Allergens and natural rubber proteins.

BACKGROUND

Allergy to natural rubber latex (NRL) results from exposure to proteins derived from Hevea brasiliensis. Type I latex hypersensitivity is observed in certain occupational and other high-risk groups with frequent exposure to NRL products. This includes health care workers (HCWs), workers in the latex industry, children with spina bifida, and atopic individuals.

OBJECTIVE

Early reliable diagnosis and avoidance are required for better patient care. Standardized reagents are not presently available for in vitro and in vivo testing and treatment of patients with latex allergy. However, a number of allergens have been isolated and characterized from Hevea latex and NRL products. Currently, a total of 11 major and minor allergens are designated by the International Allergen Nomenclature Committee. This article reviews the structural and functional characteristics of these latex allergenic proteins.

RESULTS

NRL-allergenic proteins include those involved in the biosynthesis of polyisoprene and coagulation of latex rubber elongation factor, small rubber particle protein, prohevein, and patatin. Pathogenesis-related proteins include beta-1,3-glucanases, chitinases, and hevamine; and the structural proteins include microhelix protein complex, proline-rich protein, profilins, enolases, and manganese superoxide dismutase. Recombinant allergens demonstrated skin test reactivity in patients with latex allergy. The minimal level of skin test reactivity was about 70 pg/mL for NRL and 1 ng/mL for recombinant allergens. The use of selected recombinant latex allergens (Hev b 5, Hev b 6, and Hev b 7) in skin prick tests identified 93% of allergic individuals, mainly health care workers.

CONCLUSIONS

Recombinant latex allergens are clinically reactive and can be produced in a standardized manner, which could potentially provide safe and sensitive reagents for the diagnosis and treatment of type I latex allergy.