Autoimmune Diseases Are Linked to Type IIb Autoimmune Chronic Spontaneous Urticaria

Efficacy and Mechanism of Acupoint Catgut Embedding in the Treatment of Chronic Spontaneous Urticaria: Protocol for a Randomized Double-Blind Placebo-Controlled Trial

BACKGROUND

Chronic spontaneous urticaria (CSU) is a common chronic inflammatory skin disease that manifests as itching and wheals, seriously affecting quality of life. Clinical observations and previous research trials have shown that acupuncture is safe and effective for the treatment of CSU. However, there are problems, such as a short duration of action and frequent treatment. Compared with traditional acupuncture, acupoint catgut embedding (ACE) has the advantages of a longer effect and higher compliance. Clinical trials are needed to prove its efficacy and mechanism of action.

OBJECTIVE

This trial aims to provide definitive evidence for the treatment of CSU with ACE and explore the mechanism of ACE.

METHODS

This is a randomized, double-blind, placebo-controlled trial. In this trial, 108 participants aged 18-60 years with a diagnosis of CSU and no history of ACE will be randomly assigned to 2 groups (1:1 ratio) using the Statistical Analysis System: treatment (ACE) and control (sham ACE). The participants and efficacy evaluators will be blinded to the grouping. Both the ACE and sham ACE groups will undergo acupuncture, but the sham ACE group will not receive catgut sutures. Treatment will be performed twice weekly for 8 weeks, with a 1-week run-in period and a 16-week follow-up period. Twenty patients will be randomly selected to undergo functional magnetic resonance imaging before and after the treatment period. The primary outcome will be the urticaria activity score over 7 days (UAS7). We will use R (version 4.0.1; R Project for Statistical Computing) to perform ANOVA and independent samples t tests to compare the differences within and between groups before and after treatment by judging the rejection range based on a significance level of .05.

RESULTS

The study protocol has been approved by the Ethics Committee of Guang'anmen Hospital on September 7, 2022, and has been registered on November 30, 2022. Recruitment began on March 1, 2023. A total of 4-6 participants are expected to be recruited each month. The recruitment is planned to be completed on March 1, 2025, and we expect to publish our results by the winter of 2025. As of November 1, 2023, we have enrolled 25 participants with CSU.

CONCLUSIONS

This randomized, double-blind, placebo-controlled trial aims to provide definitive evidence for the treatment of CSU with ACE and explore the mechanism of ACE. We hypothesize that wheals and itching will show greater improvement in participants receiving active therapy than in those receiving sham treatment. The limitations of this study include its single-center trial design, small sample size, and short treatment duration, which may have certain impacts on the research results.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiCTR2200066274; https://www.chictr.org.cn/showprojEN.html?proj=179056.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/54376.

In chronic spontaneous urticaria, increased Galectin-9 expression on basophils and eosinophils is linked to high disease activity, endotype-specific markers, and response to omalizumab treatment

BACKGROUND

Galectin-9 (Gal-9) has been implicated in allergic and autoimmune diseases, but its role and relevance in chronic spontaneous urticaria (CSU) are unclear.

OBJECTIVES

To characterize the role and relevance of Gal-9 in the pathogenesis of CSU.

METHODS

We assessed 60 CSU patients for their expression of Gal-9 on circulating eosinophils and basophils as well as T cell expression of the Gal-9 receptor TIM-3, compared them with 26 healthy controls (HCs), and explored possible links with disease features including disease activity (urticaria activity score, UAS), total IgE, basophil activation test (BAT), and response to omalizumab treatment. We also investigated potential drivers of Gal-9 expression by eosinophils and basophils.

RESULTS

Our CSU patients had markedly increased rates of circulating Gal-9+ eosinophils and basophils and high numbers of lesional Gal-9+ cells. High rates of blood Gal-9+ eosinophils/basophils were linked to high disease activity, IgE levels, and BAT negativity. Serum levels of TNF-α were positively correlated with circulating Gal-9+ eosinophils/basophils, and TNF-α markedly upregulated Gal-9 on eosinophils. CSU patients who responded to omalizumab treatment had more Gal-9+ eosinophils/basophils than non-responders, and omalizumab reduced blood levels of Gal-9+ eosinophils/basophils in responders. Gal-9+ eosinophils/basophils were negatively correlated with TIM-3+TH17 cells.

CONCLUSION

Our findings demonstrate a previously unrecognized involvement of the Gal-9/TIM-3 pathway in the pathogenesis CSU and call for studies that explore its relevance.

Inflammatory cytokine levels and changes during omalizumab treatment in chronic spontaneous urticaria

While several studies have examined the role of T cells and related cytokines in the development of chronic spontaneous urticaria (CSU), there is a limited amount of research focusing on the changes in cytokine levels during omalizumab treatment. The primary objective of this study was to investigate the inflammatory cytokine profile (including IL-4, IL-5, IL-10, IL-13, IL-17, IL-31, IL-33, and TNFα) among CSU patients undergoing to omalizumab treatment. Plasma levels of cytokines were measured using ELISA. Measurements were taken before CSU treatment, at the 3rd and 6th months of omalizumab treatment, and once in the control group. The severity of the patients' disease was assessed using the weekly Urticaria Activity Score(UAS7), and disease control was evaluated using the Urticaria Control Test(UCT). Thirty-one CSU patients and 56 age- and gender-matched healthy controls were included. Plasma levels of IL-4 and IL-33 were significantly lower in patients with CSU compared to healthy controls (p = 0.001; p = 0.038, respectively). During omalizumab treatment, IL-4 levels showed a significant increase in the 3rd month compared to baseline (p = 0.01), and IL-5 levels significantly decreased in the 6th month compared to both the 3rd month and baseline (6th month vs. baseline; p = 0.006, 6th month vs. 3rd month; p = 0.001). One potential mechanism of action for omalizumab may involve its regulatory effects on type 2 inflammatory cytokines in CSU patients. This finding partially explains the efficacy of anti-IL-4/13 treatments in chronic spontaneous urticaria. Further investigations on drugs targeting type 2 inflammatory cytokines in CSU are warranted.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Comorbid Inducible Urticaria Is Linked to Non-Autoimmune Chronic Spontaneous Urticaria: CURE Insights

BACKGROUND

Patients with chronic spontaneous urticaria (CSU) can have comorbid inducible urticaria (CIndU). How comorbid CIndU affects patients and their CSU is largely unclear.

