Eosinophil-associated diseases: the allergist's and clinical immunologist's perspective.

Summary: Eosinophil-associated diseases (EADs) refer to heterogeneous conditions in which eosinophils are believed to play critical pathological roles. They encompass common respiratory conditions, such as asthma, chronic rhinosinusitis with nasal polyps (CRSwNP), less common primary eosinophilic disorders of gastrointestinal tract, and rare conditions including eosinophilic granulomatosis with polyangiitis (EGPA) and hypereosinophilic syndrome (HES). A literature search was carried out in January 2024 in the MEDLINE and Scopus databases using the PubMed search engine (PubMed, National Library of Medicine, Bethesda, MD). We focused on blood eosinophilia and hypereosinophilia. A diagnostic workup is proposed. From allergist's point of view, we focused the review on 4 groups of eosinophilic disorders of specific interest. Our increased understanding of type 2 inflammation and biology has recently led to development of highly effective precision targeted therapies that are now approved for a growing number of eosinophilic disorders. Novel targeted biologics have a major impact on treatment strategies and have resulted in major advances in our understanding of the pathogenesis of these disorders. In the context of EADs, according to the heterogeneity of eosinophilic disorders a multidisciplinary approach should be adopted. Allergists and Clinical Immunologists play an important role as they have a clear understanding of the eosinophilic inflammation and the role of cytokines and are trained to recognize and characterize type 2 (T2) inflammation and its associated pathologies.

Why is Pet (cat/dog) allergen immunotherapy (ait) such a controversial topic? current perspectives and future directions.

Summary: Dogs and cats are the most common pets worldwide. In Italy, the prevalence of allergic sensitization to cats and dogs is 16% and 9% respectively. The limited standardization of allergenic extracts, especially for dogs, emphasizes the importance of Component Resolved Diagnosis (CRD) for accurate diagnosis and subsequent prescription of allergen immunotherapy (AIT). However, this low standardization is the main factor contributing to the unsatisfactory clinical efficacy of traditional AIT, AIT with modified allergens, and intralymphatic allergen-specific immunotherapy (ILAIT). Emerging immunological approaches, particularly for controlling the primary cat allergen, show promise but are hindered by high costs (e.g., use of anti-Fel d 1 monoclonal antibodies in humans) or by exclusively targeting Fel d 1 produced by one's own animal (e.g., immunizing cats to induce neutralizing antibodies against Fel d 1 or including an egg product with anti Fel d 1 IgY antibodies in feline diet). Further studies are imperative for standardizing pet allergens, enhancing the efficacy of various AIT modalities, and exploring other immunological approaches, to optimize the relationship between pets and their owners and prevent distressing "forced removals."

Chronic rhinosinusitis with nasal polyposis and biological agents: the ARIA-ITALY Survey.

Summary: Background. Chronic rhinosinusitis (CRS) is an inflammatory disease that affects the nasal mucosa and the paranasal sinuses. CRS can be associated by nasal polyposis (CRSwNP phenotype) in up to 30% of patients and it is frequently associated with bronchial asthma. CRSwNP shows predominantly an underlying activation of type 2 inflammatory pathways with the involvement of eosinophils, IgE, interleukin (IL)-4, IL-5 and IL-13. Biological drugs that target these inflammatory cytokines are currently a therapeutic option recognized by guidelines for the treatment of uncontrolled form of the disease. Methods. As part of the activity of the "ARIA-Italy" working group, a panel of 255 Italian Ear, Nose and Throat (ENT) specialists, pneumologists and immuno-allergologists actively participated in this national survey and answered a series of questions geared toward understanding the main criteria for patient characterization and therapeutic decision, highlighting multidisciplinarity, and the implementation of the management of CRSwNP patients, as a part of the precision medicine concept and the appropriate use of the biologicals. Results. Two hundred and fifty-five experts and specialists participated in the survey. Conclusions. The results of this survey obtained from an extensive number of active specialists throughout Italy allow some important concluding remarks to be drawn. The main points of agreement were that multidisciplinary care teams provide many benefits but that, once the team is established, meetings and communication between members must be coordinated. Finally, the dissemination of national disease registries and the continuous updating of guidelines and position papers related to CRSwNP and comorbidities should be encouraged.

COVID-19 lockdown, personal protective equipment, hyper-hygiene and allergy.

