Kathryn Sutton¹, Megan Yu¹, Jocelyn Jiang¹, John Quin¹, Karl Baumgart¹, Andrew Broadfoot^1,

¹ Douglass Hanly Moir Pathology, Sydney, Australia

 

Introduction: Wheat (Triticum aestivum) is a vital cereal globally, but it can trigger IgE-mediated food hypersensitivity in some individuals, including wheat-dependent exercise-induced anaphylaxis (WDEIA). Omega-5 gliadin serves as a key serological marker for WDEIA. However, the natural history of omega-5 specific IgE antibodies remains poorly understood.

Aim: to analyse the number and trends of positive omega-5 specific IgE (sIgE) antibodies in our laboratory from August 2011 to June 2024.

Method: De-identified data was retrospectively extracted from laboratory records for patients with documented omega-5 sIgE levels measured by ImmunoCAP® (Phadia). Key variables recorded include omega-5 gliadin results, wheat sIgE results, patient age and gender.

 

Results: 579 positive results were obtained during the specified time period, of which 499 represented unique patients. Forty patients (8%) had serial testing with 2 or more results available over a mean of 53 months (range 1-143 months). None of these patients became negative for sIgE to omega-5 gliadin over the testing period. In patients that also had sIgE to wheat requested, 31% were negative despite having positive sIgE to omega-5. The number of requests for omega-5 gliadin per year increased over the study period, however the absolute number of positives per year remained relatively constant.

 

Discussion: This study provides information that aids to enhance understanding of anti-omega-5 gliadin specific IgE antibodies. The persistent of sIgE to Omega-5 gliadin suggests that WDEIA may be a long-term condition. Furthermore, around one third of patients had negative specific IgE to wheat, emphasising the importance of component resolved diagnostics in these patients.