IgE antibodies to prohevein, hevein, and rubber elongation factor in children with latex allergy

Background: Prohevein (Hev b 6.01) and hevein (Hev b 6.02) have been shown to be major IgE-binding allergens in health care workers and other adult patients allergic to natural rubber latex (NRL). Rubber elongation factor (REP; Hev b 1) and the 23/27 kd NRL allergen (Hev b 3) are characteristic of children with latex allergy who have spina bifida and other children requiring multiple operations at an early age, In addition, there are children with latex allergy and no history of multiple operations in whom sensitizing allergens are not known. Objectives: We studied IgE antibodies to NRL allergens in children with latex allergy who had not undergone surgery and compared the findings with those in children with latex allergy and a history of multiple operations. Methods: Sera from 30 children with latex allergy who had not undergone surgery, 12 children with Latex allergy with a history of multiple operations, and 19 control children without evidence of NRL allergy were examined, Immunoblotting was used to study IgE binding to NRL proteins, and purified prohevein, hevein, and REP were used in ELISA to measure specific IgE antibodies. Results: In immunoblotting, sera from 21 (70%) children who had not undergone surgery and from 4 (33%) children with a history of multiple operations showed IgE binding to a 20-kd protein band (known to contain prohevein), and 9 (30%) and 8 (67%) sera, respectively, to a 14-kd protein band (known to contain REP). In ELISA, sera from 26 (86%) children who had not undergone surgery and from 7 (58%) children with a history of multiple operations had IgE antibodies to prohevein and 19 (63%) and 7 (58%) sera, respectively, to hevein. Eight (27%) sera from the children who had not undergone surgery had IgE antibodies to REP in contrast to 8 (67%) sera from children with a history of multiple operations. Conclusions: The IgE antibody pattern differs between children with Latex allergy who had not undergone surgery and those with a history of multiple operations. The major allergens in children with no history of surgery appear to be prohevein and hevein and not REF, a finding that agrees well with that reported for health care workers with allergy to latex.