Platelet‐activating factor acetylhydrolase is a biomarker of severe anaphylaxis in children. Issue 9 (13th April 2022)

• Record Type: Journal Article
• Authors: Upton, Julia E. M.; Hoang, Jennifer A.; Leon‐Ponte, Matilde; Finkelstein, Yaron; Du, Yue (Jennifer); Adeli, Khosrow; Eiwegger, Thomas; Grunebaum, Eyal; Vadas, Peter
• Is Part Of: Allergy. Volume 77:Issue 9(2022)
• Page Start: 2665
• Page End: 2676
• Publication Date: 2022-04-13
• Subjects: anaphylaxis -- biomarker -- mediator -- platelet‐activating factor -- severity; Allergy -- Periodicals; 616.97
• DOI: 10.1111/all.15308
• Languages: English
• ISSNs: 0105-4538

Abstract

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. Abstract : Biomarker analysis during anaphylaxis indicates that low serum PAF‐AH and high tryptase are significantly associated with severe anaphylaxis in children. Follow‐up assessment demonstrate elevated PAF and tryptase during anaphylaxis, whereas PAF‐AH during anaphylaxis is consistent with follow‐up and therefore PAF‐AH is both a biomarker and potential mediator of severity.Abbreviations: ICU, intensive care unit; PAF, platelet‐activating factor; PAF‐AH, platelet‐activating factor acetylhydrolase