LTP syndrome with a child: clinical picture and profile of sensitization to plant products and pollen.

Author: Zlobina Zhanna Michalovna

Tula Allergy-Immunological Center

Russia, Tula

Lipid transfer proteins are widespread plant food allergens, highly resistant to food processing and to the gastrointestinal environment and they are a common cause of food-induced anaphylaxis.  Sensitization to nsLTP has become a crucial problem for the last 20 years. Nowadays sensitization to nsLTP and food allergy associated with LTP proteins the so-called LTP syndrome remains widely written for Mediterranean areas. [1,2]. Although the number of cases of allergic reactions associated with LPT proteins increases in Russia, this problem is not highlighted.

Let us introduce a case of LTP syndrome in child 6 years old , who has had repeated episodes of urticaria with angioedema, gastrointestinal symptoms when eating sunflower seeds, hazelnuts,  and anaphylaxis after 15 minutes of  eating a cake with poppy seeds which required emergency resuscitation….After improving the patient’s condition the skin prick tests were made with inhalant allergens: ragweed – weal 7 mm, artemisia – weal 7 mm, timothy — weal 5 mm, birch — weal 3 mm. Prick-prick tests with native allergens: fresh kiwi  — weal 2 mm, raw walnut — weal 9 mm, hazelnut   — weal 7 mm, poppy seeds  — weal 10 mm. According to complaints, medical history and skin prick test results, the patient underwent an examination with the multicomponent molecular allergotest ALEX2MADx to identify the exact cause of a severe systemic reaction.

The multicomponent molecular allergotest ALEX2MADx allows to estimate the level of specific IgE to 117 allergen extracts and 178 allergenic molecules at the same time. [3]. As a result of the molecular testing, a sensitization to 11 different nsLTP proteins of plant foods and plant pollens–a peach, hazelnut, walnut, kiwi, corn, apple, strawberry, grape, tomato, artemisia, platanus tree was found. Ig E values ​​for these proteins ranged from 0.45 to 5.4 kUA/L. The level of total IgE did not differ from normal level ​​and was less than 20 kU/L

The results of the study allowed us to diagnose food anaphylaxis, LTP syndrome and confirm immunologically (using the multicomponent molecular allergotest ALEX2MADx) that non-specific lipid transfer proteins caused the development of allergic reactions, including anaphylaxis.

Diagnosis of food allergy, which is connected with sensitization to nsLTP proteins can be especially very difficult, considering that the range of plant foods involved in the development of allergic reactions is extremely wide: from oral allergy syndrome, lesions of skin, respiratory system, gastrointestinal tract to generalized anaphylaxis. 

Defining IgE to nsLPT proteins is a useful marker for identifying sensibilization profile among patients with unknown cause of life-threatening allergic reactions and can be used as a marker of the disease severity, which will allow to reveal the exact allergic product and avoid the risk of potentially dangerous reaction to it, choose a diet, and, therefore, improve the patient’s life quality.

Bibliography.

1. R. Asero, M. Piantanida, E. Pinter, V. Pravettoni. The clinical relevance of lipid transfer protein Clin Exp Allergy. 2018; 48:6–12.

2. Asero R, Pravettoni V, Anaphilaxis to plant-food and pollen allergens in patients with lipid transfer protein syndrome. CurrO pin Allergy Clin Immunol.2013;13:379-85

3. Heffler E, Puggioni F, Peveri S, Montagni M, Canonica GW, Melioli G. World Extended. IgE profile based on an allergen macroarray: a novel tool for precision medicine in allergy diagnosis.Allergy Organ J. 2018 Apr 26;11(1):7.