1 – Serviço de Imunoalergologia do Hospital Dona Estefânia, Centro Hospitalar Universitário Lisboa Central, Lisboa, Portugal
- Reunião Internacional, publicação sob a forma de poster no Congresso Anual da EACCI – Lisboa, Junho 2019
Background: Nonspecific lipid transfer proteins (LTP) are among the most important panallergens in pollen/plant food allergic patients. However, sensitization profiles and clinical manifestations vary widely between allergic patients. Our aims were to assess the frequency of sensitization to LTP (Pru p3) and investigate the onset of new food allergies (FA) in these patients.
Method: For 4 months, all patients with positive skin prick tests (SPT) to pollens/fruits/vegetables were tested to LTP and profilin. LTP sensitized patients were clinically evaluated over a 5 years period. Patients co‐sensitized to profilin were excluded.
Results: 233 patients were included, 32 (14%) mono‐sensitized to LTP, 5 co‐sensitized to profilin and 196 with negative SPT to LTP. In the study group (56% males, median age 25 years), 30 (94%) had at least one atopic disease and 27 (84%) had positive SPT to pollens. At the initial evaluation, 24 of these 32 patients had FA, 20 (83%) to Rosaceae/Prunoideae, 9 (38%) to tree nuts and 6 (25%) to peanut. Twelve patients experienced symptoms following ingestion of more than one LTP‐containing plant‐derived food. Half of the sample had anaphylaxis. In the follow up period 14/24 (58%) developed new FA, 8 (57%) had anaphylaxis at the initial evaluation comparing with 4/10 (40%) who did not experience new FA reaction (P = 0.41). Four reported systemic symptoms with previously tolerated foods. Most new allergies were caused by Rosaceae/Prunoideae (n = 17), other fruits/vegetables (n = 15) and tree nuts (n = 3). Of the 32 patients sensitized to LTP, 8 didn't have FA, 88% had positive SPT to pollens and all remain asymptomatic. Baseline Pru p3 IgE levels did not differ significantly between patients with oral allergy syndrome or systemic symptoms (P = 0.99), neither between patients who developed new FA or who did not experience new FA (P = 0.42).
Conclusion: In agreement to literature, Rosaceae/Prunoideae were the most commonly implicated in LTP syndrome. During the 5 years follow up, more than half of the FA patients developed new allergies against previously tolerated foods. None of the evaluated parameters allow us to predict which patients will develop new FA. All the patients sensitized to LTP without FA remain asymptomatic and also there's no evaluated parameters that distinguish them from the other patients.