Acetylsalicylic acid (ASA) represents a cornerstone of antiplatelet therapy for the treatment of atherosclerotic coronary artery disease (CAD). ASA is in fact indicated in case of an acute coronary syndrome or after a percutaneous coronary intervention with stent implantation. Aspirin hypersensitivity is frequently reported by patients, and this challenging situation requires a careful evaluation of the true nature of the presumed sensitivity and of its mechanisms, as well as to differentiate it from a more frequent (and more easily manageable) aspirin intolerance. Two main strategies are available to allow ASA administration for patients with CAD and suspected ASA hypersensitivity: a low-dose ASA challenge, aimed at assessing the tolerability of ASA at the antiplatelet dose of 100 mg, and desensitization, a therapeutic procedure which aims to induce tolerance to ASA. For those patients who cannot undergo ASA challenge and desensitization due to previous serious adverse reactions, or for those in whom desensitization was unsuccessful, a number of further alternative strategies are available, even if these have not been validated and approved by guidelines. The aim of this state-of-the-art review is therefore to summarize the established evidence regarding pathophysiology, clinical presentation, diagnosis, and management of aspirin hypersensitivity and to provide a practical guide for cardiologists (and clinicians) who have to face the not uncommon situation of a patient with concomitant coronary artery disease and aspirin hypersensitivity.

Randomized controlled trials have demonstrated responses to clinical parameters, but a significant proportion of allergy patients in real-life settings would have been excluded from such studies. Therefore, real-world research is needed, and there is a growing body of information on allergen immunotherapy’s long-term effectiveness and safety. Real-world evidence can be a valuable instrument to better understand the patient’s journey and the effectiveness and safety of therapies. For this purpose, a registry will be used for the first time in Italy to evaluate the impact of allergen immunotherapy on several outcomes, including quality of life and disease-related effects in the pediatric and adult allergic population with a socio-economic assessment and respect to real-world health.

Epithelial barrier damage plays a central role in the development and maintenance of allergic inflammation. Rises in the epithelial barrier permeability of airways alter tissue homeostasis and allow the penetration of allergens and other external agents. Different factors contribute to barrier impairment, such as eosinophilic infiltration and allergen protease action—eosinophilic cationic proteins’ effects and allergens’ proteolytic activity both contribute significantly to epithelial damage. In the airways, allergen proteases degrade the epithelial junctional proteins, allowing allergen penetration and its uptake by dendritic cells. This increase in allergen–immune system interaction induces the release of alarmins and the activation of type 2 inflammatory pathways, causing or worsening the main symptoms at the skin, bowel, and respiratory levels. We aim to highlight the molecular mechanisms underlying allergenic protease-induced epithelial barrier damage and the role of immune response in allergic asthma onset, maintenance, and progression. Moreover, we will explore potential clinical and radiological biomarkers of airway remodeling in allergic asthma patients.

Staphylococcus aureus frequently colonizes the skin and upper airways and produces a broad repertoire of immunomodulatory molecules. In asthma, the most consistent evidence concerns staphylococcal enterotoxins (SEs), which can act both as superantigens and as allergens, and IgE sensitization to SEs (SE-sIgE). SE-sIgE is associated with severe asthma, type 2 inflammation, chronic rhinosinusitis with nasal polyps (CRSwNP), exacerbations, and, in some longitudinal studies, persistent airflow obstruction. However, this relationship is not necessarily causal: SE-sIgE may reflect exposure, an immune response, or a biologically active endotype, whereas colonization, local toxin production, and systemic sensitization are not equivalent. SEs simultaneously bind class II MHC molecules and Vbeta regions of the T-cell receptor, activating large fractions of T lymphocytes; they also promote IL-4, IL-5, and IL-13 production, polyclonal B-cell activation, local IgE synthesis, mast-cell degranulation, eosinophilia, and IL-8/neutrophil circuits. Alpha-toxin (Hla) and SEB can damage the epithelial barrier, facilitating allergen penetration and alarmin signalling. These observations support an interaction model in which dysbiosis, barrier dysfunction, and type 2 immunity mutually reinforce one another along the nasobronchial axis. Corticosteroids and antibiotics may modify selected nodes in this circuit, but current evidence is insufficient to recommend decolonization or antitoxin therapy in stable asthma. Biologics interrupt downstream pathways potentially fuelled by toxins: omalizumab neutralizes free IgE; mepolizumab and benralizumab reduce the eosinophilic axis; dupilumab blocks IL-4/IL-13 signalling; and tezepelumab acts upstream on TSLP. Nevertheless, randomized trials stratified by SE-sIgE are lacking, and no evidence demonstrates that these treatments eliminate colonization or toxin production. SE-sIgE therefore appears to be a promising biomarker, particularly in severe asthma with CRSwNP, but it is not yet an autonomous criterion for biologic selection. A broader barrier-organ analysis also identifies nasal, cutaneous, and intestinal colonization as distinct ecological states; atopic dermatitis as a complementary model of toxin-amplified type 2 inflammation; and biofilms and extracellular vesicles as candidate mechanisms of persistent toxin delivery. These data increase biological plausibility but remain indirect for asthma.

