Background: Peach allergy is prevalent, persistent, and potentially severe and as such is a target for immunotherapy. Our aims were to evaluate the profile of sensitization to Rosaceae allergens and the effects of sublingual peach immunotherapy on immunoglobulin (Ig) E levels to these allergens, to monitor for neosensitizations, and to check if this treatment modified other Rosaceae fruit and pollen-related sensitizations.

Methods: A double-blind placebo-controlled trial was conducted on 56 peach-allergic patients who received, sublingually, a standardized peach extract quantifi ed in mass units of Pru p 3, or placebo for 6 months. IgE to recombinant (r) Mal d 1, rMal d 4, rPru p 3, and natural (n) Art v 3 and skin prick test (SPT) reactivity to Platanus pollen and apple extracts evaluated before treatment (T0), after 1 month (T1) and after and 6 months (T6) were recorded.

Results: In total, 18.5% of patients recognized rMal d 1, 83.3%, rPru p 3, 24.1%, rMal d 4, and 25.9% nArt v 3. IgE to Pru p 3 rose from T0 to T1 in both the active group (P=.003) and the placebo group (P=.022), and remained elevated at T6 in the active group (P=.001).
IgE to other purified allergens did not change significantly and no relevant neosensitizations were detected. SPT reactions to peach decreased from T0 to T6 in the active group (P<0.05). Reactivity to peach (T1 and T6) and apple (T6) was lower in the active group than in the control group.

Conclusions: The main allergen was Pru p 3. Changes in rPru p 3 IgE levels and in peach and apple extract SPT were induced by sublingual immunotherapy.

Key words: Food allergy. Immunotherapy. Sublingual immunotherapy. Food allergens. Peach. Food immunotherapy. Molecular allergens.