OBJECTIVE

To compare patients with CSU with and without comorbid CIndUs for differences in demographic features, clinical characteristics, and laboratory markers.

METHODS

We analyzed 708 patients with CSU of our Urticaria Center of Reference and Excellence enrolled in CURE, the chronic urticaria registry. CURE data collected until October 2022 were used to compare patients with and without comorbid CIndU for their demographic characteristics, disease onset, activity, impact, and control, as well as concomitant allergic and autoimmune diseases and laboratory parameters associated with autoimmune CSU.

RESULTS

Of 708 patients with CSU, 247 (35%) had comorbid CIndU. Compared with patients with standalone CSU, patients with CSU with comorbid CIndU were significantly younger, had earlier disease onset, longer disease duration, higher impact on quality of life, and a higher rate of concomitant allergic diseases. Moreover, patients with CSU with comorbid CIndU less often had features linked to autoimmune CSU such as angioedema, concomitant autoimmune diseases, eosinopenia, low levels of total IgE, and low total IgE combined with elevated anti-thyroid peroxidase IgG.

CONCLUSIONS

Autoimmune CSU may be less common in patients with comorbid CIndU than without, and comorbid CIndU may point to autoallergic CSU.

Mechanisms of histamine release from mast cells beyond the high affinity IgE receptor in severe chronic spontaneous urticaria

There is growing evidence suggesting that in a subset of patients with severe chronic urticaria [CSU] mast cells are activated via mechanisms that bypass the high affinity IgE receptor. This might explain why some patients do not respond at all to anti-IgE therapy [omalizumab]. The present article reviews the pathogenic mechanisms able to lead to histamine release from mast cells described so far in patients with CSU. These include the activation of the coagulation cascade, the activation of the complement system, the activation of the MRGPRX2 receptor, and the platelet activating factor vicious circle. The article suggests some possible interpretations for the clinical events occurring in this specific subset of patients.

Chronic spontaneous urticaria: Evidence of systemic microcirculatory changes

BACKGROUND

Chronic spontaneous urticaria (CSU) is a chronic inflammatory skin disease where activation of endothelial cells (ECs) at sites of skin lesions leads to increased blood flow, leakage of fluid into the skin, cellular infiltration, and vascular remodeling. To understand the disease duration and the sometimes vague systemic symptoms accompanying flares, the objective of this study was to examine if CSU comes with systemic vascular changes at the microcirculatory level.

METHODS

We investigated CSU patients (n = 49) and healthy controls (HCs, n = 44) for microcirculatory differences by nailfold videocapillaroscopy (NVC) and for blood levels of the soluble EC biomarkers serum vascular endothelial growth factor (VEGF), soluble E-selectin, and stem cell factor (SCF). Patients were also assessed for clinical characteristics, disease activity, and markers of autoimmune CSU (aiCSU).

RESULTS

CSU patients had significantly lower capillary density, more capillary malformations, and more irregular capillary dilations than HCs on NVC. Serum levels of VEGF, soluble E selectin and SCF were similar in CSU patients and HCs. CSU patients with higher VEGF levels had significantly more abnormal capillaries. Patients with markers of aiCSU, that is, low IgE levels or increased anti-TPO levels, had significantly more capillaries and less capillary dilations than those without.

CONCLUSION

Our results suggest that CSU comes with systemic microcirculatory changes, which may be driven, in part, by VEGF.

Autoimmune Diseases and Low Baseline IgE in Chronic Spontaneous Urticaria: A Clinical and Therapeutic Prospective Analysis in Real-Life Clinical Practice

BACKGROUND

Autoimmunity contributes to the pathogenesis of chronic spontaneous urticaria (CSU). The subtyping of CSU has revealed an autoimmune form of CSU. Despite autoimmune diseases having been associated with CSU, there are few prospective studies that have evaluated the characteristics and biomarkers of patients with CSU and autoimmune disease in a real-life practice setting.

OBJECTIVE

To evaluate the presence of specific biomarkers for the presence of autoimmune disease in CSU and to analyze the clinical and therapeutic features of patients with CSU and autoimmune disease.

METHODS

The clinical, laboratory, and therapeutic features of patients with CSU at a tertiary-level center were prospectively collected. Data obtained were compared in function of the presence/absence of autoimmune disease and typified according to IgE levels.

RESULTS

Patients with CSU who had associated autoimmune disease corresponded to middle-aged women with a common pattern of blood test findings: both low baseline IgE and high-affinity receptor of IgE expression, basopenia, eosinopenia, higher baseline erythrocyte sedimentation rate and D-dimer, increased presence of antinuclear antibodies, IgG against thyroid peroxidase, and positive autologous serum skin test result. Total baseline IgE less than or equal to 43.8 IU/mL was both the optimal cutoff to predict autoimmune disease in the CSU cohort and a significant risk factor for the presence of autoimmune disease in the regression analysis.

