Sublingual Immunotherapy with Quantified Peach Extract: An Alternative Treatment in Legumes Allergy

The legume family plays a fundamental role in human nutrition as a substantial protein source. In the countries where they are widely consumed (Mediterranean area), legumes are one of the most common foods causing allergic reactions particularly in children [1]. It has been documented that seed storage proteins represent major allergens of legumes [2], but recent studies have strengthened the paper of Lipid Transfer Proteins (LTP) as novel legume allergens whose sensitization is directly linked to adult peanut allergy in our country [3,4].


Short Communication
The legume family plays a fundamental role in human nutrition as a substantial protein source. In the countries where they are widely consumed (Mediterranean area), legumes are one of the most common foods causing allergic reactions particularly in children [1]. It has been documented that seed storage proteins represent major allergens of legumes [2], but recent studies have strengthened the paper of Lipid Transfer Proteins (LTP) as novel legume allergens whose sensitization is directly linked to adult peanut allergy in our country [3,4].
We report a 34-year-old man with a previous history of well controlled mild persistent allergic rhinitis and asthma due to house dust mites and olive pollen sensitizations. He presented three episodes of generalized rash with facial angioedema, cough, upper dyspnea and syncope immediately (15-30 minutes of latency) after the ingestion of lentil, chickpea and walnut. No coincidental cofactors like exercise or non-steroid anti-inflammatory drugs intake were associated. Intramuscular adrenaline was necessary to resolve the reactions. Curiously he mentioned he did not eat fruit; since the avoidance of all legumes and nuts no new similar adverse episode has occurred.
But the patient expressed his active desire to eat legumes, soPru p3 quantified peach sublingual immunotherapy extract (SLIT-peach, ALK-Abello, Madrid, Spain) was prescribed. Following standard recommendations a four vials (0.05, 0.5, 5 and 50 µg/ml of Pru p3-Peach peel LTP) and days rush schedule was applied. From an initial dose of 0.242 µg of Pru p3 the first day, the maintenance dose consisted of 10 µg of Pru p3 everyday [5].  [6]. Both challenges were negative. Oral challenge with nuts was not performed due to patient refusal.
Consistent with published data, LTP syndrome could include a complex clinical manifestation associated with a large group of taxonomically unrelated food [7]. Our patient suffered anaphylactic reactions principally after the ingestion of legumes, but he presented positive SPT to almost all legumes and nuts. Storage proteins were expected to be the causal allergens especially considering the low LTPs sensitization previously described in our influence area [8]. Nevertheless component resolved diagnosis demonstrated a high and exclusive LTPs sensitization establishing specific IgE recombinant techniques as a fundamental tool for unmasking complicated sensitizations in the search for the primary allergen.
It has been demonstrated allergen sublingual immunotherapy increases allergen tolerance via reorientation of allergen-specificCD4+ T-cell responses from a T helper 2 (Th2) to Th1 and regulatory T-cell profiles [9]. Few papers have been published concerning peach sublingual immunotherapy and none with the specific target of legume desensitization. In 2009, Pereira et al. described a LTPs-allergic patient who presented a negative double-blind placebo-controlled food challenge -acumulative dose of 150 grams of fresh peach-and a secondary good tolerance of legumes after four months of native Pru p3 specific sublingual immunotherapy with a maintenance dose of 200 µg of nPru p3 per month [10], similar to our monthly dose of 280 µg. One year later Garcia BE et al demonstrated changes in peach allergic patientsr Pru p3 IgE levels and in peach and apple extract SPT induced by a six month period of peach sublingual immunotherapy [11]. This study was not designed to evaluate legume sensitization.
Currently our patient tolerates all kinds of legumes, which he is recommended to ingest several times a week.