Summary: At the beginning of SARS-CoV 2 pandemic, in the absence of "targeted" therapies, the national health authorities have introduced some measures aimed at reducing the spread of infection in the community (lockdown, social distancing, personal protective equipment (PPE), personal hygiene and disinfection of living environments). All the containment measures have led to both positive and negative effects in patients with allergic diseases. We believe that further studies should be undertaken to investigate the possible correlations between SARS-CoV-2 infection and allergy, from a broader perspective. In particular, the risk factors for the development of undesirable effects should be investigated, especially in healthcare professionals forced to use PPE and sanitizing agents for a long time. However, since the COVID-19 pandemic probably will not be short-lived, the use of such protective aids will necessarily be widespread even in the general population. Therefore, further studies on the materials used for the production of PPE and sanitizing agents would be necessary to reduce their sensitizing and, in some cases, toxic potential.

Severe asthma: follow-up after one year from the Italian Registry on Severe Asthma (IRSA)

Summary: Background. Asthma affects millions of people worldwide, with a subgroup suffering from severe asthma (SA). Biologics have revolutionized SA treatment, but challenges remain in managing different patient traits. This study analyzed data from the Italian Registry on Severe Asthma (IRSA) to investigate changes in SA characteristics and effectiveness of treatments after one year of follow-up, and to identify factors associated with response to treatments in a real-world setting. Methods. Data on SA patients with one year of follow-up were extracted from IRSA. Asthma control, exacerbations, lung function, and treatments, were assessed at follow-up and analyzed against baseline characteristics. Results. After one year of follow-up, notable improvements were observed in all the outcomes of SA of the included patients (n = 570). The effectiveness of biologic therapies was particularly evident, as they contributed significantly to these positive outcomes. Additionally, certain factors were found to be associated with improvement, namely T2 phenotype, baseline eosinophil count (BEC), and area of residence. On the other hand, comorbidities (obesity, gastro-esophageal reflux disease) and poor lung function were risk factors. Notably, poor-responders to biologics exhibited lower level of education, BEC, and exacerbations, and higher frequency of atopy and ACT score ≥ 20. Conclusions. The findings demonstrate the effectiveness of biologics in asthma management, when implemented as part of a planned follow-up strategy aimed at optimizing and fine-tuning the therapy. Moreover, the study highlights the importance of considering key traits such as the T2 phenotype, BEC, education, and comorbidities when tailoring SA treatment. Overall, this study contributes to enhancing our understanding of SA management and guiding the development of personalized treatment approaches for patients with SA.

From triggers to asthma: a narrative review on epithelium dysfunction.

Summary: It is currently recognized that the airway epithelium plays a pivotal role in orchestrating inflammatory, immune, and regenerative responses to allergens, viruses and environmental pollutants that contribute to asthma pathogenesis. The impact of pollen on respiratory epithelium is multifaceted and goes beyond the direct barrier damage driven by the best-known Type-2 response. After pollen-driven activation, airway epithelial cells play an active role in triggering several pathways. In particular, the release of epithelial cytokines (or alarmins) activates both innate and adaptive immunity, with downstream effects implicated to the pathogenesis of asthma. Pollutants also have a pleiotropic effect on respiratory epithelium. Diesel exhaust particles can directly damage the respiratory epithelium with consequent barrier dysfunction, increased permeability, and local inflammation, but they can also activate Th2 responses. Innate immune responses also are triggered by pollutants through release of epithelial cytokines and redox-sensitive pathways that generate mechanical and immunologic changes in the respiratory epithelium. In addition to the typical Type-1 immune response, respiratory virus infections stimulate type-2 innate lymphoid cells in the airway epithelium to release epithelial cytokines. Finally, the action of epithelial triggers on airway smooth muscle is the central element in the induction of remodeling and hyperreactivity of the airways in asthma. This article reviews the pathophysiology and functions of the airway epithelium and the role of epithelial damage by different triggers in the development, persistence, and exacerbations of asthma.

Hypersensitivity reactions to iodinate contrast media in Italy: a retrospective study. Characteristics of patients and risk factors.

