Latex allergy: allergen identification in Hevea braziliensis fractions by immunoblotting

BACKGROUND: Latex is the cause of several clinical symptoms of allergy, but the identification of allergens is not completely known. OBJECTIVE: The aim of this report was to study the immunoreactivity of purified stable latex fractions from Hevea braziliensis. METHODS: We purified the cytoplasm of Hevea braziliensis and obtained three fractions: latex particles (LP), lutoids (L) and cytosolic serum (CS). Using Western blot, specific IgE directed to latex allergens was found in 80 patients with latex allergy. RESULTS: Five major groups of allergens migrating as 14, 25, 29, 37-45 and 50 kDa were recognized. They were unequally distributed with the latex fractions: 37-45 kDa proteins were essentially recognized in CS and LP, whereas 14 and 29 kDa proteins were mainly labelled in the L fraction. As a control, aqueous glove extracts exhibited a more restricted pattern of reactivity, because only 14 and 29 kDa proteins were recognized by patient sera. The pattern of reactivity was not correlated specifically with IgE levels, but sera from patients suffering from spina bifida reacted specifically with the minor protein of 25 kDa located in LP. CONCLUSIONS: The present results show that latex allergic patients recognize several allergens which are differently distributed in subcellular fractions extracted from H. braziliensis and aqueous GE. The L fraction and GE were enriched in low molecular weight proteins and apparently contained the same allergens.