D2.205 - Profilin Allergy: Study of the Efficacy and Safety of an Immunotherapy Protocol for the Treatment of Profilin-Related Oral Allergy Syndrome

Profilin is a ubiquitous plant protein present in all pollens and foods of plant origin, characterized by its thermal and digestive lability. The most frequent clinical manifestation is oral allergy syndrome (OAS), which consists of mild and self-limited symptoms such as oropharyngeal pruritus and/or perioral erythema and lip edema. Consequently, it has traditionally been considered of low clinical relevance; however, in patients with dietary restrictions due to very intense symptoms, quality of life may be compromised.

Allergen-specific immunotherapy is a cornerstone in the management of allergic disease. For example, sublingual immunotherapy with Pru p 3 has proven to be effective in patients with lipid transfer protein (LTP) syndrome.

Specific immunotherapy with profilin is emerging as a promising therapeutic strategy, using melon as the delivery vehicle, as it is the most frequent causal food and has a high profilin content.

Adult patients diagnosed with food OAS due to profilin allergy, confirmed by blood test for profilin-specific IgE and prick-prick testing with melon, were included in the study. Selected patients (a total of fifteen) underwent an oral food challenge with up to 300g of melon to determine the dose at which symptoms began.

Tolerance to 10ml melon ice cubes, with a calculated profilin content of 29μg/10ml, was also tested. Once tolerance was confirmed, patients were instructed to consume one ice cube daily at home. After six months, tolerance was reassessed with a new oral food challenge using up to 300g of fresh melon.

At baseline, patients showed a range of tolerance to melon from 10g to 150g (average of 50g), with symptoms including oral pruritus and, in some cases, perioral erythema. Following home-based immunotherapy, 25% of the patients achieved increased tolerance up to 300g without symptoms. In the remaining patients, tolerance increased by 10-fold, before the appearance of oropharyngeal pruritus. Only one dropped out this study due to the appearance of gastrointestinal symptoms.

This study evaluated the clinical efficacy and safety of specific sublingual immunotherapy with melon extract in patients diagnosed with profilin-mediated oral allergy syndrome. After six months of treatment, a significant increase in tolerance was observed in our patients.