CONCLUSIONS

In real-life clinical practice, characteristics of patients with CSU and autoimmune disease share common features with type IIb autoimmune CSU. Total baseline IgE less than or equal to 43.8 IU/mL has been detected as a possible biomarker of autoimmune disease in patients with CSU.

Anti-heat shock protein 10 IgG in chronic spontaneous urticaria: Relation with miRNA-101-5p and platelet-activating factor

BACKGROUND

Anti-heat shock protein (HSP) autoantibodies are detected in autoimmune diseases. We sought to ascertain whether anti-HSP10 IgG is present in patients with CSU and to elucidate the role of HSP10 in CSU pathogenesis.

METHOD

Using a human proteome microarray, six potential autoantibodies had higher expression in 10 CSU samples compared with 10 normal controls (NCs). Among them, HSP10 IgG autoantibody was quantified by immune dot-blot assay in sera from 86 CSU patients and 44 NCs. The serum levels of HSP10 and microRNA-101-5p were measured in CSU patients and NCs. The effects of HSP10 and miR-101-5p on mast cell degranulation in response to IgE, compound 48/80, and platelet-activating factor (PAF) were investigated.

RESULTS

CSU patients had higher IgG positivity to HSP10 (40.7% vs. 11.4%, p = .001), lower serum HSP10 levels (5.8 ± 3.6 vs. 12.2 ± 6.6 pg/mL, p < .001) than in NCs, and their urticaria severity was associated with anti-HSP10 IgG positivity, while HSP10 levels were related to urticaria control status. MiR-101-5p was increased in CSU patients. PAF enhanced IL4 production in PBMCs from CSU patients. IL-4 upregulated miR-101-5p and reduced HSP10 expression in keratinocytes. Transfection of miR-101-5p reduced HSP10 expression in keratinocytes. MiR-101-5p promoted PAF-induced mast cell degranulation, while HSP10 specifically prevented it.

CONCLUSION

A new autoantibody, anti-HSP10 IgG was detected in CSU patients, which showed a significant correlation with UAS7 scores. A decreased serum HSP10 level was associated with upregulation of miR-101-5p due to increased IL-4 and PAF in CSU patients. Modulation of miR-101-5p and HSP10 may be a novel therapeutic approach for CSU.

Biomarkers of Autoimmune Chronic Spontaneous Urticaria

PURPOSEOF REVIEW

Chronic spontaneous urticaria and chronic inducible urticaria (CSU/CindU) are caused by mast cell and basophil activation leading to degranulation and the release of histamine and several other mediators. Three kinds of factors can trigger mast cells in CSU: (1) activation of stimulating receptor(s) on the mast cell membrane, (2) upregulation of certain receptor(s), and (3) intracellular dysregulation in signaling with overexpression of the spleen tyrosine kinase (SYK) or reduced activation of the inhibitory Src homology 2 (SH2)-containing inositol phosphatases (SHIP)-related pathways. In CSU, two major endotypes exist based on the primary receptor activating mechanism: type I hypersensitivity (IgE-mediated, directed against auto-allergens) and type IIb (autoimmune, via IgG autoantibodies directed against IgE or the IgE-receptor). Their treatment responses vary. We discuss in vitro and in vivo biomarkers.

RECENT FINDINGS

Patients with auto-allergic CSU have clinical characteristics that can distinguish them partly from those with autoimmune CSU. Most importantly, their disease generally presents a less aggressive course, a better response to second generation (up-dosed) antihistamines and a good response to omalizumab, if necessary. Meanwhile, autoimmune CSU/CindU patients fare less well and often need immunosuppressive drugs. Biomarkers that might help endotype CSU/CindU patients and select the most appropriate treatment, dose, and duration, e.g., for autoallergic CSU, high total IgE and IgE against auto-allergens; for autoimmune CSU, low IgE, basopenia, and IgG against autoantigens like thyroid peroxidase and a positive autologous serum skin test (but sometimes also positive in autoallergy). Some biomarkers are easily accessible but of low specificity; others are highly specific but more futuristic.

Research progress in the pathogenesis of chronic urticaria

Chronic urticaria is very common in clinic, but its pathogenesis is not fully elucidated. Most patients can't find the exact cause, resulting in misdiagnosis or delayed treatment. Previous studies have found that mast cell activation is the central link in the pathogenesis of chronic urticaria. Genetics, autoimmune, coagulation disorders, and infection may also be involved in the pathophysiological process of chronic urticaria. With the deepening of research, more immune and non-immune mechanisms have been gradually revealed in the pathogenesis of chronic urticaria, such as the interaction of immune cells in the microenvironment of urticaria, intestinal flora and metabolism, neuroimmunity, environmental factors and hormones. Clarifying the pathogenesis of chronic urticaria will help to find more treatment targets and provide more diversified ideas for clinical diagnosis and treatment.

Chronic spontaneous urticaria: new evidences on the role of autoimmunity

PURPOSE OF REVIEW

The purpose of this review is to provide an overview of the recent advancements and relevance of the autoimmune theories in chronic spontaneous urticaria (CSU).

RECENT FINDINGS

Two primary types of autoimmunity, Type I and Type IIb, have emerged as major contributors to CSU, characterized by immunoglobulin E (IgE) and immunoglobulin G (IgG) autoantibodies, respectively. Genetic evidence supports the notion that CSU shares more similarities with other autoimmune diseases rather than atopic diseases. Novel autoallergens such as FcεRI and tissue transglutaminase have been identified, contributed to our understanding of autoimmune mechanisms. Furthermore, the potential overlap between Type I and Type IIb autoimmunity has been recognized. Evaluating the autoimmune status of CSU patients through biomarkers and understanding their clinical implications is vital for effective management. For instance, CSU patients with Type IIb autoimmunity, with or without coexisting Type I autoimmunity, may exhibit resistance to H1-antihistamines and omalizumab treatment but could potentially respond well to cyclosporine or Bruton's tyrosine kinase inhibitors.

