EAACI Biologicals Guidelines-Omalizumab for the treatment of chronic spontaneous urticaria in adults and in the paediatric population 12-17 years old

Eosinophilic granulomatous polyangiitis with central nervous system involvement in children: a case report and literature review

Objective

To explore the clinical characteristics and treatment outcomes of children with central nervous system (CNS) involvement in eosinophilic granulomatosis with polyangiitis (EGPA).

Methods

A child who presented with EGPA complicated by CNS involvement was admitted to our hospital in June 2023. The clinical features were analyzed retrospectively, and relevant literatures were reviewed to provide a comprehensive overview of this condition.

Results

A ten-year-old girl, who had a history of recurrent cough and asthma accompanied by peripheral blood eosinophilia for eight months, was admitted to our hospital. On admission, spotted papules were visible on her hands and feet, bilateral pulmonary rales were audible. The laboratory examination revealed that the proportion of eosinophils (EOS) exceeded 10% of white blood cells, the anti-neutrophil cytoplasmic antibody (MPO-ANCA) was positive, the immunoglobulin G level was 15.80g/L, and the immunoglobulin E level was greater than 2500.00IU/mL. The imaging examination showed multiple patchy and nodular high-density shadows in both lungs as well as sinusitis. Pulmonary function tests indicated moderate ventilation and diffusion dysfunction. Bone marrow cytology demonstrated a significant increase in the proportion of eosinophils. Skin pathology confirmed leukocytoclastic vasculitis. During the hospitalization, the child had a convulsion. The magnetic resonance imaging (MRI) scan of the brain showed multiple abnormal signal shadows in the bilateral cerebral cortex and the electroencephalogram (EEG) showed epileptic waves. Following the administration of methylprednisolone pulse therapy in combination with cyclophosphamide treatment, her cough and asthma resolved, the skin rash disappeared without any further convulsions. We found that only a young EGPA patient with CNS involvement had been previously reported. The previously reported case began with long-term fever, weight loss, and purpuric rash. Both patients responded well to treatment with glucocorticoids and cyclophosphamide, experiencing significant improvement in their clinical symptoms and normalization of their peripheral blood eosinophils.

Conclusion

The diagnosis of EGPA in children can be challenging. When a child is affected by EGPA, it is essential to remain vigilant for signs of CNS involvement. The treatment with glucocorticoids and cyclophosphamide is effective in managing EGPA in children.

Disparities in chronic spontaneous urticaria: Eligibility for drug reimbursement associated with clinical outcomes

Background

Chronic spontaneous urticaria (CSU) is an immunologic condition with an estimated prevalence of 0.1%. For CSU that is poorly controlled despite the use of antihistamines, omalizumab is the only treatment approved and recommended by international guidelines.

Objective

Our aim was to outline the impact of treatment accessibility on CSU outcomes in the real world.

Methods

Serial data on adult patients with CSU receiving care for at least 6 months at a dedicated, immunologist-led urticaria clinic at Grantham Hospital in Hong Kong between 2018 and 2023 were analyzed. Patients' clinicodemographic data, drug eligibility status (eligible for reimbursement or not), treatment step, and disease activity (weekly Urticaria Activity Score [UAS7]) were collected and compared according to drug eligibility status.

Results

This study included 238 patients, 80 (33.6%) of whom were eligible for reimbursement and 158 of whom were not. No significant clinicodemographic differences, including disease activity, were found at baseline. At latest follow-up, significantly more patients in the eligible group were receiving omalizumab (28.7% vs 5.7% [P < .001]), which is equivalent to a multivariate odds ratio of 9.35 (95% CI = 3.689-23.703 [P < .001]). The discrepancy persisted even in patients with moderate-to-severe CSU whose UAS7 was 16 or higher (40.6% [13 of 32] vs 10.2% [6 of 59]; P < .001). In addition, there was significantly less dose reduction (<300 mg every 4 weeks) in the eligible omalizumab users (4.3% vs 44.4% [P = .015]). Clinically, significantly greater improvements in UAS7 were reported by the eligible group (median change -8.0 vs -5.0 [P = .021]).

Conclusion

Patterns of management varied largely among patients with different drug eligibility statuses and led to disparities in health outcomes. More efforts to secure equitable access to guideline-based CSU care are warranted.

