Latin name: Hevea brasiliensis
Common names: Hevein
Hevea brasiliensis allergen Hev b 6.02.
Hev b 6.02 (1-3), hevein, is a small protein, which has been identified as the most common allergen for healthcare workers (HCW) allergic to Latex. About 75% of these workers allergic to Latex had hevein-specific antibodies (4). Hevein is not only a major IgE-binding allergen in Natural rubber latex (NRL) but also in other Latex manufactured products (5-6). Prohevein, Hev b 6.01, is cleaved naturally to yield 2 allergenic fragments, the N-terminal hevein, Heb b 6.02, and the C-terminal portion, Hev b 6.03 (5, 7). All 3 allergens exist in the plant, although the ratio between Hev b 6.01 and Hev b 6.03 is about 30:1 (8). All 3 components act as independent allergens (1).
In a study, serum-specific IgE to hevein was detected by ELISA in 48 of 64 (75%) sera from HCW allergic to Latex, and in 3 of 11 (27%) sera from patients with spina bifida (SB) and hypersensitivity reactions to Latex. Skin-positive tests hevein was found in 17 of 21 (81%) patients with Latex allergy (9).
Hevein (Hev b 6.02) is the main allergen cross-reacting with Avocado in subjects with Latex allergy. Results of immunoblots and immunoblot inhibition with 11 serum samples confirmed that a 30-kDa protein in Avocado was the major IgE-binding component; the IgE-binding reactivity to this protein could be inhibited by hevein in all sera tested. Sixty-seven of 91 (73%) subjects from the HCW group and all 19 subjects in the SB group with positive IgE antibodies to hevein also had elevated IgE values to Avocado (4).