B-cells depletion after treatment with rituximab predicts relapse of IgG4-related disease.

OBJECTIVES: B cell depletion therapy with rituximab is effective in most patients with IgG4-related disease (IgG4-RD) but requires repeated cycles to prevent disease flares. We here aimed to assess B cells after rituximab to predict relapse of IgG4-RD and guide retreatment. METHODS: Patients with active IgG4-RD included in this retrospective study fulfilled the ACR/EULAR Classification Criteria. Total CD19+ B cells, plasmablasts, naïve and memory B cells were measured on peripheral blood by flow-cytometry at baseline and six months after rituximab. All patients were treated with two 1 g infusions of rituximab 15 days apart and monitored for 48 months. Disease response was assessed using the IgG4-RD Responder Index. RESULTS: Thirty-three patients were included. Six months after rituximab, disease response was observed in all patients. Complete depletion of CD19+ B cells, plasmablasts, naïve and memory B cell depletion was achieved in 30%, 55%, 39%, and 42% of cases, respectively. Twenty-three relapses (70%) were observed at a median time of 24 months after rituximab. Relapse rate was significantly higher in patients who failed to achieve complete depletion of CD19+ cells (60% vs 17%, p= 0.02), naïve B cells (54% vs 15%, p= 0.01), or memory B cells (50% vs 16%, p= 0.03) six months after rituximab. The median relapse free survival time was shorter in patients who failed to achieve complete depletion of CD19+ cells (19 vs 38 months, p= 0.02), naïve B cells (16 vs 38 months, p= 0.01), or memory B cells (19 vs 38 months, p= 0.03) six months after rituximab. CONCLUSIONS: The degree of B cell depletion six months after rituximab may predict disease flare and may instruct on the pacing of B cell depletion therapy in IgG4-RD.

Post-traumatic stress disorder in patients with systemic lupus erythematosus heavily affects quality of life. A cross-sectional web survey-based study.

OBJECTIVES: Neuropsychiatric symptoms develop in up to 20% of the patients with Systemic Lupus Erythematosus (SLE). Growing evidence is accruing on the association of SLE with Post-traumatic Stress Disorder (PTSD), but little is known about its contribution on patient-reported outcomes. This study focuses on PTSD prevalence in our SLE cohort and on its impact on quality of life. METHODS: Trauma and Loss Spectrum - Self Reported (TALS-SR) and Lupus Quality of Life (Lupus QoL) questionnaires were administered via web to the patients with SLE in our cohort, along with questions on demographical and disease-related aspects. RESULTS: Among 99 patients who completed the questionnaire, fatigue prevalence was 75% and 31% scored TALS-SR test consistently with PTSD. Patients with PTSD achieved lower scores compared to those without PTSD in three Lupus QoL domains: planning (83.3 vs. 100, p = .035), body image (85.0 vs. 95.0, p = .031) and fatigue (66.7 vs. 91.7, p = .001). An inverse correlation was found between TALS-SR domains and Lupus QoL scores, particularly regarding fatigue with reaction to losses or upsetting events (ρ -0.458, p < .001). CONCLUSIONS: PTSD is possibly far more frequent in patients with SLE than in general population and exerts a detrimental influence on quality of life.

ERN ReCONNET points to consider for treating patients living with autoimmune rheumatic diseases with antiviral therapies and anti-SARS-CoV-2 antibody products.

