The Potential of Exosomes in Allergy Immunotherapy

Allergic diseases represent a global health and economic burden of increasing significance. The lack of disease-modifying therapies besides specific allergen immunotherapy (AIT) which is not available for all types of allergies, necessitates the study of novel therapeutic approaches. Exosomes are small endosome-derived vesicles delivering cargo between cells and thus allowing inter-cellular communication. Since immune cells make use of exosomes to boost, deviate, or suppress immune responses, exosomes are intriguing candidates for immunotherapy. Here, we review the role of exosomes in allergic sensitization and inflammation and we discuss the mechanisms by which exosomes could be used in immunotherapeutic approaches for the treatment of allergic diseases. We propose the following approaches: a) Mast cell derived exosomes expressing IgE receptor FcεRI could absorb IgE and down-regulate systemic IgE levels. b) Tolerogenic exosomes could suppress allergic immune responses via induction of regulatory T cells. c) Exosomes could promote TH1-like responses towards an allergen. d) Exosomes could modulate IgE-facilitated antigen presentation.

Non-allergic severe asthma: is it really always non-allergic? The IDENTIFY project

Background This differential diagnosis of allergic vs non-allergic asthma is typically made on the basis of sensitization to allergens, such that absence of sensitization could result in a patient being managed as having non-allergic asthma. In Germany, the number of specific allergen tests is limited and non-standardized (across clinicians and laboratories), with the potential for false negative diagnoses. IDENTIFY aimed to gain data on sensitizations toward aeroallergens in patients with severe asthma who had tested negative to perennial aeroallergens in previous tests. Methods This was a single visit, non-randomized, non-interventional study conducted in 87 centers across Germany. The only inclusion criteria were that patients had to be adults (at least 18 years of age) with a diagnosis of severe asthma (receiving at least Global Initiative for Asthma Step IV therapy), and who had previously tested negative to perennial aeroallergens. Patients were then tested for sensitization to a panel of 35 perennial aeroallergens, with positive sensitization indicated by CAP ≥ 0.35 kU/L. Results Of 588 patients recruited, 454 had complete and valid data, and had previously tested negative to perennial aeroallergens. Overall, 43.6% of the analyzed patients tested positive for at least one of the included aeroallergens, with 18.7% testing positive for three or more, and 4.2% positive for more than ten. The five most common sensitizations were to Staphylococcus aureus enterotoxin B, Aspergillus fumigatus, Candida albicans, Dermatophagoides farinae, and Rhizopus nigricans, each of which tested positive in at least 9.7% of the population. Conclusions In this group of patients being managed as having non-allergic asthma (and who had all previously tested negative to perennial aeroallergens), a high proportion tested positive to a broad panel of aeroallergens. A diagnosis of allergic asthma therefore cannot be excluded purely on the basis of standard aeroallergen panels.

Allergen Immunotherapy: Tactic in manipulating food allergen induced anaphylaxis

The pervasiveness of food allergy and associated anaphylactic reactions are proliferating consecutively and the absence of a proper treatment adds to it. Food, both animal as well as plant derived, are presented as the major risk factors. There are several pathways deduced in favour of the food-induced anaphylaxis, ultimately leading to the activation of T-cells. One of the efficient way to solve this issue is allergen immunotherapy that involves the administration of small doses of modified allergen content and increasing the dose geometrically until tolerant level is achieved. The present treatment includes the symptomatic treatment just though a perpetual fix can be accomplished through the immunotherapy. It focus on the development of innate and adaptive immunity and further acts as a shield to prevent recurrent episodes of anaphylaxis. Specific allergen induced immunotherapy can induce a response that can benefit up to a period of 3 years even after discontinuation of the therapy. Persistent advancement of immunology and bioengineering improves understanding diagnostics. Oral and subcutaneous routes are mostly exploited for the allergen immunotherapy. There is also a need to shed more light on the availability of a standardized allergen extract for the specific treatment of food allergy. Additional research on possible pathogenesis/ pathways and newer route of administration can lead to more safe and efficient treatment methodology.

Mechanisms of allergen-specific immunotherapy for allergic rhinitis and food allergies

Allergen-specific immunotherapy (AIT) is currently the only potential treatment for allergies including allergic rhinitis (AR) and food allergies (FA) that can modify the underlying course of the diseases. Although AIT has been performed for over a century, the precise and detailed mechanism for AIT is still unclear. Previous clinical trials have reported that successful AIT induces the reinstatement of tolerance against the specific allergen. In this review, we aim to provide an updated summary of the knowledge on the underlying mechanisms of IgE-mediated AR and FA as well as the immunological changes observed after AIT and discuss on how better understanding of these can lead to possible identification of biomarkers and novel strategies for AIT.

Selected aspects of patients’ functioning before and after desensitization with specific allergen immunotherapy

Introduction. Allergic diseases belong to the most important health problems responsible for the incidence of various types of discomfort. The application of specific allergen therapy (SAI) is becoming a more and more frequent method aimed at treating allergic diseases. However, this approach requires a strict adherence to medical treatment, which may affect patients’ quality of life.Aim. Assessment of quality of life and everyday functioning in the group of patients who underwent a specific allergen therapy.Material and methods. The study group consisted of 80 adult patients who decided to undergo SAI treatment and were treated in two health care facilities in Małopolska region. The study included an assessment of life quality and selected aspects of functioning (as well as their retrospective assessment). As far as the applied methods are concerned, the study was based on the authors’ own questionnaire and an abbreviated version of the World Organization Quality of Life-BREF questionnaire.Results. SAI treatment made it possible to reduce both the incidence (Me=4.00 to 2.00; p<0.001) and intensity (Me=4.00 to 2.00; p<0.001) of allergic symptoms. Also the discomfort caused by the allergy was decreased (Me=4.00 to 2.00; p<0.001). Moreover, some improvement in general well-being (Me=4.00 to 5.00; p<0.001) and life satisfaction (Me=4.00 to 5.00; p<0.001) was observed.Conclusions. Specific allergen immunotherapy seems to be worth considering as it improves patients’ life satisfaction and reduces discomfort caused by the allergy itself.