Api m 5
Summary
Api m 5, a glycoprotein of the venom dipeptidyl peptidase IV (DPPIV) family, is a major allergen of Apis mellifera (honeybee) venom (HBV). It exhibits cross-reactivity with homologous Vespid venom DPPIV allergens.
Epidemiology
Worldwide distribution
Api m 5 sensitization has a prevalence of 16% to 70% among HBV-allergic populations (reviewed in [1]). Thus, Api m 5 is considered a major allergen in HBV-allergic patients.
Clinical Relevance
Cross-reactive molecules
Api m 5 belongs to the DPPIV family of allergens, which is widespread among Hymenoptera and contributes to cross-reactivity between these venoms [1, 2].
Disease severity
Various patterns of sensitization to HBV allergens have been described, but no clinical correlate of severity has been identified so far [1].
Diagnostics
Cross-reactivity between HBV and Vespid venoms
Cross-reactivity between Api m 5 and its homologous Vespid DPPIV allergens contribute to the double-positivity to HBV and Vespid venom whole extracts [1, 6].
Disease Severity
In Hymenoptera IgE testing, the quantitative result of specific IgE to a molecular allergen or whole venom extract is neither predictive of, nor correlated to the severity of the reaction [1].
Sensitivity of in vitro assays
The prevalence of sensitization to individual HBV allergens, including Api m 5, in HBV-allergic patients varies depending on multiple factors such as geography, patient inclusion criteria, single or double positivity to HBV and Vespid venoms, underlying sensitization profile, use of a recombinant allergen versus a natural purified allergen, and the assay format [1, 7, 8]. Thus, the diagnostic sensitivity of specific IgE to rApi m 5 ranges from 16 to 70% in HBV-allergic patients [1]. Using a panel of HBV allergens including rApi m 5 besides available HBV marker allergens Api m 1, Api m 3, and Api m 10 improves the rate of confirmation of genuine HBV sensitization [1, 7, 8].
Api m 5 sensitization can be detected with commercially available singleplex methods.
The diagnostic specificity of IgE to rApi m 5 in HBV-allergic patients was reported as 100% when compared to HBV-negative controls [7]. Detectable rApi 5-specific IgE were found in 3/40 (7.5%) cases of Vespid venom allergic patients without HBV allergy, and in 2/6 (30%) of nonallergic controls sensitized to HBV extract [8].
References
- Author: Prof. Joana Vitte
- Reviewer: Dr. Merima Mehic Chaveton
- Dramburg S, Hilger C, Santos AF, de Las Vecillas L, Aalberse RC, Acevedo N, et al. EAACI Molecular Allergology User's Guide 2.0. Pediatr Allergy Immunol. 2023;34 Suppl 28:e13854.
- Spillner E, Blank S, Jakob T. Hymenoptera allergens: from venom to "venome". Front Immunol. 2014;5:77.
- UniProt. UniProt B2D0J4 for Api m 5 2023 [Available from: https://www.uniprot.org/uniprotkb/B2D0J4/entry.
- Blank S, Seismann H, Bockisch B, Braren I, Cifuentes L, McIntyre M, et al. Identification, recombinant expression, and characterization of the 100 kDa high molecular weight Hymenoptera venom allergens Api m 5 and Ves v 3. J Immunol. 2010;184(9):5403-13.
- IUIS/WHO. IUIS/WHO Apis mellifera 2023 [Available from: http://allergen.org/search.php?allergenname=&allergensource=apis+mellifera&TaxSource=&TaxOrder=&foodallerg=all&bioname=.
- Jovanovic D, Peric-Popadic A, Djuric V, Stojanovic M, Lekic B, Milicevic O, et al. Molecular diagnostics and inhibition of cross-reactive carbohydrate determinants in Hymenoptera venom allergy. Clin Transl Allergy. 2023;13(3):e12230.
- Vachova M, Panzner P, Kopac P, Bidovec Stojkovic U, Korosec P. Routine clinical utility of honeybee venom allergen components. J Allergy Clin Immunol Pract. 2018;6(6):2121-3 e1.
- Kohler J, Blank S, Muller S, Bantleon F, Frick M, Huss-Marp J, et al. Component resolution reveals additional major allergens in patients with honeybee venom allergy. J Allergy Clin Immunol. 2014;133(5):1383-9, 9 e1-6.