SUMMARY

Further investigations are needed to explore new autoallergens and autoantibodies in CSU, establishing their connection to the development of autoimmunity. The efficacy of novel drugs targeting different mechanisms should be examined to determine their responses in both autoimmune CSU and nonautoimmunity-related CSU.

Efficacy and safety of Runzao Zhiyang capsule for chronic urticaria: a systematic review and meta-analysis of randomized controlled trials

Background: Chronic urticaria (CU) is a commonly seen skin disorder featured by recurring wheals, with or without angioedema, lasting for at least 6 weeks. Runzao Zhiyang capsule (RZC) has been widely applied to treat patients with CU. This study is aimed at systematically evaluating the efficacy and safety of RZC in treating CU. Materials and Methods: Randomized controlled trials (RCTs) of RZC on treating CU from Chinese and English databases were searched. Data were collected by two independent researchers. The Cochrane Collaboration tool was adopted for evaluating the risk of bias. The meta-analysis was performed with Review Manager 5.3 software. Sensitivity analysis and publication bias assessment were conducted by Stata 14.0 software. Results: Totally 27 studies were included in the analysis, involving 2,703 patients. The pooled results showed that compared with second-generation H1-antihistamines (sgAHs) therapy alone, RZC combined with sgAHs is more effective in improving the total effective rate (RR = 1.32, 95% CI: 1.25 to 1.39, p < 0.00001), the quality of life measured by Dermatology Life Quality Index (DLQI) (MD = -2.63, 95% CI: -3.68 to -1.58, p < 0.00001) and the serum IFN-γ level (SMD = 3.10, 95% CI: 1.58 to 4.62, p < 0.0001), and reducing the recurrence rate (RR = 0.39, 95% CI: 0.27 to 0.55, p < 0.00001), the serum total IgE level (SMD = -2.44, 95% CI: -3.51 to -1.38, p < 0.00001), the serum IL-4 level (SMD = -2.96, 95% CI: -4.10 to -1.83, p < 0.00001), and the incidence of adverse events including dizziness, fatigue, dry mouth, and constipation (RR = 0.53, 95% CI: 0.33 to 0.85, p = 0.009; RR = 0.46, 95% CI: 0.26 to 0.84, p = 0.01; RR = 0.57, 95% CI: 0.34 to 0.95, p = 0.03; RR = 0.24, 95% CI: 0.07 to 0.85, p = 0.03). Conclusion: The current evidence indicates that RZC may be an efficient therapeutic regimen in patients with CU. Nevertheless, owing to the suboptimal quality of the included studies, more large-scale, well-designed RCTs are required to verify the obtained findings. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/; Identifier: CRD42022313177.

Chronic Spontaneous Urticaria: The Role and Relevance of Autoreactivity, Autoimmunity, and Autoallergy

Chronic spontaneous urticaria (CSU) is a frequent and often severely disabling disease. A large number of studies were performed during the last 2 decades to clarify its pathogenesis. These studies shed light on the underlying autoimmune mechanisms of CSU pathogenesis and have led us to understand that different mechanisms may exist and, sometimes, coexist behind the same clinical presentation. The present article reviews the meaning of the terms autoreactivity, autoimmunity, and autoallergy, which have been variably used over the years to define different endotypes of the disease. Furthermore, we discuss the methods potentially able to lead us to the correct classification of CSU patients.

Chronic Spontaneous Urticaria: How to Measure It and the Need to Define Treatment Success

Chronic spontaneous urticaria (CSU) is a complex skin disease characterized by the spontaneous appearance of wheals, angioedema, or both, for more than 6 weeks. Many patients experience a relapsing-remitting disease course for years. Owing to the unpredictability of wheal recurrence and the severity of pruritis, patients suffer considerable impairment in their quality of life. Physicians face multiple challenges, not least of which is a lack of clear guidance on what constitutes "treatment success". There is a lack of awareness of which measures should be used to best assess the various aspects of CSU, including disease activity, disease control, and quality of life-which themselves each comprise multiple components-and how to apply the results of each score to treatment decision-making. Although the overarching aim of treatment is for patients to be completely free of signs and symptoms of CSU, a more realistic definition of "treatment success" is needed to guide ongoing, long-term disease management for each individual patient. In this review, we consider what lessons can be learned from the current evidence base to provide further direction toward a universal definition of "treatment success".

Thyroid Autoimmunity in CSU: A Potential Marker of Omalizumab Response?

The response of severe chronic spontaneous urticaria (CSU) to omalizumab largely depends on the autoimmune or autoallergic endotype of the disease. Whether thyroid autoimmunity may predict omalizumab response along with total IgE in CSU is still unclear. Three hundred and eighty-five patients (M/F 123/262; mean age 49.5 years; range 12-87 years) with severe CSU were studied. Total IgE levels and thyroid autoimmunity (levels of anti-thyroid peroxidase [TPO] IgG) were measured before omalizumab treatment. Based on the clinical response, patients were divided into early (ER), late (LR), partial (PR) and non (NR) responders to omalizumab. Thyroid autoimmunity was detected in 92/385 (24%) patients. Altogether, 52%, 22%, 16% and 10% of patients were ER, LR, PR and NR to omalizumab, respectively. Response to omalizumab was not associated with thyroid autoimmunity (p = 0.77). Conversely, we found a strongly positive association between IgE levels and omalizumab response (p < 0.0001); this association was largely driven by early response (OR = 5.46; 95% CI: 2.23-13.3). Moreover, the predicted probabilities of early response strongly increased with increasing IgE levels. Thyroid autoimmunity alone cannot be used as a clinical predictor of omalizumab response. Total IgE levels remain the only and most reliable prognostic marker for omalizumab response in patients with severe CSU.

