Pistachio vicilin, Pis v 3, is immunoglobulin E-reactive and cross-reacts with the homologous cashew allergen, Ana o 1

L. N. Willison, P. Tawde, J. M. Robotham, R. M. Penney, Suzanne S Teuber, S. K. Sathe, K. H. Roux

Research output: Contribution to journalArticle

54 Scopus citations

Abstract

Background Patients allergic to cashew nuts often report allergy to pistachio, which could be a result of cross-reactivity between the two as both are members of the Anacardiaceae family. Objective Because cashew 7S globulin (vicilin, Ana o 1) is a recognized major allergen, we cloned the pistachio homologue and assayed it for IgE reactivity and cross-reactivity with Ana o 1. Methods Degenerate primers for 7S globulin were used in PCR to amplify DNA from a pistachio cDNA library. An isolate was sequenced, cloned and expressed in Escherichia coli. Reactivity to the allergen was screened by dot blot using 19 pistachio and/or cashew-allergic patients' sera. Cross-reactivity was investigated by inhibition dot- and Western immunoblot assays using pistachio/cashew-allergic patients' sera, and monoclonal antibodies (MAbs) raised against recombinant Ana o 1 (rAna o 1). Results An isolate was found that coded for a 7S vicilin-like protein, designated Pis v 3. IgE reactivity to Pis v 3 was found in the serum of seven of the 19 (37%) patients with histories of allergy to both pistachio and cashew or who were allergic to cashew but had never eaten pistachio. The seven patients with IgE that recognized rPis v 3 also recognized rAna o 1. Six of nine anti-rAna o 1 MAbs also showed reactivity to rPis v 3 on dot blots. Conclusion Of the 37% of pistachio/cashew-allergic patients' sera that recognized the pistachio allergen, rPis v 3, all showed complete cross-reactivity with rAna o 1. The data does not identify the primary sensitizing agent but suggests that IgE reactivity to rPis v 3 and rAna o 1 is focused on the most conserved regions of the proteins. Clinical histories suggest that in some cases, cashew was the sensitizing agent. rPis v 3 is a likely contributor to the observed co-sensitivity to pistachio and cashew in some patients.

Original languageEnglish (US)
Pages (from-to)1229-1238
Number of pages10
JournalClinical and Experimental Allergy
Volume38
Issue number7
DOIs
StatePublished - Jul 2008

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Keywords

  • Cashew
  • Cross-reactivity
  • Food allergy
  • Pistachio
  • Tree nut
  • Vicilin

ASJC Scopus subject areas

  • Immunology
  • Immunology and Allergy
  • Medicine(all)

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