Molecular Characterization of the Allergenic Arginine Kinase from the Edible Insect Hermetia illucens (Black Soldier Fly).

SCOPE: Arginine kinase (AK) is an important enzyme for energy metabolism of invertebrate cells by participating in the maintenance of constant levels of ATP. However, AK is also recognized as a major allergen in insects and crustaceans capable of cross-reactivity with sera of patients sensitized to orthologous proteins. In the perspective of introducing insects or their derivatives in the human diet in Western world, it is of primary importance to evaluate possible risks for allergic consumers. METHODS AND RESULTS: This work reports the identification and characterization of AK from Hermetia illucens commonly known as the black soldier fly, a promising insect for human consumption. To evaluate allergenicity of AK from H. illucens, putative linear and conformational epitopes are identified by bioinformatics analyses, and Dot-Blot assays are carried out by using sera of patients allergic to shrimp or mites to validate the cross-reactivity. Gastrointestinal digestion reduces significantly the linear epitopes resulting in lower allergenicity, while the secondary structure is altered at increasing temperatures supporting the possible loss or reduction of conformational epitopes. CONCLUSION: The results indicate that the possible allergenicity of AK should be taken in consideration when dealing with novel foods containing H. illucens or its derivatives.

The New Therapeutic Frontiers in the Treatment of Eosinophilic Esophagitis: Biological Drugs.

Eosinophilic esophagitis (EoE) is a multifaceted disease characterized by a wide heterogeneity of clinical manifestations, endoscopic and histopathologic patterns, and responsiveness to therapy. From the perspective of an effective approach to the patient, the different inflammatory mechanisms involved in the pathogenesis of EoE and biologics, in particular monoclonal antibodies (mAbs), targeting these pathways are needed. Currently, the most relevant is dupilumab, which interferes with both interleukin (IL)-4 and IL-13 pathways by binding IL-4 receptor α, and is the only mAb approved by the European Medicine Agency and US Food and Drug Administration for the treatment of EoE. Other mAbs investigated include mepolizumab, reslizumab, and benralizumab (interfering with IL-5 axis), cendakimab and dectrekumab (anti-IL-13s), tezepelumab (anti-TSLP), lirentelimab (anti-SIGLEG-8), and many others. Despite the undeniable economic impact of biologic therapies, in the near future, there will be room for further reflection about the opportunity to prescribe biologic agents, not only as a last-line therapy in selected cases such as patients with comorbidities involving common pathways. Although recent findings are very encouraging, the road to permanent success in the treatment of EoE is still long, and further studies are needed to determine the long-term effects of mAbs and to discover new potential targets.

Factors and co-factors influencing clinical manifestations in nsLTPs allergy: between the good and the bad.

Non-specific lipid transfer proteins (nsLTPs) are a family of plant pan-allergens that represent the primary cause of food allergies in the Mediterranean area, characterized by a wide range of clinical manifestations, ranging from the total absence of symptoms up to anaphylaxis. This wide variety of symptoms is related to the intrinsic capacity of nsLTPs to cause an allergic reaction in a specific subject, but also to the presence of co-factors exacerbating (i.e., exercise, NSAIDs, PPIs, alcohol, cannabis, prolonged fasting, menstruation, acute infections, sleep deprivation, chronic urticaria) or protecting from (i.e., co-sensitization to PR10, profilin or polcalcin) severe reactions. In this picture, recognizing some nsLTPs-related peculiarities (i.e., route, type and number of sensitizations, concentration of the allergen, cross-reactions) and eventual co-factors may help the allergist to define the risk profile of the single patient, in order to promote the appropriate management of the allergy from dietary advices up to the prescription of life-saving epinephrine autoinjector.

Causes of Non-Adherence to Allergen-Specific Immunotherapy: A Foundation towards a Patient-Personalized Approach.

BACKGROUND: Allergen-specific immunotherapy (AIT) is the only disease-modifying therapy for allergic conditions, resulting in a long-lasting tolerance beyond the duration of the treatment. Due to the strong relationship between the effectiveness, its optimal duration (at least three years) and the observation of the correct administration protocol, appropriate adherence to the plan of treatment represents a critical factor for the therapeutical success of AIT. METHODS: Analysis of studies about the rate of adherence in subcutaneous and sublingual immunotherapy, which are the main routes of administration of AIT. RESULTS: There are different causes leading to a premature interruption of the therapy or to it being incorrectly carried out; the most reported include erroneous expectations of the effectiveness and the adverse effects, economic issues, inconvenience and unrelated clinical conditions. CONCLUSIONS: An attentive analysis of the main causes of dropouts may be useful to improve the management of these patients and to develop new strategies for a personalized approach. These strategies should be dynamic, involving attentive communication between the physician and the patient about all the possible criticalities, especially in the initial phase of the therapy, and facilitating, as much as possible, access to healthcare providers over the course of the maintenance phase, including by exploiting technological tools.

Safety and adverse reactions in subcutaneous allergen immunotherapy: a review.

