Hev b 9, the latex enolase, a necessary reagent of a mold allergy diagnostic panel?

Abstract

Rationale Enolases are important mold allergens. We investigated mold allergic patients' sensitization to the allergenic latex enolase Hev b 9 and its cross-reactivity with the allergenic mold enolase Alt a 5. Methods Sera of 167 subjects with allergy to molds, 57 subjects with allergy to latex, and 19 patients with allergy to molds and latex—characterized by positive clinical history and positive CAP—were evaluated in ELISA experiments on recombinant (r)Hev b 9 or rAlt a 5, the enolase from Alternaria alternata. Results In the group of mold allergic subjects 45/167 displayed IgE to rAlt a 5, 35/167 to rHev b 9, and 16/167 to both allergens. Sera of 4/57 latex allergic patients contained IgE specific for rAlt a 5, 3/57 for rHev b 9, and 2/57 for both allergens. Sera of 2/19 of the mold and latex allergic patients displayed IgE to rAlt a 5 or rHev b 9, one recognizing both allergens. In inhibition studies with the 19 sera displaying IgE to rHev b 9 and rAlt a 5, IgE binding to both allergens with the homologous protein could be weakly inhibited for only one patient. Conclusions Alt a 5 and Hev b 9 showed only very weak cross-reactivity. Nevertheless, the high number of mold allergic people sensitized to Hev b 9 indicates that cross-reactivity is induced by various enolases of other mold sources. Therefore, Hev b 9 should be part of an allergen panel for diagnosis of mold allergy.