Immunopathogenesis of urticaria: a clinical perspective on histamine and cytokine involvement

BACKGROUND

Urticaria is a clinical condition characterized by the appearance of wheals (hives), angioedema, or both. Over the last several decades, a better understanding of the mechanisms at play in the immunopathogenesis of urticaria has underscored the existence of numerous urticaria subtypes. Separating the different kinds of urticaria explicitly helps find the best detection method for the management of this skin disorder. Subtypes of urticaria also include both spontaneous and physical types. The conventional ones include spontaneous urticaria, constituting both acute and chronic urticaria. Therefore, a broad and effective therapy is essential for the diagnosis and treatment of urticaria.

METHODS

To understand the immunopathogenesis of urticaria, various databases, including PubMed, Scopus, and Web of Science, were used to retrieve original articles and reviews related to urticaria. While information on several clinical trials were obtained from clinicaltrials.gov database.

RESULTS

This article highlights the immunopathogenesis involved in the intricate interaction between cellular infiltration, immune reactions, coagulation cascades, and autoantibodies that underlie urticaria's pathophysiology.

CONCLUSION

The recent progress in understanding urticaria can help to understand the intricate characteristics in the immunopathogenesis of urticaria and could play a beneficial role in the management of urticaria.

Mapping the intellectual structure of the research of omalizumab in chronic spontaneous urticaria: A bibliometric analysis

Background

The guidelines for treating chronic spontaneous urticaria (CSU) recommend using the IgE-targeted biologic omalizumab in patients with antihistamine-refractory disease.

Objective

Our aim was to present a bibliometric review of publications related to omalizumab and CSU over the past 2 decades.

Methods

Relevant publications from 2003 to 2022 were extracted from the Science Citation Index-Expanded (SCI-EXPANDED) database in the Web of Science Core Collection database as of January 8, 2023. We utilized CiteSpace (version 6.1.R3), VOSviewer (version 1.6.18), and the R package (version 4.2.1) to analyze and visualize the data. The R package bibliometrix (version 4.2.1) was also used.

Results

Between 2003 and 2022, a total of 566 articles on omalizumab and CSU were published. Since 2014, there has been a rapid increase in publication output. According to the collaboration network, the most influential country, institute, and scholar were the United States, Charité Universitätsmedizin Berlin, and Marcus Maurer, respectively. The study identified the Journal of Allergy and Clinical Immunology: In Practice as the most productive journal and the Journal of Allergy and Clinical Immunology as the most cocited journal. The analysis of key words revealed the presence of high-frequency terms such as angioedema, IgE, treatment, anti-IgE, asthma, and atopic dermatitis. Moreover, recent studies in this area have concentrated mainly on biomarkers, dupilumab, and coronavirus 2019 (COVID-19).

Conclusion

There has been a growing interest in the use of omalizumab in CSU in recent years. The current trending topics in this research are the identification of biomarkers and the development of new mAbs for the treatment of CSU.

Comparative efficacy and safety of the treatment by Omalizumab for chronic idiopathic urticaria in the general population: A systematic review and network meta-analysis

BACKGROUND

Omalizumab is the only licensed drug that serves as a third-line treatment for chronic idiopathic urticaria (CIU). The optimum doses of omalizumab remain controversial. Therefore, this study aims to estimate the efficacy and safety of different doses of omalizumab in the treatment of CIU patients.

MATERIALS AND METHODS

Four databases were searched from the database's creation to April 8, 2023. Several keywords such as omalizumab and urticarias were used to retrieve related studies. The meta-analytical outcomes were analyzed in R 4.2.1 software and Stata 15.1 software. Cochrane risk-of-bias tool Ver. 2 was used to evaluate the risk of bias in randomized controlled trials (RCTs).

RESULTS

In total, 2331 patients were included. Five indexes were employed to assess, including weekly Itch Severity Score (ISS7), weekly Hive Severity Score (HSS7), weekly Urticaria Activity Score (UAS7), Dermatology Life Quality Index (DLQI), and adverse events (AE). A 300 mg dose of omalizumab was the optimum dose to treat CIU, followed by the 150 mg dose. Furthermore, 600 mg of omalizumab only showed a significant difference from the placebo in HSS7. No significant statistical difference was observed in AE. Meta-regression analysis revealed that time, as a covariate, was statistically significant in the comparison of omalizumab 150 mg with placebo.

CONCLUSION

300 mg of omalizumab was the optimum dosage to treat CIU patients, with a 150 mg dose also exhibiting good efficacy. Further studies are required to explore the efficacy and safety of different doses of omalizumab in the treatment of CIU patients.

