Oral Sebetralstat for On-Demand Treatment of Hereditary Angioedema Attacks.

BACKGROUND: Approved on-demand treatments for hereditary angioedema attacks need to be administered parenterally, a route of administration that is associated with delays in treatment or withholding of therapy. METHODS: In this phase 3, double-blind, three-way crossover trial, we randomly assigned participants at least 12 years of age with type 1 or type 2 hereditary angioedema to take up to two oral doses of sebetralstat (300 mg or 600 mg) or placebo for an angioedema attack. The primary end point, assessed in a time-to-event analysis, was the beginning of symptom relief, defined as a rating of "a little better" on the Patient Global Impression of Change scale (ratings range from "much worse" to "much better") at two or more consecutive time points within 12 hours after the first administration of the trial agent. Key secondary end points, assessed in a time-to-event analysis, were a reduction in attack severity (an improved rating on the Patient Global Impression of Severity [PGI-S] scale, with ratings ranging from "none" to "very severe") at two or more consecutive time points within 12 hours and complete attack resolution (a rating of "none" on the PGI-S scale) within 24 hours. RESULTS: A total of 136 participants were assigned to one of six trial sequences, with 110 treating 264 attacks. The time to the beginning of symptom relief with the 300-mg dose and the 600-mg dose was faster than with placebo (P<0.001 and P = 0.001 for the two comparisons, respectively), with median times of 1.61 hours (interquartile range, 0.78 to 7.04), 1.79 hours (1.02 to 3.79), and 6.72 hours (1.34 to >12), respectively. The time to reduction in the attack severity with the 300-mg dose and the 600-mg dose was faster than with placebo (P = 0.004 and P = 0.003), with median times of 9.27 hours (interquartile range, 1.53 to >12), 7.75 hours (2.19 to >12), and more than 12 hours (6.23 to >12). The time to complete resolution was faster with the 300-mg and 600-mg doses than with placebo (P = 0.002 and P<0.001). The percentage of attacks with complete resolution within 24 hours was 42.5% with the 300-mg dose, 49.5% with the 600-mg dose, and 27.4% with placebo. Sebetralstat and placebo had similar safety profiles; no serious adverse events related to the trial agents were reported. CONCLUSIONS: Oral sebetralstat provided faster times to the beginning of symptom relief, reduction in attack severity, and complete attack resolution than placebo. (Funded by KalVista Pharmaceuticals; KONFIDENT ClinicalTrials.gov number, NCT05259917; EudraCT number, 2021-001226-21.).

Untimely TGFß responses in COVID-19 limit antiviral functions of NK cells.

SARS-CoV-2 is a single-stranded RNA virus that causes COVID-19. Given its acute and often self-limiting course, it is likely that components of the innate immune system play a central part in controlling virus replication and determining clinical outcome. Natural killer (NK) cells are innate lymphocytes with notable activity against a broad range of viruses, including RNA viruses1,2. NK cell function may be altered during COVID-19 despite increased representation of NK cells with an activated and adaptive phenotype3,4. Here we show that a decline in viral load in COVID-19 correlates with NK cell status and that NK cells can control SARS-CoV-2 replication by recognizing infected target cells. In severe COVID-19, NK cells show defects in virus control, cytokine production and cell-mediated cytotoxicity despite high expression of cytotoxic effector molecules. Single-cell RNA sequencing of NK cells over the time course of the COVID-19 disease spectrum reveals a distinct gene expression signature. Transcriptional networks of interferon-driven NK cell activation are superimposed by a dominant transforming growth factor-ß (TGFß) response signature, with reduced expression of genes related to cell-cell adhesion, granule exocytosis and cell-mediated cytotoxicity. In severe COVID-19, serum levels of TGFß peak during the first two weeks of infection, and serum obtained from these patients severely inhibits NK cell function in a TGFß-dependent manner. Our data reveal that an untimely production of TGFß is a hallmark of severe COVID-19 and may inhibit NK cell function and early control of the virus.

Chronic urticaria: unmet needs, emerging drugs, and new perspectives on personalised treatment.