Recent studies have shown that people who are immunocompromised may inadvertently play a role in spurring the mutations of the virus that create new variants. This is because some immunocompromised individuals remain at risk of getting COVID-19 despite vaccination, experience more severe disease, are susceptible to being chronically infected and remain contagious for longer if they become infected and considering that immunocompromised individuals represent approximately 2% of the overall population, this aspect should be carefully considered. So far, some autoimmune rheumatic disease (ARD) patients with COVID-19 have been treated with antiviral therapies or anti-SARS-CoV-2 antibody products. However, there is no homogeneous approach to these treatment strategies. This issue was addressed within the European Reference Network (ERN) on Rare and Complex Connective Tissue and Musculoskeletal Diseases (ReCONNET) in a discussion among experts and patient's representatives in the context of the rare and complex connective tissue diseases (rCTDs) covered by the Network. ERN ReCONNET is one of the 24 ERNs launched by the European Commission in 2017 with the aim of tackling low prevalence and rare diseases that require highly specialised treatment and promoting concentration of knowledge and resources through virtual networks involving healthcare providers (HCPs) across the European Union (EU). Considering the urgent need to provide guidance not only to the rCTDs community, but also to the whole ARDs community, a multidisciplinary Task Force, including expert clinicians and European Patient Advocacy Group (ePAG) Advocates, was created in the framework of ERN ReCONNET with the aim of developing overarching principles (OP) and points-to-consider (PtC) on a homogenous approach to treat immunocompromised patients with ARDs (with a particular focus on CTDs) affected by COVID-19 using antiviral therapies and anti-SARS-CoV-2 antibody products. The present work reports the final OP and PtC agreed by the Task Force.

Predictors and outcomes of delirium in the emergency department during the first wave of the COVID-19 pandemic in Milan.

BACKGROUND: Respiratory infections can be complicated by acute brain failure. We assessed delirium prevalence, predictors and outcomes in COVID-19 ED patients. METHODS: This was a retrospective observational study conducted at the San Raffaele ED (Italy). Patients age >18 years attending the ED between 26 February 2020 and 30 May 2020 and who had a positive molecular nasopharyngeal swab for SARS-CoV-2 were included. The Chart-Based Delirium Identification Instrument (CHART-DEL) was used to retrospectively assess delirium. Univariable and multivariable logistic regression analyses were used to evaluate delirium predictors. Univariable binary logistic regression analyses, linear regression analyses and Cox regression analyses were used to assess the association between delirium and clinical outcomes. Age-adjusted and sex-adjusted models were then run for the significant predictors of the univariable models. RESULTS: Among the 826 included patients, 123 cases (14.9%) of delirium were retrospectively detected through the CHART-DEL method. Patients with delirium were older (76.9±13.15 vs 61.3±14.27 years, p<0.001) and more frequently living in a long-term health facility (32 (26%) vs 22 (3.1%), p<0.001). Age (OR 1.06, 95% CI 1.04 to 1.09, p<0.001), dementia (OR 17.5, 95% CI 7.27 to 42.16, p<0.001), epilepsy (OR 6.96, 95% CI 2.48 to 19.51, p<0.001) and the number of chronic medications (OR 1.09, 95% CI 1.01 to 1.17, p=0.03) were significant predictors of delirium in multivariable analyses. Delirium was associated with increased in-hospital mortality (adjusted HR 2.16, 95% CI 1.55 to 3.03, p<0.001) and with a reduced probability of being discharged home compared with being institutionalised (adjusted OR 0.39, 95% CI 0.25 to 0.61, p<0.001). CONCLUSIONS: Chart review frequently identified ED delirium in patients with COVID-19. Age, dementia, epilepsy and polypharmacy were significant predictors of ED delirium. Delirium was associated with an increased in-hospital mortality and with a reduced probability of being discharged home after hospitalisation. The findings of this single-centre retrospective study require validation in future studies.

Evidence for charge-based mimicry in anti dsDNA antibody generation.

Mechanisms for the generation of anti-dsDNA autoantibodies are still not completely elucidated. One theory states that dsDNA interacts for mimicry with antibodies raised versus other antigens but molecular features for mimicry are unknown. Here we show that, at physiological acid-base balance, anti-Annexin A1 binds IgG2 dsDNA in a competitive and dose-dependent way with Annexin A1 and that the competition between the two molecules is null at pH 9. On the other hand, these findings also show that dsDNA and Annexin A1 interact with their respective antibodies on a strictly pH-dependent basis: in both cases, the binding was minimal at pH 4 and maximal at pH9-10. The anionic charge of dsDNA is mainly conferred by the numerous phosphatidic residues. The epitope binding site of Annexin A1 for anti-Annexin A1 IgG2 was here characterized as a string of 34 amino acids at the NH2 terminus, 10 of which are anionic. Circulating levels of anti-dsDNA and anti-Annexin A1 IgG2 antibodies were strongly correlated in patients with systemic lupus erythematosus (n 496) and lupus nephritis (n 425) stratified for age, sex, etc. These results show that dsDNA competes with Annexin A1 for the binding with anti-Annexin A1 IgG2 on a dose and charged mediated base, being able to display an inhibition up to 75%. This study provides the first demonstration that dsDNA may interact with antibodies raised versus other anionic molecules (anti-Annexin A1 IgG2) because of charge mimicry and this interaction may contribute to anti-dsDNA antibodies generation.

