Clinical efficacy of omalizumab in chronic spontaneous urticaria is associated with a reduction of FcεRI-positive cells in the skin

Sustained clinical and histopathological remission in a patient with eosinophilic esophagitis and type-2 comorbidities at 18 months after discontinuation of dupilumab

Eosinophilic esophagitis (EoE) is a chronic, allergen-mediated, type-2 inflammatory disease with the potential to significantly impact an individual's quality of life. Conventional treatments often result in varied responses, prompting the need for novel therapeutic approaches. We present the case of a 19-year-old male with a medical history marked by eosinophilic esophagitis, severe atopic dermatitis (AD), asthma, and allergic rhinitis. Despite undergoing diverse topical and systemic interventions to address his AD and EoE, the patient's symptoms persisted. However, following the initiation of dupilumab therapy-a dual IL-4 and IL-13 receptor antagonist-the patient experienced a substantial reduction in his Eczema Area and Severity Index score. Notably, a marked improvement was also seen regarding his symptoms of eosinophilic esophagitis. A subsequent esophageal biopsy revealed a significant decrease in eosinophilic inflammation, consistent with established clinical and histologic remission criteria. These findings corroborate the patient's reported relief from symptoms. This case underscores the potential efficacy of dupilumab as a promising therapeutic agent in managing eosinophilic esophagitis. Dupilumab offers a dual benefit of alleviating symptoms and achieving histologic and clinical remission. This novel approach presents a noteworthy advancement in the treatment of EoE.

Time-course and dose-effect of omalizumab in treating chronic idiopathic urticaria/chronic spontaneous urticaria

PURPOSE

Several studies have shown that subcutaneous injections of omalizumab can treat chronic idiopathic/spontaneous urticaria (CIU/CSU) patients by only assessing the efficacy on specific endpoints. This study aimed to quantitatively analyze different doses of omalizumab in CIU/CSU and compare it with ligelizumab.

METHODS

Literature searches were performed in PubMed, Embase, and Web of Science databases. A model-based meta-analysis (MBMA) was utilized to develop a model incorporating time since the initiation of treatment and dose for omalizumab, with the change from baseline in Urticaria Activity Score (CFB-UAS7) as the primary efficacy endpoint. The time-course and dose-effect relationship throughout the omalizumab treatment period was analyzed, and the findings were compared with those of the investigational ligelizumab.

RESULTS

The model equation for the CFB-UAS7 was established as E = -Emax × time/(ET50 + time) × (b0 + b1 × dose). The estimated values of the model parameters E max ,ET 50 , b 0 , and b 1 were -1.16, 1.26 weeks, -9.90, and -0.0361 mg-1, respectively. At week 12 after the first dose, the model-predicted CFB-UAS7 for 150 mg and 300 mg of omalizumab were -16.0 (95% CI, -17.2 to -14.8) and -21.7 (95% CI, -22.9 to -20.5), respectively. In the PEARL-1 trial, the CFB-UAS7 for 72 mg and 120 mg of ligelizumab were -19.4 (95% CI, -20.7 to -18.1) and -19.3 (95% CI, -20.6 to -18.0), respectively. In the PEARL-2 trial, these values were -19.2 (95% CI, -20.5 to -17.9) and -20.3 (95% CI, -21.6 to -19.0), respectively.

CONCLUSION

Omalizumab showed a significant dose-dependent effect in the treatment of CSU. Both 72 mg and 120 mg ligelizumab might have the potential to outperform 150 mg (but not 300 mg) omalizumab.

Research hotspots in urticaria: A bibliometric study of the top 100 most cited articles

BACKGROUND AND PURPOSE

Urticaria is a prevalent recurrent skin allergic condition. Severe itching significantly impacts patients' quality of life. This paper aims to investigate the development status of urticaria through bibliometric analysis to predict future research hotspots and trends.

METHODS

On October 29, 2023, a literature search was conducted in the Web of Science (WOS) database to collect urticaria-related publications. The top 100 most cited articles were charted, and VOSviewer software was utilized for the literature data analysis. A visual analysis was performed on the number of articles, journals, main researchers, keywords, and so on.

RESULTS

The research involved 415 authors from 28 countries, published across 25 journals, ranging from 1963 to 2023. Marcus Maurer was the leading author, with the United States being the foremost country in urticaria research. CEH Grattan received the most citations, and The Medical University of South Carolina had the highest number of publications. Key research focuses include epidemiology, pathogenesis, drug therapy, and quality of life assessments. "Anti-high affinity IgE receptor α chain (FcεRIα)," "chronic idiopathic urticaria," "autoantibodies," "histamine-release" emerged as the keywords with the highest prominence.

CONCLUSION

The field of urticaria research has attracted substantial attention over the past few decades, witnessing rapid development. This study highlighted the top 100 articles by citation frequency within the urticaria field. Bibliometric analysis revealed a shift in treatment methods from traditional antihistamines to biological agents, with significant emphasis on improving the quality of life in chronic urticaria management. These areas represent the current research focal points and indicate future trends in urticaria research.

BTK signaling-a crucial link in the pathophysiology of chronic spontaneous urticaria

Chronic spontaneous urticaria (CSU) is an inflammatory skin disorder that manifests with itchy wheals, angioedema, or both for more than 6 weeks. Mast cells and basophils are the key pathogenic drivers of CSU; their activation results in histamine and cytokine release with subsequent dermal inflammation. Two overlapping mechanisms of mast cell and basophil activation have been proposed in CSU: type I autoimmunity, also called autoallergy, which is mediated via IgE against various autoallergens, and type IIb autoimmunity, which is mediated predominantly via IgG directed against the IgE receptor FcεRI or FcεRI-bound IgE. Both mechanisms involve cross-linking of FcεRI and activation of downstream signaling pathways, and they may co-occur in the same patient. In addition, B-cell receptor signaling has been postulated to play a key role in CSU by generating autoreactive B cells and autoantibody production. A cornerstone of FcεRI and B-cell receptor signaling is Bruton tyrosine kinase (BTK), making BTK inhibition a clear therapeutic target in CSU. The potential application of early-generation BTK inhibitors, including ibrutinib, in allergic and autoimmune diseases is limited owing to their unfavorable benefit-risk profile. However, novel BTK inhibitors with improved selectivity and safety profiles have been developed and are under clinical investigation in autoimmune diseases, including CSU. In phase 2 trials, the BTK inhibitors remibrutinib and fenebrutinib have demonstrated rapid and sustained improvements in CSU disease activity. With phase 3 studies of remibrutinib ongoing, it is hoped that BTK inhibitors will present an effective, well-tolerated option for patients with antihistamine-refractory CSU, a phenotype that presents a considerable clinical challenge.

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.

Different doses and courses of omalizumab for patients with chronic spontaneous urticaria: A systematic review with meta-analysis and trial sequential analysis

Background

The stability, efficacy, and safety of omalizumab at different doses and regimens for chronic spontaneous urticaria (CSU) are yet to be studied.

Objective

A systematic review (SR) with meta-analysis (MA) and trial sequential analysis (TSA) was performed to assess the efficacy and safety of omalizumab in CSU.

Methods

Randomised controlled trials (RCTs) of administering omalizumab versus placebo for CSU were searched. Random-effects MAs were performed using planned subgroup analyses. TSA was performed to control for the risk of random errors and assess the stability of our MA results. Publication bias was visually assessed using a contour-enhanced funnel plot and the trim-and-fill method. The quality of RCTs was assessed using the Cochrane Risk of Bias Tool 2.

