Multidisciplinary Decision-Making-ITAlian Consensus After Two Years of Real Practice on the Management of Severe Uncontrolled CRSwNP by Biologics (ITACA Study).

PURPOSE OF REVIEW: We aimed to reach an Italian multidisciplinary consensus on some crucial aspects of treatment decision making in CRSwNP, following 2 years of clinical experience in order to support specialists in the management of CRSwNP in clinical practice. We addressed issues relating to therapeutic decision-making and shared criteria for the treatment choice, as well as appropriate timing and criteria for evaluating treatment response, and highlighted the need for repeated multidisciplinary assessments. RECENT FINDINGS: A national survey has been conducted recently to understand how rhinology practice has changed in Italy with the advent of biologics and how this affects patients with uncontrolled, severe CRSwNP. Despite the many published consensus documents, practical recommendations, and protocols on the use of biologics in CRSwNP, heterogenous behaviors in practice are still observed mainly conditioned by the novelty of the topic. The consensus procedure followed a modified Delphi approach. The scientific board included 18 otorhinolaryngologists and 8 allergists, who selected the 4 main topics to be addressed and developed overall 20 statements. Consensus on these statements was sought by a larger group of 48 additional experts, through two rounds of voting, the first web-based, the second in presence with discussion and possible refinement of the statements. The statements reaching an average score ≥ 7 at the second voting round were approved. Five statements were proposed for each of the following topics: baseline evaluation of patients eligible for biologic therapy; choice between different therapeutic options; assessment of the response to biologic treatment; multidisciplinary management. At the first voting round, 19 out of the 20 statements reached a mean score ≥ 7. Following the discussion and a few consequent amendments, at the second round of voting all the 20 statements were approved.

Safety of omalizumab in chronic urticaria during pregnancy: a real-life study.

BACKGROUND: Managing a pregnant patient with chronic spontaneous urticaria (CSU) is often challenging. Recent data have shown that most CSU treatments in pregnant patients are second-generation H1 antihistamines (sgAHs), while data on the safety of omalizumab are scant. OBJECTIVES: To evaluate, in a routine clinical practice setting, the efficacy and safety of omalizumab in patients with severe CSU refractory to sgAHs who either became pregnant during treatment or who started the drug during pregnancy. METHODS: We conducted a retrospective study of women aged ≥ 18 years who were pregnant, who received one or more doses of omalizumab at any time during their pregnancy or who were taking omalizumab at the time of, or in the 8 weeks before, conception. RESULTS: Twenty-nine pregnant patients were evaluated: 23 (79%) conceived a child while taking omalizumab (group A), while 6 (21%) started omalizumab treatment during pregnancy (group B). Among patients in group A, we observed 23 births (21 liveborn singletons and 1 liveborn twin pair) and 1 miscarriage. Fifteen (65%) patients discontinued omalizumab after confirming their pregnancy, while eight (35%) were exposed to omalizumab during their entire pregnancy. In group B, omalizumab was introduced at a mean (SD) 10.83 (3.60) weeks' gestation and all patients were exposed to it until the end of pregnancy. In this group, there were seven liveborn infants (five singletons and one twin pair). No adverse events, pregnancy complications or congenital anomalies in newborns were recorded in either group. CONCLUSIONS: Omalizumab for CSU treatment before and during pregnancy does not appear to have negative effects on maternal or fetal outcomes.

Short-, mid- and long-term efficacy of dupilumab in moderate to severe atopic dermatitis: a real life multicenter Italian study on 2576 patients.

