IgE response to Aed al 13 and Aed al 14 recombinant allergens from Aedes albopictus saliva in humans.

Background: Mosquito bite is normally associated with mild allergic responses, but severe localized or systemic reactions are also possible. Reliable tools for the diagnosis of mosquito allergy are still unavailable. Here, we investigated the IgE response to 3 potential salivary allergens identified in the saliva of the tiger mosquito Aedes albopictus. Methods: Serum from 55 adult individuals (28 controls and 27 allergic people), were analysed using an in-house Enzyme Linked ImmunoSorbent Assay (ELISA) against the Salivary Gland Extract (SGE) and the recombinant proteins albD7l2 (Aed al 2), albAntigen5-3 (Aed al 13) and albLIPS-2 (Aed al 14). Results: Fifteen of the 27 (56%) individuals having hypersensitive reactions to mosquito bites had IgE serum levels recognizing SGE. Negative sera did not show detectable levels of IgE targeting the SGE from the most common sympatric mosquito Culex pipiens. Among the positive individuals, 2 subjects displayed IgE targeting Aed al 2 (13%), while IgE recognizing Aed al 13 and Aed al 14 were detected in ten (67%) and seven (47%) individuals, respectively. Two sera from non-hypersensitive subjects had detectable levels of IgE targeting Aed al 13, suggesting possible cross-reaction with the homologue salivary proteins of multiple mosquito species or, more generally, of hematophagous insects. Conclusions: Our results indicate that Aed al 13 and Aed al 14 hold the potential to be developed as tools for the diagnosis of allergy to Ae. albopictus bites. Such tools would facilitate epidemiological studies on tiger mosquito allergy in humans and might foster the development of further protein-based assays to investigate cross-species allergies.

Efficacy and Safety of Anti-SARS-CoV-2 Antiviral Agents and Monoclonal Antibodies in Patients with SLE: A Case-Control Study.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-related disease (COVID-19) has spread pandemically with high rates of morbidity and mortality. COVID-19 has also posed unprecedented challenges in terms of rapid development of pharmacological countermeasures to prevent or contrast SARS-CoV-2 pathogenicity. Anti-SARS-CoV-2 antiviral agents and monoclonal antibodies have been specifically designed to attenuate COVID-19 morbidity and prevent mortality in vulnerable subjects, such as patients with immune-mediated diseases, but evidence for the safe and effective use of these drugs in this latter population group is scarce. Therefore, we designed a retrospective, multicentre, observational, case-control study to analyse the impact of these treatments in COVID-19 patients with systemic lupus erythematosus (SLE), a paradigmatic, multi-organ autoimmune disease. We identified 21 subjects treated with antivirals and/or monoclonal antibodies who were matched with 42 untreated patients by age, sex, SLE extension and duration. Treated patients had higher baseline SLE disease activity index 2000 scores [SLEDAI-2K median (interquartile range) = 4 (1-5) vs. 0 (0-2); p = 0.009], higher prednisone doses [5 (0-10) mg vs. 0 (0-3) mg; p = 0.002], and more severe COVID-19 symptoms by a five-point World Health Organisation-endorsed analogue scale [1 (0-1) vs. 0 (0-1); p < 0.010] compared to untreated patients. There was no difference between groups in terms of COVID-19 outcomes and sequelae, nor in terms of post-COVID-19 SLE exacerbations. Three subjects reported mild adverse events (two with monoclonal antibodies, one with nirmatrelvir/ritonavir). These data suggest that anti-SARS-CoV-2 antivirals and monoclonal antibodies might be safely and effectively used in patients with SLE, especially with active disease and more severe COVID-19 symptoms at presentation.

Hypersensitivity reactions to anti-SARS-CoV-2 vaccines: Basophil reactivity to excipients.

Basophil activation test (BAT) can tackle multiple mechanisms underlying acute and delayed hypersensitivity to drugs and vaccines and might complement conventional allergy diagnostics but its role in anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine-related hypersensitivity is ill-defined. Therefore, 89 patients with possible hypersensitivity (56 % with delayed mucocutaneous manifestations) to anti-SARS-CoV-2 vaccines were tested with BAT for Macrogol 3350, DMG-PEG 2000, PEG 20000, polysorbate-80 and trometamol and compared to 156 subjects undergoing pre-vaccine BAT. A positive BAT was associated with delayed reaction onset (p = 0.010) and resolution (p = 0.011). BAT was more frequently positive to DMG-PEG 2000 than to other excipients in both groups (p < 0.001). DMG-PEG 2000 reactivity was less frequent in vaccine-naïve (6 %) than vaccinated subjects (35 %, p < 0.001) and associated with mRNA-1273 vaccination. DMG-PEG 2000 BAT might therefore have a diagnostic role in subjects with delayed hypersensitivity reactions. Natural immunity might be a key player in basophil activation.

