Protein and allergen assays for natural rubber latex products

The major issues in the efforts to alleviate allergy to natural rubber latex (NRL) proteins are prevention of allergic reactions and decreasing future sensitization. An accurate estimate of the potential allergenicity of NRL products is essential as guidance to manufacturers and users. Development of a reliable in vitro method for the quantitation of NRL allergens has been impeded by (1) limited knowledge of the individual allergens among NRL proteins, (2) variations in the protein profiles among NRL products, and (3) heterogeneity of responses to NRL allergens among sensitized individuals. The current methods include measurement of either the total or the antigenic NRL proteins. Although these methods provide valuable information, all except one have not been validated or standardized. The lack of sensitivity and specificity of this standardized method and poor correlation with the allergenic protein levels have mandated the need for a better assay. In the past year, an immunologic method for the quantitation of all antigenic proteins has been developed as a national standard. The method provides a significant improvement in sensitivity and specificity of NRL protein measurement, but the question of relevance to allergen content remains open. In the last several years, the intensive research aimed at purifying and characterizing individual allergens among NRL proteins resulted in the identification of more than 10 major allergens. On the basis of this knowledge, present efforts are focused on the development of a method for quantitation of relevant allergenic NRL proteins.