Apart from avoiding exposure, allergen immunotherapy (AI) is the only causal method of treating allergic diseases. The results of numerous studies have been published concerning the safety and effectiveness of the AI in treating allergic rhinitis, asthma or allergy to the venom of Hymenoptera insects. It has also been proven that administration of increasing preparation doses of allergen extractions alleviates the symptoms in patients after the exposure to some sensitizing allergens. The effect of the AI remains visible many years after completion of the therapy. Studies have been done in an attempt to employ specific immunotherapy in patients with food allergy symptoms. They have been mostly concerned with populations of patients suffering from allergy to the protein found in cow’s milk and hen eggs. It appears that a need arises to create a new therapeutic method for successful treatment of food allergies and specific allergen immunotherapy seems to be a promising step. Although still in its experimental phase, in many well documented cases the method allows for building patient’s tolerance towards small doses of sensitizing allergen and seems conducive to protecting the patient from anaphylactic reactions after incidental allergen consumption.
Apart from avoiding exposure, allergen immunotherapy (AI) is the only causal method of treating allergic diseases. The first successful allergen immunotherapy (AI) described for food allergy was published in 1912 by Oscar Schloss [
The effectiveness of immunotherapy has been proven to depend on a change of lymphocyte profile Th2 into allergen-protective Th1. The change causes inhibition of the production of cytokines by Th2, such as interleukins (IL) -4, -5, and -13, and also an increase in the production of cytokines like interferon-γ (INF-γ) or IL-12. In the process of AI activation of regulatory T lymphocytes (Treg), synthesis increases of both the IL-10 and the transforming growth factor-β (TGF-β). Initially, an increase and then a decrease in immunoglobulin E (IgE) are observed along with some increase in IgG4 (the change of class IgG1 into IgG4) and/or IgA. Consequently, inhibition is seen of such effector cells as eosinophils, basofils and mast cells. Irrespective of the route of administering the allergen (subcutaneous or sublingual), the immunological answer is similar and strictly depends both on dose and length of the therapy [
Analysis of the AI mechanism has been carried out along with some research on the role of the receptors for the fragment of Fc IgE of high affinity (Fcε receptor type I, FcεRI) and of histamine receptors (HR). The studies of Nowak et al. on the early inhibition of basophile activation during the AI by HR2 done on a group of patients undergoing immunotherapy has proven that it may have a significant importance in building a very early allergen tolerance and a distant desensitizing effect [
According to Gell and Coombs’ classification, pathomechanism of food allergy (FA) involves all types of immunological responses [
Reactions Type 1 that are immediate and IgE dependent constitute about 50% of all FA cases. The occurrence of such reactions is connected with the activation of mast cells of the alimentary system (gastrointestinal associated lymphoid tissue, GALT), of the skin (skin associated lymphoid tissue, SALT), and of the bronchi (bronchial associated lymphoid tissue, BALT) [
IgE-independent reactions, cytotoxic type II, type III―with the participation of immunological complexes, and type IV―cellular ones, are found in 6%, 10%, and 18% of cases, respectively. Due to hypersensitivity, symptoms in 28% of patients are caused by more than one type of reaction [
Cross reactions may also be responsible for the manifestation of symptoms and our insight into them allows for a more penetrating analysis of the development mechanism of symptoms seen in patients upon food products consumption. Differentiation of reaction types resulting from true allergy is necessary due to variations in treatment (symptomatic treatment or specific immunotherapy).
Cross-reactivity defined as an allergy to common epitopes binding specific IgE of various allergens is seen as one of the most important issues in modern allergy. Reactions are triggered when antibodies of class E produced primarily towards one allergen recognize a different source protein. This may possibly lead to a situation in which a patient experiences at the same time hypersensitivity to inhalant, food and contact allergens. Of basic pathogenetic importance is the similarity between structures of primary and tertiary allergen proteins and the aminoacid sequence whose compatibility of over 70% constitutes a real risk of cross-reactivity [
Profilins constitute a family of proteins of specific weight from 15 to 18 kDa. Found in grass, tree and weed pollens and many fruits and vegetables, they regulate the actin binding in eukaryotic cells and are responsible for passing the signal along the phosphatidylinositol path [
Chitinases are recognized as two groups of proteins: chitinases of class I and class II. Hevein, a protein of specific weight of 30 - 45 kDa, represents class I. It constitutes the main allergen found in fruit that is connected with the so called latex-fruit syndrome (Hev b 11 and Hev b 6.02). Class II chitinases show a 60%-homology to class I. The two classes are found in avocados, bananas and chestnuts (Castanea sativa) [
Lipid transfer proteins (LTP) are proteins of specific weight from 10 to 13 kDa that are widely spread in nature and are highly stable and resistant to being digested with pepsin. They take part in transport of lipids within the cellular membrane and contribute to plant protective mechanism against various environmental pathogens. They are also present in fruit, vegetables and legume as well as grass, tree and weed pollens [
Cross-reactive carbohydrate determinants (CCDs) are common for plant, fruit and vegetable pollens [
Other plant- origin allergens that cause cross-reactions have not been found to create this dependence on latex allergen. Such allergens include polycalcines-allergen proteins of pollens which have the ability to bind calcium [
Similarly, among the allergens of non-plant origin, there are allergens that have the ability to trigger cross- reactions whose the reactivity, however, towards latex allergy has not been proven. Tropomyosin, one of these allergens, originates from muscle fibres of shrimps, crabs and oysters and is a marker of cross-reactions between house dust mites, shellfish and cockroaches [
Studies have been done in an attempt to employ specific immunotherapy in patients with food allergy symptoms. They have been mostly concerned with populations of patients suffering from allergy to the protein found in cow’s milk [
Genetically modified food was first used a few years ago for AI [
It appears that a need arises to create a new therapeutic method for successful treatment of food allergies and specific allergen immunotherapy seems to be a promising step. Although still in its experimental phase, in many well documented cases the method allows for building patient’s tolerance towards small doses of sensitizing allergen and seems conducive to protecting the patient from anaphylactic reactions after incidental allergen consumption. Creating recombinant allergens and standardized concentrations of allergens in vaccines allows credible comparison of the results of immunotherapy [
Marta Chełmińska,Katarzyna Puźniakowska, (2016) Pathophysiological Justification for Allergen Immunotherapy in Food Allergy. Food and Nutrition Sciences,07,294-300. doi: 10.4236/fns.2016.74031