Chronic urticaria is a common and debilitating mast cell-driven skin disease presenting with itchy wheals, angio-oedema, or both. Chronic urticaria is classified as spontaneous (without definite triggers) and inducible (with definite and subtype-specific triggers; eg, cold or pressure). Current management guidelines recommend step-up administration of second-generation H1-antihistamines to four-fold the approved dose, followed by omalizumab and ciclosporin. However, in many patients, chronic urticaria does not respond to this linear approach due to heterogeneous underlying mechanisms. A personalised endotype-based approach is emerging based on the identification of autoantibodies and other drivers of urticaria pathogenesis. Over the past decade, clinical trials have presented promising options for targeted treatment of chronic urticaria with the potential for disease modification, including Bruton's tyrosine kinase inhibitors, anti-cytokine therapies, and mast cell depletion. This Therapeutics article focuses on the evidence for these novel drugs and their role in addressing an unmet need for personalised management of patients with chronic urticaria.

Efficacy and safety of ligelizumab in adults and adolescents with chronic spontaneous urticaria: results of two phase 3 randomised controlled trials.

BACKGROUND: Many patients with chronic spontaneous urticaria (CSU) do not achieve complete control of their symptoms with current available treatments. In a dose-finding phase 2b study, ligelizumab improved urticaria symptoms in patients with H1-antihistamine (H1-AH) refractory CSU. Here, we report the efficacy and safety outcomes from two ligelizumab phase 3 studies. METHODS: PEARL-1 and PEARL-2 were identically designed randomised, double-blind, active-controlled and placebo-controlled parallel-group studies. Patients aged 12 years or older with moderate-to-severe H1-AH refractory CSU were recruited from 347 sites in 46 countries and randomly allocated in a 3:3:3:1 ratio via Interactive Response Technology to 72 mg ligelizumab, 120 mg ligelizumab, 300 mg omalizumab, or placebo, dosed every 4 weeks, for 52 weeks. Patients allocated to placebo received 120 mg ligelizumab from week 24. The primary endpoint was change-from-baseline (CFB) in weekly Urticaria Activity Score (UAS7) at week 12, and was analysed in all eligible adult patients according to the treatment assigned at random allocation. Safety was assessed throughout the study in all patients who received at least one dose of the study drug. The studies were registered with ClinicalTrials.gov, NCT03580369 (PEARL-1) and NCT03580356 (PEARL-2). Both trials are now complete. FINDINGS: Between Oct 17, 2018, and Oct 26, 2021, 2057 adult patients were randomly allocated across both studies (72 mg ligelizumab n=614; 120 mg ligelizumab n=616; 300 mg omalizumab n=618, and placebo n=209). A total of 1480 (72%) of 2057 were female, and 577 (28%) of 2057 were male. Mean UAS7 at baseline across study groups ranged from 29·37 to 31·10. At week 12, estimated treatment differences in mean CFB-UAS7 were as follows: for 72 mg ligelizumab versus placebo, -8·0 (95% CI -10·6 to -5·4; PEARL-1), -10·0 (-12·6 to -7·4; PEARL-2); 72 mg ligelizumab versus omalizumab 0·7 (-1·2 to 2·5; PEARL-1), 0·4 (-1·4 to 2·2; PEARL-2); 120 mg ligelizumab versus placebo -8·0 (-10·5 to -5·4; PEARL-1), -11·1 (-13·7 to -8·5; PEARL-2); 120 mg ligelizumab versus omalizumab 0·7 (-1·1 to 2·5; PEARL-1), -0·7 (-2·5 to 1·1; PEARL-2). Both doses of ligelizumab were superior to placebo (p<0·0001), but not to omalizumab, in both studies. No new safety signals were identified for ligelizumab or omalizumab. INTERPRETATION: In the phase 3 PEARL studies, ligelizumab demonstrated superior efficacy versus placebo but not versus omalizumab. The safety profile of ligelizumab was consistent with previous studies. FUNDING: Novartis Pharma.

Transcriptional licensing is required for Pyrin inflammasome activation in human macrophages and bypassed by mutations causing familial Mediterranean fever.