Real-World Effectiveness of Omalizumab in Chronic Urticaria: A Clinical Observational Study

INTRODUCTION

The purpose of this study was to assess the clinical effectiveness and safety profile of omalizumab as a therapeutic intervention for chronic urticaria (CU).

METHODS

From March 1, 2023, to September 30, 2023, data on a cohort comprising 96 patients with CU, who underwent treatment with omalizumab at our medical institution's allergy clinic, were systematically compiled. Subsequent to the administration of omalizumab, the therapeutic efficacy was assessed utilizing the 7-day urticaria activity score and the urticaria control test.

RESULTS

Based on the statistical analysis, the mean duration of therapeutic intervention was 2.4 ± 1.3 months, with a corresponding mean cumulative dosage of 765 ± 450 mg. Of the subset of 42 patients with CU who were subjected to a follow-up period exceeding 3 months, it was observed that the treatment led to complete symptom remission, and no instances of recurrence were documented. Notably, there were statistically significant differences in the treatment duration and the cumulative dosage between patients who experienced co-morbid conditions and those who did not (p < 0.01, 95% CI: 0.280-1.326; p < 0.01, 95% CI: 0.597-2.997). Furthermore, there were significant differences in the treatment duration and cumulative dosage between patients in the combined allergic rhinitis group and those in the non-combined allergic rhinitis group (p < 0.01, 95% CI: 0.204-1.305; p = 0.01, 95% CI: 0.326-2.860).

CONCLUSION

Omalizumab demonstrates efficacy in the management of CU among Chinese patients by exerting effective symptom control and facilitating the regression of skin lesions. The assessment of its therapeutic efficacy typically requires a 12-week treatment period. Moreover, the co-occurrence of CU with other allergic disorders serves as a pertinent consideration for the adjustment of omalizumab dosing regimens.

Evaluation of Pediatric Chronic Urticaria with Emphasis on Clinical and Laboratory Characteristics and Treatment Response to Omalizumab: A Real-Life Experience from a Tertiary Allergy Center

Pediatric data on the clinical and etiologic features, treatment response, and use of omalizumab for chronic urticaria (CU) are quite limited. The aim of this study was to evaluate the clinical and demographic characteristics, laboratory findings, and response to treatment of CU in children. Children with a diagnosis of CU between 2019 and 2023 were included in the study. Information on demographic characteristics, clinical features, laboratory tests, provocation tests for inducible urticaria, urticaria activity scores (UAS7), and treatment responses were obtained from patients' medical records. A total of 150 children (50.7% male) with CU were enrolled in the study. A total of 14 (9.3%) patients had autoimmune diseases of which 11 (7.3%) had autoimmune thyroiditis. Overall, 97 (64.7%) patients had chronic spontaneous urticaria (CSU) and 53 (35.3%) had chronic inducible urticaria. A total of 16 patients who remained symptomatic despite high-dose antihistamines were treated with omalizumab, with a good response in 13 (81.3%) and a partial response in 3 (18.7%) patients. CSU accounts for the majority of pediatric CU, with the etiology being in part related to an autoimmune background. This study provides an overview of CU in children and demonstrates the safety and efficacy of treatment with omalizumab.

Omalizumab for Patients with Chronic Spontaneous Urticaria: A Narrative Review of Current Status

Chronic spontaneous urticaria (CSU) is a debilitating inflammatory disorder of the skin, characterized by a fluctuating natural history, a complex mechanism of action, and a significant burden on patients, including effect on quality of life, development of psychosocial disorders, and a range of comorbidities. Recent international guidelines recommend a therapeutic approach of first-line treatment with second generation H1-antihistamines and second-line treatment with the biologic omalizumab. Here, the salient aspects of CSU and current status of data for omalizumab for patients with CSU are reviewed, with a focus on mechanism of action, efficacy and real-world effectiveness (including patient outcomes, response, relapse, and remission), and safety (including consideration of the risk of anaphylaxis). The review also considers recent data on COVID-19, CSU, and omalizumab and presents our perspective on future needs. Overall, the data suggest that omalizumab is an effective and well-tolerated treatment for patients with CSU that provides benefits for a wide range of patients.

Systematic Review and Critical Appraisal of Urticaria Clinical Practice Guidelines: A Global Guidelines in Dermatology Mapping Project (GUIDEMAP)

BACKGROUND

Management of urticaria can be optimized with clinical practice guidelines (CPGs). However, the quality of recent urticaria CPGs remains unclear.

