Identification of hevamine and Hev b 1 as major latex allergens in Taiwan

Background: Proteins from latex gloves have been documented to trigger occupational latex allergy among health care workers. Allergen characterization of latex glove extract has never been studied in Taiwan. This study aimed to identify allergenic proteins from latex gloves. Methods: Crude extracts of latex gloves were prepared with phosphate-buffered saline and 20 medical workers with a history of latex allergy were enrolled in this study. The specific IgE antibody was determined by the Pharmacia CAP system and in-house enzyme-linked immunoassay and immunoblotting. The target proteins were excised from two-dimensional PAGE and analyzed by electrospray ionization tandem mass spectrometry. Results: Immunoblotting of glove extracts revealed three IgE-binding proteins at a molecular mass of 45, 30 and 14 kDa. Peptide mass fingerprinting revealed that the protein at 45 kDa, which was recognized by 10% (2/20) of atopic sera tested, was an allergenic lipolytic esterase from Hevea brasiliensis (Hev b 13). The 30- and 14-kDa proteins, which were recognized by 55% (11/20) and 85% (17/20) of patients' sera, were found to be hevamine and rubber elongation factor (Hev b 1), respectively. Conclusions: Our results indicated that hevamine and Hev b 1 are the major allergens from latex gloves in Taiwan, which differs from the reports in Western countries.