Results

Twelve studies met the inclusion criteria. Omalizumab had remarkable effects on the patient percentage of the weekly urticaria activity score is zero (UAS = 0) [RR 4.64, 95% CI (3.38, 6.37)], percentage of no angioedema-burdened days [MD 3.15, 95% CI (0.10, 6.19], patient percentage of UAS ≤6 [RR 3.05, 95% CI (2.46, 3.78)], and patient percentage of the weekly itch severity score minimally important difference (ISS7 MID) [RR 1.50, 95% CI (1.36, 1.66)]. Omalizumab was well tolerated across studies [RR 0.98, 95% CI (0.90, 1.08)]. TSA confirmed the above results, except for "the percentage of no angioedema-burdened day".

Conclusion

Among the different doses and courses assessed, omalizumab (300 mg, 12 weeks) can be recommended as an effective treatment for patients with CSU. However, whether omalizumab improves angioedema requires further investigation. The clinical management of angioedema accompanying CSU requires further attention.

Early Assessment of Efficacy and Safety of Biologics in Pediatric Allergic Diseases: Preliminary Results from a Prospective Real-World Study

BACKGROUND

Despite the increasing interest in biologics for the management of allergic diseases, sparse real-world data are still available in the pediatric population. This study aimed to evaluate the early real-life efficacy and safety of omalizumab for patients with moderate-to-severe asthma and chronic spontaneous urticaria (CSU), and Dupilumab for patients with moderate-to-severe atopic dermatitis (AD).

METHODS

A prospective study enrolling children aged 6-18 years was designed to assess the efficacy and safety of biologic drugs at 16 weeks of treatment (T1). The effectiveness was measured using validated questionnaires (ACQ-5 for asthma, UAS7 for CSU, and EASI score for AD). Secondary outcome measures included reductions in inhaled corticosteroid (ICS) dosages, asthma-related hospitalizations/exacerbations, and quality of life (QoL) indicators (iNRS, sNRS, DLQI/cDLQI) for CSU and AD. Safety was expressed according to the descriptions of adverse events provided by EMA and FDA.

RESULTS

The study cohort consisted of eighteen children (mean age 12.9 ± 3.4 years). The omalizumab treatment significantly reduced ACQ-5 and UAS7 scores (p = 0.002 and p < 0.001, respectively). In patients with asthma, decreased ICS dosage and hospitalization/exacerbation rates were observed. QoL parameters significantly improved in CSU and AD patients. No severe adverse events were reported for either treatment.

CONCLUSIONS

Our findings validate omalizumab and dupilumab as effective and safe therapeutic options for managing moderate-to-severe allergic diseases in children and adolescents.

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.

Comparative effectiveness and safety of drug therapy for chronic urticaria: a network meta-analysis and risk-benefit assessment

BACKGROUND

Chronic urticaria (CU) is a prevalent chronic skin condition characterized by recurrent wheals. Clinical guidelines recommend multiple drugs for CU treatment. Our study aims to compare the effectiveness and safety of drug therapy for CU.

METHODS

We conducted a comprehensive search of randomized controlled trials (RCTs) and real-world studies (RWSs) in PubMed, EMBASE, and Cochrane. A network meta-analysis (NMA) was conducted to assess the response rate, decline in Urticaria Activity Score over 7 Days (UAS7), Dermatology Life Quality Index (DLQI), and adverse event rates of standard-dose and high-dose H1 antihistamine (H1AH), omalizumab (OMA) 75, 150, and 300 mg, cyclosporine and placebo. The risk-benefit assessment was conducted by probabilistic simulation and stochastic multicriteria acceptability analysis (SMAA).

RESULTS

A total of 39 studies were identified, including 37 RCTs and 2 RWSs. OMA 300 mg and 150 mg both had significantly higher response rate than standard-dose H1AH (p < 0.05, respectively). OMA 300 mg and 150 mg both consistently led to a huge drop in UAS7 and DLQI compared to standard-dose H1AH and high-dose H1AH (p < 0.05).

CONCLUSION

Regarding risk-benefit assessment, OMA 300 mg emerges as the optimal pharmacological intervention for CU, while OMA 150 mg stands as a secondary alternative compared to H1 antihistamines and cyclosporine.

Higher House Dust Mite-Specific IgE Levels among Chronic Spontaneous Urticaria Patients May Implicate Higher Basophil Reactivity

INTRODUCTION

Allergen-specific IgE (sIgE) sensitization exists in a considerable fraction of chronic spontaneous urticaria (CSU) patients. Basophils have been implicated in the pathogenesis of CSU. This paper aimed to explore the relationship between allergic sensitization and basophil reactivity in CSU and the possible underlying mechanism.

METHODS

Basophil-enriched leukocytes were isolated from the peripheral blood of 76 CSU patients and 9 healthy controls. Basophil CD63 and FcεRIα (the alpha subunit of the high-affinity IgE receptor) expression in the blood samples with various house dust mite (HDM)-sIgE levels were determined by flow cytometry. Basophil reactivity and SHIP-1 (a molecule related to the IgE/FcεRI signaling pathway) expression were analyzed after stimulation with an HDM allergen or other stimuli.

RESULTS

HDM-sIgEstrong positive (≥3.5 kU/L) CSU patients had a significantly higher mean percentage of basophil CD63 and higher baseline levels of FcεRIα expressed by basophils than HDM-sIgEnormal (<0.35 kU/L) CSU patients and healthy controls; the same went for total serum IgE. After stimulation with Dermatophagoides pteronyssinus peptidase 1 (Derp1) alone or together with Derp1-sIgE, the stimulation index of CD63 and levels of FcεRIα expressed by basophils in HDM-sIgEstrong positive CSU patients were significantly higher than those in HDM-sIgEnormal CSU patients and healthy controls. Significantly more SHIP-1 mRNA expression in HDM-sIgEstrong positive CSU patients was induced after the combined stimulation in comparison to other subjects.

CONCLUSION

CSU patients with higher HDM-sIgE levels (≥3.5 kU/L) may have higher CD63 and FcεRIα expression on peripheral blood basophils. Peripheral blood basophils in these CSU patients are more responsive to HDM allergen stimulation. Higher HDM-sIgE levels among CSU patients may implicate higher basophil reactivity.

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.

Biomarkers for Monitoring Treatment Response of Omalizumab in Patients with Chronic Urticaria

Chronic urticaria (CU) is a debilitating skin disease affecting around 1% of the population. CU can be subdivided into chronic spontaneous urticaria (CSU) and chronic inducible urticaria (CIndU). Different pathophysiological mechanisms have been proposed to play a role in the development of CU, and these are also being investigated as potential biomarkers in the diagnosis and management of the disease. As of now the only assessment tools available for treatment response are patient reported outcomes (PROs). Although these tools are both validated and widely used, they leave a desire for more objective measurements. A biomarker is a broad subcategory of observations that can be used as an accurate, reproducible, and objective indicator of clinically relevant outcomes. This could be normal biological or pathogenic processes, or a response to an intervention or exposure, e.g., treatment response. Herein we provide an overview of biomarkers for CU, with a focus on prognostic biomarkers for treatment response to omalizumab, thereby potentially aiding physicians in personalizing treatments.