Frailty as a predictor of mortality in COVID-19 patients receiving CPAP for respiratory insufficiency.

OBJECTIVE: Exploring the association between frailty and mortality in a cohort of patients with COVID-19 respiratory insufficiency treated with continuous positive airway pressure. METHODS: Frailty was measured using a Frailty Index (FI) created by using the baseline assessment data on comorbidities and body mass index and baseline blood test results (including pH, lactate dehydrogenase, renal and liver function, inflammatory indexes and anemia). FI > 0.25 identified frail individuals. RESULTS: Among the 159 included individuals (81% men, median age of 68) frailty was detected in 69% of the patients (median FI score 0.3 ± 0.08). Frailty was associated to an increased mortality (adjusted HR 1.99, 95% CI 1.02-3.88, p = 0.04). CONCLUSIONS: Frailty is highly prevalent among patients with COVID-19, predicts poorer outcomes independently of age. A personalization of care balancing the risk and benefit of treatments (especially the invasive ones) in such complex patients is pivotal.

Baseline characteristics of systemic lupus erythematosus patients included in the Lupus Italian Registry of the Italian Society for Rheumatology.

OBJECTIVE: To report baseline data of SLE patients enrolled in the Lupus Italian Registry (LIRE). METHODS: Patients affected by SLE aged ≥ 16 years were consecutively recruited in a multicenter prospective study comparing two cohorts: patients starting biologic immunosuppressants (BC) and patients starting non-biologic immunosuppresants (NBC). RESULTS: 308 patients were enrolled, 179 in NBC and 129 in BC. Mean age at disease onset and at diagnosis was significantly higher in NBC (p = 0.023, p = 0.045, respectively). Disease duration was longer in BC (p = 0.022). Patients in BC presented arthritis more frequently (p = 0.024), those in NBC nephropathy (p = 0.03). Quality of life was worse in BC (p = 0.031). Anti-dsDNA, low C3, were significantly more frequent in BC (p < 0.001, p = 0.009, respectively). Mycophenolate, methotrexate and azathioprine were the drugs more frequently prescribed in NBC, Belimumab and Rituximab in BC. CONCLUSION: The predominant organ involvement was different in the two cohorts: kidney involvement predominated in NBC, joint involvement in BC. Despite the younger age at disease onset, patients of the BC had a longer disease duration and more frequently had taken a cumulative prednisone dosage greater than 10 g. Even the pattern of clinical manifestations inducing to prescribe biological rather than conventional immunosuppressants was quite different.Keywords: Autoantibody(ies), autoimmune disease, belimumab, cohort studies, glucocorticoids, immunosuppressants, rituximab, systemic lupus erythematosus.

Beyond Neuropsychiatric Manifestations of Systemic Lupus Erythematosus: Focus on Post-traumatic Stress Disorder and Alexithymia.

PURPOSE OF REVIEW: To deepen the comprehension of the role of specific psychological conditions in the pathogenesis and in the treatment of systemic lupus erythematosus (SLE). Specifically, the present comprehensive review aims at examining the association between SLE, alexithymia (AT)-a personality construct referring to the inability to identify, describe, and express sensations, emotions, and physical state-and post-traumatic stress disorder (PTSD), to infer potential biological relationships between these psychopathological issues and disease course, and to draw up a research agenda on gray areas of these topics. RECENT FINDINGS: Whereas several studies document the presence of neuropsychiatric symptoms in patients with SLE, psychological distress, alexithymia, and post-traumatic manifestations are usually neglected by healthcare professionals and poorly investigated in research contexts. However, the interplay of these aspects, which affect physiologic stress coping mechanisms, potentially plays an important role in SLE pathogenesis. In particular, research documents that cytokine repertoire pattern alteration and hypothalamic-pituitary-adrenal axis impairment leading to inflammation and pain represent the main links between emotional health and immunity. AT and PTSD seem to be common in patients with SLE and account for multiple aspects of SLE-related morbidity. Furthermore, abnormal processing of stressful stimuli as hallmarks of PTSD and AT might promote neuroendocrine dysfunction and dysregulated immunity, thus contributing to the pathogenesis of SLE. A comprehensive, multidisciplinary clinical approach, based on a cooperation between immunologists, rheumatologists, neurologists, and mental health professionals, is crucial to promote patients' global health.

