Comprehending the allergen repertoire of shrimp for precision molecular diagnosis of shrimp allergy

Abstract

Background Clinical management of shrimp allergy is hampered by the lack of accurate tests. Molecular diagnosis has been shown to more accurately reflect the clinical reactivity but the full spectrum of shrimp allergens and their clinical relevance are yet to be established. We therefore sought to comprehend the allergen repertoire of shrimp, investigate and compare the sensitization pattern and diagnostic value of the allergens in allergic subjects of two distinct populations. Methods Sera were collected from 85 subjects with challenge‐proven or doctor‐diagnosed shrimp allergy in Hong Kong and Thailand. The IgE‐binding proteins of Penaeus monodon were probed by Western blotting and identified by mass spectrometry. Recombinant shrimp allergens were synthesized and analyzed for IgE sensitization by ELISA. Results Ten IgE‐binding proteins were identified, and a comprehensive panel of 11 recombinant shrimp allergens was generated. The major shrimp allergens among Hong Kong subjects were troponin C (Pen m 6) and glycogen phosphorylase (Pen m 14, 47.1%), tropomyosin (Pen m 1, 41.2%) and sarcoplasmic‐calcium binding protein (Pen m 4, 35.3%), while those among Thai subjects were Pen m 1 (68.8%), Pen m 6 (50.0%) and fatty acid‐binding protein (Pen m 13, 37.5%). Component‐based tests yielded significantly higher area under curve values (0.77–0.96) than shrimp extract‐IgE test (0.70–0.75). Yet the best component test differed between populations; Pen m 1‐IgE test added diagnostic value only in the Thai cohort, whereas sensitizations to other components were better predictors of shrimp allergy in Hong Kong patients. Conclusion Pen m 14 was identified as a novel shrimp allergen predictive of challenge outcome. Molecular diagnosis better predicts shrimp allergy than conventional tests, but the relevant component is population dependent.

Disparities in pediatric anaphylaxis triggers and management across Asia

“…Intriguingly, shellfish‐induced anaphylaxis was less severe (Ring and Messmer Grade II > III) in Europe, 21 but it accounted for most grade 5 reactions among food allergens that elicited severe allergic reactions in our registry. It will be intriguing to evaluate allergens other than tropomyosin that may contribute to these severe allergic reactions, 22 and further research is necessary to understand the mechanism underlying shellfish anaphylaxis in Asia, where a high prevalence of HDM allergies is reported 23,24 . On the other hand, peanut is not a common weaning food in Asian infants, in contrast with infants in Israel, 25 However, peanuts are ubiquitous in Asian cuisines, such as Thai and Chinese dishes, where peanuts are often used in the form of oil, crumbs or flour to add flavor, texture, and nutrition to dishes.…”

Precision allergy molecular diagnosis applications in food allergy

“…Pen m 1 (Tropomyosin) had a higher diagnostic value than shrimp extract. Recently, Wai et al [47] investigated sensitization profiles of shrimp allergens using sera from 85 patients with shrimp allergy. The study showed that Pen m 14 was identified as a novel shrimp allergen predicting shrimp allergy.…”

The origins and longevity of IgE responses as indicated by serological and cellular studies in mice and humans

“…That is, there is something about certain allergens that affects the disease prognosis. Allergies likely to persist into adulthood are associated with higher amounts of serum IgE, with distinctive and diverse IgE‐binding epitope patterns on allergen, more diverse allergen recognition, and different V gene use of B cells relative to individuals that are tolerant to allergen or regularly ingesting it 67–73 . An allergy to one protein is also likely to copresent with allergies to others 28,60,74,75 .…”