Pyrin is a cytosolic immune sensor that nucleates an inflammasome in response to inhibition of RhoA by bacterial virulence factors, triggering the release of inflammatory cytokines, including IL-1ß. Gain-of-function mutations in the MEFV gene encoding Pyrin cause autoinflammatory disorders, such as familial Mediterranean fever (FMF) and Pyrin-associated autoinflammation with neutrophilic dermatosis (PAAND). To precisely define the role of Pyrin in pathogen detection in human immune cells, we compared initiation and regulation of the Pyrin inflammasome response in monocyte-derived macrophages (hMDM). Unlike human monocytes and murine macrophages, we determined that hMDM failed to activate Pyrin in response to known Pyrin activators Clostridioides difficile (C. difficile) toxins A or B (TcdA or TcdB), as well as the bile acid analogue BAA-473. The Pyrin inflammasome response was enabled in hMDM by prolonged priming with either LPS or type I or II interferons and required an increase in Pyrin expression. Notably, FMF mutations lifted the requirement for prolonged priming for Pyrin activation in hMDM, enabling Pyrin activation in the absence of additional inflammatory signals. Unexpectedly, in the absence of a Pyrin response, we found that TcdB activated the NLRP3 inflammasome in hMDM. These data demonstrate that regulation of Pyrin activation in hMDM diverges from monocytes and highlights its dysregulation in FMF.

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.

Dupilumab in patients with chronic spontaneous urticaria (LIBERTY-CSU CUPID): Two randomized, double-blind, placebo-controlled, phase 3 trials.

BACKGROUND: Chronic spontaneous urticaria (CSU) is a chronic inflammatory disease characterized by recurrent pruritic wheals (hives) and/or angioedema. Patients with CSU could remain symptomatic despite standard-of-care H1 antihistamines (H1-AH) or anti-IgE (omalizumab) treatment. Dupilumab blocks IL-4/IL-13 signaling and is approved for multiple type 2/atopic indications. OBJECTIVE: We conducted two phase 3, randomized, placebo-controlled, double-blind trials comparing dupilumab with placebo in patients with symptomatic CSU despite H1-AH. METHODS: In LIBERTY-CSU CUPID Study A, patients were omalizumab-naive (n = 138, aged ≥6 years). In Study B, patients were omalizumab-intolerant/incomplete responders (n = 108, aged ≥12 years). The primary end point was either change from baseline over 7 days in the Urticaria Activity Score (UAS7) or Itch Severity Score (ISS7) at week 24, with the other as a key secondary end point, depending on regional regulatory requirements. Studies were pooled for safety assessment. RESULTS: In Study A, UAS7 and ISS7 improved with dupilumab versus placebo (difference -8.5 [95% CI, -13.2 to -3.9; P = .0003] and -4.2 [95% CI, -6.6 to -1.8; P = .0005]). In Study B, tested at α = 0.043 after interim analysis, UAS7 improved (difference -5.8 [95% CI, -11.4 to -0.3; P = .0390]), with a numerical trend in ISS7 (difference -2.9 [95% CI, -5.7 to -0.07; nominal P = .0449, not significant]). Pooled safety data were consistent between dupilumab and placebo and with the known dupilumab safety profile. CONCLUSIONS: Dupilumab reduced urticaria activity by reducing itch and hives severity in omalizumab-naive patients with CSU uncontrolled with H1-AH. Although the primary end point for Study B was not met, dupilumab effects were small in patients who were omalizumab-intolerant/incomplete responders.

An investigational oral plasma kallikrein inhibitor for on-demand treatment of hereditary angioedema: a two-part, randomised, double-blind, placebo-controlled, crossover phase 2 trial.

