Purified and Recombinant Latex Proteins Stimulate Peripheral Blood Lymphocytes of Latex Allergic Patients

Abstract

Background: Natural rubber latex proteins have been implicated in severe allergy in individuals exposed to latex products, particularly health care workers. Until recently, only crude antigens were available to study the immune response in these patients. In recent years a number of relevant allergens have been purified, but few have been used in lymphocyte studies. Hence, to better understand the immunological mechanisms involved in latex allergy, we investigated the response of peripheral blood mononuclear cells (PBMCs) to various purified natural rubber latex allergens. Methods: Using conventional protein purification methods and gene cloning, we have obtained 6 natural rubber latex proteins. We studied allergen–specific IgE levels and PBMC responses to these allergens along with 3 crude latex antigen preparations. Results: Of the 28 latex–allergic health care workers studied, 16 reacted to one or more of the allergens studied, but PBMCs from controls failed to respond to these antigens. Serum IgE to the antigens was detected in 11–90% of the patients. Conclusion: Fifty–seven percent of the latex–allergic patients demonstrated PBMC responses to at least one of the latex allergens tested, but there was no direct correlation between serum IgE levels and PBMC responses. However, since none of the control subjects showed any PBMC stimulation, this may prove useful in determining sensitization to latex. Among the allergens studied, the predominant mononuclear cell responses were directed against Hev b 2, while serum IgE against rHev b 6 was demonstrable in the greatest number of patients. The crude latex allergens were toxic to PBMCs and hence, the purified allergens may be of greater value in demonstrating sensitization of patients to latex allergens.