Six-month respiratory outcomes and exercise capacity of COVID-19 acute respiratory failure patients treated with continuous positive airway pressure.

BACKGROUND: COVID-19 long-term sequelae are ill-defined since only a few studies have explored the long-term consequences of this disease so far. AIMS: To evaluate the 6-month respiratory outcome and exercise capacity of COVID-19 acute respiratory failure (ARF) patients treated with continuous positive airway pressure (CPAP) during the first wave of the ongoing COVID-19 pandemic. METHODS: A retrospective observational study included COVID-19 patients with ARF. Interventions included CPAP during hospitalisation and 6-month follow up. Frailty assessment was carried out through frailty index (FI), pO2 /FiO2 during hospitalisation and at follow up, respiratory parameters, 6-min walking test (6MWT) and the modified British Medical Research Council (mMRC) and Borg scale at follow up. RESULTS: More than half of the patients had no dyspnoea according to the mMRC scale. Lower in-hospital pO2 /FiO2 correlated with higher Borg scale levels after 6MWT (ρ 0.27; P 0.04) at the follow-up visit. FI was positively correlated with length of hospitalisation (ρ 0.3; P 0.03) and negatively with the 6MWT distance walked (ρ -0.36; P 0.004). CONCLUSIONS: Robust and frail patients with COVID-19 ARF treated with CPAP outside the intensive care unit setting had good respiratory parameters and exercise capacity at 6-month follow up, although more severe patients had slightly poorer respiratory performance compared with patients with higher PaO2 /FiO2 and lower FI.

Clinical phenotypes of IgG4-related disease reflect different prognostic outcomes.

INTRODUCTION: Four clinical phenotypes of IgG4-related disease (IgG4-RD) have been recently identified by latent class analysis (LCA): pancreato-biliary (group 1); retroperitoneum/aortitis (group 2); head and neck limited (group 3); and Mikulicz/systemic (group 4). The reproducibility of this classification in clinical practice and its relevance for patient management, however, remain unknown. METHODS: The study included 179 patients. Four IgG4-RD experts were asked to classify a validation cohort of 40 patients according to published LCA-derived phenotypes based on clinical judgement. Agreement between LCA and clinical clustering was calculated. To assess differences among disease phenotypes, the following variables were recorded on an additional 139 patients: serum IgG4 and IgE; inflammatory markers; eosinophils; plasmablasts; IgG4-RD responder index (RI); history of atopy, diabetes, osteoporosis, relapses and malignancy; cumulative dose of glucocorticoids; and use of rituximab. RESULTS: Clinical judgement replicated LCA classification with strong agreement among IgG4-RD experts (κ = 0.841, P < 0.0005). At disease onset, group 1 showed the highest levels of serum IgG4 and IgE. Groups 2 and 4 had the lowest and highest IgG4-RD RI, respectively. At 2 years' follow-up, group 3 received the highest cumulative dose of glucocorticoids, but higher incidences of diabetes mellitus were observed in groups 1 and 4, consistent with the higher likelihood of pancreatic involvement in groups 1 and 4. No difference among the four groups was observed in terms of disease recurrence, time to relapse and frequency of rituximab infusion. CONCLUSION: Clinical phenotypes of IgG4-RD reflect differences in epidemiological features and prognostic outcomes.

Urticaria: recommendations from the Italian Society of Allergology, Asthma and Clinical Immunology and the Italian Society of Allergological, Occupational and Environmental Dermatology.