BACKGROUND: The efficacy and safety of dupilumab in atopic dermatitis (AD) have been defined in clinical trials but limited real-world evidence on long term treatment outcomes are currently available to inform clinical decisions. OBJECTIVES: to describe long-term effectiveness and safety of dupilumab up to 48 months in patients with moderate-to-severe AD. METHODS: a multicenter, retrospective, dynamic cohort study was conducted to assess long term effectiveness and safety of dupilumab in patients with moderate to severe AD in a real-world setting. Predictors of minimal disease activity (MDA) optimal treatment target criteria (defined as the simultaneous achievement of EASI90, itch NRS score ≤1, sleep NRS score ≤1 and DLQI ≤1) were investigated. RESULTS: 2576 patients were enrolled from June 2018 to July 2022. MDA optimal treatment target criteria were achieved by 506 (21.91%), 769 (40.63%), 628 (50.36%), 330 (55.37%) and 58 (54.72%) of those that reached 4, 12, 24, 36 and 48 months of follow-up, respectively. Logistic regression revealed a negative effect on MDA achievement for conjunctivitis and food allergy at all timepoints. Adverse events (AE) were mild and were observed in 373 (15.78%), 166 (7.02%), 83 (6.43%), 27 (4.50%) and 5 (4.55%) of those that reached 4, 12, 24, 36 and 48 months of follow-up. Conjunctivitis was the most frequently reported AE during the available follow-up. AE led to treatment discontinuation in <1% of patients during the evaluated time periods. CONCLUSION: High long-term effectiveness and safety of dupilumab were confirmed in this dynamic cohort of patients with moderate to severe AD, regardless of clinical phenotype and course at baseline. Further research will be needed to investigate the effect of Th2 comorbidities and disease duration on the response to dupilumab and other newer therapeutics for AD.

Association between maternal dupilumab exposure and pregnancy outcomes in patients with moderate-to-severe atopic dermatitis: A nationwide retrospective cohort study.

BACKGROUND: There is limited epidemiological evidence on outcomes associated with dupilumab exposure during pregnancy; monitoring pregnancy outcomes in large populations is required. OBJECTIVE: To investigate the potential association between exposure to dupilumab in pregnant women with atopic dermatitis and any adverse pregnancy, neonatal, congenital and post-partum outcomes. METHODS: We performed a multicentre retrospective cohort study across 19 Italian tertiary referral hospital. Childbearing women were eligible if aged 18-49 years and carried out the pregnancy between 1 October 2018 and 1 September 2022. RESULTS: We retrospectively screened records of 5062 patients receiving dupilumab regardless of age and gender, identifying 951 female atopic dermatitis patients of childbearing age, 29 of whom had been exposed to the drug during pregnancy (3%). The median duration of dupilumab treatment prior to conception was 22.5 weeks (range: 3-118). The median time of exposure to the drug during pregnancy was 6 weeks (range: 2-24). All the documented pregnancies were unplanned, and the drug was discontinued in all cases once pregnancy status was reported. The comparison of the study cohort and the control group found no significant drug-associated risk for adverse pregnancy, congenital, neonatal or post-partum outcomes. The absence of a statistically significant effect of exposure on the event was confirmed by bivariate analysis and multivariate analysis adjusted for other confounding factors. CONCLUSIONS: This cohort of pregnant patients exposed to dupilumab adds to the existing evidence concerning the safety of biologic agents in pregnancy. No safety issues were identified regarding the primary outcome assessed. In clinical practice, these data provide reassurance in case of dupilumab exposure during the first trimester. However, the continuous use of dupilumab throughout pregnancy warrants further research.

Contact allergy to SIDAPA baseline series allergens in patients with eyelid dermatitis: An Italian multicentre study.