OBJECTIVE

To identify and appraise urticaria CPGs worldwide published in the last 5 years.

METHODS

A search for relevant urticaria CPGs was conducted between January 1, 2017, and May 31, 2022, using the following databases: MEDLINE, Embase, National Institute for Health and Care Excellence (NICE) Evidence Search, Guidelines International Network, ECRI Guidelines Trust, Australian Clinical Practice Guidelines, Trip Medical Database, and DynaMed. The included CPGs were critically appraised using the Appraisal of Guidelines for Research and Evaluation (AGREE) II instrument, Lenzer et al's red flags, and the Institute of Medicine (IOM) criteria of trustworthiness.

RESULTS

We included 21 urticaria CPGs. Most guidelines reviewed treatment recommendations of chronic spontaneous urticaria. The majority of guidelines were from European and Asian countries with high and high-middle sociodemographic index, written in English, and openly accessible. Seventeen guidelines (81%) had at least 1 AGREE II domain rated poor quality. Applicability, rigor of development, and stakeholder involvement were the 3 AGREE II domains that scored the lowest across guidelines. Appraisal with Lenzer et al's red flags showed that 18 guidelines (86%) raised at least 1 red flag indicating potential bias. The top 3 domains raising red flags were: no inclusion of nonphysician experts/patient representative/community stakeholders, no or limited involvement of a methodologist in the evaluation of evidence, and lack of external review. Based on IOM's criteria of trustworthiness, 20 guidelines (95%) had 1 or more criteria that did not meet best practice standards. The 3 domains with the highest number of best practice standards not met were updating procedures, rating strength of recommendations, and external review. Guidelines scored highest for the AGREE II domains of defining scope and purpose and clarity of presentation, and had the most fully met IOM's best practice standard for articulation of recommendations. However, only 1 urticaria CPG by NICE was identified as rigorously developed across all 3 appraisal tools.

CONCLUSIONS

The quality of urticaria CPGs in the last 5 years varied widely. Only the NICE urticaria guideline consistently demonstrated excellent quality, high trustworthiness, and low risk of bias. Use of a rigorous framework to rate certainty of evidence and grade strength of recommendation, involvement of methodologists, stakeholder engagement with external review, and clear guidance for updating can help improve the quality of future CPGs.

Type 2 chronic inflammatory diseases: targets, therapies and unmet needs

Over the past two decades, significant progress in understanding of the pathogenesis of type 2 chronic inflammatory diseases has enabled the identification of compounds for more than 20 novel targets, which are approved or at various stages of development, finally facilitating a more targeted approach for the treatment of these disorders. Most of these newly identified pathogenic drivers of type 2 inflammation and their corresponding treatments are related to mast cells, eosinophils, T cells, B cells, epithelial cells and sensory nerves. Epithelial barrier defects and dysbiotic microbiomes represent exciting future drug targets for chronic type 2 inflammatory conditions. Here, we review common targets, current treatments and emerging therapies for the treatment of five major type 2 chronic inflammatory diseases - atopic dermatitis, chronic prurigo, chronic urticaria, asthma and chronic rhinosinusitis with nasal polyps - with a high need for targeted therapies. Unmet needs and future directions in the field are discussed.

Omalizumab in Chronic Spontaneous Urticaria (CSU): Real-Life Experience in Dose/Interval Adjustments and Treatment Discontinuation

BACKGROUND

Data on real-life experience with omalizumab dose/interval adjustments are still limited, as well as on omalizumab discontinuation.

OBJECTIVE

To evaluate efficacy and safety of omalizumab dose/interval adjustment in a Portuguese cohort of patients with chronic spontaneous urticaria (CSU) and to characterize those who discontinued omalizumab.

METHODS

A retrospective study of patients who started omalizumab for CSU at a Portuguese Urticaria Center of Reference and Excellence (UCARE) was conducted between 2009 and 2021. Response criteria were based on a weekly Urticaria Activity Score (UAS7) <7 points (partial: UAS7 7-15 points; nonresponders: UAS7 >15 points) and minimal important difference >10 points.