BACKGROUND: Urticaria is a disorder affecting skin and mucosal tissues characterized by the occurrence of wheals, angioedema or both, the latter defining the urticaria-angioedema syndrome. It is estimated that 12-22% of the general population has suffered at least one subtype of urticaria during life, but only a small percentage (estimated at 7.6-16%) has acute urticaria, because it is usually self-limited and resolves spontaneously without requiring medical attention. This makes likely that its incidence is underestimated. The epidemiological data currently available on chronic urticaria in many cases are deeply discordant and not univocal, but a recent Italian study, based on the consultation of a national registry, reports a prevalence of chronic spontaneous urticaria of 0.02% to 0.4% and an incidence of 0.1-1.5 cases/1000 inhabitants/year. METHODS: We reviewed the recent international guidelines about urticaria and we described a methodologic approach based on classification, pathophysiology, impact on quality of life, diagnosis and prognosis, differential diagnosis and management of all the types of urticaria. CONCLUSIONS: The aim of the present document from the Italian Society of Allergology, Asthma and Clinical Immunology (SIAAIC) and the Italian Society of Allergological, Occupational and Environmental Dermatology (SIDAPA) is to provide updated information to all physicians involved in diagnosis and management of urticaria and angioedema.

Quantitative measurement of 18F-FDG PET/CT uptake reflects the expansion of circulating plasmablasts in IgG4-related disease.

Objective: [18F]Fluorodeoxyglucose (18F-FDG) PET/CT is increasingly used to assess organ involvement and response to treatment in IgG4-related disease (IgG4-RD), but clear correlations between 18F-FDG uptake and disease activity have not been established yet. We aimed to correlate the intensity and distribution of 18F-FDG uptake with validated clinical, serological and immunological parameters of IgG4-RD activity. Methods: Twenty patients with active IgG4-RD underwent a baseline 18F-FDG PET/CT. Ten patients repeated 18F-FDG PET/CT after immunosuppressive treatments. 18F-FDG tissue uptake was measured using the standardized uptake value corrected for the partial volume effect (PVC-SUV) and the total lesion glycolysis (TLG) with (TLGtot+ln) and without (TLGtot-ln) lymph nodes. Disease activity was assessed by means of clinical parameters [IgG4-RD Responder Index (RI)], serological (ESR and CRP) and immunological (serum IgG4 and circulating plasmablasts) biomarkers. The enhanced liver fibrosis score was exploited as a biomarker for fibroblast activation. Results: Thirteen (65%) patients had two or more organs affected by IgG4-RD. All patients had active IgG4-RD as defined by a median IgG4-RD RI value of 9 (range 6-15; normal < 3). Serum IgG4 and plasmablasts were elevated in 85% of patients. Circulating plasmablasts positively correlated with PVC-SUV (P = 0.027), inversely correlated with TLGtot-ln (P = 0.023) and did not correlate with TLGtot+ln (P > 0.05). No statistically significant correlation was found between PVC-SUV or TLG and IgG4-RD RI, ESR, CRP, serum IgG4 or enhanced liver fibrosis score (P > 0.05). Clinical response to immunosuppressive therapies was associated with a consensual reduction of circulating plasmablasts, PVC-SUV, TLGtot+ln and TLGtot-ln values (P < 0.05 for all comparisons). Conclusions: 18F-FDG uptake of IgG4-RD lesions reflects immunological perturbations of the B cell compartment rather than fibroblast activation and extracellular matrix deposition. Conventional biomarkers of disease activity, namely IgG4-RD RI, ESR, CRP and serum IgG4 levels, do not appear to correlate with the radiometabolic activity of IgG4-RD lesions. In light of our results PET/CT represents a reliable instrument for assessing IgG4-RD activity, although lymph-node uptake deserves careful interpretation.

Drug induced exfoliative dermatitis: state of the art.

Drug induced exfoliative dermatitis (ED) are a group of rare and severe drug hypersensitivity reactions (DHR) involving skin and usually occurring from days to several weeks after drug exposure. Erythema multiforme (EM), Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are the main clinical presentations of drug induced ED. Overall, T cells are the central player of these immune-mediated drug reactions. Here we provide a systematic review on frequency, risk factors, pathogenesis, clinical features and management of patients with drug induced ED.