Case Report: Off-label treatment of idiopathic hypereosinophilic syndrome with Omalizumab

Idiopathic hypereosinophilic syndrome (IHES) is a rare disease characterized by causeless persistent hypereosinophilia and eosinophilia-associated end-organ damage. Current treatment modalities don't meet the needs due to adverse events of steroids as first-line therapy and the limited efficacy of second-line treatments, underscoring the need for new therapeutic strategies. Here we presented two cases of IHES with different clinical manifestations that were both refractory to corticosteroids. Patient #1 experienced rashes, cough, pneumonia, and steroid-induced side effects. Patient #2 had severe gastrointestinal symptoms attributed to hypereosinophilia. They both had high levels of serum IgE, didn't respond well to second-line treatments of interferon-α (IFN-α) and imatinib, and Mepolizumab was not accessible. We then innovatively switched to Omalizumab, an anti-IgE monoclonal antibody approved for allergic asthma and chronic idiopathic urticaria. Patient #1 was treated with Omalizumab 600 mg per month for 20 months; his absolute eosinophil count (AEC) decreased significantly and has stabilized at around 1.0×10⁹/L for 17 months, with complete relief from erythra and cough. Patient #2 recovered promptly from severe diarrhea with a sharp drop in AEC after 3 months of treatment with omalizumab at 600 mg per month. Therefore, we concluded that Omalizumab may be a seminal therapeutic strategy for IHES patients who are refractory to corticosteroids, whether as long-term management of AEC or as an urgent intervention to address severe symptoms caused by eosinophilia.

Urticaria and basophils

Chronic spontaneous urticaria (CSU) is a common skin disease without an etiology in the vast majority of cases. The similarity of symptoms and pathology to allergen-induced skin reactions supports that skin mast cell IgE receptor activation is also involved in CSU. Accumulating evidence also supports a role for blood basophils in disease expression. Blood basopenia is noted in active CSU disease with the recruitment of blood basophils to skin lesion sites. Blood basophils further display altered IgE receptor mediated degranulation patterns in two phenotypes that improve in remission. In active CSU subjects, changes in IgE receptor signaling molecule expression levels accompany the altered degranulation function in blood basophils. The success of therapies targeting IgE in CSU patients have also shown that altered blood basophil phenotypes and enumeration have potential use as a disease biomarker.

Chronic urticaria and the pathogenic role of mast cells

The signs and symptoms of chronic urticaria (CU) are caused by the activation and degranulation of skin mast cells (MCs). Recent studies have added to our understanding of how and why skin MCs are involved and different in CU. Also, novel and relevant mechanisms of MC activation in CU have been identified and characterized. Finally, the use of MC-targeted and MC mediator-specific treatments has helped to better define the role of the skin environment, the contribution of specific MC mediators, and the relevance of MC crosstalk with other cells in the pathogenesis of CU. Here, we review these recent findings and their impact on our understanding of CU, with a focus on chronic spontaneous urticaria (CSU). Also, we highlight open questions, issues of controversy, and unmet needs, and we suggest what studies should be performed moving forward.

Differences in allergen-specific basophil activation and T cell proliferation in atopic dermatitis patients with comorbid allergic rhinoconjunctivitis treated with a monoclonal anti-IL-4Rα antibody or allergen-specific immunotherapy

BACKGROUND

Atopic dermatitis (AD), a chronic inflammatory disorder, is often accompanied by allergic rhinoconjunctivitis (ARC) as a co-morbidity. The use of a monoclonal anti-IL-4Rα antibody has been effective in controlling moderate to severe AD symptoms. Allergen-specific immunotherapy (AIT) is widely used for the treatment of ARC and asthma. The effects of AIT on basophil reactivity/effector functions have already been examined and used as indicators of the treatment efficacy. However, it is unclear, how an anti-IL-4Rα antibody can influence allergen-specific immune responses of basophils and T cells of AD patients with comorbid ARC.

OBJECTIVE

To investigate the effect of a monoclonal anti-IL-4Rα antibody on the in vitro allergic responses of basophils and T cells deriving from AD patients with comorbid ARC.

METHODS

Blood samples of 32 AD patients were obtained before, after 4 and 16 weeks of an anti-IL-4Rα antibody therapy (300 mg subcutaneously/2 weeks; n = 21) or AIT (daily sublingual application; n = 11). Patients treated with an anti-IL-4Rα antibody were grouped according to their serum specific immunoglobulin E levels and ARC symptoms, while patients receiving an AIT were additionally grouped according to the allergen specificity of their AIT. Basophil activation test and T cell proliferation assays were undertaken after an in vitro allergen stimulation.

RESULTS

A significant reduction of the immunoglobulin E levels and the allergen-specific T cell proliferation was observed in AD patients treated with an anti-IL-4Rα -antibody, while the allergen-specific basophil activation/sensitivity were found to be significantly increased. In patients receiving an AIT, the in vitro allergen-specific basophil activation and the T cell proliferation were found to be significantly decreased in response to seasonal allergens.

CONCLUSIONS

An IL-4Rα blockade induced by a monoclonal anti-IL-4Rα antibody leads to an increased activity/sensitivity of early effector cells (such as basophils), in contrast to a decreasing reactivity observed under an AIT. The late-phase T cell reaction to allergens did not differ between the herein assessed treatments.

Chronic spontaneous urticaria: Focus on pathophysiology to unlock treatment advances

Chronic spontaneous urticaria (CSU) is a debilitating skin disease characterized by intensely itchy wheals, angioedema, or both. Symptoms recur spontaneously, on a near-daily basis, over >6 weeks; many patients experience flare-ups over several years and, consequently, reduced quality of life. Differences between the inflammatory profiles of the skin of CSU patients (wheals and nonlesional sites) and healthy controls indicate that key drivers such as mast cells, eosinophils, and basophils interact, release vasoactive mediators, and prime the skin, leaving patients predisposed to symptoms. Many cytokines and chemokines involved in these inflammatory networks and their corresponding intracellular signaling cascades have been identified. These insights informed the development of therapies such as omalizumab, dupilumab, and Bruton's tyrosine kinase (BTK) inhibitors, marking a renewed focus on pathogenesis in CSU clinical research. Despite progress, current therapies provide symptomatic control but do not appear to redress the inflammatory balance in the skin permanently. A deeper understanding of CSU pathogenesis will permit a more targeted approach to developing novel treatments with curative intent. Here, we review what is known about the pathogenesis of CSU and consider how this can be used to identify rational targets to improve patient care further.

Evidence Gaps in Clinical Trials of Pharmacologic Treatment for H1-Antihistamine-Refractory Chronic Spontaneous Urticaria: A Systematic Review and Future Perspectives

No data addressing issues concerning disparities in participant and trial characteristics and trial outcome reporting have been established in clinical trials for H1-antihistamine-refractory chronic spontaneous urticaria (CSU). To better harmonize and compare the different treatment interventions, we systematically evaluated the overall landscape of pharmacological treatments for H1-antihistamine-refractory CSU clinical trials published between 2000 and 2021. This systematic review included 23 randomized clinical trials involving 2480 participants from 22 countries. We found significant increases in the number of globally published and newly tested drugs, especially biologic drugs. Regarding relatively small trials, we found that people living with H1-antihistamine-refractory CSU who were identified as members of minority groups (non-white population), populations of regions other than North America/Europe, and populations of low- to lower/upper-middle-income countries are underrepresented. Most trials were designed to evaluate treatment efficacy and safety profiles; however, less than half of the included trials reported the patient’s perspective in terms of patient-reported outcomes. Disparities in outcome reporting, including clinimetric tools for assessing treatment response and outcome sets, were observed. To close the evidence gap in H1-antihistamine-refractory CSU trials, strategies for improving trial and participant enrollment and standardizing core outcome sets for trial reporting are needed.