Heart Rate Variability in Subjects with Severe Allergic Background Undergoing COVID-19 Vaccination.

Anti-Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) vaccination is the world's most important strategy for stopping the pandemic. Vaccination challenges the body's immune response and can be complicated by hypersensitivity reactions. The autonomic nervous system can modulate the inflammatory immune response, therefore constituting a potential marker to characterize individuals at high risk of hypersensitivity reactions. Autonomic nervous system functionality was assessed through measurement of the heart rate variability (HRV) in subjects with a history of severe allergic reactions and 12 control subjects. HRV parameters included the mean electrocardiograph RR interval and the standard deviation of all normal R-R intervals (SDNN). All measurements were performed immediately before the anti-SARS-CoV-2 vaccination. The median RR variability was lower in the study than in the control group: 687 ms (645-759) vs. 821 ms (759-902); p = 0.02. The SDNN was lower in the study group than in the control group: 32 ms (23-36) vs. 50 ms (43-55); p < 0.01. No correlation was found between age and the SDNN. Autonomic nervous system activity is unbalanced in people with a severe allergy background.

Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS): Focus on the Pathophysiological and Diagnostic Role of Viruses.

Drug reaction with eosinophilia and systemic symptoms (DRESS) is a heterogeneous, multiorgan and potentially life-threatening drug-hypersensitivity reaction (DHR) that occurs several days or weeks after drug initiation or discontinuation. DHRs constitute an emerging issue for public health, due to population aging, growing multi-organ morbidity, and subsequent enhanced drug prescriptions. DRESS has more consistently been associated with anticonvulsants, allopurinol and antibiotics, such as sulphonamides and vancomycin, although new drugs are increasingly reported as culprit agents. Reactivation of latent infectious agents such as viruses (especially Herpesviridae) plays a key role in prompting and sustaining aberrant T-cell and eosinophil responses to drugs and pathogens, ultimately causing organ damage. However, the boundaries of the impact of viral agents in the pathophysiology of DRESS are still ill-defined. Along with growing awareness of the multifaceted aspects of immune perturbation caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during the ongoing SARS-CoV-2-related disease (COVID-19) pandemic, novel interest has been sparked towards DRESS and the potential interactions among antiviral and anti-drug inflammatory responses. In this review, we summarised the most recent evidence on pathophysiological mechanisms, diagnostic approaches, and clinical management of DRESS with the aim of increasing awareness on this syndrome and possibly suggesting clues for future research in this field.

Interactions between Severe Allergy and Anxiety in Anti-SARS-CoV-2 Vaccinees.

Severe drug allergy affects patient hesitancy to new treatments, posing unprecedented challenges to anti-SARS-CoV-2 vaccination campaigns. We aimed to analyze the psychological profile of vaccinees with a history of severe allergy in comparison to subjects with a milder allergy history. Patients attending a dedicated vaccination setting were administered an anonymized questionnaire including clinical data and the State-Trait Anxiety Inventory (STAI) scale (score range 20−80). Patients were also asked whether being in a protected setting affected their attitude toward vaccination. Data are expressed as median (interquartile range). We enrolled 116 patients (78% women), of whom 79% had a history of drug anaphylaxis. The median state anxiety score was 36.5 (30−47.2), while the trait anxiety score was 37 (32−48). State anxiety was higher in those with severe than mild allergy [39 (32−50) vs. 30 (25−37); p < 0.001], with the highest score found in a patient with previous drug anaphylaxis (42.5 [32−51.7]). More than 50% of patients reported that being in a protected setting had lowered their anxiety. Severe allergy is associated with a higher burden of situational anxiety in the setting of vaccination without affecting patient constitutional (trait) levels of anxiety. Vaccination in dedicated facilities might overcome issues related to hesitancy and improve patients' quality of life.