BACKGROUND: Guidelines recommend effective on-demand therapy for all individuals with hereditary angioedema. We aimed to assess the novel oral plasma kallikrein inhibitor, sebetralstat, which is in development, for on-demand treatment of hereditary angioedema attacks. METHODS: In this two-part phase 2 trial, individuals with type 1 or 2 hereditary angioedema aged 18 years or older were recruited from 25 sites, consisting of specialty outpatient centres, across nine countries in Europe and the USA. Individuals were eligible if they had experienced at least three hereditary angioedema attacks in the past 93 days, were not on prophylactic therapy, and had access to and the ability to self-administer conventional attack treatment. In part 1 of the trial, participants were given a single 600 mg open-label oral dose of sebetralstat to assess safety, pharmacokinetics, and pharmacodynamics of the dose. Part 2 was a randomised, double-blind, placebo-controlled, two-sequence, two-period (2 × 2) crossover trial; participants were randomly assigned (1:1) to either sequence 1, in which they were given a single dose of 600 mg of sebetralstat to treat the first eligible attack and a second dose of placebo to treat the second eligible attack, or sequence 2, in which they were given placebo to treat the first eligible attack and then 600 mg of sebetralstat to treat the second eligible attack. Participants and investigators were masked to treatment assignment. The primary endpoint was time to use of conventional attack treatment within 12 h of study drug administration, which was assessed in all participants who were randomly assigned to treatment and who received study drug for two attacks during part 2 of the study. Safety was assessed in all participants who received at least one dose of study drug, starting in part 1. This study is registered with ClinicalTrials.gov, NCT04208412, and is completed. FINDINGS: Between July 2, 2019, and Dec 8, 2020, 84 individuals were screened and 68 were enrolled in part 1 and received sebetralstat (mean age 38·3 years [SD 13·2], 37 [54%] were female, 31 [46%] were male, 68 [100%] were White). 42 (62%) of 68 participants completed pharmacokinetic assessments. Sebetralstat was rapidly absorbed, with a geometric mean plasma concentration of 501 ng/mL at 15 min. In a subset of participants (n=6), plasma samples obtained from 15 min to 4 h after study drug administration had near-complete protection from ex vivo stimulated generation of plasma kallikrein and cleavage of high-molecular-weight kininogen. In part 2, all 68 participants were randomly assigned to sequence 1 (n=34) or sequence 2 (n=34). 53 (78%) of 68 participants treated two attacks (25 [74%] in the sequence 1 group and 28 [82%] in the sequence 2 group). Time to use of conventional treatment within 12 h of study drug administration was significantly longer with sebetralstat versus placebo (at quartile 1: >12 h [95% CI 9·6 to >12] vs 8·0 h [3·8 to >12]; p=0·0010). There were no serious adverse events or adverse event-related discontinuations. INTERPRETATION: Oral administration of sebetralstat was well tolerated and led to rapid suppression of plasma kallikrein activity, resulting in increased time to use of conventional attack treatment and faster symptom relief versus placebo. Based on these results, a phase 3 trial to evaluate the efficacy and safety of two dose levels of sebetralstat in adolescent and adult participants with hereditary angioedema has been initiated (NCT05259917). FUNDING: KalVista Pharmaceuticals.

Serum TGF-ß as a predictive biomarker for severe disease and fatality of COVID-19.

For targeted intervention in coronavirus disease 2019 (COVID-19), there is a high medical need for biomarkers that predict disease progression and severity in the first days after symptom onset. This study assessed the utility of early transforming growth factor ß (TGF-ß) serum levels in COVID-19 patients to predict disease severity, fatality, and response to dexamethasone therapy. Patients with severe COVID-19 had significantly higher TGF-ß levels (416 pg/mL) as compared to patients with mild (165 pg/mL, p < 0.0001) or moderate COVID-19 (241 pg/mL; p < 0.0001). Receiver operating characteristics area under the curve values were 0.92 (95% confidence interval [CI] 0.85-0.99, cut-off: 255 pg/mL) for mild versus severe COVID-19, and 0.83 (95% CI 0.65-1.0, cut-off: 202 pg/mL) for moderate versus severe COVID-19. Patients who died of severe COVID-19 had significantly higher TGF-ß levels (453 pg/mL) as compared to convalescent patients (344 pg/mL), and TGF-ß levels predicted fatality (area under the curve: 0.75, 95% CI 0.53-0.96). TGF-ß was significantly reduced in severely ill patients treated with dexamethasone (301 pg/mL) as compared to untreated patients (416 pg/mL; p < 0.05). Early TGF-ß serum levels in COVID-19 patients predict, with high accuracy, disease severity, and fatality. In addition, TGF-ß serves as a specific biomarker to assess response to dexamethasone treatment.

Mast cell silencing: A novel therapeutic approach for urticaria and other mast cell-mediated diseases.

Chronic urticaria (CU) is a mast cell (MC)-dependent disease with limited therapeutic options. Current management strategies are directed at inhibiting IgE-mediated activation of MCs and antagonizing effects of released mediators. Due to the complexity and heterogeneity of CU and other MC diseases and mechanisms of MC activation-including multiple activating receptors and ligands, diverse signaling pathways, and a menagerie of mediators-strategies of MC depletion or MC silencing (i.e., inhibition of MC activation via binding of inhibitory receptors) have been developed to overcome limitations of singularly targeted agents. MC silencers, such as agonist monoclonal antibodies that engage inhibitory receptors (e.g., sialic acid-binding immunoglobulin-like lectin8 -[Siglec-8] [lirentelimab/AK002], Siglec-6 [AK006], and CD200R [LY3454738]), have reached preclinical and clinical stages of development. In this review, we (1) describe the role of MCs in the pathogenesis of CU, highlighting similarities with other MC diseases in disease mechanisms and response to treatment; (2) explore current therapeutic strategies, categorized by nonspecific immunosuppression, targeted inhibition of MC activation or mediators, and targeted modulation of MC activity; and (3) introduce the concept of MC silencing as an emerging strategy that could selectively block activation of MCs without eliciting or exacerbating on- or off-target, immunosuppressive adverse effects.