Effectiveness and Safety of Immunosuppressants and Biological Therapy for Chronic Spontaneous Urticaria: A Network Meta-Analysis

Chronic spontaneous urticaria (CSU) is the most common phenotype of chronic urticaria. We compared treatment effects and safety profiles of the medications in patients with CSU. We searched PubMed, MEDLINE, and Web of Science for randomized control trials (RCTs), from 1 January 2000 to 31 July 2021, which evaluated omalizumab and immunosuppressants. Network meta-analyses (NMAs) were performed with a frequentist approach. Outcome assessments considered the efficacy (Dermatology Life Quality Index (DLQI) and weekly urticaria activity score (UAS7)) and tolerability profiles with evaluations of study quality, inconsistencies, and heterogeneity. We identified 14 studies which we included in our direct and indirect quantitative analyses. Omalizumab demonstrated better efficacy in DLQI and UAS7 outcomes compared to a placebo, and UAS7 assessments also demonstrated better outcomes compared to cyclosporine. Alongside this, omalizumab demonstrated relatively lower incidences of safety concerns compared to the other immunosuppressants. Cyclosporin was also associated with higher odds of adverse events than other treatment options. Our findings indicate that omalizumab resulted in greater improvements in terms of the DLQI and UAS7 with good tolerability in CSU patients compared to the other immunosuppressants.

Taiwanese dermatological association consensus for the definition, classification, diagnosis, and management of urticaria: A 2021 update

Urticaria is a prevalent disease with substantial physical, psychological, and economic impacts. With the advent of understandings of the disease and the emerging evidence of treatments, the international guidelines for treating urticaria have been updated in recent years. In order to update the 2014 edition of the Taiwanese Dermatological Association (TDA) consensus of urticaria, a total of 17 dermatologists with extensive experience in urticaria management were invited to and attended the TDA consensus meetings. All the specific aspects of the content were approved by at least 75% of the experts in attendance. Comparing to the former edition, several substantial modifications were made. For diagnosis, D-dimer was added as the recommended routine test in patients with chronic spontaneous urticaria. For pharmacological management, treatment suggestions were simplified. The approved-dosed, the up-dosed second-generation antihistamines, omalizumab, and cyclosporine were listed as the first-line to the fourth-line treatment, respectively. In addition, the management for patients of special considerations, such as the elderly, children, and pregnant women, were all discussed and mentioned in the consensus. We hope the updated TDA consensus can serve as a reference for all physicians and can help the physicians providing up-to-dated managements for these patients.

The Potential Role of Basophils in Urticaria

Urticaria is a symptom of acute skin allergies that is not clearly understood, but mast cell histamine is hypothesized to cause swelling and itching. Omalizumab, an anti-human IgE antibody that traps IgE and prevents its binding to high-affinity IgE receptors, is effective in treating urticaria. We recently experienced a case of urticaria refractory to antihistamine therapy in which the peripheral-blood basophil count responded to omalizumab therapy and its withdrawal. Furthermore, the peripheral-blood basophils showed an unexpected increase in the expression of a cell surface activation marker. This phenomenon has been reported by other analyses of basophil and mast cell dynamics during omalizumab treatment. Here, we analyze these observations and formulate a hypothesis for the role of basophils in urticaria. Specifically, that activated basophils migrate to the local skin area, lowering peripheral-blood counts, omalizumab therapy alters basophilic activity and causes their stay in the peripheral blood. We hope that our analysis will focus urticaria research on basophils and reveal new aspects of its pathogenesis.

Role of Basophils in a Broad Spectrum of Disorders

Basophils are the rarest granulocytes and have long been overlooked in immunological research due to their rarity and similarities with tissue-resident mast cells. In the last two decades, non-redundant functions of basophils have been clarified or implicated in a broad spectrum of immune responses, particularly by virtue of the development of novel analytical tools for basophils. Basophils infiltrate inflamed tissues of patients with various disorders, even though they circulate in the bloodstream under homeostatic conditions. Depletion of basophils results in the amelioration or exaggeration of inflammation, depending on models of disease, indicating basophils can play either beneficial or deleterious roles in a context-dependent manner. In this review, we summarize the recent findings of basophil pathophysiology under various conditions in mice and humans, including allergy, autoimmunity, tumors, tissue repair, fibrosis, and COVID-19. Further mechanistic studies on basophil biology could lead to the identification of novel biomarkers or therapeutic targets in a broad range of diseases.

Rapid Disease Control in First-Line Therapy-Resistant Mucous Membrane Pemphigoid and Bullous Pemphigoid with Omalizumab as Add-On Therapy: A Case Series Of 13 Patients

The role of IgE autoantibodies has been demonstrated in the pathogenesis of bullous pemphigoid for many years. Recently, omalizumab (OMZ), a humanized monoclonal anti-IgE antibody that depletes total serum IgE, has been used off-label in a few case series of bullous pemphigoids demonstrating a rapid efficacy and allowing significant improvements or complete remission as add-on therapy in first-line treatment-resistant patients. Herein, we report the largest retrospective study to evaluate OMZ effectiveness in patients with subepidermal autoimmune blistering diseases. Our series included 13 patients from a single center with bullous pemphigoid or mucous membrane pemphigoid, of whom 7 had mucous membrane involvement. OMZ was added to the unchanged immunosuppressive therapies. Detailed clinical and immunological data during the first year were collected, notably for specific anti-BP180-NC16A IgE and IgG, and the median total follow-up was 30 months (range: 3-81). Our series demonstrated that OMZ induced a significant improvement in pruritus, urticarial score, and daily blister count on day 15, allowing disease control to be achieved in a 1-month median time and complete remission (CR) in a 3-month median time in 85% of these patients previously in therapeutic impasse. At the end of the follow-up, 31% of patients achieved CR on minimal therapy after OMZ weaning without relapses, and 54% achieved CR on OMZ continuation with a minimal dose of concomitant treatment. Two patients experienced therapeutic failure (15%). At baseline, clinical variables reflecting activity were significantly positively correlated with eosinophil blood count, total IgE serum level, specific anti-BP180 IgE and IgG. While baseline anti-BP180 IgG and specific anti-BP180 IgE were significantly positively correlated, only the two patients who experienced a therapeutic failure with OMZ did not fit with this correlation, demonstrating elevated levels of anti-BP180 IgG with no measurable BP180-specific IgE. Follow-up of immunological variables demonstrated a rapid decrease of eosinophilia towards normalization, whereas a slower decline towards negativation was observed over 1 year for anti-BP180 IgG and anti BP180 IgE in patients who responded to OMZ. This case series demonstrated that OMZ is a rapidly effective biologic therapy for refractory bullous pemphigoid and mucous membrane pemphigoid, permitting rapid disease control and reduction of concomitant therapeutics.

Omalizumab for the Treatment of Bullous Pemphigoid: A Systematic Review of Efficacy and Safety

Bullous pemphigoid (BP) is an autoimmune blistering skin disease. Current treatment strategies are limited by their efficacy and/or side effect profile and the need for safer and effective alternatives is undeniable. We aimed to conduct a systematic review focusing on the efficacy and safety of omalizumab in BP patients. Embase, PubMed, Cochrane, and clinicaltrials.gov were searched for English and French articles published from inception to July 1, 2021, using search terms "omalizumab" OR "Xolair" OR "IGE025" OR "olizumab" AND "bullous pemphigoid." Screening and data extraction was performed by two raters independently. The primary outcome was complete response (CR), and secondary outcomes were partial response (PR), flare-ups, adverse events/vital status. In total, 22 articles were included, with a total of 56 patients. All patients had a refractory BP with mean disease duration of 13.5 ± 20.2 months (Standard Deviation (SD)) and failed 3.1 ± 1.6 therapies and many remained corticosteroids dependent. Overall, 87.5% of patients responded to treatment (55.4% CR and 32.1% PR), 7.1% discontinued the protocol and only 5.4% were non responders. A third of patients were able to discontinue all other therapies and most others were able to discontinue or taper systemic corticosteroids to <10 mg daily. Flare-ups occurred in 57.7% of patients upon discontinuation of omalizumab and/or steroid tapering, most patients recaptured response thereafter. Omalizumab was well tolerated by most patients. Omalizumab appears to be a promising treatment for BP with a good response rate and safety profile. However, several limitations were identified in current literature, and highlight the need for randomized controlled trials of omalizumab in BP.