RESULTS

A total of 138 patients were enrolled in the study; 83% of them were women, and the median age was 49 years (interquartile range: 40-58 years). On 300 mg q4 weeks, 96 (70%) patients were responders, 29 (21%) partial responders, and 13 (9%) nonresponders. After dose/interval adjustments (up to 600 mg q2 weeks), 108 (78%) were responders, 27 (20%) partial responders, and 3 (2%) nonresponders. No adverse events were reported. Updosing was more frequent in patients with angioedema, body mass index >30 kg/m2, positive basophil activation test, and autologous serum test. A total of 71 (51%) patients lengthened interval, presenting higher median pre-omalizumab D-dimer (0.2 vs 0 mcg/mL, P = .038) and C-reactive protein (0.3 vs 0.1 mg/dL, P = .030) values than those with a standard dose. In total, 37 patients (27%) stopped omalizumab, but 14 (38%) of them needed retreatment on average 11 months after discontinuation. Patients with angioedema and a longer omalizumab duration had higher chance of relapse.

CONCLUSIONS

Omalizumab dose and/or interval adjustment is effective and safe and should be implemented in partial/nonresponders for response improvement and in responders for further discontinuation. A protocol for regimen adjustments is proposed.

Effects of omalizumab combined with budesonide formoterol on clinical efficacy, pulmonary function, immune function, and adverse reactions in children with moderate and severe allergic asthma

OBJECTIVE

To evaluate the clinical efficacy and safety of combining omalizumab with budesonide formoterol to treat children with moderate and severe allergic asthma, and investigate the effect of this combination therapy on pulmonary and immune functions.

METHODS

The data of 88 children with moderate and severe allergic asthma, who were admitted to our hospital between July 2021 and July 2022, were included in the study. The patients were randomly assigned either to control group (n = 44; received budesonide formoterol inhalation therapy) or experimental group (n = 44; received omalizumab subcutaneous injection + budesonide formoterol inhalation therapy) using computer-generated randomization. The clinical efficacy, asthma control (measured using childhood Asthma-Control Test [C-ACT] score), pulmonary function (forced expiratory volume in 1 s, forced vital capacity, and peak expiratory flow), immune function (cluster of differentiation 3 cells [CD3⁺ cells], cluster of differentiation 4 cells [CD4⁺ cells], immunoglobulin G, immunoglobulin A, and immunoglobulin E), and adverse reactions were observed and compared between both groups.

RESULTS

After treatment, the experimental group had improved levels of pulmonary function and immune function indexes, higher C-ACT scores, and a higher overall response rate than the control group (P < 0.05). In addition, the incidence of adverse reactions was not significantly different between both groups (P > 0.05).

CONCLUSION

The combination of omalizumab with budesonide formoterol for treating moderate and severe allergic asthma in children demonstrated promising clinical efficacy and improved their pulmonary and immune functions, leading to more rational asthma control. The combined regimen demonstrated satisfactory clinical safety and deserved clinical promotion.

Long-Term Safety of Omalizumab in Children with Asthma and/or Chronic Spontaneous Urticaria: A 4-Year Prospective Study in Real Life

Background: Insufficient data are available on the long-term "real-life" safety profile of omalizumab in children. This study evaluated the long-term safety of omalizumab in a pediatric cohort with severe asthma or chronic spontaneous urticaria (CSU). Methods: A monocentric, prospective study evaluated the long-term safety of omalizumab in patients aged 6-18 years. Each patient completed the standardized MedDRA questionnaire to identify adverse events (AEs). Results: In total, 23 patients, median age 15 (14-18) years, affected by severe asthma (60.8%) or CSU (39.2%), treated with omalizumab for 2 (1-4) years were enrolled. The most common AEs belong to the system organ class (SOC) of general disorders and administration-site conditions (37.17%). Skin and subcutaneous tissue problems represent the second most frequently reported AEs (24.35%). Central nervous system and musculoskeletal disorders were quite frequent (15.38% and 8.97%, respectively). Other adverse events were tachycardia (5.12%), vertigo and abdominal pain (2.60% and 3.86%, respectively), and dry eye (1.3%). Only one patient reported herpes virus infection during treatment (1.3%). No cases of anaphylaxis, hemopathies, uronephropathies, respiratory, psychiatric, hepatobiliary, or oncological pathologies were reported. Conclusions: Long-term "real-life" treatment with omalizumab in children appears well tolerated. Its safety and efficacy profile makes omalizumab an excellent alternative in severe asthma and CSU in children.