Efficacy and safety of on-demand versus daily rupatadine in chronic spontaneous urticaria: A randomized trial.

BACKGROUND: Non-sedating H1 -antihistamines (nsAH) are the most commonly used treatment for chronic spontaneous urticaria (CSU). Many patients use them as on-demand (OD) therapy rather than a maintenance treatment. Here, we compared OD versus daily maintenance treatment with the nsAH rupatadine, assessed the efficacy of rupatadine updosing, and investigated potential long-term disease-modifying effects. METHODS: This multicenter, randomized study consisted of 2 weeks of screening, 8 weeks of double-blind treatment, and 6 weeks of treatment-free follow-up (OD allowed). Adult patients were randomized to 10 mg rupatadine OD or 10 mg rupatadine daily. At Week 4, if patients did not have a complete response, they switched from 10 to 20 mg rupatadine daily or underwent sham updosing (patients on 10 mg rupatadine OD). The primary aim was to compare CSU disease activity at the end of follow-up between daily versus OD. Additionally, we assessed the efficacy of rupatadine updosing. Major outcomes were disease activity, CSU-related quality of life (QoL), and disease control. RESULTS: At Week 4, disease activity and QoL significantly improved in daily versus OD-treated patients. Updosing of rupatadine did not improve the mean disease activity, but the number of complete responders increased during updosing from 5% to 22%. At the end of follow-up, the disease activity of patients treated OD versus daily was not significantly different. CONCLUSIONS: Daily rupatadine treatment significantly improved CSU disease activity and QoL during treatment versus OD treatment but not after discontinuation of rupatadine, indicating the benefits of a daily maintenance nsAH schedule.

Targeting histamine receptor 4 in cholinergic urticaria with izuforant (LEO 152020): results from a phase IIa randomized double-blind placebo-controlled multicentre crossover trial.

BACKGROUND: Cholinergic urticaria (CholU) is a common subtype of chronic inducible urticaria, where signs and symptoms (e.g. pruritic wheals and angioedema) are triggered by sweating due to physical exercise, passive warming and by other sweat-inducing situations. While guidelines recommend treatment with second-generation H1 antihistamines, approximately 90% of patients report uncontrolled disease. Targeting the histamine 4 receptor (H4R) has shown promise in preclinical/clinical studies of allergic/inflammatory diseases. Izuforant (LEO 152020) is a selective oral H4R antagonist with expected dual antipruritic and anti-inflammatory effects. OBJECTIVES: To assess the effects of izuforant in adults with CholU, a common type of chronic urticaria driven by histamine and characterized by high skin levels of H4R expression. METHODS: This was a phase IIa randomized double-blind placebo-controlled multicentre crossover trial where patients with CholU with an inadequate response to ≥ 1 standard dose of H1 antihistamine received izuforant 100 mg twice daily or placebo (EUCTR2020-004961-38-DE; NCT04853992). The primary endpoint was change from baseline in Urticaria Activity Score. Exploratory endpoints included CholU activity score over 7 days, urticaria control test, Physician Global Assessment, patient global assessment of severity (PGA-S), provocation tests, Dermatology Life Quality Index and CholU quality of life (CholU-QoL). Pharmacokinetic and pharmacodynamic parameters, and serum biomarkers were assessed, as well as safety and tolerability. RESULTS: Nineteen patients were randomized and included in the full analysis set; 18 completed treatment [mean (SD) age 29.5 (9.8) years; mean (SD) CholU duration 8.0 (6.3) years]. The primary and most of prespecified exploratory endpoints were not met; there were significant improvements in PGA-S for izuforant vs. placebo (P = 0.02), and nonsignificant improvements for other endpoints in quality of life and histamine skin prick test. All adverse events (AEs) experienced with izuforant were considered mild. The most frequently reported (> 1 patient) were nausea (three patients) and upper abdominal pain (two patients), occurring more frequently with izuforant vs. placebo (one patient each). There were no treatment-related serious AEs and no patient receiving izuforant discontinued the study. Treatment with izuforant did not cause downregulation of H4R. CONCLUSIONS: This is the first study to explore the role of H4R as a therapeutic target in urticaria. Targeting H4R with izuforant was well tolerated but did not demonstrate significant improvements vs. placebo in the primary endpoint and all but one prespecified exploratory endpoint in CholU.