Are atopy and eosinophilic bronchial inflammation associated with relapsing forms of chronic rhinosinusitis with nasal polyps?

BACKGROUND: The aetiopathogenesis of chronic rhinosinusitis with nasal polyps (CRSwNP) is still unknown. The role of atopy and the concept of united airways in such patients are still a matter of debate. In this pilot study we aimed at evaluating the degree of eosinophilic inflammation and the frequency of atopy in a cohort of CRSwNP patients candidate for Functional Endoscopic Sinus Surgery (FESS) and assessing the association between these factors and relapsing forms of CRSwNP. METHODS: 30 patients (18 men, 12 women) with CRSwNP eligible for FESS were evaluated before and after surgery. Preoperative investigation included: history of previous relapse after FESS, clinical and laboratory allergologic assessment, spirometry, methacholine challenge, blood eosinophilia and determination of the fraction of nitric oxide in exhaled air (FeNO). Nasal fibroendoscopy, spirometry and FeNO determination were also assessed prospectively at 3 and 27 months post-FESS. RESULTS: 18/30 subjects were atopic, 6/18 (33 %) were monosensitized, 16/30 (53 %) were asthmatics and 10/30 (33 %) had non steroidalantinflammatory drugs (NSAIDs) hypersensitivity. Twenty-one patients (70 %) were classified as relapsers, 15/18 (83 %) among atopics, 6/12 (50 %) among non atopics (p = 0.05). Among patients with NSAIDs hypersensitivity, 9/10 (90 %) were relapsers. The median IgE concentration was 161.5 UI/mL in relapsers and 79 UI/mL in non-relapsers (ns). The mean FeNO decreased after FESS (43.1-26.6 ppb) in 84 % of patients, but this effect disappeared over time (FeNO = 37.7 ppb at 27 months). Higher levels of FeNO pre-FESS were detected in atopics, and in particular in relapsing ones (median 51.1 ppb vs 22.1, ns). Higher levels of FeNO pre-FESS were detected in asthmatic patients, especially in those who relapsed (median: 67 vs 64.85 ppb in non-relapsed patients, ns). The Tiffeneau Index (FEV1/FVC) was significantly lower in asthmatic relapsers than in non relapsers asthmatics (94.7 ± 11.1 versus 105 ± 5.9-p = 0.04). Patients with asthma and atopy had a major risk of relapse (p = 0.05). CONCLUSION: In our pilot study, atopy, severe asthma, bronchial inflammation, NSAIDs hypersensitivity and high level of total IgE are possible useful prognostic factors for the proneness to relapse after FESS. The role of allergy in CRSwNP pathogenesis should consequently be given deeper consideration. Allergen specific immunotherapy, combined with anti-IgE therapy, may have an immunomodulatory effect preventing polyps relapse and need to be investigated.

Efficacy of Siltuximab and 1,927 nm Fractional Laser for the Treatment of Cutaneous Manifestations in Castleman's Disease: The Role of Dermoscopy and Reflectance Confocal Microscopy for Lesion Evaluation.

Introduction: Multicentric Castleman's disease (MCD) with cutaneous involvement has rarely been discussed in dermatologic literature, with few reports. Cutaneous lesions in MCD may induce deep scars, causing a significant impact in the daily life of the patients. The treatment of Castleman's disease (CD) is usually a challenge, especially in case of cutaneous involvement. Case Presentation: We report the case of a 35-year-old Caucasian man with a 3-year-old history of MCD with cutaneous involvement that we treated with a combined therapy characterized by siltuximab and 1,927 nm fractional laser. The patient showed a therapeutic response, characterized by a reduction of systemic symptoms and cutaneous manifestations. Conclusion: We believe that the combination of siltuximab and 1,927 nm fractional laser might have a synergistic beneficial role in patients with cutaneous iMCD and maximize esthetic outcomes. Anyway, additional evidence is needed to validate our findings.

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.

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.