SUMMARY: Objective. The purpose of the study was to describe the characteristics of patients experiencing hypersensitivity reactions (HRs) to iodinated contrast media (ICM) in a large Italian population and to investigate potential risks factors in order to obtain a risk stratification, helpful in the management of these patients. Methods. Data of 407 patients investigated in 9 Italian Allergy Centers for suspected HRs to ICM were analyzed and compared with a control group of 152 subjects that tolerated one or more ICM-enhanced examinations. The univariate and multivariate logistic regression model was used to evaluate associated factors. Results. The mean age of reactive patients was 61 years and 60% were female; 67% of patients reported immediate reactions and 35% experienced the reaction, more frequently with immediate onset, at the first examination in life. Iomeprol, iopromide and iodixanol were the most frequent culprit agents and 20% of patients showed a positive skin test result. Previous adverse reactions to ICM were reported by 15.6% of patients, whereas 35% of subjects experienced the reaction, more frequently immediate, after the first ICM-enhanced examination in their life. The multivariate analysis showed that male gender and age > 65 were associated with ICM reactions as protective factors [ORadja = 0.51; 95% CI: 0.33-0.77 and ORadja = 0.60; 95% CI: 0.39-0.92 respectively]. Cardio-vascular disease [ORadja = 2.06; 95% CI: 1.22-3.50)], respiratory allergy [ORadja = 2.30; 95% CI: 1.09-4.83)] and adverse drug reactions [ORadja = 1.99; 95% CI: 1.05-3.77)] were identified as risk factors for ICM reactions. Food allergy was not significantly associated with reactions [ORadja = 1.51; 5% CI: 0.41-5.56]. Conclusions. This is the largest study on Italian patients experiencing hypersensitivity reactions to ICM. Most results are in line with other studies, showing some association with factors that could influence the incidence of hypersensitivity reactions but not allowing an easy risk stratification.

Lessons from peculiar cases of anaphylaxis: why allergists should be prepared for the unexpected.

Summary: Anaphylaxis is the most severe systemic hypersensitivity reaction, it can be caused by a number of well identified triggers such as foods, drugs, stinging insects and facilitated by predisposing clinical conditions. However, sometimes anaphylaxis shows up with uncommon or peculiar characteristics which could delay diagnosis and therapeutic treatment. In this report we aimed to describe less accounted / difficult-to-approach shapes of anaphylaxis to facilitate clinicians to suspect these severe reactions even in uncommon conditions. We choose to present data on anaphylaxis regarding simulation, mode of exposure to sensitizing agents, pregnancy, exposure to animals, intimate behaviour, psychological stress and other situations.

Sensitization to Gibberellin-Regulated Protein (Peamaclein) Among Italian Cypress Pollen-Sensitized Patients.

BACKGROUND AND OBJECTIVES: Peach gibberellin-regulated protein (peamaclein) has recently emerged as a relevant food allergen in cypress pollen-hypersensitive patients. Objective: We investigated monosensitization to peamaclein among Italian cypress pollen-allergic patients. MATERIAL AND METHODS: A total of 835 cypress pollen-hypersensitive patients from 28 Italian allergy centers underwent a thorough work-up to determine food-allergic reactions and performed skin prick testing with a commercial peach extract containing peamaclein. IgE to rPru p 3 was measured in peach reactors, and those with negative results were enrolled as potentially monosensitized to peamaclein. IgE reactivity to rPru p 7 was evaluated using immunoblot and an experimental ImmunoCAP with rPru p 7. RESULTS: Skin prick tests were positive to peach in 163 patients (19.5%); however, 127 (77.9%) were excluded because they reacted to Pru p 3. Twenty-four patients (14.7%) corresponding to 2.8% of the entire study population) were considered potentially monosensitized to peamaclein. No geographic preference was observed. Seventeen of the 24 patients (70.8%) had a history of food allergy, mainly to peach (n=15). Additional offending foods included other Rosaceae, citrus fruits, fig, melon, tree nuts, and kiwi. On peach immunoblot, only 3 of 18 putative peamaclein-allergic patients reacted to a band at about 7 kDa; an additional 4 patients reacted at about 50-60 kDa. Ten of 18 patients (56%) had a positive result for Pru p 7 on ImmunoCAP. CONCLUSION: Allergy and sensitization to peamaclein seem rare in Italy. Most patients react to peach, although other Rosaceae fruits and several citrus fruits may also be offending foods. Peach and cypress pollen probably also share cross-reacting allergens other than peamaclein.