Cholinergic urticaria (CholU) is a common subtype of an inflammatory skin condition called chronic inducible urticaria, where signs and symptoms (e.g. hives and swelling in the skin) are triggered by sweating caused by physical exercise, passive warming and other sweat-inducing situations. While guidelines recommend treatment with second-generation H1 antihistamines (a type of medication), approximately 90% of people with the condition report that these medications do not control the disease. Targeting the histamine 4 receptor (H4R) has shown promise in studies of allergic/inflammatory diseases. CholU is driven by histamine (a chemical released in the body) and characterized by high skin levels of H4R. Izuforant is a medication that may reduce itch and inflammation. In our study, which was carried out across multiple sites in Germany, we assessed the effects of izuforant 100 mg in 18 patients with CholU using a range of measures covering symptom control, disease severity, provocation response and quality of life. The primary endpoint (the main result measured at the end of the study to see if the treatment worked) was change from baseline in the post-provocation Urticaria Activity Score, where areas of skin were provoked and the time until common symptoms of CholU appeared (sweating and whealing (hives)) was measured. Overall, the primary endpoint and most of the exploratory endpoints were not met. There were significant improvements in patients' global assessment for izuforant versus placebo. This was the first study to explore the role of H4R as a therapeutic target in urticaria. Our findings suggest that targeting H4R with izuforant was well tolerated but did not demonstrate significant improvements versus placebo in the primary endpoint, and all but one prespecified exploratory endpoint in CholU.

A Novel Method for Total IgE Purification from Human Serum.

For Ab purification, high-affinity chromatography is commonly used. This technique results in high-purity Abs, but it requires highly specific knowledge and equipment. Commercial kits for purification of IgE are not available. Therefore, we established a (to our knowledge) novel method for the purification of total IgE from human serum. Sera from 19 allergic and nonallergic patients were included. After depletion of polyclonal IgG, total serum IgE was captured using anti-human IgE Abs coupled to beads, eluted from the beads, and incubated with protein G-coupled beads to increase the final purity. Purity analysis and Ab detection were performed by Western blot. Total serum IgE and purified IgE concentrations were analyzed using ELISA. To determine their functionality, primary human mast cells were sensitized with purified IgE and activated with anti-IgE or a relevant allergen. CD63+ expression and histamine release were used as readout parameters. Concentrations of purified total IgE corresponded with the levels of total serum IgE. Minor fractions of IgE remained attached to the beads, confirming an effective elution of IgE Abs. Only minimal amounts of IgG were found in the purified IgE fractions, confirming a high purity of IgE. Mast cells sensitized with purified IgE and subsequent activation with anti-IgE Ab or a relevant allergen showed increased expression of CD63+ and increased histamine release. This (to our knowledge) novel method represents a highly effective and widely accessible approach for purification of human serum IgE, which can improve the use of IgE-based in vivo and in vitro models and contribute to allergy research.

Online Depiction of Urticaria Is Often Flawed and Does Not Reflect the Spectrum of Clinical Manifestation.

INTRODUCTION: The internet is a popular source of health information including images of disease manifestations. Online photographs of skin lesions may aid patients in identifying their disease, if these pictures are of good quality and of the disease they claim to show. If not, patients may be at risk of delayed diagnosis, misdiagnosis, and suboptimal treatment. For urticaria, the mismatch rate and quality of online pictures are unknown. The objective of this study was therefore to evaluate the content and quality of online images of urticaria. METHODS: The search term "urticaria" was applied to Google Images and Shutterstock. The top 100 photographs from each search engine were retrieved on October 9th, 2022. Illustrations, drawings, and heavily edited photographs were excluded. Each image was evaluated for patient characteristics, characteristics of urticarial lesions, and image quality. RESULTS: Across 194 unique images of urticaria (after removing duplicates), 35 (18.0%) did not depict urticarial lesions, and 38 (19.6%) were ambiguous. Less than two-thirds of images 121 (62.4%) showed bona fide urticarial lesions. Pictures of urticarial lesions under-represented children and did not reflect female preponderance of the disease. Images predominantly depicted urticaria lesions on Caucasian skin (59.8%) and were typical of spontaneous rather than inducible urticaria. Only 3 (1.5%) pictures showed angioedema, a common clinical sign in patients with urticaria. The overall quality of online urticaria pictures was mostly good or very good. CONCLUSION: Physicians and patients should be aware that one in five online pictures of urticaria does not show urticarial skin lesions, and children, females, non-Caucasian patients, inducible urticaria, and angioedema are under-represented. These findings should prompt efforts to improve the accuracy and representativeness of online urticaria pictures.