Emerging treatments for chronic urticaria

INTRODUCTION

Across the globe, chronic urticaria (CU), i.e. chronic spontaneous urticaria (CSU) and chronic inducible urticaria (CINDU), is common, long-persisting and difficult to manage. Still, at least one-fifth is not sufficiently controlled by guideline-recommended treatment with H1-antihistamines and add-on therapy with the anti-IgE monoclonal antibody omalizumab.

AREAS COVERED

Using PubMed, ClinicalTrials.gov, Congress websites, and websites of the manufacturers, this review explored the pipeline, namely anti-IgE-, anti-cytokine-, anti-receptor biologics, and small molecules, in clinical development for CU.

EXPERT OPINION

The CU pipeline is promising. While three omalizumab biosimilars are investigated, the assumed early approval of ligelizumab will expand the effective and safe anti-IgE approach observed with omalizumab. For other anti-IgEs like UB-221, the development is behind. Data are too limited so far to clearly define the role of anti-cytokine and anti-cytokine receptor biologics such as dupilumab, tezepelumab, mepolizumab, benralizumab, and CDX-0159, of which only dupilumab is actually investigated in phase 3. Among three selective oral BTK inhibitors, remibrutinib, rilzabrutinib, and fenebrutinib, the development of remibrutinib is most advanced (phase 3). As the pipeline addresses different targets, study results will give deeper insights into the pathomechanisms of CU. Hopefully, in the next future additional approved and also more targeted approaches will be available.

IgE and high-affinity IgE receptor in chronic inducible urticaria, pathogenic, and management relevance

BACKGROUND

IgE and high-affinity IgE receptor (FcεRI) expression on basophils have been scarcely explored in patients with chronic inducible urticaria (CIndU).

OBJECTIVES

To investigate baseline serum IgE and FcεRI expression on blood basophils in a large cohort of CIndU patients and its relationship to treatment response.

METHODS

Baseline total serum IgE and basophil FcεRI expression measured by flow cytometry in 165 patients with CIndU was studied. The relationship of both parameters with the response to antihistamine and anti-IgE (omalizumab) treatment was considered in a subsample of CIndU patients. FcεRI expression in basophils was assessed by mean fluorescence intensity (MFI) and basophil FcεRI standardized density (receptors/cell).

RESULTS

The median FcεRI expression standardized per density in blood basophils was found significantly higher in patients with CIndU compared to HCs. A positive correlation was found between IgE serum levels and basophil FcεRI expression. Basal FcεRI expression was not related to antihistamine treatment response. However, it was related to omalizumab, and patients responding to omalizumab showed higher basal basophil expression of FcεRI levels. Non-responders to the antihistamine showed significantly higher IgE serum levels.

CONCLUSIONS

FcεRI receptor overexpression in patients with CIndU shows almost the same pattern than chronic spontaneous urticaria. It seems to be independent of CIndU subtypes. Although additional studies would be welcome, our work highlights the relevance of FcεRI receptor regulation in CIndU supporting autoimmune basophil and mast cell activation and may be a biomarker for response to anti-IgE therapy.

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

Chronic spontaneous urticaria (CSU) imposes a significant burden on patients, families and healthcare systems. Management is difficult, due to disease heterogeneity and insufficient efficacy of classical drugs such as H₁ R-antihistamines. Better understanding of the mechanisms has enabled a stratified approach to the management of CSU, supporting the use of targeted treatment with omalizumab. However, many practical issues including selection of responders, the definition of response, strategies to enhance the responder rate, the duration of treatment and its regimen (in the clinic or home-based) and its cost-effectiveness still require further clarification. The EAACI Guidelines on the use of omalizumab in CSU follow the GRADE approach in formulating recommendations for each outcome. In addition, future therapeutic approaches and perspectives as well as research priorities are discussed.

Evaluation of Pharmacologic Treatments for H1 Antihistamine-Refractory Chronic Spontaneous Urticaria: A Systematic Review and Network Meta-analysis

Importance

The comparative benefits and harms of all available treatments for H1 antihistamine-refractory chronic spontaneous urticaria (CSU) have not been established.

Objective

To evaluate different treatment effects of pharmacologic treatments among patients with H1 antihistamine-refractory CSU.

Data Sources

Searches were conducted of MEDLINE, Embase, PubMed, Cochrane Library, Web of Science, Scopus, and CINAHL from inception to April 19, 2021, with no language restrictions. Gray literature from Google Scholar, ongoing trial registers, and preprint reports was added to the searches of electronic databases.

Study Selection

Randomized clinical trials using validated measurement tools that investigated the benefits and harms of pharmacologic treatments among adolescent or adult patients with CSU who had an inadequate response to H1 antihistamines were screened for inclusion independently by 2 investigators.

Data Extraction and Synthesis

Two investigators independently extracted study data according to the predefined list of interests. A random-effects model was used to calculate the network estimates reported as standardized mean differences and odds ratios with corresponding 95% CIs.

Main Outcomes and Measures

The primary outcomes that reflect the patient's perspective included changes in urticaria symptoms from baseline and unacceptability of treatment (all-cause dropouts).

Results

Twenty-three randomized clinical trials with 2480 participants that compared 18 different interventions or dosages and placebo were included. The standardized mean differences for change in urticaria symptoms were -1.05 (95% CI, -1.37 to -0.73) for ligelizumab, 72 mg; -1.07 (95% CI, -1.39 to -0.75) for ligelizumab, 240 mg; -0.77 (95% CI, -0.91 to -0.63) for omalizumab, 300 mg; and -0.59 (95% CI, -1.10 to -0.08) for omalizumab, 600 mg. No significant differences in treatment unacceptability were observed. With respect to benefits and harms, the network estimates illustrated that the most efficacious treatments were achieved with ligelizumab, 72 or 240 mg (large beneficial effect) and omalizumab, 300 or 600 mg (moderate beneficial effect).

Conclusions and Relevance

The findings in this meta-analysis suggest that the biologic agents ligelizumab, 72 or 240 mg, and omalizumab, 300 or 600 mg, can be recommended as effective treatments for patients with CSU who have had an inadequate response to H1 antihistamines. Head-to-head trials with high methodologic quality and harmonized design and outcome definitions are needed to help inform subsequent international guidelines for the management of CSU.

The Classification, Pathogenesis, Diagnostic Workup, and Management of Urticaria: An Update

Wheals and angioedema are the signature signs of urticaria, and itch is the key symptom. Urticaria, in most patients, is acute and resolves within days (acute urticaria, AU). Chronic urticaria (CU) can be of long duration and results not only in severely impaired quality of life but also has a socioeconomic impact due to work productivity impairment. In some patients with CU, the wheals and angioedema are induced exclusively by defined and definite triggers (chronic inducible urticaria, CIndU). In most patients with CU, wheals and angioedema develop unprompted, spontaneously (chronic spontaneous urticaria, CSU). The management of CU aims for the complete control and absence of its signs and symptoms. This is achieved, in most patients, by prophylactic treatment until spontaneous remission occurs. Modern, second-generation H1-antihistamines are the first-line therapy, with the option of updosing to fourfold, and omalizumab is used when this fails.

Basophils and their effector molecules in allergic disorders

Basophils are the rarest granulocytes which represent <1% of peripheral blood leukocytes. Basophils bear several phenotypic similarities to tissue-resident mast cells and therefore had been erroneously considered as blood-circulating mast cells. However, recent researches have revealed that basophils play nonredundant roles in allergic inflammation, protective immunity against parasitic infections and regulation of innate and acquired immunity. Basophils are recruited to inflamed tissues and activated in an IgE-dependent or IgE-independent manner to release a variety of effector molecules. Such molecules, including IL-4, act on various types of cells and play versatile roles, including the induction and termination of allergic inflammation and the regulation of immune responses. Recent development of novel therapeutic agents has enabled us to gain further insights into basophil biology in human disorders. In this review, we highlight the recent advances in the field of basophil biology with a particular focus on the role of basophils in allergic inflammation. Further studies on basophils and their effector molecules will help us identify novel therapeutic targets for treating allergic disorders.

