Couriers of asthma: antigenic proteins in natural rubber latex.

Natural rubber latex (NRL) is a milky, white liquid containing the polymer cis-1,4-polyisoprene, derived from the laticifer cells of the rubber tree, Hevea brasiliensis. Reports of allergic reactions to NRL, ranging in severity from skin rashes to anaphylaxis and death, have been increasing. High rates of latex allergy are seen in children with spina bifida. Healthcare workers, especially those who frequently use powdered latex medical gloves, can develop NRL allergy and asthma, often resulting in considerable disability. Atopy and, possibly, pre-existing dermatitis predispose to sensitization and allergic symptoms. NRL protein antigens are found in many NRL products and also have been shown to bind to cornstarch glove-donning powders. Of the approximately 240 polypeptides in NRL, nearly 60 are antigenic, and nine have been identified and registered (Hev b 1&ndash9). Many natural latex antigens share epitopes with structural proteins and enzymes from other plant species. Current knowledge indicates that proposed reductions in total glove protein and limitations on the use of powder on NRL gloves are likely to result in a decline in the prevalence and severity of NRL allergies among healthcare workers.