Unraveling the Diagnosis of Kiwifruit Allergy: Usefulness of Current Diagnostic Tests

• Main Authors: Azofra, J. (Author), Beristain, A. (Author), Bernad, A. (Author), Bueno-Díaz, C. (Author), D'Amelio, C.M (Author), Díaz Perales, A. (Author), Ferrer, M. (Author), García-Figueroa, B.E (Author), Garrido-Arandia, M. (Author), Garrido-Fernández, S. (Author), Gastaminza, G. (Author), Goikoetxea, M.J (Author), Villalba, M. (Author)
• Format: Article
• Language: English
• Published: NLM (Medline) 2022
• Subjects: Allergy; Component-resolved diagnosis; Kiwifruit; Skin test; Storage protein
• Online Access: View Fulltext in Publisher

 OBJECTIVES: To determine the usefulness of the in vitro and in vivo methods used in the diagnosis of kiwifruit allergy and to specifically assess the impact of seed proteins on sensitivity. METHODS: We performed skin prick tests (SPTs) using various commercial extracts, homemade pulp, and seed extracts and prick-prick tests with kiwifruit on 36 allergic patients. The presence of specific IgE (sIgE) was assessed using the ImmunoCAP (kiwifruit extract), ELISA (Act d 1, Act d 2), ISAC, and FABER assays. Immunoblotting of seed extract was carried out, and a single-blind oral food challenge was performed with whole seeds in seed-sensitized individuals. 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 using 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. Sensitization to Act d 1 was associated with positive sIgE results to whole kiwifruit extract detected by ImmunoCAP (P<.000). A positive SPT result to kiwifruit seeds was associated with severe symptoms induced by kiwifruit (P=.019) as a marker of advanced disease, but not with clinically relevant sensitization. Challenge testing with kiwifruit seeds performed on 8 seed-sensitized patients yielded negative results. CONCLUSION: Sensitization to Act d 1 is associated with a positive result in conventional diagnostic techniques, whereas kiwifruit seed sensitization does not increase the sensitivity of the diagnostic techniques evaluated.