BACKGROUND: Eyelid dermatitis is a frequent reason of dermatological consultation. Its aetiology is not univocal, being contact dermatitis, both allergic and irritant, the most frequent. The primary sources of allergen exposure include cosmetics, metals, and topical medications, from direct, indirect, or airborne contact. OBJECTIVES: To define the frequency of positive patch test reactions to SIDAPA baseline series allergens, to document positive allergens, and to precise the final diagnosis in patients with eyelid involvement. METHODS: A total of 8557 consecutive patients from 12 Italian Dermatology Clinics underwent patch testing with SIDAPA baseline series in 2018 and 2019. Patients were divided into two groups: (i) with eyelid involvement with or without other involved sites (E-Group) and (ii) without eyelid involvement (NE-Group). The final diagnosis and the frequency of positive relevant patch test reactions were evaluated. RESULTS: E-Group consisted of 688 patients (females 78.6%, mean age 45.3 years), 8.0% of 8557 consecutively patch-tested patients. The final diagnosis in E-Group was ADC in 42.4%, ICD in 34.2%, and AD in 30.5%. The highest reaction rates were elicited by nickel sulphate and methylchloroisothiazolinone/methylisothiazolinone in both E-Group and NE-Group, even if these allergens were significantly more frequently positive in NE-Group patients than in E-Group ones. Positive patch test reactions to fragrance Mix II, dimethylaminopropylamine, and sorbitan sesquiolate were significantly more frequent in E-Group patients than in NE-Group ones. CONCLUSIONS: Eyelid dermatitis is a frequent dermatological complaint. Allergic contact dermatitis is the most frequent diagnosis commonly caused by nickel sulphate, isothiazolinones, and fragrances. The surfactants dimethylaminopropylamine and sorbitan sesquioleate are emerging causes of eyelid allergic contact dermatitis.

Atopic Dermatitis and Autism Spectrum Disorders: Common Role of Environmental and Clinical Co-Factors in the Onset and Severity of Their Clinical Course.

Increasing evidence suggests an association between atopic dermatitis, the most chronic inflammatory disease of the skin, and autism spectrum disorders, which are a group of neurodevelopmental diseases. Inflammation and immune dysregulation associated with genetic and environmental factors seem to characterize the pathophysiological mechanisms of both conditions. We conducted a literature review of the PubMed database aimed at identifying the clinical features and alleged risk factors that could be used in clinical practice to predict the onset of ASD and/or AD or worsen their prognosis in the context of comorbidities.

Systemic drug-related intertriginous and flexural exanthema-like eruption after Oxford-AstraZeneca COVID-19 vaccine.

Systemic drug-related intertriginous and flexural exanthema (SDRIFE) is an adverse drug reaction which manifests as a symmetrical erythematous rash involving the skin folds after systemic drug exposure. A vast array of possible side effects associated with administration of different anti-SARS-CoV-2 vaccines have been reported in literature since the beginning of the COVID-19 pandemic, but only few times SDRIFE-like eruptions have been described in this context. We discuss here a case of SDRIFE-like eruption following the second dose of Oxford-Astrazeneca Vaxzevria vaccine.

Effectiveness and safety of dupilumab in patients with chronic rhinosinusitis with nasal polyps and associated comorbidities: a multicentric prospective study in real life.

BACKGROUND: Biologics are currently one of the main treatment options for a number of diseases. The IgG4 monoclonal antibody dupilumab targets the Interleukin-4 receptor alpha chain, thus preventing the biological effects of the cytokines IL-4 and IL-13, that are essential for the Th2 response. Several controlled trials showed that dupilumab is effective and safe in patients with atopic dermatitis (AD), severe asthma and chronic rhinosinusitis with nasal polyps (CRSwNP), thus resulting in approval by regulatory agencies. Aim of the study was to evaluate the efficacy and safety of dupilumab in adult patients with CRSwNP stratified by common overlapping comorbid conditions. METHODS: We performed a multicenter, observational, prospective study enrolling adult patients with severe CRSwNP who had started dupilumab treatment in the context of standard care from January 2021 to October 2021. Data were collected from twentynine Italian secondary care centers for allergy and clinical immunology, all of which were part of the Italian Society of Allergy, Asthma and Clinical Immunology (SIAAIC). A number of efficacy parameters were used. Patient data were compared using the Wilcoxon test for paired data. All statistical analyses were performed with SPSS version 20 (IBM, Armonk, NY, USA). RESULTS: In total, 82 patients with nasal polyposis were identified. A significant improvement was detected for all the applied efficacy parameters, i.e. 22-item Sino-Nasal Outcome Test (SNOT-22) and bilateral endoscopic nasal polyp score (NPS) scores for CRSwNP, Rhinitis Control Scoring System (RCSS) and Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) scores for allergic perennial rhinitis, Forced Expiratory Volume in the 1st second (FEV1) and Asthma Quality of Life Questionnaire (AQLQ) scores for asthma, Eczema Area and Severity Index (EASI) and Dermatology Life Quality Index (DLQI) scores for AD. A non-significant improvement was also obtained in the Urticaria Activity Score over 7 days (UAS7) for chronic spontaneous urticaria. Treatment with dupilumab was well tolerated. CONCLUSIONS: These data suggest that dupilumab treatment in patients suffering from CRSwNP and associated comorbidities may be suitable. Such outcome, although confirmation by trials is warranted, suggests the possibility to treat different disorders with a single therapy, with favorable effects especially under the cost-effectiveness aspect.

