Unraveling Kiwifruit Allergy Diagnosis: Usefulness of the Current Diagnostic Tests
D’Amelio CM1,2,3*, Bernad A1,4*, García-Figueroa BE2,3,5, Garrido-Fernández S5, Azofra J6, Beristain A6, Bueno-Díaz C7,8, Garrido-Arandia M9,10, Gastaminza G1,2,3, Ferrer M1,2,3, Díaz Perales A9,10, Villalba M7,8, Goikoetxea MJ1,2,3
1Allergology Department, Clínica Universidad de Navarra, Pamplona, Spain
2Member of the Spanish Research Network on Allergies (ARADyAL) RD 1600060031 of the ISCIII. Madrid, Spain
3Instituto de Investigación Sanitaria de Navarra (IDISNA), Spain
4Allergology, Service of Fundación Hospital Calahorra, Calahorra, Spain
5Allergology Department, Complejo Hospitalario de Navarra, Pamplona, Spain
6Allergology Department, Hospital Universitario Central de Asturias, Asturias, Spain
7Department of Biochemistry and Molecular Biology, Faculty of Chemical Sciences, Universidad Complutense de Madrid, Madrid, Spain
8Member of the Spanish Research Network on Allergies (ARADyAL) RD1600060014 of the ISCIII, Madrid, Spain
9Department of Biotechnology and Plant Biology, Universidad Politécnica de Madrid, Madrid, Spain
10Member of the Spanish Research Network on Allergies (ARADyAL) RD160006003 of the ISCIII, Madrid, Spain
*Both authors contributed equally.
J Investig Allergol Clin Immunol 2022; Vol. 32(2)
Objectives: To determine the usefulness of the in vitro and in vivo methods used in the diagnosis of kiwifruit allergy, focusing on the impact of the seed proteins on their sensitivity.
Methods: Skin prick tests (SPTs) using different commercial extracts, homemade pulp and seed extracts, and prick-prick test with kiwifruit were performed on 36 allergic patients. The presence of specific IgE (sIgE) was assessed using ImmunoCAP (kiwifruit extract), ELISA (Act d 1, Act d 2), ISAC and FABER assays. Immunoblotting of seed extract was carried out, and a single blinded oral food challenge with whole seeds was performed in seed-sensitized subjects.
Results: The prick prick test with kiwifruit demonstrated the highest diagnostic capacity (81.8% sensitivity and 94.1% specificity) among the in vivo tests. The sIgE levels measured by ImmunoCAP-kiwifruit extract showed a similar sensitivity to that of global ISAC and FABER (63.9%, 59.5% and 58.3%, respectively). Act d 1 was the major allergen, and sensitization to it was associated with positive sIgE to whole kiwifruit extract detected by ImmunoCAP (p <0.000). A positive SPT with kiwifruit seeds was associated with severe symptoms with kiwifruit (p = 0.019) as a marker of an advanced disease, but not with clinically relevant sensitization. The challenge to kiwifruit seeds performed on eight seed-sensitized patients resulted negative.
Conclusions: Sensitization to Act d 1 is related to a positive result in conventional diagnostic techniques, whereas kiwifruit seed sensitization
Key words: Allergy, Component-resolved diagnosis, Kiwifruit, Skin test, Storage protein