The socio-economic burden of H1-antihistamine-refractory chronic spontaneous urticaria in Germany.

BACKGROUND AND STUDY AIM: Data from the AWARE study (A Worldwide Antihistamine-Refractory chronic urticaria patient Evaluation) illustrate a substantial disease burden in German patients with H1-antihistamine (-H1-AH)-refractory chronic spontaneous urticaria (CSU). Detrimental effects on patients' quality of life, poor disease control and impairment in the ability to work and perform other daily activities are reported. Based on these findings, this study aims to quantify the epidemiological and socio-economic burden of H1-AH-refractory CSU in Germany. METHODS: To determine the epidemiological burden of H1-AH-refractory CSU, the age- and gender-specific prevalence of CSU and the proportion of H1-AH-refractory patients in Germany anonymized data from the InGef research database have been used. In a second step, the socio-economic burden in terms of lost numbers of hours in paid and unpaid work was calculated by extrapolating the age- and gender-specific work productivity and activity impairment (WPAI) observed in AWARE to the H1-AH-refractory CSU population in Germany. Finally, productivity losses in paid and unpaid work were monetized using the human capital and the friction cost approach respectively. Moreover, socio-economic burden was calculated depending on symptom control of the patients (measured by urticaria control test [UCT]). RESULTS: In Germany, over 203,000 patients (20 years or older) had H1-AH-refractory CSU in 2018. The avoided lost paid and unpaid work hours attributable to H1-AH-refractory CSU summed up to over 100 million. Overall, the socio-economic burden of H1-AH-refractory CSU in monetary terms was evaluated at € 2.2 billion and the majority of this was due to unpaid work loss. Patients with poor disease control, as indicated by UCT score < 12, were more likely to suffer from high impairment than patients with controlled disease, resulting in a higher socio-economic burden. CONCLUSION: The results of our analyses picture the substantial socio-economic burden of H1-AH-refractory CSU and therefore the tremendous impact it has on daily lives of individuals and society overall.

Modelling of patient journey in chronic spontaneous urticaria: Increasing awareness and education by shorten patients' disease journey in Germany.

BACKGROUND: Chronic spontaneous urticaria (CSU) is both physically and emotionally stressful, and guideline recommendations are often not optimally implemented in clinical practice. The objective of this study was to provide an overview on the patient journey in CSU and to develop a mathematical model based on solid data. METHODS: The journey of CSU patients in Germany was traced through literature review and expert meetings that included medical experts, pharmacists and representatives of patient organizations. The current situation's main challenges in the patient journey (education, collaboration and disease management) were discussed in depth. Then, a probabilistic model was developed in a co-creation approach to simulate the impact of three potential improvement strategies: (1) patient education campaign, (2) medical professional education programme and (3) implementation of a disease management programme (DMP). RESULTS: Chronic spontaneous urticaria patients are severely burdened by delays in diagnosis and optimal medical care. Our simulation indicates that in Germany, it takes on average of 3.8 years for patients to achieve disease control in Germany. Modelling all three optimization strategies resulted in a reduction to 2.5 years until CSU symptom control. On a population level, the proportion of CSU patients with disease control increased from 44.2% to 58.1%. CONCLUSION: In principle, effective CSU medications and a disease-specific guideline are available. However, implementation of recommendations is lagging in practice. The approach of quantitative modelling of the patient journey validates obstacles and shows a clear effect of multiple interventions on the patient journey. The data generated by our simulation can be used to identify strategies for improving patient care. Our approach might helping in understanding and improving the management of patients beyond CSU.

The 7-day recall period version of the Urticaria Control Test-UCT7.