Orofacial granulomatosis: Clinical and therapeutic features in an Italian cohort and review of the literature.

BACKGROUND: Orofacial granulomatosis (OFG) is characterized by granulomatous inflammation of the soft tissues of maxillofacial region. We explored OFG patients from 10 different Italian centers and summarized the most recent literature data. METHODS: A review of patients with OFG was carried out. An extensive online literature search was performed to identify studies reporting diagnosis and management of OFG. RESULTS: Thirty-nine patients were recruited between January 2018 and February 2020. Most of them (97.4%) displayed involvement of the lips, and 28.2% suffered from Melkersson-Rosenthal syndrome. Two patients received diagnosis of CD and one patient of sarcoidosis, suggesting secondary OFG. Oral aphthosis and cervical lymphadenopathy were also described. The mean diagnostic delay was 3.4 years. Histological evaluation was performed in 34/39 patients (87.2%); non-caseating granulomas were found in 73.5% of them. Neurological symptoms (28.2%), gastrointestinal symptoms in absence of overt inflammatory bowel disease (IBD) (20.5%), and atopy (35.9%) were also identified. Therapeutic approaches varied among the centers. Steroids (51.3%) were used with good or partial results. Anti-TNF-α and anti-IgE monoclonal antibodies were used in 6 (15.4%) and 1 (2.6%) patients, respectively, with variable results. Surgery was the choice for 2 patients with good response. CONCLUSIONS: OFG is a rare and neglected disease showing multiple clinical phenotypes. While early diagnosis is crucial, management is difficult and highly dependent on the expertise of clinicians due to the lack of international guidelines. There is a need to establish registry databases and address challenges of long-term management.

Angioedema associated with dipeptidyl peptidase-IV inhibitors.

BACKGROUND: Dipeptidyl peptidase-IV (DPP-IV) inhibitors, also known as gliptins, are a class of oral antidiabetic agents. Postmarketing reports have documented the occurrence of angioedema in patients treated with gliptins and it was found that these drugs increased the risk of angioedema in patients concurrently treated with angiotensin-converting enzyme inhibitors (ACEIs). The aim of this manuscript is to provide an overview of the risk of angioedema associated with gliptins. METHODS: The keywords used for the literature search in the PubMed database included "angioedema" and "dipeptidyl peptidase", "gliptins", or the name of each DPP-IV inhibitor. Articles in English published up to December 2020 were taken into consideration. RESULTS: The available data appear to rule out a higher risk of angioedema associated with gliptin monotherapy and have revealed an increased susceptibility in patients simultaneously treated with gliptins and ACEIs. However, one single multicenter phase IV trial and case reports, even if very limited in number, have shown that angioedema can also occur during treatment with DPP-IV inhibitors without the concomitant use of ACEIs. The involvement of other drugs and drug interactions has occasionally been suggested. In a few patients, deficiency of enzymes involved in bradykinin catabolism was detected and this finding can constitute a risk factor for angioedema exacerbated by treatment with DPP-IV inhibitors. CONCLUSIONS: This risk of angioedema associated with the use of gliptins has mostly been related to the concurrent administration of ACEIs, and has been considered rare, but it might be underestimated and underreported. The role of additional risk factors or drug interactions deserves further investigations. Caution should be taken when considering the use of DPP-IV inhibitors in patients treated with ACEIs or presenting with other known risk factors for angioedema.

