Laboratory trials unveil risk of false results in allergy tests
Recent laboratory trials warn of varied and false-negative results in allergy tests conducted with commercial shellfish extracts, highlighting a pressing need for improvements to safeguard allergy sufferers globally.
Shellfish allergies, affecting approximately 3% of the population, are raising concerns due to their lifelong high risk of severe allergic reactions, including anaphylaxis. However, there's a deeper layer of concern here. The significant variation in allergen content in commercially available skin prick test (SPT) extracts for shellfish allergies adds to the worries. Shellfish includes both crustaceans such as crabs and shrimps, and mollusks such oysters and squids.
“Standardisation of allergen extracts is urgently needed to improve the accuracy and reliability of SPTs,” said Dr Thimo Ruethers, Research Fellow in Human Health & Aging at the Tropical Futures Institute (TFI) at James Cook University (JCU) in Singapore, and Adjunct to JCU’s Australian Institute of Tropical Health and Medicine (AITHM), who spearheaded the study.
SPT, a widely used diagnostic method, has its limitations due to inconsistent extracts. Similar concerns arose from the team’s earlier research in 2019, uncovering unpredictable allergen levels in SPT extracts for fish allergy. Dr Ruethers cautioned that the lack of standardisation in commonly-utilised commercial allergen extracts for SPT restricts the diagnostic precision of results. This also means SPTs that show a person being tested is not allergic to shellfish may be wrong.
In the new study led by Dr Ruethers — where 11 crustacean and 5 mollusc SPT extracts were sourced— it was revealed there were substantial differences in protein content, allergen presence and potency across different species and manufacturers. Additionally, concerns arose about potential protein degradation in some extracts, emphasising the need for standardised procedures.
The absence of standardised commercial SPT extracts presents challenges for individuals with allergies. Conducting allergy tests with enhanced diagnostic tools could also offer insights into cross-sensitisation and individual sensitisation profiles.
“Improvements in blood tests, along with the development of region-specific allergen extracts with known quantities of clinically well-characterised allergen components, are critical to achieve considerable improvements in allergy testing,” emphasised TFI and AITHM group leader Professor Andreas Lopata.
This research will be presented at the Asia Pacific Association of Allergy, Asthma and Clinical Immunology (APAAACI ) 2023 International Conference in Singapore (23-26 October 2023).
Ruethers T, Johnston EB, Karnaneedi S, Nie S, Nugraha R, Taki AC, Kamath SD, Williamson NA, Mehr SS, Campbell DE, Lopata AL. Commercial shellfish skin prick test extracts show critical variability in allergen repertoire. Allergy. doi: 10.1111/all.15853
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Dr Thimo Ruethers [email protected]
Professor Andreas Lopata [email protected]
Media: Ms Pinky Sibal [email protected]