Allergen immunotherapy: progress and future outlook

INTRODUCTION

Allergy, the immunological hypersensitivity to innocuous environmental compounds, is a global health problem. The disease triggers, allergens, are mostly proteins contained in various natural sources such as plant pollen, animal dander, dust mites, foods, fungi and insect venoms. Allergies can manifest with a wide range of symptoms in various organs, and be anything from just tedious to life-threatening. A majority of all allergy patients are self-treated with symptom-relieving medicines, while allergen immunotherapy (AIT) is the only causative treatment option.

AREAS COVERED

This review will aim to give an overview of the state-of-the-art allergy management, including the use of new biologics and the application of biomarkers, and a special emphasis and discussion on current research trends in the field of AIT.

EXPERT OPINION

Conventional AIT has proven effective, but the years-long treatment compromises patient compliance. Moreover, AIT is typically not offered in food allergy. Hence, there is a need for new, effective and safe AIT methods. Novel routes of administration (e.g. oral and intralymphatic), hypoallergenic AIT products and more effective adjuvants holds great promise. Most recently, the development of allergen-specific monoclonal antibodies for passive immunotherapy may also allow treatment of patients currently not treated or treatable.

Efficacy of Different Dosing Regimens of IgE Targeted Biologic Omalizumab for Chronic Spontaneous Urticaria in Adult and Pediatric Populations: A Meta-Analysis

Chronic urticaria is a debilitating skin condition that is defined as itchy hives at least twice a week and lasting for six or more weeks, with or without angioedema. Chronic spontaneous urticaria (CSU) is a form of disease that is witnessed in two-thirds of those with chronic urticaria. This meta-analysis explores the efficacy of differential dosages of omalizumab for outcomes of weekly itching scores, weekly wheal scores, urticarial assessment score 7 (UAS7), and responder rates. Adhering to PRISMA Statement 2020 guidelines, a systematic search of PubMed/MEDLINE, Scopus, Embase, and Web of Science was conducted until 15 September 2022. A combination of the following keywords was used: omalizumab and chronic urticaria. Data comprising clinical trial ID, name, author/year, country, dosage and time of intervention, inclusion criteria, mean age, female gender, and racial grouping information were obtained. The meta-analytical outcomes were analyzed in RevMan 5.4. The risk-of-bias assessment was conducted using version 2 of the Cochrane risk-of-bias tool for randomized trials (RoB 2). A total of 10 trials comprising 1705 patients with CSU were included. Notably, 1162 belonged to the intervention group, while 543 were controls. A total of 70.4% of the participants were female in the intervention group, while 65.6% of them were female in the control group. The overall mean age was 38.64 ± 10.66 years. Weekly itch score outcomes were most notable with 150 mg dosage (Cohen’s d = −2.6, 95% CI = −4.75, −0.46, p = 0.02). The weekly wheal score outcomes had the largest effect size with 300 mg dosage (Cohen’s d = −1.45, 95% CI = −2.2, −0.69, p = 0.0002). For UAS7 outcomes, the largest effect size was yielded with 150 mg dosage (Cohen’s d = −6.92, 95% CI: −10.38, −3.47, p < 0.0001). The response rate to omalizumab had a likelihood of being higher with 300 mg of intervention compared to placebo (OR = 8.65, 95% CI = 4.42, 16.93, p < 0.0001). Well-rounded urticarial symptom resolution was observed with 150 mg and 300 mg dosages of omalizumab. Improvement of UAS7 was more comparable with 150 mg dosage, whereas the chance of response to treatment was higher with 300 mg dosage. Our findings support omalizumab as an effective intervention for adult and pediatric populations that are resistant to many therapies, including high-dose H1-antihistamines.

Ligelizumab impairs IgE ‐binding to plasmacytoid dendritic cells more potently than omalizumab and restores IFN ‐α production and FOXP3 + Treg generation

BACKGROUND

Ligelizumab is an anti-IgE monoclonal antibody binding IgE with higher affinity than omalizumab that is under clinical investigation for several IgE-mediated diseases. We previously showed that omalizumab removes IgE bound to FcεRI on plasmacytoid dendritic cells (pDCs) and restores their ability to produce IFN-α and regulatory T cells (Tregs). The aim of this work is to investigate the capacity of ligelizumab to regulate functional properties of pDCs in comparison with omalizumab.