The efficacy of omalizumab treatment in chronic spontaneous urticaria is associated with basophil phenotypes

BACKGROUND

The mechanisms underlying disease pathogenesis in chronic spontaneous urticaria (CSU) and improvement with omalizumab are incompletely understood.

OBJECTIVES

This study sought to examine whether the rate of clinical remission is concordant with baseline basophil features or the rate of change of IgE-dependent functions of basophils and/or plasmacytoid dendritic cells during omalizumab therapy.

METHODS

Adults (n = 18) with refractory CSU were treated with omalizumab 300 mg monthly for 90 days. Subjects recorded daily urticaria activity scores, and clinical assessments with blood sampling occurred at baseline and on days 1, 3, 6, 10, 20, 30, 60, and 90 following omalizumab. At baseline, subjects were categorized by basophil functional phenotypes, determined by in vitro histamine release (HR) responses to anti-IgE antibody, as CSU-responder (CSU-R) or CSU-non-responder (CSU-NR), as well as basopenic (B) or nonbasopenic (NB).

RESULTS

CSU-R/NB subjects demonstrated the most rapid and complete symptom improvement. By day 6, CSU-R/NB and CSU-NR/NB had increased anti-IgE-mediated basophil HR relative to baseline, and these shifts did not correlate with symptom improvement. In contrast, CSU-NR/B basophil HR did not change during therapy. The kinetics of the decrease in surface IgE/FcεRI was similar in all 3 phenotypic groups and independent of the timing of the clinical response. Likewise, plasmacytoid dendritic cells' surface IgE/FcεRI decline and TLR9-induced IFN-α responses did not reflect clinical change.

CONCLUSIONS

Changes in basophil IgE-based HR, surface IgE, or FcεRI bear no relationship to the kinetics in the change in clinical symptoms. Baseline basophil count and basophil functional phenotype, as determined by HR, may be predictive of responsiveness to omalizumab.

Biologics for the Use in Chronic Spontaneous Urticaria: When and Which

Guidelines for the treatment of chronic spontaneous urticaria (CSU) recommend the use of the IgE-targeted biologic omalizumab in patients with antihistamine-refractory disease. The rationale for this is supported by the key role of IgE and its high-affinity receptor, FcεRI, in the degranulation of skin mast cells that drives the development of the signs and symptoms of CSU, itchy wheals, and angioedema. Here, we review the current understanding of the pathogenesis of CSU and its autoimmune endotypes. We describe the mechanisms of action of omalizumab, the only biologic currently approved for CSU, its efficacy and ways to improve it, biomarkers for treatment response, and strategies for its discontinuation. We provide information on the effects of the off-label use, in CSU, of biologics licensed for the treatment of other diseases, including dupilumab, benralizumab, mepolizumab, reslizumab, and secukinumab. Finally, we discuss targets for novel biologics and where we stand with their clinical development. These include IgE/ligelizumab, IgE/GI-310, thymic stromal lymphopoietin/tezepelumab, C5a receptor/avdoralimab, sialic acid-binding Ig-like lectin 8/lirentelimab, CD200R/LY3454738, and KIT/CDX-0159. Our aim is to provide updated information and guidance on the use of biologics in the treatment of patients with CSU, now and in the near future.

Effects of a topical treatment with spleen tyrosine kinase inhibitor in healthy subjects and patients with cold urticaria or chronic spontaneous urticaria: Results of a phase 1a/b randomised double-blind placebo-controlled study

AIMS

To explore the safety, tolerability, pharmacokinetics and pharmacodynamics (PD) of GSK2646264 using skin challenge models.

METHODS

Healthy volunteers (HV) with a positive allergen skin prick test received GSK2646264 (0.5% or 1% ww) and placebo creams on up to 10% body surface area (BSA). Cold (ColdU) or chronic spontaneous (CSU) urticaria patients received 1% GSK2646264 or placebo on up to 10% BSA. PD assessments included weal characteristics after skin allergen challenge, critical temperature threshold (CTT) in ColdU patients and defined area urticaria activity score in CSU patients.

RESULTS

Thirty-four patients were randomised (17 HV, 12 ColdU, 5 CSU). Topical application of GSK2646264 and placebo was well tolerated. Systemic pharmacokinetics (AUC [0-24] h*ng/mL) was similar between HVs (Geomean 97.9 [%CV 37]) and ColdU patients (Geomean 68.2 [%CV 14; 3.5% BSA] or 167 [%CV 120; 10% BSA]). Whilst in HVs a similar reduction in skin allergen challenge weal area was observed following 3 applications of GSK2646264 and placebo, a trend towards a greater reduction was seen in ColdU with GSK2646264 compared to placebo. A clinically meaningful reduction in CTT, in ColdU patients treated with GSK2646264, was observed in 4 of 9 patients, who demonstrated either a complete inhibition of ColdU to ≤4°C (n = 2) or partial response (reduction by >4°C, n = 2). Due to the small number of CSU patients recruited, no meaningful conclusions could be drawn from the defined area urticaria activity score PD endpoint.

CONCLUSION

This Phase 1/1b study confirms that GSK2646264 cream applied topically penetrates the skin and some reduction in CTT was observed. (NCT02424799).

Urticaria as a manifestation of hyperthyroidism

In clinically euthyroid patients presenting with urticaria, a trial period of withholding antithyroid medications can be exercised. In clinically hyperthyroid patients, antithyroid medications may be stopped with close observation of response.

Non-IgE-mediated anaphylaxis

Anaphylaxis is a rapidly evolving, acute, life-threatening reaction that occurs rapidly on contact with a trigger. Anaphylaxis is classically defined as an allergen-driven process that induces specific IgE and the activation of mast cells and basophils through the cross-linking of IgE receptors. However, it is clear that non-IgE-mediated pathways can induce symptoms indistinguishable from those of classic anaphylaxis, and their activation could explain the severity of IgE-mediated anaphylaxis. Indeed, mast cells and basophils can be activated by antibodies against IgE or their receptors, by molecules such as anaphylatoxins, or through G-coupled receptors. Some other allergens can induce antibodies of class IgG that can activate neutrophils to produce a molecule similar to histamine to induce anaphylaxis. Finally, some inflammatory mediators such as bradykinin or prostaglandin can also modulate mast cell and basophil activation as well as directly cause vasodilation and bronchoconstriction, resulting in anaphylaxis-like reactions.

What is the contribution of IgE to nasal polyposis?

Taking a novel approach, this narrative review collates knowledge about nasal polyposis and the biological functions of IgE in several diseases (allergic rhinitis, allergic asthma, nonsteroidal anti-inflammatory drugs-exacerbated respiratory disease, and chronic spontaneous urticaria) to consider which IgE-mediated mechanisms are relevant to nasal polyposis pathology. A type 2 eosinophil-dominated inflammatory signature is typical in nasal polyp tissue of European patients with nasal polyposis, with a shift toward this endotype observed in Asian populations in recent years. Elevated polyclonal IgE is present in the nasal tissue of patients with and without allergy. It is derived from many different B-cell clones and, importantly, is functional (proinflammatory). Staphylococcus aureus enterotoxins are thought to act as superantigens, inducing production of polyclonal IgE via B-cell and T-cell activation, and triggering release of inflammatory mediators. In some patients, exposure to antigens/triggers leads to production of high levels of antigen-specific IgE, which mediates cross-linking of the high-affinity IgE receptor on various cells, causing release of inflammatory mediators. The efficacy of omalizumab confirms IgE as an important inflammatory mediator in nasal polyposis. By blocking IgE, omalizumab targets the T2 inflammation in nasal polyposis, reduces nasal polyp score and improves symptoms.