Omalizumab treatment in combination with any other biologics: Is it really a safe duo?

BACKGROUND

Chronic spontaneous urticaria (CSU) is a mast cell-mediated disease, which is sometimes associated with various inflammatory disorders. Omalizumab is a commonly used biological agent, which is a recombinant, humanized, monoclonal antibody against human immunoglobulin E. However, there are only few reports about the combination of omalizumab for CSU with any other biologics for accompanying inflammatory diseases in the literature. The aim of this study was to evaluate the patients whose treatment of omalizumab for CSU were combined with any other biologics for associated inflammatory disorders and to describe whether these combinations might have any safety concerns.

METHODS

We conducted a retrospective cohort study of adult patients with CSU treated with omalizumab concurrently using another biological agent for their other dermatological conditions.

RESULTS

Thirty-one patients, 19 women and 12 men, were evaluated. The mean age was 45.13 years. The median duration of omalizumab was 11 months. Biological agents which patients were treated other than omalizumab were as follows: adalimumab biosimilar (n = 3), ustekinumab (n = 4), secukinumab (n = 17) and ixekizumab (n = 7). The median duration of concurrent use of omalizumab and other biologics was 8 months. None of the drug combinations was stopped because of side effects.

CONCLUSION

This observational study demonstrated that omalizumab treatment for CSU in combination with any other biological agents for dermatological disorders appeared to be well tolerated without any major safety concerns.

Consecutive injections of low-dose interleukin-2 improve symptoms and disease control in patients with chronic spontaneous urticaria

PURPOSE

To describe the effectiveness and tolerability of low-dose interleukin (IL)-2 in treating patients with chronic spontaneous urticaria (CSU) refractory to H₁-antihistamines.

METHODS

This retrospective study included CSU patients who received treatment with at least one cycle of IL-2, injected intramuscularly at a dose of 1.0 million international units daily for 7 consecutive days, after failing treatment with H₁-antihistamines. Patients were followed up for ≥12 weeks.

RESULTS

Of the 15 patients, 7 (46.7%) and 11 (73.3%) achieved complete response at Week 2 and Week 12, respectively. The mean change of urticaria control test (UCT) and weekly urticaria activity score (UAS7) from baseline was 6.6 (95% CI, 4.2 to 8.9) and - 16.9 (95% CI, -24.0 to -9.8), respectively, at Week 12. Local injection-site reactions were the most common adverse events. No serious adverse events were reported.

CONCLUSION

Low-dose IL-2 treatment improves symptoms and disease control for CSU patients refractory to H₁-antihistamines.

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.

Prevalence of Autoimmune and Autoinflammatory Diseases in Chronic Urticaria: Pathogenetic, Diagnostic and Therapeutic Implications

Chronic spontaneous urticaria (CSU) is defined as the almost daily occurrence of widespread wheals, angioedema, or both, for more than 6 weeks. It affects 1-2% of the general population, with a higher prevalence in female patients, and is more frequent patients over 20 years of age. More than half of all cases of chronic idiopathic urticaria are thought to occur due to an autoimmune mechanism, specifically the production of autoantibodies against the high-affinity immunoglobulin E (IgE) receptor (FcεRI). The quality of life in these patients is often greatly compromised, also due to the onset of comorbidities represented by other autoimmune diseases, such as thyroid disease, rheumatoid arthritis, systemic lupus erythematosus, Sjögren's syndrome, celiac disease, and type 1 diabetes, among others. This review aimed to analyze the close correlation between CSU and some autoimmune and autoinflammatory diseases, in order to encourage a multidisciplinary and multimorbid approach to the patient affected by CSU, which allows not only control of the natural course of the disease, but also any associated comorbidities.

Urticaria and Angioedema: Understanding Complex Pathomechanisms to Facilitate Patient Communication, Disease Management, and Future Treatment

Chronic spontaneous urticaria (CSU) is primarily a T2-dominant disease with a complex genetic background. Skin mast cell activation can be induced not only via the IgE-FcεRI axis but also from several other distinct mechanisms, molecules, and receptors involved in CSU onset, persistence, and exacerbation. These include autoallergy, autoimmunity, central or peripheral neuroimmune dysregulation, activation of both extrinsic and intrinsic coagulation pathways, and microbial infections. Besides mast cells, recent reports suggest the active and direct involvement of basophils and eosinophils. Several biological characteristics or biomarkers have been linked with CSU's known endotypes and may help forecast therapeutic responses. The introduction of biologic therapy for CSU has been a major advance in the last 10 years. The cornerstone of angioedema (AE) pathogenesis is increased vascular permeability and plasma leakage into the deeper dermis and subcutis, either mediated by histamine or bradykinin (BK). C1-inhibitor deficiency, hereditary or acquired, is the primary cause of BK-mediated AE due to increased plasma BK concentration. Other complex conditions have been identified, with some likely involving contact system dysregulation and other putative mechanisms related to vascular endothelial dysfunction. The approval of multiple hereditary-AE-specific therapies for both prevention and acute attacks has revolutionized treatment of this disease. Any new knowledge of the pathogenesis of CSU and AE offers the opportunity to improve patient information, physician-patient communication, prediction of therapeutic responses, selection of precise tailor-made treatment for each patient, and exploration of novel treatment options for those who do not achieve disease control with current medications.