METHODS

pDCs were isolated from atopic donors and IgE was detached from FcεRI on pDCs with designed ankyrin repeat protein (DARPin) bi53-79. pDCs were resensitized with IgE alone or in the presence of ligelizumab or omalizumab prior to IgE-FcεRI crosslinking and Toll-like receptor 9 (TLR9) stimulation. Flow cytometry, ELISA, coculture experiments and intranuclear staining were performed to determine cytokine production and Treg generation. An antigen-specific model of resensitization and IgE-crosslinking was also performed.

RESULTS

The levels of serum total free IgE show a non-linear positive correlation with the frequency of IgE⁺ pDCs displaying IgE bound to FcεRI within the 43 individual donors included in the study. Ligelizumab displays stronger capacity than omalizumab to block the binding of free IgE to FcεRI on human pDCs, resulting in a greater restoration of TLR9-L-induced IFN-α production. Ligelizumab also restores the ability of pDCs to generate FOXP3⁺ Tregs as previously reported for omalizumab.

CONCLUSIONS

The uncovered novel molecular mechanisms of ligelizumab to regulate functional properties of pDCs from atopic donors might have important clinical implications for anti-IgE treatments in different IgE-mediated diseases.

Urticaria

Urticaria is an inflammatory skin disorder that affects up to 20% of the world population at some point during their life. It presents with wheals, angioedema or both due to activation and degranulation of skin mast cells and the release of histamine and other mediators. Most cases of urticaria are acute urticaria, which lasts ≤6 weeks and can be associated with infections or intake of drugs or foods. Chronic urticaria (CU) is either spontaneous or inducible, lasts >6 weeks and persists for >1 year in most patients. CU greatly affects patient quality of life, and is linked to psychiatric comorbidities and high healthcare costs. In contrast to chronic spontaneous urticaria (CSU), chronic inducible urticaria (CIndU) has definite and subtype-specific triggers that induce signs and symptoms. The pathogenesis of CSU consists of several interlinked events involving autoantibodies, complement and coagulation. The diagnosis of urticaria is clinical, but several tests can be performed to exclude differential diagnoses and identify underlying causes in CSU or triggers in CIndU. Current urticaria treatment aims at complete response, with a stepwise approach using second-generation H1 antihistamines, omalizumab and cyclosporine. Novel treatment approaches centre on targeting mediators, signalling pathways and receptors of mast cells and other immune cells. Further research should focus on defining disease endotypes and their biomarkers, identifying new treatment targets and developing improved therapies.

Pediatric chronic spontaneous urticaria: a brief clinician's guide

INTRODUCTION

Chronic urticaria (CU) appears with daily or intermittent/recurrent wheals with/without angioedema for more than six weeks. When no specific eliciting factors are found, chronic urticaria is defined as spontaneous (CSU). Up to 50% of patients with CSU do not respond to therapy, leading to a prolonged disease course and the need for expensive therapies, impacting the quality of life (QoL) and healthcare resources.

AREAS COVERED

: Diagnosis of CSU is made when other potential causes of chronic urticaria are excluded. CSU therapy aims to achieve complete control of symptoms and normalization of QoL. Current treatment options for urticaria aim to target mast cell mediators such as histamine, or activators, such as autoantibodies. Guidelines recommend starting with second generation antihistamines (sgAHs) and adding omalizumab therapy if symptoms are not controlled. This review aims to provide a practical guide for CSU in the pediatric population.

EXPERT OPINION

: Treatment options for pediatric CSU are primarily based on adult data that have been extrapolated for children. Current guidelines should be re-evaluated based on pediatric data, new biological treatments, and the COVID-19 pandemic. Future research is needed to investigate strategies to personalize current treatments and identify potential predictive biomarkers.

Controversies in Allergy: Choosing a Biologic for Patients with Severe Asthma

The availability of a range of new biological treatments targeting type-2 inflammation has provided new opportunities for patients with more severe asthma. Treatment has a bigger effect on exacerbations than day-to-day symptoms, and efficacy increases with increasing intensity of type-2 airway inflammation as reflected by the blood eosinophil count and fractional exhaled nitric oxide. The similarity of the clinical effects and target populations coupled with the absence of direct head-to-head comparative data makes it difficult to choose the right biologic for a given patient. In this review, we summarize the key efficacy data from phase 3 trials; discuss indirect comparisons; review clinical and laboratory variables that may be associated with a differential response to treatment; outline practical considerations that might be important to individual patients; and suggest an algorithm for choosing the most appropriate biologic to start with and the first choice to switch to.