BACKGROUND: The Urticaria Control Test (UCT) is a well-established, very easy to use and calculate 4-item patient-reported outcome measure to assess chronic urticaria disease control during the previous 4 weeks. Clinical trials and practice may benefit from the use of a UCT version with a shorter recall period, but this does not exist. OBJECTIVES: We sought to develop and validate a UCT version with a 7-day recall period, the UCT7. METHODS: The UCT7 was developed, based on the UCT, and tested, in 152 patients with chronic urticaria (spontaneous: n = 101, inducible: n = 51) for its reliability, validity and screening accuracy, and clinimetric properties, in other words, the cutoff for well-controlled disease and the minimal clinically important difference. RESULTS: The UCT7 showed excellent internal consistency reliability with a Cronbach αvalue of 0.91 and test-retest reliability with an intraclass correlation coefficient of 0.83. Convergent validity was high and strongly correlated with anchors of disease control, wheal and angioedema frequency, and urticaria-related quality of life impairment. The UCT7 showed excellent sensitivity to change; however, changes in angioedema activity and impact did not correlate well with changes in UCT7. Based on receiver-operating characteristic curve analysis, the proportion of correctly classified patients, and patients' assessment of treatment efficacy, we recommend a cutoff value of 12 points for identifying patients with well-controlled disease. The UCT7 minimal clinically important difference for improvement was estimated to be 2 points. CONCLUSIONS: The UCT7 is a validated 7-day recall period version of the UCT. It is ideal for the assessment of disease control at short intervals in patients with chronic urticaria in clinical studies and practice.

Altered Sweat Composition Due to Changes in Tight Junction Expression of Sweat Glands in Cholinergic Urticaria Patients.

In cholinergic urticaria (CholU), small, itchy wheals are induced by exercise or passive warming and reduced sweating has been reported. Despite the described reduced muscarinic receptor expression, sweat duct obstruction, or sweat allergy, the underlying pathomechanisms are not well understood. To gain further insights, we collected skin biopsies before and after pulse-controlled ergometry and sweat after sauna provocation from CholU patients as well as healthy controls. CholU patients displayed partially severely reduced local sweating, yet total sweat volume was unaltered. However, sweat electrolyte composition was altered, with increased K+ concentration in CholU patients. Formalin-fixed, paraffin-embedded biopsies were stained to explore sweat leakage and tight junction protein expression. Dermcidin staining was not found outside the sweat glands. In the secretory coils of sweat glands, the distribution of claudin-3 and -10b as well as occludin was altered, but the zonula occludens-1 location was unchanged. In all, dermcidin and tight junction protein staining suggests an intact barrier with reduced sweat production capability in CholU patients. For future studies, an ex vivo skin model for quantification of sweat secretion was established, in which sweat secretion could be pharmacologically stimulated or blocked. This ex vivo model will be used to further investigate sweat gland function in CholU patients and decipher the underlying pathomechanism(s).

Virus-infected mast cells activate virus-specific CD8+ T cells.

Efficient anti-viral responses of CD8+ T cells require signals that promote their effector cell differentiation, that are mainly provided by dendritic cells (DCs). Mast cells (MCs) are key drivers of DC maturation, but also influence their migration and antigen presenting properties and therefore indirectly mediate CD8+ T cell activation. MCs initiate innate immune responses at pathogen entry sites, promote the development of adaptive immune responses after infection, and release mediators including chemokines that recruit and activate immune cells including T cells during viral infections. However, whether MCs can directly activate virus-specific CD8+ T cells remains largely unknown. Here, we used an in vitro viral infection model with lymphocytic choriomeningitis virus (LCMV)-infected MCs or DCs co-cultured with either LCMV-specific CD8+ T cells or with WT (unspecific) CD8+ T cells. Similar to LCMV-infected DCs, LCMV-infected MCs clustered with virus-specific CD8+ T cells and induced their activation and production of antiviral cytokines. In addition, the co-stimulatory molecules CD86 and OX40L, but not CD80, were upregulated on MCs and an increased production of IL-6 and type I interferons after LCMV infection was shown. Our findings suggest that MCs can promote CD8+ T cell activation during viral infections. MC-mediated CD8+ T cell activation might be especially important within infected tissues where direct cellular interaction can take place. A better understanding of anti-viral functions of MCs may help developing new strategies to better treat viral infections.

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.