Are peas a safe food for LTP-allergic patients?

Background: Food companies are currently introducing on the market several products containing peas (Pisum sativum) to exploit their emulsifying and gelling properties and as plant-based meat substitutes. Three main peas allergens were reported in the literature, a vicilin (Pis s 1), a convicilin (Pis s 2) and a 9k-lipid transfer protein (LTP, allergen Pis s 3). Objective: this study sought to isolate the peas LTP and evaluate its allergenicity in an Italian population. Methods: The protein was purified and identified by the classical biochemical methods. Then its immunological features were investigated using the multiplex FABER® test. Clinical data were collected by the allergy specialists. Results: Out of 11,466 tested sera, 896 resulted positive to at least one of the ten plant food LTPs present on the FABER biochip. In line with literature data, LTP from peach (Pru p 3) displayed the highest prevalence (93%) of sensitization than the homologous allergens from other sources. In this cohort, Pis s 3 proved to be the 9-kDa LTP showing the lowest sensitization prevalence (8.4%). In addition, all the patients IgE positive to the peas LTP had the habit to eat peas without reporting any symptom. Conclusion: this study reports for the first time that a cohort of Italian LTP-allergic patients can safely consume peas. This is in line with the results of a previous investigation. However, the reported observations also raise intriguing questions concerning the relationships between protein sequence identities, IgE co-recognition, tolerance and clinical symptoms, which require further studies.