Background: Long COVID remains a challenging and heterogeneous condition, with mechanisms that are still incompletely understood. Emerging evidence suggests that patients with allergic disease may experience more persistent post-COVID symptoms, possibly due to immune dysregulation and epithelial barrier fragility. Methods: We carried out an observational, single-center study at the Allergy and Clinical Immunology Unit of Policlinico Universitario A. Gemelli IRCCS (Rome, Italy). Seventeen adults with confirmed allergic disease and long COVID were evaluated between July and December 2024. Biomarkers reflecting allergic inflammation and barrier integrity, blood eosinophil count, total immunoglobulin E (IgE), eosinophil cationic protein (ECP), and serum free light chains (FLCs), were measured and analyzed for interrelationships and symptom correlations. Results: Participants (10 men, 7 women; mean age 43.7 years) showed variable biomarker profiles, consistent with the heterogeneity of allergic inflammation. Mean eosinophil count was 179 ± 72 cells/µL, total IgE 165.4 ± 140.6 kU/L, ECP 64.2 ± 48.5 ng/mL, and the kappa/lambda FLC ratio 1.20 ± 0.69. Notably, elevated kappa FLC levels (>19.4 mg/L) were significantly associated with high ECP (>20 ng/mL) (χ² = 10.6, p = 0.001) and increased IgE (>200 kU/L) (χ² = 6.0, p = 0.015). Individuals with higher ECP and FLCs more often reported respiratory and systemic symptoms, especially fatigue, dyspnea, and cognitive fog, that persisted beyond six months. Conclusions: These findings suggest that biomarkers of allergic inflammation and barrier dysfunction, particularly ECP and FLCs, may contribute to the persistence of long-COVID symptoms in allergic patients. The observed links between humoral activation, eosinophilic activity, and prolonged symptom burden support a model of sustained inflammation and delayed epithelial recovery. Larger, longitudinal studies including non-allergic controls are warranted to confirm these associations and to explore whether restoring barrier integrity could shorten recovery trajectories in this vulnerable population.

Background/Objectives: Severe asthma remains difficult to treat, even with the range of biologics we now have that target type 2 inflammation. Some patients do not respond well enough to the first biologic they try, which raises the question of whether switching to another option can help. In this study, we looked at how patients who had unsatisfactory therapeutic outcomes on other biologics responded—both clinically and at the biomarker level—after switching to dupilumab. Methods: We reviewed data from the Allergy and Clinical Immunology Unit of Fondazione Policlinico Universitario A. Gemelli-IRCCS, Rome, Italy, between January and June 2025. The study included fifteen adults with uncontrolled severe asthma who had previously been treated for at least six months with benralizumab, omalizumab, or mepolizumab before switching to dupilumab. We evaluated demographic, clinical and laboratory data. Lung function (Forced Expiratory Volume in 1 s (FEV₁)), blood eosinophils, total and specific IgE to staphylococcal enterotoxins, eosinophil cationic protein (ECP), free light chains (FLC), and FeNO were assessed at the time of the switch and again after 12 months. Comparisons were made using paired tests, and a p-value < 0.05 was considered statistically significant. Results: After a year on dupilumab, we saw clear improvements: mean FEV₁ went up by about 10.8% predicted (p = 0.002), FeNO dropped by an average of 22 ppb (p = 0.005), blood eosinophils fell by roughly 400 cells/µL (p = 0.003), and ECP levels decreased by 13 µg/L (p = 0.009). Kappa FLCs also showed a significant drop (p = 0.04). Clinically, 40% of patients met criteria for a meaningful response, and 20% achieved complete remission. Dependence on oral corticosteroids was notably reduced. Baseline levels of eosinophils, ECP, IgE, and FLCs correlated with response to treatment. Conclusions: Our study, despite the small sample size, highlights that in patients with severe asthma who do not show a good response to their first biologic, switching to dupilumab can lead to significant improvements. Markers of type 2 inflammation at baseline might help predict who benefits most. Larger, multi-center, prospective studies are needed to confirm these results.