Prevalence of IgE antibodies to an extract from rubber tree (Hevea brasiliensis) latex and recombinant pollen allergens (Phl P 1, Phl P 2, Phl P 5, Bet v 1 and Bet v 2) in the sera of Italian atopic patients

Background: Previous studies have reported cross-reactivity between latex and grass allergens. Inhibition studies have indicated cross-reactivity of IgE with latex and grass pollen proteins. A panel consisting of a few recombinant allergens, namely rPhI p 1, rPhl p 2, rPhl p 5 and profilin, was sufficient to diagnose grass pollen allergy in patients allergic to grass pollen. Methods: Serum samples from 528 consecutive outpatients with IgE antibodies towards at least one allergen (IgE level > 0.35 kAU/L) were selected for this retrospective study. Total and specific serum IgE to rPhl p 1, rPhl p 2, rPhl p 5, rBet v 1, rBet v 2, latex, birch, hazel, mugwort, wall pellitory, Dermatophagoides pteronissinus, Alternaria tenuis, cat and apple were measured by the immunoenzymatic capsulated hydrophilic carrier polymer (CAP) FEIA system (Pharmacia & Upjohn). Results: Of 123 polysensitized patients with antilatex Ig1E, 12 (9.76%) had symptoms after latex exposure. Ten of 12 subjects monosensitized to latex had symptoms after latex exposure. Symptomatic patients had higher IgE levels to latex than symptomless patients (P = 0.046). A higher prevalence of antilatex IgE was seen in sera containing specific IgE to rPhl p 1, rPhl p 5 and rBet v 2. A good correlation (Spearman's r = 0.52; P = 0.001) between high levels of antilatex IgE and total serum IgE was found. Conclusions: The findings of the present study may support the concept that a high proportion of sera containing IgE to rBet v 2, rPhl p 1 and rPhl p 5 simultaneously contain antilatex IgE. Therefore, patients with specific IgE to these recombinant allergens with no history of current latex exposure may need additional evaluation