Stinging insect allergy tests evolve to improve diagnosis precision

Stinging insect allergies impact almost 16.5 million Americans1 and is one of the allergies most frequently associated with anaphylaxis in both adults and children.2 Resulting in 90 to 100 deaths per year4, anaphylaxis to stinging insects occurs in 3% of adults and can be fatal on the first reaction.3 Additionally, people who have experienced an allergic reaction to an insect sting have a 60% chance of a similar or worse reaction if stung again4; therefore, allergies to insect venom can pose a huge risk to patients if gone unchecked.

Allergy Testing Evolves

The standard for clinical management of a patient’s allergy, whether to insect venom or another cause, has evolved as allergy testing practices have become more precise. Historically, diagnosing allergies involved assessment of a patient’s symptoms and history, followed by skin prick testing and/or immunoassays of specific whole allergen immunoglobulin E (IgE). But the emerging field of molecular allergology is changing all that with innovative, enhanced methods that help healthcare providers refine the diagnosis and treatment of allergies.

Today, a routine blood test coupled with advanced diagnostics can allow healthcare providers to identify, on a molecular level and with great specificity, which component proteins a patient is sensitized to. These new specific IgE blood tests, which are also called component tests, quantify IgE antibodies to single, pure allergen components, and they can be used to help pinpoint the cause of an allergy.

Improving the diagnosis of allergies to venom from stinging insects

Recently, the U.S. Food & Drug Administration (FDA) approved diagnostic specific IgE blood testing for a number of allergenic components associated with honeybees and wasps. To help refine the diagnosis, several honeybee and wasp allergens have been characterized and are now available as recombinant antigens for component-resolved diagnostics. Along with clinical history, specific IgE tests with component-resolved diagnostics can help specialists and other health care providers discriminate between true sensitization and cross reactivity. They can also help identify culprit insect(s) in patients with inconclusive patient history and guide the selection of future therapy, including prescription of venom immunotherapy.

Here are just two examples to illustrate my point: 68% of patients with a history of reactions to honeybee venom are sensitized to protein components Api m 3 or Api m 10, and 4.8% are sensitized to these components exclusively.5However, because these allergen components are under-represented or absent from standard preparations for honey bee venom immunotherapy, patients with Api m 3 or Api m 10 sensitivity exclusively may not receive treatment that is clinically relevant and as a result, it is less likely to be effective.5 Similarly, up to 50% of venom allergic patients test positive for both honey bee and wasp venom.6 For them, specific IgE blood testing with recombinant protein allergens rApi m 1, rVes v 1, and rVes v 5 can help discriminate double sensitization from cross reactivity and nonspecific sensitization related to carbohydrate determinants frequently found in Hymenoptera venom.7 As these examples show, specific IgE tests with component-resolved diagnostics using recombinant venom allergens can improve the specificity of results, leading to selection of clinically relevant venom immunotherapy.

Better diagnostics means better allergy management

This new generation of advanced component diagnostics can help clinicians provide allergy management strategies tailored to each patient’s needs. This is particularly important when it comes to diagnosing stinging insect allergies, which can be life threatening.

Combining specific IgE allergen component blood tests with whole allergen testing and a comprehensive clinical history allows specialists and other health care providers to better assess their patients’ sensitizations to stinging insects and other common allergens. This comprehensive approach allows clinicians to identify allergy triggers more precisely. Then, they can discriminate between true sensitization and cross reactivity and create optimal allergy management protocols.

_References

• _{Ludman, Sian W, and Robert J Boyle. “Stinging Insect Allergy: Current Perspectives on Venom Immunotherapy.” Journal of Asthma and Allergy, Dove Medical Press, 23 July 2015, www.ncbi.nlm.nih.gov/pmc/articles/PMC4517515/.}
• _{“Anaphylaxis.” ACAAI Public Website, 14 Nov. 2018, acaai.org/allergies/anaphylaxis.}
• _{Golden, David B K. “Insect Sting Anaphylaxis.” Immunology and Allergy Clinics of North America, U.S. National Library of Medicine, May 2007, www.ncbi.nlm.nih.gov/pmc/articles/PMC1961691/.}
• _{“Insect Sting Allergies: Symptoms & Treatment.” ACAAI Public Website, acaai.org/allergies/types/insect-sting-allergy.}
• _{“Component Resolution Reveals Additional Major Allergens in Patients with Honeybee Venom Allergy.” Journal of Allergy and Clinical Immunology, Mosby, 17 Jan. 2014, reader.elsevier.com/reader/sd/pii/S0091674913018502?token=CF68A298A94EABBFDD34F82EB722FA4622B6D99DE9003426CE763C48F0897D25571DC5C5EB7A2764EA9FFE1F85FB94E0.}
• _{Jakob, Thilo, et al. “Diagnostics in Hymenoptera Venom Allergy: Current Concepts and Developments with Special Focus on Molecular Allergy Diagnostics.” Allergo Journal International, vol. 26, no. 3, Nov. 2017, pp. 93–105., doi:10.1007/s40629-017-0014-2.}
• _{Müller U, Schmid-Grendelmeier P, Hausmann O, Helbling A. IgE to recombinant allergens Api m 1, Ves v 1, and Ves v 5 distinguish double sensitization from cross reaction in venom allergy. Allergy. 2012;67:1069–1073. doi: 10.1111/j.1398-9995.2012.02847.x.}