GWAS of Chronic Spontaneous Urticaria Reveals Genetic Overlap with Autoimmune Diseases, Not Atopic Diseases

Although chronic spontaneous urticaria (CSU) is a common disease, GWASs of CSU are lacking. We aimed to identify susceptibility SNPs by performing a GWAS in Chinese Han adults with CSU. The discovery cohort included 430 CSU cases and 482 healthy controls. The GWAS findings were validated in 800 CSU cases and 900 healthy controls. Genetic, functional enrichment, and bioinformatic analyses of genome-wide significant SNPs were performed to assess the association between CSU and autoimmunity or atopy. Five genome-wide significant SNPs were identified: rs434124/LILRA3, rs61986182/IGHG1/2, rs73075571/TDGF1, rs9378141/HLA-G, and rs3789612/PTPN22. The first four SNPs were in linkage disequilibrium with autoimmune-related diseases‒associated SNPs and were cis-expression quantitative trait loci in immune cells. The five SNPs-annotated genes were significantly enriched in immune processes. Higher polygenic risk scores and allele frequencies of rs3789612∗T, rs9378141∗C, and rs73075571∗G were significantly associated with autoimmune-related CSU phenotypes, including positive antithyroglobulin IgG, positive anti-FcεRIα IgG, total IgE <40 IU/ml, and positive antithyroid peroxidase IgG but not with atopic or allergic sensitized CSU phenotypes. This GWAS of CSU identifies five risk loci and reveals that CSU shares genetic overlap with autoimmune diseases and that genetic factors predisposing to CSU mainly manifest through associations with autoimmune traits.

Effectiveness of Hydroxychloroquine and Omalizumab in Chronic Spontaneous Urticaria: A Real-World Study

BACKGROUND

Chronic spontaneous urticaria (CSU) not controlled by optimized doses of antihistamines is referred to as refractory CSU. Add-on therapies recommended by guidelines include omalizumab, immunosuppressive, and anti-inflammatory agents.

OBJECTIVES

The objective of the study was to assess the real-world effectiveness of different add-on treatment options for refractory CSU in 2 large clinical practices.

METHODS

A retrospective chart review was conducted in 264 patients with refractory CSU not adequately controlled for ≥6 weeks with optimized doses of second-generation histamine-1 blockers. Omalizumab and hydroxychloroquine were the most frequently prescribed add-on therapies, allowing comparisons of clinical outcomes for these 2 agents. Complete response included absent or infrequent urticaria and patient satisfaction with treatment. Partial response was reduced hives, but requiring a second add-on therapy. Sustained response was complete response to an add-on therapy for ≥1 year.

RESULTS

Omalizumab add-on treatment was significantly more likely to be associated with a complete response versus hydroxychloroquine. Complete sustained response at 1 year was observed in 82% (111 of 134) of patients on omalizumab and 66% (73 of 111) on hydroxychloroquine as the first add-on therapy (P < .01). Patients with thyroid disease had a poorer response to add-on treatments (45% responded vs 63%; P = .03). In patients with incomplete responses to first add-on interventions (n = 45), 65% and 62% subsequently had complete responses to omalizumab and hydroxychloroquine, respectively.

CONCLUSIONS

Although omalizumab was superior, hydroxychloroquine achieved a complete response in two-thirds of treated patients. Given a favorable safety profile, hydroxychloroquine should be considered as an add-on treatment for refractory CSU.

Comorbidities of Chronic Urticaria: A glimpse into a complex relationship

Chronic Urticaria (CU) is a chronic inflammatory, predominantly mast cell-driven disease, characterized by the development of wheals and/or angioedema for more than 6 weeks. It affects approximately 1%-5% of the total population worldwide and imposes a substantial burden on health-related quality of life, significantly affecting patients' daily life. The economic impact on the health system is also not negligible, with an estimated cost per patient per year of approximately 2.000 $ in the United States. Although the underlying pathophysiology is not fully explored, autoimmune mechanisms have been proposed, including type I ("autoallergy" by means of autoantibodies to self-antigens) and type IIb (autoimmunity). Atopic, autoimmune, and psychiatric disorders are prevalent comorbidities in both children and adults with Chronic Spontaneous Urticaria (CSU). Although malignancies, cardiovascular diseases and other comorbidities have also been reported as associated diseases in patients with CSU, data remain scarce. It is still unknown whether the aforementioned comorbidities share common pathophysiological mechanisms with specific endotypes of CSU. The current review aims to overview current data on comorbidities of CU, and furthermore to comment on the potential linked pathways underlying these diseases.

Urticaria

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

Detection of serum IgG autoantibodies to FcεRIα by ELISA in patients with chronic spontaneous urticaria

Background

Mast cells are a key effector cell in the pathogenesis of chronic spontaneous urticaria (CSU) and activated by circulating FcεRI-specific IgG as well as IgE. This study evaluated the prevalence of circulating autoantibodies to FcεRIα in the sera of CSU patients.

Methods

Eighty-eight patients with CSU and 76 healthy controls (HCs) were enrolled. To detect circulating autoantibodies (IgG/IgA/IgM) to FcεRIα, ELISA was done using YH35324 (as a solid phase antigen), and its binding specificity was confirmed by the ELISA inhibition test. The antibody levels were presented by the ratio of YH35324-preincubated to mock-preincubated absorbance values. Clinical and autoimmune parameters, including atopy, urticaria activity score (UAS), serum total/free IgE levels, serum antinuclear antibody (ANA) and autologous serum skin test (ASST) results, were assessed. The autoimmune group was defined if CSU patients had positive results to ASST and/or ANA.