Anaphylaxis.

Summary: Anaphylaxis is the most severe systemic hypersensitivity reaction, and it can be life-threatening or even fatal. It involves the activation of multiple immune and non immune pathways beyond IgE, thus exhibiting different phenotypes. New symptoms of hypersensitivity caused by chemotherapy drugs, monoclonal antibodies, and biological agents have been suggested to be recognized as anaphylaxis phenotypes. No biomarker has been described that allows an unequivocal diagnosis of anaphylaxis. Moreover, more biomarkers for specific endotypes are needed to stratify severity, to predict risk, and to optimaze tretament choice in the individual patient. Food, drugs and stinging insects represent the most commly identified triggers. Idiopathic anaphylaxis is a diagnosis of exclusion and it can hide a clonal mast cell disorder. Individual risk factors and co-factors may influence the severity of anaphylaxis or its onset, and they should be identified to implement the appropriate measures to prevent recurrence. Prompt recognition and treatment are critical in anaphylaxis, adrenaline being the first-line saving therapy. Individualized anaphylaxis action plan should include avoidance measures, prescription of an adrenaline autoinjector, education, optimal management of relevant comorbidities, venom specific immunotherapy, food oral immunotherapy, and drug desensitization, when appropriate. However, the quality of acute and long-term anaphylaxis management is variable influencing the poor outcomes experienced by many patients. Clinical practice guidelines have the potential to improve outcomes, but they often prove challenging to implement in routine clinical care.

Severe asthma management in the era of biologics: insights of the Italian Registry on Severe Asthma (IRSA).

Summary: Background. The Italian Registry on Severe Asthma (IRSA) is the most recent and largestregistry in Italy. Objective. To improve the knowledge on the clinical and biological features of severe asthma (SA), and to monitor its treatments. Methods. To analyze clinical,functional, inflammatory, and treatment characteristics of severe asthmatics from the IRSA registry. Results. 851 subjects were enrolled. 31.8% and 64.5% of patients were submitted to oral corticosteroids (OCS), and monoclonal antibodies (MABs), respectively. At least tw ocomorbidities affected 77.4% patients. Asthma was uncontrolled in 62.2% patients. Uncontrolled patients had a higher frequency of exacerbations, and hospitalization, showing a highere osinophilic phenotype, a greater use of OCS, and being treated with MAB less frequently. However, uncontrolled patients treated with MAB had a lower use of OCS and a lower rateof hospitalization. Comparing SA patients with atopy and without atopy, the latter showeda greater use of OCS, and more frequent nasal polyposis and osteoporosis. Among SA patients with atopy treated with MAB, 36% were on a treatment targeting the IL-5 pathway. Conclusions and clinical relevance. This study shows the features of the greatest Italian registryof SA patients, revealing at the time of enrollment a poor disease control, and the use of OCSand MABs in about one third and two thirds of patients, respectively. SA is a complex diseasethat requires a more precise phenotyping and a greater disease control.

Recommendations for the Use of Tryptase in the Diagnosis of Anaphylaxis and Clonal Mastcell Disorders.

Summary: Tryptase is a serin-protease produced and released by mast cells after IgE-mediated or non-IgE mediated stimuli. We here review the various aspects related to the molecular characteristics of the enzyme and its biological effects, the genetic basis of its production and the release kinetics. Recommendations for the clinical use of tryptase measurement developed by a task force of Società Italiana di Patologia Clinica e Medicina di Laboratorio and Associazione Allergologi Immunologi Italiani Territoriali e Ospedalieri are given on the best procedure for a correct definition of the reference values in relation to the inter-individual variability and to the correct determination of tryptase in blood and other biological liquids, in the diagnosis of anaphylaxis (from drugs, food, insect sting, or idiophatic), death from anaphylaxis (post mortem assessment) and cutaneous or clonal mastcell disorders.

Hymenoptera Venom Allergy: Management of Children and Adults in Clinical Practice.

