiwegger; Eyal Grunebaum; Peter Vadas

doi:10.1111/all.15308

Platelet-activating factor acetylhydrolase is a biomarker of severe anaphylaxis in children

Allergy. 2022 Sep;77(9):2665-2676. doi: 10.1111/all.15308. Epub 2022 Apr 13.

Authors

Julia E M Upton^{1

2

3}, Jennifer A Hoang⁴, Matilde Leon-Ponte⁵, Yaron Finkelstein^{1

6}, Yue Jennifer Du¹, Khosrow Adeli⁷, Thomas Eiwegger^{1

2

4

8

9}, Eyal Grunebaum^{1

2

4

5}, Peter Vadas³

Affiliations

¹ Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada.
² Department of Pediatrics, Division of Immunology and Allergy, The Hospital for Sick Children, Toronto, Ontario, Canada.
³ Department of Medicine, Division of Clinical Immunology and Allergy, St. Michael's Hospital, University of Toronto, Toronto, Ontario, Canada.
⁴ Department of Immunology, University of Toronto, Toronto, Ontario, Canada.
⁵ Developmental and Stem Cell Biology Program, The Hospital for Sick Children, Toronto, Ontario, Canada.
⁶ Department of Pediatrics, Division of Emergency Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada.
⁷ Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada.
⁸ Translational Medicine, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada.
⁹ University of Health Sciences, University Hospital St. Poelten, Krems, Austria.

PMID: 35396721
DOI: 10.1111/all.15308

Abstract

Background: There is limited ability to predict the severity of allergic reactions in children. Data derived predominantly from adults have implicated the platelet-activating factor pathway as a potential contributor to severe anaphylaxis. In this study, we sought to prospectively assess involvement of key components of the platelet-activating factor pathway in pediatric patients with anaphylaxis.

Methods: Forty-six pediatric patients (<18 years) presenting with acute anaphylaxis were assessed. Anaphylaxis severity was graded and serum anaphylaxis markers were measured acutely and in 36 children who returned for follow-up >4 weeks after their acute presentation. These markers were compared with pediatric laboratory reference sera.

Results: Severe anaphylaxis was experienced by 12/46 (26%) and mild-moderate anaphylaxis in 34/46 (74%) children. Platelet-activating factor acetylhydrolase (PAF-AH) activity was inversely associated with severe anaphylaxis: 9/12 children with severe anaphylaxis had reduced PAF-AH activity as compared with 14/34 with mild-moderate anaphylaxis (p < .05). Furthermore, 3/3 children who required intensive care had markedly reduced mean PAF-AH (nmol/ml/min) (13.73, 95%CI: 7.42-20.03) versus 20/23 who required ward/emergency department care (17.81, 95%CI: 16.80-18.83; p < .05). In children with anaphylaxis, PAF-AH during acute anaphylaxis was unchanged relative to the child's basal levels (mean, 17.26, 95%CI: 16.10-18.42 vs 17.50, 95%CI: 16.21-18.78, p = .63) and was lower than healthy pediatric controls (mean 19.21; 95%CI:18.21-20.21; p < .05).

Conclusion: Decreased serum PAF-AH activity is a biomarker of severe anaphylaxis. Levels of this enzyme do not change from basal levels during acute anaphylaxis. Our results show that PAF-AH is a biomarker of anaphylaxis severity in children. This key regulatory enzyme may modulate susceptibility to severe anaphylaxis.

Keywords: anaphylaxis; biomarker; mediator; platelet-activating factor; severity.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

1-Alkyl-2-acetylglycerophosphocholine Esterase*
Adult
Anaphylaxis* / diagnosis
Anaphylaxis* / etiology
Biomarkers
Child
Humans
Platelet Activating Factor / metabolism

Substances

Biomarkers
Platelet Activating Factor
1-Alkyl-2-acetylglycerophosphocholine Esterase