Results

The ratio of serum IgG to FcεRIα was significantly lower in CSU patients than in HCs (P<0.05), while no differences were noted in serum levels of IgG to recombinant FcεRIα or IgA/IgM autoantibodies. The autoimmune CSU group had significantly lower ratios of IgG/IgA (not IgM) autoantibodies to FcεRIα than the nonautoimmune CSU group (P<0.05 for each). No significant associations were found between sex, age, atopy, urticaria duration, UAS, or serum total/free IgE levels according to the presence of IgG/IgA/IgM antibodies.

Conclusions

This study confirmed the presence of IgG to FcεRIα in the sera of CSU patients, especially those with the autoimmune phenotype.

STAT3 gain-of-function is not responsible for low total IgE levels in patients with autoimmune chronic spontaneous urticaria

Background

The pathogenesis of chronic spontaneous urticaria (CSU) has not been clarified entirely. Type IIb autoimmune chronic spontaneous urticaria (CSUaiTIIb) is a distinct subtype of CSU that is often difficult to treat and is connected to low levels of total IgE. Previous findings indicate that an enhanced signal transducer and activator of transcription 3 (STAT3) may be responsible for reduced IgE serum levels.

Objective

Our aim was to investigate a possible underlying gain-of-function mutation or activating polymorphism in STAT3 that could be responsible for the low levels of IgE in patients with CSUaiTIIb.

Methods

We included 10 patients with CSUaiTIIb and low levels of IgE and sequenced selected single nucleotide polymorphisms (SNP) in STAT3 associated with common autoimmune diseases. Exon sequencing was performed for the most relevant exons of STAT3. To test for a gain-of-function of STAT3, we performed a phospho-specific flow cytometry analysis of STAT3 in peripheral blood mononuclear cells before and after stimulation with interleukin-6.

Results

No differences were found in the prevalence of the tested SNPs between our patients and a control population. Moreover, we could not find any mutations or variants on the tested exons of STAT3. The function of STAT3 was also not altered in our patients.

Conclusion

In total, we could not find any evidence for our hypothesis that low IgE in patients with CSUaiTIIb is linked to mutations in STAT3 or altered activity of STAT3. Thus, it remains to be discovered what causes the low serum levels of IgE in patients with CSUaiTIIb.

Unmet Medical Needs in Chronic, Non-communicable Inflammatory Skin Diseases

An estimated 20-25% of the population is affected by chronic, non-communicable inflammatory skin diseases. Chronic skin inflammation has many causes. Among the most frequent chronic inflammatory skin diseases are atopic dermatitis, psoriasis, urticaria, lichen planus, and hidradenitis suppurativa, driven by a complex interplay of genetics and environmental factors. Autoimmunity is another important cause of chronic skin inflammation. The autoimmune response may be mainly T cell driven, such as in alopecia areata or vitiligo, or B cell driven in chronic spontaneous urticaria, pemphigus and pemphigoid diseases. Rare causes of chronic skin inflammation are autoinflammatory diseases, or rheumatic diseases, such as cutaneous lupus erythematosus or dermatomyositis. Whilst we have seen a significant improvement in diagnosis and treatment, several challenges remain. Especially for rarer causes of chronic skin inflammation, early diagnosis is often missed because of low awareness and lack of diagnostics. Systemic immunosuppression is the treatment of choice for almost all of these diseases. Adverse events due to immunosuppression, insufficient therapeutic responses and relapses remain a challenge. For atopic dermatitis and psoriasis, a broad spectrum of innovative treatments has been developed. However, treatment responses cannot be predicted so far. Hence, development of (bio)markers allowing selection of specific medications for individual patients is needed. Given the encouraging developments during the past years, we envision that many of these challenges in the diagnosis and treatment of chronic inflammatory skin diseases will be thoroughly addressed in the future.

Autoimmune chronic spontaneous urticaria

Chronic spontaneous urticaria (CSU) is a debilitating mast cell-driven disease characterized by recurrent wheals and/or angioedema. Substantial progress has been made in dissecting the 2 main autoimmune mechanisms that drive the pathogenesis of CSU. Type I autoimmune (autoallergic) CSU is associated with IgE antibodies against autoantigens, for example, thyroid peroxidase and IL-24. Type IIb autoimmune CSU is mediated by autoantibodies that activate mast cells, for example, via IgE and FcεRI, and is present in less than 10% of patients with CSU when strict criteria are used, that is, triple positivity of autologous serum skin test, immunoassays for IgG autoantibodies, and basophil activation tests. A subpopulation of patients with CSU has both types. Type IIb autoimmune CSU is characterized by higher disease severity, concomitant autoimmune diseases, low levels of total IgE, elevated levels of IgG-anti-thyroid peroxidase, basopenia, eosinopenia, poor response to antihistamines and to omalizumab, and a good response to cyclosporine. Novel targeted therapies for CSU are under development such as ligelizumab, an anti-IgE, fenebrutinib and remibrutinib, Bruton's tyrosine kinase inhibitors, and dupilumab, an anti-IL-4Rα. Further studies should investigate the overlap between autoallergic and type IIb autoimmune CSU, optimize the diagnosis of both autoimmune endotypes using easy-to-perform, noninvasive, and inexpensive markers, and assess differences in response to therapy.