Basal Serum Diamine Oxidase Levels as a Biomarker of Histamine Intolerance: A Retrospective Cohort Study.

Background: Histamine Intolerance (HIT) is a multifaceted pseudoallergic disorder possibly due to defective histamine metabolism. Diamine oxidase (DAO) contributes to histamine degradation and can be measured in the serum. The role of DAO measurement in the diagnostic work-up of HIT still remains unclear, and conflicting results have been reported in the literature. Therefore, we aimed to evaluate the possible clinical usefulness and consistency of DAO value ranges as provided by the assay manufacturer and verify whether they could predict the response to treatment. Methods: We retrospectively analyzed 192 outpatients with HIT symptoms and measured serum DAO values at baseline. Patients were prescribed either with low-histamine diet and/or enzymatic supplementation according to symptom severity and re-evaluated six to eight months later. Patients were stratified into three groups according to DAO levels: <3 U/mL, 3−10 U/mL, and >10 U/mL. HIT severity was assessed on a scale of 1 to 5 before and after treatment. Results: A total of 146 patients completed the study. Gastrointestinal and cutaneous symptoms, often associated with headache, were more frequent in subjects with DAO < 10 U/mL. Symptom severity and DAO ranges were correlated. Patients with intermediate DAO levels (3−10 U/mL) showed a more complex clinical phenotype but also a more significant improvement in symptom severity (score reduction 50%, interquartile range (IQR) = 33−60%) when compared to patients with low DAO (40%, IQR = 20−60%; p = 0.045) or high DAO (33%, IQR = 0−50%; p < 0.001). Complex clinical phenotypes were also more frequent in patients with intermediate DAO levels. Conclusions: HIT is characterized by typical symptoms and low levels of DAO activity. Symptom severity was associated with the degree of DAO deficiency. Patients with DAO values between 3 and 10 U/mL show the best response to treatment (low-histamine diet and/or DAO supplementation). DAO value could arguably be considered as a predictor of clinical response to treatment. Prospective studies are needed to confirm these data.

Challenges to Vaccination against SARS-CoV-2 in Patients with Immune-Mediated Diseases.

Aberrant deployment of the immune response is a hallmark pathogenic feature of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-related disease (COVID-19), possibly accounting for high morbidity and mortality, especially in patients with comorbidities, including immune-mediated disorders. Immunisation with SARS-COV-2 vaccines successfully instructs the immune system to limit viral spread into tissues, mitigate COVID-19 manifestations and prevent its most detrimental inflammatory complications in the general population. Patients with immune-mediated diseases have been excluded from vaccine registration trials, foreclosing the acquisition of specific efficacy and safety data. In this review, we aimed to summarise and critically discuss evidence from real-world studies addressing this issue to provide a comprehensive view of the impact of vaccination practices in patients with allergy, autoimmunity or immunodeficiency. We analysed clinical and laboratory data from 34 studies involving more than 13,000 subjects with various immune disorders who were vaccinated with mRNA- DNA- or inactivated viral particle-based vaccines. These data globally support the safe and effective use of SARS-CoV-2 vaccines in patients with immune-mediated diseases, although patient-tailored strategies to determine vaccination timing, vaccine choice and background therapy management are warranted to optimise vaccination outcomes. More data are needed regarding patients with primary immunodeficiencies.

Efficacy of a rational algorithm to assess allergy risk in patients receiving the BNT162b2 vaccine.

Among 6146 hospital employees, 118 subjects with severe allergic background were identified through a screening questionnaire and stratified into 3 groups (Low-risk (LR), Intermediate (IR) and High-risk (HR) group), based on their allergic anamnesis. Data reports on hypersensitivity reactions (HypR) have been collected in both allergic and non-allergic subjects. Seventeen patients (14%) in the allergic population had a HypR after the first, the second or both doses. Skin manifestations were the most frequent ones. Allergic events were more frequent in HR (35%) than IR (10%; p = 0.005) or LR (0%; p = 0.074) subjects. No patient had anaphylaxis. All patients completed the vaccination schedule. 13 HypR occurred in patients without severe allergic background (13/6028, 0,2%) including one (1/6148, 0.016% of total population) WAO grade-4 anaphylaxis. Our data suggest that BNT162b2 mRNA Covid-19 vaccine is relatively safe also in patients with severe allergic background; however, some precautions are required for high-risk patients.