Antibody response to natural rubber latex following mucosal exposure

Natural rubber latex (NRL) allergy has become commonplace although it is unclear why. Intraperitoneal immunization studies in BALB/c mice with NRL and ovomucoid (Gal d1) allergens have not revealed differences in response. We investigated intranasal immunization to emulate clinical exposure. Groups of 5 BALB/c mice received intranasal immunization with 20ul of NRL or Gal d1 in alum weekly for 8 weeks. Doses were ten-fold increments 1ug/ml to 10mg/ml; animals were bled every two weeks. Sera were analyzed for antibody of the IgG 1, IgG 2a and IgE classes to the two allergens by ELISA. Results are expressed as designated antibody units (AU) by comparison to a hyperimmune serum. Levels of all isotypes to both allergens appeared at 100 ug. IgG 1 and IgE titers to Gal d1 decreased at the 10 mg dose (IgE=433 ± 18AU at 1mg vs. 154 ± 11AU at 10mg), while antibody to NRL continued to rise (IgE=973 ± 48AU at 1mg vs. 1515 ± 86AU at 10mg). IgG 1 and IgE mouse antibodies are associated with atopy/anaphylaxis. While Gal d1 has a suppressive effect on production of antibodies at high allergen doses, NRL elicits continually increasing titers, suggesting a qualitative difference between allergens. This phenomenon may explain frequency of NRL allergy relative to other allergens.