Allergy to LTP: to eat or not to eat sensitizing foods? A follow-up study

Background. Follow-up data about the onset of novel food allergies in patients allergic to lipid transfer protein (LTP) are missing. We investigated the occurrence of novel allergies over time in LTP hypersensitive patients. Methods. Sixty-seven LTP-allergic patients recommended to avoid foods responsible for systemic reactions and encouraged to eat other sensitizing foods avoiding the association with known co-factors, were re-evaluated after >= 1 year to assess the occurrence of allergy to novel foods. IgE to rPru p 3, rBet v 1, and r Phl p 12 were measured. Results. At baseline, the most frequent offending foods were Rosaceae / Prunoideae, tree nuts, and peanut. Most patients reacted to > 1 food, and 77% experienced systemic allergic reactions. Those monosensitized to LTP showed a higher prevalence of food-induced systemic reactions than patients co-sensitized to profilin and/or PR-10 (p < 0.01). Baseline Pru p 3 IgE levels did not differ between patients with local symptoms or systemic symptoms. 1-16 years after the baseline evaluation 18/67 (27%) patients had experienced new food allergies; 8 and 10 reported local or systemic symptoms following the ingestion of previously tolerated foods. Again, most new allergies were caused by Rosaceae / Prunoideae, tree nuts, and peanut. The clinical evolution did not depend on baseline total IgE, co-sensitization to PR-10 and/or profilin, or Pru p 3 IgE levels. Conclusions. Rosaceae / Prunoideae, nuts and peanut are the most frequent cause of new food allergies in the long term. Their exclusion from patient's diets at baseline should be considered on an individual basis.