BACKGROUND: Allergen immunotherapy (AIT) is the only treatment which acts on the causes of allergic diseases by modifying their natural history. In the eighties subcutaneous immunotherapy (SCIT) with high biological power allergen extracts caused a number of severe systemic reactions and also fatalities in the UK and the US, resulting in its limitation and in the introduction of other routes of administration. A decisive advance for SCIT safety was understanding that the major cause of mortality was injecting the allergen extract to patients with uncontrolled asthma at the time of injection. AREAS COVERED: This awareness resulted in a significant decrease in fatalities, but not in their abolition. In 2019, an increase in SCIT-related mortality was observed, suggesting to continue the research for still unidentified factors favoring severe reactions, such as the administration of a wrong extract or of allergen doses higher than listed, unintentional intravenous administration, and missed dose reduction after protracted interruption. Moreover, in the context of the improving of the safety, the role played in tolerance-promoting by adjuvants such as CpG oligodeoxynucleotides has to be taken into account, as well as the potential preventive effect performed by the monoclonal anti-IgE antibody omalizumab against the exacerbation of severe reactions during SCIT. CONCLUSION: The safety of SCIT is good, but the research to improve it further must continue. In particular, the pathophysiological mechanisms related to AIT for inhalants and for Hymenoptera venom should be studied, based on the evident diversity demonstrated by the complete absence of fatal reactions to Hymenoptera venom immunotherapy from its introduction in comparison with the history of serious and fatal offenses examined in this review.

Intranasal corticosteroid and antihistamine combinations in the treatment of allergic rhinitis: the role of the novel formulation olopatadine/mometasone furoate.

INTRODUCTION: Allergic rhinitis (AR) is a common disease with an important impact on the quality of life and very high management costs. In many patients, the poor control of rhinitis symptoms often requires the use of different drugs, and polytherapy tends to reduce therapeutic adherence. According to the latest version of ARIA guidelines, the currently recommended drugs for the treatment of moderate-to-severe AR are second-generation antihistamines, intranasal corticosteroids, and their combination, even in a single nasal spray device. A single medication with a rapid onset of action, acting on breakthrough symptoms too, would be advantageous, also in terms of patient compliance. AREAS COVERED: GSP301 (olopatadine 600 µg - mometasone furoate 25 µg) is a novel intranasal formulation, combining the second-generation antihistamine olopatadine hydrochloride with mometasone furoate. Here, we review the evidence for GSP301, especially concerning the efficacy and safety profile of this intranasal combination in the treatment of AR. EXPERT OPINION: The evidence provided in the current review clearly supports the use of GSP301 as a novel intranasal corticosteroid/antihistamine combination with a well-documented efficacy and safety profile in terms of rapid symptom relief and good tolerability.

Lipid transfer protein syndrome: How to save a life through careful education.

Introduction: Lipid transfer proteins (nsLTPs) are ubiquitous allergens. Patients affected by nsLTP syndrome experience symptoms to various plant-derived foods, ranging from local manifestations to anaphylaxis, the critical treatment of which is represented by self-administration of adrenaline. The principle aim of this study is to assess how dietary recommendations influence the occurrence of new and severe cases and if poly-sensitization to different nsLTPs may play a role. We also investigated about the appropriate use of adrenaline auto-injector during the episodes of anaphylaxis. Moreover, we examinated how other features (ie, co-sensitization to profilin and PR-10 and the presence of risk co-factors) affect these events. Materials and methods: We evaluated 78 patients allergic to nsLTPs, investigating adherence to diet and ability to use the adrenaline auto-injector. Number of sensitization to nsLTPs, co-sensitization to other panallergens, and presence of risk factors for new reactions were also assessed. Diagnosis was based on clinical history and positivity to in vivo and in vitro tests. During the follow-up, compliance, diet modifications, and new reactions were noted, and re-training for the use of epinephrine auto-injector was performed. At the last visit we evaluated the patients' ability to use the self-injector. Results: The whole of fruits belonging to the Rosaceae family emerged as the most frequent culprit foods (28%), followed by walnut (17%), peanut (17%), and hazelnut (10%). At the baseline visit 23% of the patients described the presence of a risk factor during the allergic reaction (mainly nonsteroidal anti-inflammatory drugs [NSAIDs] and exercise). Forty-five percent of the patients reported anaphylactic reactions; no association between the type of food and the severity of the reactions was found. The presence of sensitization to 4 or more nsLTPs was associated to more severe reactions (p < .05; OR 1.67). During the follow-up 38% of the patients experienced at least 1 new allergic reaction: in 79% of them the culprit food was previously tolerated, and in 69% the reaction was an anaphylaxis. Only 47% of the patients showed a proper use of adrenaline auto-injector during the final evaluation, but a significant correlation between periodic education and reduction of the probability of mistakes in the use was reported (p < .05; OR 0.34). Furthermore, an association between co-sensitization to PR-10 (in particular Bet v1) and profilin and less severe symptoms was found, but without a significant odds ratio. Conclusion: A careful education aimed to the prevention of new reactions, through dietary restrictions and avoidance of risk co-factors, and to the management of anaphylaxis, through the training for the correct use of adrenaline auto-injector, should be a routine practice in nsLTP syndrome.