Hev b 7 is a Hevea brasiliensis protein associated with latex allergy in children with spina bifida

Abstract

Background: In addition to their disease-associated handicaps, patients with spina bifida (SB) are at high risk of developing latex allergy. Individuals with SB represent a special group of latex-allergic patients, inasmuch as their IgE-binding patterns differ from those of other populations of latex-allergic individuals. Two allergens strongly associated with latex allergy in patients with SB—Hev b 1 and Hev b 3—have already been identified. Objective: We intended to identify a predominant IgE-binding band—in addition to Hev b 1 and 3—at 43 kDa in a study population of 38 latex-allergic (IgE antibodies to latex and symptoms on provocation with latex gloves) and 15 latexsensitized (IgE antibodies to latex but no symptoms on provocation) children with SB (mean age, 12.3 years) and to determine its frequency of recognition. Methods: Sera of latex-sensitized or latex-allergic patients with SB were tested on latex C extract containing natural Hev b 1, Hev b 3, and Hev b 7 and with the recombinant 43-kDa Hev b 7 in immunoblot and inhibition studies. Results: Natural Hev b 1 was recognized by 82% and natural Hev b 3 by 79% of the latex-allergic children with SB. In addition to some other proteins, 15 (39.5%) of 38 latex-allergic and 2 (13%) of 5 latex-sensitized children with SB revealed IgE binding to a 43-kDa band in the latex protein extract. We identified this 43-kDa IgE-binding band as natural Hev b 7 by immunoblotting and inhibition experiments using recombinant Hev b 7. Conclusion: From these data, we conclude that Hev b 7, the patatinlike Hevea latex protein, is the third SB-associated latex allergen. Future immunotherapy for latex-allergic individuals with SB will have to include Hev b 7 in addition to Hev b 1 and Hev b 3. (J Allergy Clin Immunol 2001;108:621-7.)