Hymenoptera venom allergy is an epidemiologically underestimated condition and a major cause of morbidity worldwide. Preventing future allergic reactions in patients who experience a systemic reaction is based on the correct management of the emergency followed by an accurate diagnosis, prescription of adrenaline autoinjectors, and, where indicated, specific venom immunotherapy. Some epidemiological studies highlight our poor knowledge of this disease and the frequent inadequacy of its management. Moreover, they emphasize the importance of such a life-saving treatment as specific immunotherapy. The availability of high-quality hymenoptera venom extracts for diagnostic and therapeutic use has dramatically improved the prognosis and quality of life of allergic patients. Subcutaneous venom immunotherapy is currently the most effective form of allergen-based immunotherapy, with a carry-over effect lasting up to several years after its interruption. This report on the management of hymenoptera venom-allergic children and adults was prepared by a panel of Italian experts. The main objective of this consensus document is to review the scientific evidence related to diagnosis, therapy, and management of patients allergic to hymenoptera venom. Thus, we can improve our knowledge of the disease and promote good clinical practices. The present document provides practical suggestions for correct diagnosis, prescription of emergency therapy and immunotherapy, and strategies for patient care.

Clinical aspects of hymenoptera venom allergy and venom immunotherapy.

Summary: Hymenoptera venom allergy (HVA) is the most frequent cause of anaphylaxis in Europe, accounting for most of the severe reactions occurring in adults, and being the second cause of anaphylaxis in children. Prevention of further episodes in patients who developed a systemic reaction (SR) is based on the correct management of the allergic emergency, the referral to an allergist for a correct diagnosis, prescription of adrenaline auto-injectors (AAI) and specific venom immunotherapy (VIT), if recommended. Diagnosis is based on the classification of the type of reaction, confirmation of an IgE-mediated pathogenesis and the identification of the offending insect. The use of component resolved diagnostics may be helpful in case of poly-sensitization or negative allergy tests with a proven history of previous SRs. When a severe SR occurs, baseline serum tryptase levels should always be assessed. The prescription of AAI is recommended or suggested for untreated patients, patients undergoing VIT and after discontinuation of treatment, according to multiple evidence. VIT is the most effective treatment available for HVA patients, as confirmed by recent European guidelines. VIT has an early, sustained and persistent protective effect and modifies the natural course of the disease. Moreover, VIT proved to be safe and well tolerated. According to a recent systematic review, no treatment-related fatalities were recorded to date. Compared to AAI, VIT significantly improves the quality of life of HVA patients by reducing the anxiety and limitations in daily activities caused by the fear of stinging insects. The memory of a life-threatening experience is the most likely reason why adherence to VIT is higher compared to immunotherapy with inhalant allergens. Several risk factors in HVA have been identified that can influence not only the severity of sting reactions in untreated patents, but also the occurrence of side effects, treatment effectiveness and the risk of relapse after discontinuation of VIT. Patient and treatment-related risk factors must be considered while selecting the best candidates for VIT, the type and duration of treatment. In this paper we address the most important issues related to HVA and VIT that may have an impact on daily clinical practice.

Component-resolved diagnostics to direct in venom immunotherapy: Important steps towards precision medicine.

Stings of Hymenoptera can induce IgE-mediated systemic and even fatal allergic reactions. Venom-specific immunotherapy (VIT) is the only disease-modifying and curative treatment of venom allergy. However, choosing the correct venom for VIT represents a necessary prerequisite for efficient protection against further anaphylactic sting reactions after VIT. In the past, therapeutic decisions based on the measurement of specific IgE (sIgE) levels to whole venom extracts were not always straightforward, especially when the patient was not able to identify the culprit insect. In the last years, the increasing knowledge about the molecular structure and relevance of important venom allergens and their availability as recombinant allergens, devoid of cross-reactive carbohydrate determinants, resulted in the development of an advanced component-resolved diagnostics (CRD) approach in venom allergy. Already to date, CRD has increased the sensitivity of sIgE detection and enabled the discrimination between primary sensitization and cross-reactivity, particularly in patients with sensitization to both honeybee and vespid venom. Hence, CRD in many patients improves the selection of the appropriate immunotherapeutic intervention. Moreover, the detailed knowledge about sensitization profiles on a molecular level might open new options to identify patients who are at increased risk of side-effects or not to respond to immunotherapy. Therefore, increasing potential of CRD becomes evident, to direct therapeutic decisions in a personalized and patient-tailored manner. Reviewed here are the state of the art options, recent developments and future perspectives of CRD of Hymenoptera venom allergy.

Factors increasing the risk for a severe reaction in anaphylaxis: An analysis of data from The European Anaphylaxis Registry.