Response of peripheral blood basophils in subjects with chronic spontaneous urticaria during treatment with omalizumab

BACKGROUND

Treatment of patients with asthma or food allergy with omalizumab results in several consistent changes in circulating basophils. The multiple basophil phenotypes observed in patients with chronic spontaneous urticaria (CSU) present some unique attributes that may not respond in a similar fashion to patients with asthma or food allergy. As part of a clinical study on the therapeutic outcomes of omalizumab treatment in CSU, the basophil compartment was examined for changes in characteristics predicted by prior studies.

OBJECTIVE

This study sought to examine the changes in basophil function and its relationship to auto-antibodies in serum during treatment with omalizumab.

METHODS

At multiple time points before and during omalizumab treatment of patients with CSU, basophil surface IgE and FcεRI expression, cellular spleen tyrosine kinase (SYK) expression, IgE-mediated histamine release (HR), and the presence of auto-antibodies in serum were determined.

RESULTS

Three basophil phenotypes were enumerated in the clinical study and used to group results in this basophil study: subjects with (1) basopenia, (2) normal basophil numbers with normal IgE-mediated HR, and (3) normal basophil numbers with poor HR. Basopenia was highly associated with the presence of auto-antibodies to unoccupied FcεRI and basophil numbers did not change during treatment. Likewise, subjects who are basopenic showed no changes in SYK expression or HR during treatment. In basophils of subjects who are nonbasopenic, increases in SYK expression and HR showed the expected inverse relationship to starting SYK and HR levels. Treatment with omalizumab resulted in similar kinetics for decreases in surface FcεRI and IgE in all 3 groups.

CONCLUSIONS

A unifying interpretation of the results revolves around the presence of auto-antibodies to FcεRI in CSU. If present, basopenia and an absence of changes in basophils during omalizumab treatment are observed. If auto-antibodies are absent, the changes in the basophil compartment are consistent with prior studies of asthma and food allergy. These group differences also are related to efficacy of the treatment for clinical outcomes, as found in the parent clinical study.

Aripiprazole as a Candidate Treatment of COVID-19 Identified Through Genomic Analysis

Background: Antipsychotics modulate expression of inflammatory cytokines and inducible inflammatory enzymes. Elopiprazole (a phenylpiperazine antipsychotic drug in phase 1) has been characterized as a therapeutic drug to treat SARS-CoV-2 infection in a repurposing study. We aim to investigate the potential effects of aripiprazole (an FDA approved phenylpiperazine) on COVID-19-related immunological parameters. Methods: Differential gene expression profiles of non-COVID-19 vs. COVID-19 RNA-Seq samples (CRA002390 project in GSA database) and drug-naïve patients with non-affective psychosis at baseline and after three months of aripiprazole treatment were identified. An integrative transcriptomic analyses of aripiprazole effects on differentially expressed genes in COVID-19 patients was performed. Findings: 82 out the 377 genes (21.7%) with expression significantly altered by aripiprazole have also their expression altered in COVID-19 patients and in 93.9% of these genes their expression is reverted by aripiprazole. The number of common genes with expression altered in both analyses is significantly higher than expected (Fisher's Exact Test, two tail; p value = 3.2e-11). 11 KEGG pathways were significantly enriched with genes with altered expression both in COVID-19 patients and aripiprazole medicated non-affective psychosis patients (p adj<0.05). The most significant pathways were associated to immune responses and mechanisms of hyperinflammation-driven pathology (i.e.,"inflammatory bowel disease (IBD)" (the most significant pathway with a p adj of 0.00021), "Th1 and Th2 cell differentiation" and "B cell receptor signaling pathway") that have been also associated with COVID19 clinical outcome. Interpretation: This exploratory investigation may provide further support to the notion that a protective effect is exerted by aripiprazole (phenylpiperazine) by modulating the expression of genes that have shown to be altered in COVID-19 patients. Along with many ongoing studies and clinical trials, repurposing available medications could be of use in countering SARS-CoV-2 infection, but require further studies and trials.

IgE in the pathophysiology and therapy of food allergy

Food allergy is becoming a major public health issue, with no regulatory approved therapy to date. Food allergy symptoms range from skin rash and gastrointestinal symptoms to anaphylaxis, a potentially fatal systemic allergic shock reaction. IgE antibodies are thought to contribute importantly to key features of food allergy and anaphylaxis, and measurement of allergen-specific IgE is fundamental in diagnosing food allergy. This review will discuss recent advances in the regulation of IgE production and IgE repertoires in food allergy. We will describe the current understanding of the role of IgE and its high-affinity receptor FcεRI in food allergy and anaphylaxis, by reviewing insights gained from analyses of mouse models. Finally, we will review data derived from clinical studies of the effect of anti-IgE therapeutic monoclonal antibodies (mAbs) in food allergy, and recent insight on the efficiency and mechanisms through which these mAbs block IgE effector functions.

Omalizumab Updosing in Chronic Spontaneous Urticaria: an Overview of Real-World Evidence

Chronic spontaneous urticaria (CSU) is defined as the spontaneous development of itchy hives and/or angioedema due to known or unknown causes that last for at least 6 weeks. At any given time, CSU is believed to affect 0.5–1% of the global population. Omalizumab (a recombinant, humanized anti-immunoglobulin-E antibody) is the only approved treatment for antihistamine refractory CSU. However, ~ 30% of patients remain symptomatic at licensed doses of omalizumab 150 mg and 300 mg, even after a treatment period of over 6 months. In the recent years, there have been several studies on updosing of the drug, suggesting that the individualized approach for urticaria treatment with omalizumab is useful. In this article, we provide an overview of these studies and the real-world data on omalizumab updosing as it became necessary to obtain complete CSU symptom control in a proportion of patients. Published observational studies (from June 2003 to October 2019) on the updosing of omalizumab in CSU were identified using PubMed and Ovid databases. Reports mainly show that updosing/dose adjustment evaluated with the assessment of disease activity (Urticaria Activity Score) and control (Urticaria Control Test) achieves better clinical response to omalizumab with a good safety profile in a pool of patients with CSU. These real-world data will provide an overview of updosing of omalizumab in CSU and aid in setting informed clinical practice treatment expectations.

Efficacy and safety of treatment with omalizumab for chronic spontaneous urticaria: A systematic review for the EAACI Biologicals Guidelines

This systematic review evaluates the efficacy and safety of omalizumab for chronic spontaneous urticaria (CSU). PubMed, Embase, and Cochrane Library were searched for RCTs. Critical and important CSU-related outcomes were considered. The risk of bias and the certainty of the evidence were assessed using GRADE. Ten RCTs including 1620 subjects aged 12 to 75 years old treated with omalizumab for 16 to 40 weeks were evaluated. Omalizumab 150 mg does not result in clinically meaningful improvement (high certainty) of the urticaria activity score (UAS)7 (mean difference (MD) -5; 95%CI -7.75 to -2.25), and the itch severity score (ISS)7 (MD -2.15; 95% CI -3.2 to -1.1) does not increase (moderate certainty) quality of life (QoL) (Dermatology Life Quality Index (DLQI); MD -2.01; 95%CI -3.22 to -0.81) and decreases (moderate certainty) rescue medication use (MD -1.68; 95%CI -2.95 to -0.4). Omalizumab 300 mg results in clinically meaningful improvements (moderate certainty) of the UAS7 (MD -11.05; 95%CI -12.87 to -9.24), the ISS7 (MD -4.45; 95%CI -5.39 to -3.51), and QoL (high certainty) (DLQI; MD -4.03; 95% CI -5.56 to -2.5) and decreases (moderate certainty) rescue medication use (MD -2.04; 95%CI -3.19 to -0.88) and drug-related serious AEs (RR 0.77; 95%CI 0.20 to 2.91).

