Serum reactivities to latex proteins (Hevea brasiliensis)

In recent years there has been an increasing incidence of allergy to latex among health care workers and children with spina bifida. The allergic response in these individuals can be severe and occasionally fatal. Several allergens have been identified with the use of sera from different patient groups. In our effort to identify reagents for in vitro testing and clinical use, we investigated the reactivities of latex proteins to sera collected from a wide range of patients with latex allergy.

Twenty-six serum samples were obtained from adult patients with latex allergy, both hospital workers and non-hospital workers. Serum pools were made either from sera of children with spina bifida or sera of adult patients with latex allergy. Proteins from C-serum and latex particles of latex sap (nonammoniated) were separated by different gel electrophoresis techniques and evaluated for specific IgE binding by immunoblotting.

More than 50% of the sera tested reacted to an 18 kd protein, a 25.6 kd acidic protein with an isoelectric point of 3.5, or to both proteins; whereas only 23% of the individual serum samples tested reacted to the rubber elongation factor, which has been reported to be a major latex allergen. The immunoreactive patterns of children's and adults' serum pools were similar but not identical.

With the use of gel electrophoresis and immunoblotting techniques, different immunoreactive proteins were identified in C-serum and particles of latex. Rubber elongation factor, which reacted to only 23% of sera tested, did not appear to cross-react immunologically with other latex allergens.