BACKGROUND: Preventive measures to decrease the frequency and intensity of anaphylactic events are essential to provide optimal care for allergic patients. Aggravating factors may trigger or increase the severity of anaphylaxis and therefore need to be recognized and avoided. OBJECTIVE: To identify and prioritize factors associated with an increased risk of developing severe anaphylaxis. METHODS: Data from the Anaphylaxis Registry (122 centers in 11 European countries) were used in logistic regression models considering existing severity grading systems, elicitors, and symptoms to identify the relative risk of factors on the severity of anaphylaxis. RESULTS: We identified higher age and concomitant mastocytosis (OR: 3.1, CI: 2.6-3.7) as the most important predictors for an increased risk of severe anaphylaxis. Vigorous physical exercise (OR: 1.5, CI: 1.3-1.7), male sex (OR: 1.2, CI: 1.1-1.3), and psychological burden (OR: 1.4, CI: 1.2-1.6) were more often associated with severe reactions. Additionally, intake of beta-blockers (OR: 1.9, CI: 1.5-2.2) and ACE-I (OR: 1.28, CI: 1.05, 1.51) in temporal proximity to allergen exposition was identified as an important factor in logistic regression analysis. CONCLUSION: Our data suggest it may be possible to identify patients who require intensified preventive measures due to their relatively higher risk for severe anaphylaxis by considering endogenous and exogenous factors.

The urgent need for a harmonized severity scoring system for acute allergic reactions.

The accurate assessment and communication of the severity of acute allergic reactions are important to patients, clinicians, researchers, the food industry, and public health and regulatory authorities. Severity has different meanings to different stakeholders with patients and clinicians rating the significance of particular symptoms very differently. Many severity scoring systems have been generated, most focusing on the severity of reactions following exposure to a limited group of allergens. They are heterogeneous in format, none has used an accepted developmental approach, and none has been validated. Their wide range of outcome formats has led to difficulties with interpretation and application. Therefore, there is a persisting need for an appropriately developed and validated severity scoring system for allergic reactions that work across the range of allergenic triggers and address the needs of different stakeholder groups. We propose a novel approach to develop and then validate a harmonized scoring system for acute allergic reactions, based on a data-driven method that is informed by clinical and patient experience and other stakeholders' perspectives. We envisage two formats: (i) a numerical score giving a continuum from mild to severe reactions that are clinically meaningful and are useful for allergy healthcare professionals and researchers, and (ii) a three-grade-based ordinal format that is simple enough to be used and understood by other professionals and patients. Testing of reliability and validity of the new approach in a range of settings and populations will allow eventual implementation of a standardized scoring system in clinical studies and routine practice.

EAACI guidelines on allergen immunotherapy: Hymenoptera venom allergy.

Hymenoptera venom allergy is a potentially life-threatening allergic reaction following a honeybee, vespid, or ant sting. Systemic-allergic sting reactions have been reported in up to 7.5% of adults and up to 3.4% of children. They can be mild and restricted to the skin or moderate to severe with a risk of life-threatening anaphylaxis. Patients should carry an emergency kit containing an adrenaline autoinjector, H1 -antihistamines, and corticosteroids depending on the severity of their previous sting reaction(s). The only treatment to prevent further systemic sting reactions is venom immunotherapy. This guideline has been prepared by the European Academy of Allergy and Clinical Immunology's (EAACI) Taskforce on Venom Immunotherapy as part of the EAACI Guidelines on Allergen Immunotherapy initiative. The guideline aims to provide evidence-based recommendations for the use of venom immunotherapy, has been informed by a formal systematic review and meta-analysis and produced using the Appraisal of Guidelines for Research and Evaluation (AGREE II) approach. The process included representation from a range of stakeholders. Venom immunotherapy is indicated in venom-allergic children and adults to prevent further moderate-to-severe systemic sting reactions. Venom immunotherapy is also recommended in adults with only generalized skin reactions as it results in significant improvements in quality of life compared to carrying an adrenaline autoinjector. This guideline aims to give practical advice on performing venom immunotherapy. Key sections cover general considerations before initiating venom immunotherapy, evidence-based clinical recommendations, risk factors for adverse events and for relapse of systemic sting reaction, and a summary of gaps in the evidence.