Dupilumab elicits a favorable response in type-2 inflammatory comorbidities of severe atopic dermatitis.

BACKGROUND: This case is the first report describing rapid, successful treatment of severe atopic dermatitis (AD) and comorbid type-2 inflammatory diseases in the same patient, with dupilumab treatment, with no side-effects. CASE PRESENTATION: We report on effects of dupilumab in a patient with severe AD, a long-standing history of a mild, perennial allergic rhino-conjunctivitis, moderate asthma and chronic rhinosinusitis with nasal polyps (CRSwNP). CONCLUSIONS: Patients suffering from AD, asthma, allergic rhinitis and CRSwNP may be eligible for dupilumab single treatment that is possibly advantageous also from the pharmaco-economic standpoint.

Quality of life in patients with allergic and immunologic skin diseases: in the eye of the beholder.

Allergic and immunologic skin diseases negatively impact the quality of life (QoL) of affected patients with detrimental consequences. Nonetheless, in everyday clinical practice the evaluation of QoL is often overlooked. Considering the increasing prevalence of atopic dermatitis, allergic contact dermatitis, hereditary angioedema, cutaneous mastocytosis, and urticaria, it is essential to determine the effects of allergic and immunologic skin diseases on QoL. A joint meeting (GET TOGETHER 2021) of the Italian Society of Allergology, Asthma and Clinical Immunology (SIAAIC) and the Italian Society of Allergological, Occupational and Environmental Dermatology (SIDAPA) aimed to summarize the features of the main QoL tools used in these diseases and to describe the extent of QoL impairment as well as the impact of treatments on QoL, particularly biologic therapies. The assessment of QoL in patients with allergic and immunologic skin diseases relies on generic, organ-specific and disease-specific questionnaires. While generic and organ-specific questionnaires allow comparison between different diseases, disease-specific questionnaires are designed and validated for specific cohorts: the QoL Index for Atopic Dermatitis (QoLIAD) and the Childhood Atopic Dermatitis Impact Scale (CADIS) in atopic dermatitis, the ACD-11 in allergic contact dermatitis, the Angioedema QoL Questionnaire (AE-QoL) and the Hereditary Angioedema QoL questionnaire (HAE-QoL) in hereditary angioedema, the Mastocytosis QoL Questionnaires (MCQoL e MQLQ) in cutaneous mastocytosis, and the Chronic Urticaria QoL questionnaire (CU-Q2oL) in urticaria. Among the many factors that variably contribute to QoL impairment, pruritus can represent the leading cause of patient discomfort. Biologic therapies significantly ameliorate QoL in atopic dermatitis, hereditary angioedema, mastocytosis and chronic urticaria. In general, adequate management strategies are essential for improving QoL in patients with allergic and immunologic skin diseases.

Efficacy of dupilumab in atopic comorbidities associated with moderate-to-severe adult atopic dermatitis.

BACKGROUND: Dupilumab is an anti-IL-4Rα antibody used in the treatment of patients with moderate-to-severe atopic dermatitis (msAD). This study explored the potential benefit of dupilumab in perennial allergic rhinoconjunctivitis (PAR) and perennial allergic asthma (PAA) caused by indoor allergens in adults with msAD. METHODS: This multicentric, prospective, observational, real-life study included adult patients with msAD who had been treated with dupilumab in 16 Italian care centres. Efficacy outcomes regarding AD, PAR and PAA were collected at baseline and 16 weeks. Safety was also assessed. RESULTS: We enrolled 123 patients with msAD. Between baseline and 16 weeks of treatment, the following measurements decreased statistically significantly: Eczema Area and Severity Index, SCOring AD, Patient-Oriented Eczema Measure, pruritus score, sleep score, Dermatology Life Quality Index and IgE. Dupilumab treatment in patients with comorbid PAR (n = 41) was associated with significant improvements in PAR disease control (measured using a Rhinitis Control Scoring System) and in PAR Quality of life (QoL) (measured using the Rhinoconjunctivitis QoL Questionnaire scores). In 32 patients with comorbid PAA, dupilumab significantly improved PAA control (measured using the Asthma Control Test and five-item Asthma Control Questionnaire scores) and disease-related QoL (measured using the Asthma QoL Questionnaire scores). Thirty-five patients (28.5%) developed conjunctivitis during the study period. CONCLUSION: These results support the benefits of dupilumab for adult patients with PAR and/or PAA associated with msAD.