Increased serum IL-31 levels in chronic spontaneous urticaria and psoriasis with pruritic symptoms

Background

Chronic spontaneous urticaria (CSU) is a common pruritic skin condition, the pathogenesis of which remains unclear. Interleukin-31 (IL-31) is a major pruritogenic cytokine that plays a role in inducing pruritus in various skin diseases.

Aim.

To 1) compare serum IL-31 levels among CSU patients, psoriasis patients with pruritic symptoms, and healthy subjects, 2) examine the correlations between serum IL-31 levels and disease severity, and 3) compare IL-31 levels in patients with and without CSU-associated auto-antibodies.

Methods

Patients with CSU, psoriasis with pruritic symptoms, and healthy volunteers were recruited in the study. Serum IL-31 levels were measured with commercial kits. Baseline characteristics, urticaria activity score, psoriasis area severity index, pruritic intensity score, and related laboratory results were collected.

Results

Sixty-five CSU patients, 30 psoriasis patients who had pruritus, and 31 healthy subjects participated in our study. The CSU patients had significantly higher mean serum IL-31 levels than the psoriasis patients (252.4 ± 115.5 vs 121.4 ± 16.6 pg/mL, P < 0.001). Both CSU and psoriasis patients also had significantly higher mean serum IL-31 when compared with the healthy subjects. Serum IL-31 levels of CSU and psoriasis patients did not differ significantly according to disease or itching severity. Thyroid antibodies and antinuclear antibodies were positive in 22 (33.8%) and 28 (43.1%) CSU patients, respectively. The CSU patients with ANA titers ≥1:160 had significantly higher mean serum IL-31 levels than in those who were negative for ANA and those with titers of 1:80 (P < 0.003 and P < 0.008, respectively).

Conclusion

Higher serum IL-31 levels were found in patients with CSU and psoriasis with pruritic symptoms. This suggests that IL-31 has a possible role in the pathogenesis of CSU and psoriasis with pruritic symptoms.

Effects of omalizumab on basophils: Potential biomarkers in asthma and chronic spontaneous urticaria

Omalizumab is an anti-IgE humanized monoclonal antibody approved for the treatment of severe asthma and chronic spontaneous urticaria. Omalizumab binds free serum IgE and antagonizes its interaction with FcεRI, which is considered the main pharmacodynamic mechanism responsible for the clinical response to the treatment. The reduction of IgE serum concentration down-regulates the cellular expression of FcεRI on basophils. However, the biological events occurring on basophils during the therapy with omalizumab are multiple and complex. Here we review the current evidence regarding the specific biological effects of omalizumab on basophils in patients with asthma and chronic spontaneous urticaria. In addition to the modulation of IgE receptors, omalizumab may affect basophils homeostasis, intra-cellular signaling, cellular responsiveness/activation and cytokine release. These effects may be partially responsible for the clinical success of omalizumab and potentially provide useful biological markers for future assessment of the clinical response to the treatment. However, further investigation is required to better elucidate the role of basophils during the treatment with omalizumab.

Current and Potential Biologic Drugs for the Treatment of Chronic Urticaria

This article reviews biologic treatments that are currently applied for the treatment of severe chronic urticaria. Monoclonal anti-immunoglobulin E (omalizumab) is effective and safe in many patients, but accessibility and cost constitute barriers to its wider use. Questions on the optimal duration of the treatment and possible symptom recurrences after discontinuing the drug are still raised. A discussion is presented about several other biologics currently under investigation with potential to be incorporated in the near future in patients with severe chronic urticaria.

Paeoniflorin inhibits IgE-mediated allergic reactions by suppressing the degranulation of mast cells though binding with FcϵRI alpha subunits

Paeoniflorin (PF), a monoterpene glycoside isolated from the aqueous extract of the Chinese herb Radix Paeoniae Alba, has been used for treating various inflammatory diseases. In this study, we aimed to investigate the anti-allergic activities of PF. The anti-anaphylactic activity of PF was investigated using mast cell (MC) degranulation assay as well as Ca²⁺ influx in vitro and skin swelling and extravasation assays in vivo. The results showed that PF inhibited MC degranulation (histamine release from 74.5 ± 4.95 ng/ml to 58.7 ± 6.06 ng/ml) and Ca²⁺ influx challenged by DNP-BSA in vitro. In addition, PF reduced the degree of swelling and Evans blue exudation in mice paws. Furthermore, PF dose-dependently reduced serum inflammatory mediator release in mice sensitized with ovalbumin for 48 h by inhibiting MC degranulation. Molecular docking study revealed that PF bound better with the α subunit of FcϵRI than with the β subunit. SPR revealed that PF had a strong affinity interaction with FcϵRI α subunit and the K_D value was (7.08 ± 0.97) e-6 M. Our findings revealed that PF inhibited anaphylactic responses in vivo and in vitro, and it can be considered a novel FcϵRI inhibitor for preventing MC-related allergic diseases.

Presence of positive skin prick tests to inhalant allergens and markers of T2 inflammation in subjects with chronic spontaneous urticaria (CSU): a systematic literature review

BACKGROUND

Current guidelines do not recommend performing aeroallergen skin prick testing (SPT) in chronic spontaneous urticaria (CSU).

OBJECTIVE

The objective of this review was to investigate the presence of aeroallergen sensitization and markers of T2 inflammation in subjects with CSU.

METHODS

Systematic literature reviews to identify all studies that evaluated the presence of T2 markers of allergic inflammation in CSU subjects were performed.

RESULTS

In 16 studies that assessed the prevalence of positive SPT to multiple aeroallergens in CSU, 38.5% of CSU subjects had positive SPT. In three controlled studies, 34.2% of CSU subjects had positive SPT to multiple aeroallergens, compared to 13.6% of controls (p = 0.047). In 18 studies that assessed the prevalence of house dust mite (HDM) positive SPT in CSU, 27.5% of CSU subjects had positive SPT. In three controlled studies, 27.5% of CSU subjects had positive SPT to HDM, compared to 2.1% of controls (p = 0.047). Overall, CSU subjects were 3.1 times more likely to be aeroallergen-sensitized (95% CI 1.7-5.8, p = 0.0002) and 6.1 times more likely to be HDM-sensitized (95% CI 3.7-9.9, p < 0.00001) than controls. Mean total serum IgE (tIgE) levels were 238 kU/L and median tIgE levels were 164 kU/L, which was greater than the upper 90th percentile of normal (< 137 kU/L). Compared to healthy controls, CSU subjects were 6.5 times more likely to have IgG autoantibody against FcεR1α (p = 0.001), 2.4 times more likely to have IgG anti-IgE antibody (p = 0.03) and 5 times more likely to have anti-thyroid peroxidase (anti-TPO) antibody (p = 0.02). When corticosteroids were withheld for ≥ 28 days, mean blood eosinophil percentage was elevated at 5.9% (normal < 4%), but other studies reporting absolute count found the mean was in the normal range, 239 × 10 6 / L (normal < 400 × 10 6 / L).

CONCLUSION

Increased aeroallergen sensitization, tIgE, autoantibodies and blood eosinophil percentage in the CSU subjects indicates the possible importance of T2 inflammation in the pathogenesis of CSU. Further studies may be warranted to determine if specific allergen avoidance, desensitization or improvement in the mucosal allergic inflammation present in asthma and/or rhinitis has any benefit in the management of CSU.