Benralizumab improves patient reported outcomes and functional parameters in difficult-to-treat patients with severe asthma: Data from a real-life cohort.

In the last decade, an increasing number of randomized controlled trials (RCTs) on biologic therapy in patients with severe asthma have included patient-reported outcomes (PROs) as secondary efficacy measures. The majority of these RCTs showed a benefit in symptoms and quality of life. However, the magnitude of this benefit remains uncertain, because it rarely exceeded the minimal important difference (MID), owing to a significant improvement in the control group (placebo effect). Real-life studies on biologic therapies assessing PRO are scarce. They may support and integrate RCT results through their different experimental design. This real-life retrospective study provides data on 15 patients with difficult-to-treat severe eosinophilic asthma treated with benralizumab up to 6 months. Asthma quality of life questionnaire (AQLQ) and asthma control test (ACT) were assessed and administered at each visit to minimize the Hawthorne effect. Changes in general accepted efficacy measures, such as forced expiratory volume in 1 s (FEV1), peak expiratory flux (PEF), exacerbation rate and blood eosinophils, from baseline were also assessed. AQLQ and ACT improved from 3.9 ± 0.4 to 5.2 ± 0.4 and from 15.6 ± 5.7 to 18.1 ± 5.6, respectively. FEV1 increased of about 250 ml (+14%). PEF increased from 288 ± 107 to 333 ± 133 l/min. The number of exacerbations requiring OCS courses decreased from 2.8 ± 2.2 to 0.5 ± 0.8. Eosinophil counts dropped to 25.6 ± 15 cells/microliter. In conclusion, most patients reported improvements in AQLQ and ACT greater than MID, suggesting that these outcome represent a sensitive tool in real-life effectiveness studies. Our approach reduced the limitations of transition questions and the Hawthorne effect, increasing findings reliability.

Safety of measles, mumps, and rubella vaccine in egg allergy: in vivo and in vitro management.

BACKGROUND: Egg allergy is the second most prevalent form of food allergy in childhood. In spite of the evidence accumulated, inoculating egg allergy children with attenuated vaccines grown on chick embryo cell cultures, such as the measles, mumps, and rubella (MMR) vaccine, is regarded (erroneously) as potentially dangerous or even anaphylactogenic, by many. An issue perceived as particularly conflicting also by Health Professionals. CASE PRESENTATION: A 15-year-old boy, with a history of severe egg allergy in early infancy, who was still sensitized to egg allergens, including baked egg, had never received MMR vaccination, in fear of possible anaphylaxis, in spite of the fact that this vaccination is mandatory in the first year of life, in Italy. Because of that, he was not allowed to attend school, longer, and was referred to us in order to assess the potential risk of MMR vaccination. Upon thorough allergologic workup, sensitization to MMR vaccine components was excluded by an in vivo approach, consisting in skin prick tests, intradermal tests, and subcutaneous injection test, corroborated by vaccine-specific B-lymphocyte proliferation assay, ex vivo. T-cell proliferation in response to MMR vaccine was also excluded. Eventually, the boy was inoculated with MMR vaccine and was readmitted to school. CONCLUSIONS: The diagnostic strategy adopted appears feasible and easy-to-perform and may be adopted in controversial cases (as the one reported), characterized by previous severe allergic reactions to egg. The B-lymphocyte proliferation assay we developed may represent a useful and reliable tool not only in research but also in clinical practice.

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.

Maintenance-Phase Subcutaneous Immunotherapy with House Dust Mites Induces Cyclic Immunologic Effects.

BACKGROUND: Subcutaneous immunotherapy (SCIT) is an effective treatment of respiratory allergies including house dust mite (HDM) and Hymenoptera venom allergy. During the build-up phase, the allergen is administered weekly at increasing doses, while during the maintenance phase, it is administered at a fixed high dose every 4 weeks. Upon SCIT injection, the allergen is driven to the draining lymph nodes where it most likely induces an immune response. Immunologic changes are thus supposedly induced at each injection. OBJECTIVES: It is now established that SCIT induces tolerance in the long term, but the precise underlying immunologic mechanisms remain unclear. Therefore, we wanted to analyze the immunologic changes induced in both innate and adaptive immune cells at each individual SCIT administration during the maintenance phase in HDM-allergic patients. More specifically, we wondered whether the changes in regulatory T cell (Treg) and IgE+ B cell percentages, which are observed at the end of a 3-year course of SCIT, already occurred during the maintenance phase and whether these possible changes were sustained. METHODS: We enrolled 6 patients suffering from HDM allergic rhinitis and undergoing maintenance HDM SCIT for 18-24 months. The same SCIT extract was used for all patients. We collected blood samples at 5 time points: T1 (immediately before a given SCIT injection), T2 (9 days after T1), T3 (29 days after T1 and right before the successive administration), T4 (39 days after T1), and T5 (61 days after T1 and just before the next injection). Six non-allergic age-matched healthy individuals were used as controls. Using flow cytometry, we assessed the following cell subsets in peripheral blood mononuclear cells: CD4 and CD8 T cells, Tregs, B cells, IgE+ B cells, NK and NKT cells, and total and activated basophils. RESULTS: HDM-allergic patients displayed increased percentages of CD4 and CD8 T cells and NK cells compared to healthy controls. In contrast, NKT cells, total B cells, and basophils were diminished. These differences were maintained throughout the time course and seemed to be independent of the periodical SCIT injections. On the contrary, Treg percentages were significantly reduced in all HDM-allergic patients at T1. However, they increased at T2 and T4 (9 days after each SCIT injection) but decreased again at T3 and T5, just before the next one, resulting in cyclic changes. IgE+ B cells were significantly increased at T1, even more increased after each administration (T2, T4), and went back to their initial levels at T3 and T5, also resulting in a cyclic pattern. CONCLUSIONS: Our data suggest that during the SCIT maintenance phase, cycles of expansion/contraction of Tregs and IgE+ B cells occur at each SCIT injection. Therefore, the sustained induction of immune tolerance by SCIT, through the increase of Tregs, seems to depend on the periodical exposure to the allergen, at least during the early steady state.

Hereditary and Acquired Angioedema: Heterogeneity of Pathogenesis and Clinical Phenotypes.

Recurrent angioedema (AE) without wheals is increasingly recognized as a clinical entity and a frequent cause of admission to the emergency room. The Hereditary Angioedema Working Group (HAWK) classification allowed the scientific community to go beyond the semantic confusion that dominated this topic for decades. This classification distinguishes hereditary and acquired forms of AE, either related or unrelated to C1 inhibitor deficiency. Recently, additional mechanisms have been involved in the AE pathogenesis, including the uncontrolled activation of factor XII, generation of vasoactive mediators that induce dysregulation of endothelial functions, and bidirectional interactions between mast cell-derived mediators and the plasma contact system. Thus, recurrent AE can be determined by multiple and concurrent mechanisms that may generate distinct clinical phenotypes of the disease. Frequency, severity, and the location of attacks are quite different from patient to patient and, even in the same patient, they may change throughout the course of life. The severity of the clinical phenotype strongly influences the burden of the disease and patients' quality of life. Despite major advances in our understanding of recurrent AE, many unsolved questions remain, leaving several unmet needs for patients and caregivers. This review is focused on a description of different AE phenotypes and the concurrent mechanisms leading to their pathogenesis. A better definition of cellular and molecular pathways responsible for the distinct AE phenotypes may help to improve diagnosis and may lead to a personalized approach to prophylaxis and treatment of the disease.