The Role of Crosstalk of Immune Cells in Pathogenesis of Chronic Spontaneous Urticaria

Chronic spontaneous urticaria (CSU) is defined as recurrent episodes of spontaneous wheal development and/or angioedema for more than six weeks and at least twice a week. The core link in the pathogenesis of CSU is the activation of mast cells, T cells, eosinophils, and other immune cells infiltrating around the small venules of the lesion. Increased vascular permeability, vasodilatation, and recruitment of inflammatory cells directly depend on mast cell mediators’ release. Complex regulatory systems tightly influence the critical roles of mast cells in the local microenvironment. The bias toward Th2 inflammation and autoantibodies derived from B cells, histamine expressed by basophils, and initiation of the extrinsic coagulation pathway by eosinophils or monocytes exerts powerful modulatory influences on mast cells. Cell-to-cell interactions between mast cells and eosinophils/T cells also are regulators of their function and may involve CSU’s pathomechanism. This review summarizes up-to-date knowledge regarding the crosstalk between mast cells and other immune cells, providing the impetus to develop new research concepts and treatment strategies for CSU.

Integrated Bioinformatics and Validation Reveal IL1B and Its Related Molecules as Potential Biomarkers in Chronic Spontaneous Urticaria

Background

The etiopathogenesis of chronic spontaneous urticaria (CSU) has not been fully understood, and there has been extensive interest in the interaction between inflammatory dermatosis and pyroptosis. This study intends to investigate the molecular mechanism of pyroptosis-related genes in CSU via bioinformatic ways, aiming at identifying the potential key biomarker.

Methods

GSE72540, the RNA expression profile dataset of CSU, was utilized as the training set, and GSE57178 as the validation set. Differently expressed pyroptosis-related genes (DEPRGs), GO, KEGG, and DO analyses were performed. The hub genes were explored by the protein–protein interaction analysis. Moreover, CIBERSORT was employed for estimating immune cell types and proportions. Then, we constructed a DEmRNA–miRNA–DElncRNA ceRNA network and a drug–gene interaction network. Finally, ELISA was used for gene expression analysis.

Results

We recognized 17 DEPRGs, whose enrichment analyses showed that they were mostly enriched in inflammatory response and immunomodulation. Moreover, 5 hub genes (IL1B, TNF, and IRF1 are upregulated, HMGB1 and P2RX7 are downregulated) were identified via the PPI network and verified by a validation set. Then immune infiltration analysis displayed that compared with normal tissue, CSU owned a significantly higher proportion of mast cells activated, but a lower proportion of T cells CD4 naive and so on. Furthermore, IL1B was statistically and positively associated with mast cells activated in CSU, and SNHG3, the upstream factor of IL1B in the ceRNA we constructed, also related with mast cells in CSU. Further analysis exhibited that the protein subcellular localization of IL1B was extracellular, according with its intercellular regulation role; IL1B was significantly correlated with key immune checkpoints; and the NOD-like receptor signaling pathway was the mainly involved pathway of IL1B based on the couple databases. What is more, the result of ELISA of CSU patients was the same as the above analyses about IL1B. In addition, the drug–gene interaction network contained 15 potential therapeutic drugs targeting IL1B, and molecular docking might make this relationship viable.

Conclusion

IL1B and its related molecules might play a key role in the development of CSU and could be potential biomarkers in CSU.

Increased serum free IgE levels in patients with chronic spontaneous urticaria (CSU)☆

Background

IgE bound on the surface of mast cells contributes to the pathogenesis of chronic spontaneous urticaria (CSU). Atopy is a predisposing factor for CSU, where omalizumab is a widely used monoclonal antibody to control urticaria symptoms via capturing serum free IgE. However, the role of serum free IgE is not clarified in CSU. The present study evaluated the clinical relevance of serum free IgE in patients with CSU.

Methods

Eighty-eight patients with CSU and 76 healthy controls (HCs) were enrolled in this study. Serum total and Dermatophagoides pteronyssinus (Der p)-specific IgE levels were measured by ImmunoCAPs. The serum free IgE levels were measured by ELISA using a novel IgE_TRAP, and their associations with clinical parameters, including urticaria activity score (UAS), were evaluated. Changes in serum free and total IgE levels after omalizumab treatment were observed in 23 CSU patients in comparison between responders (≥50% reduction in UAS) and non-responders (<50% reduction).

Results

Significantly higher serum free/total IgE levels were noted in CSU patients than in HCs with a positive correlation between the 2 values (rho = 0.87, P < 0.001). Among CSU patients, atopics had significantly higher serum free IgE levels than non-atopics, while no associations were noted with UAS, urticaria duration, or the results of serum ANA or autologous serum skin tests. In addition, there were no significant changes in serum free IgE levels during 12 months of omalizumab treatment. No significant differences were noted in serum free/total IgE levels or clinical parameters between responders and non-responders, while responders have higher serum Der p-specific IgE level and its ratio to serum free/total IgE level than non-responders (P < 0.05, respectively).

Conclusions

These findings suggest that increased serum free IgE may be involved in the development of CSU by activating mast cells, especially in atopics. High Der p-specific IgE level and its ratio to serum free IgE level may be a potential biomarker for predicting favorable responses to omalizumab in CSU.

Chronic spontaneous urticaria after BNT162b2 mRNA (Pfizer-BioNTech) vaccination against SARS-CoV-2

Background: The factors that trigger and exacerbate chronic spontaneous urticaria (CSU) are well known, but it is not unclear whether messenger RNA (mRNA) vaccination against severe acute respiratory syndrome coronavirus 2 can trigger new cases of CSU or a relapse of CSU after long-term remission. Objective: To study the clinical cases of patients with new-onset CSU and CSU in remission who relapsed within 3 months after BNT162b2 mRNA vaccination. Methods: All patients with a CSU diagnosis within 12 weeks of BNT162b2 mRNA vaccination were retrospectively identified and included in the new-onset CSU and the relapsed CSU groups. The first control group (CSU control group) retrospectively consisted of patients diagnosed with CSU in complete clinical remission for ≥ 6 months, with no CSU relapse after vaccination. The second control group (healthy control group) consisted of subjects who were fully vaccinated and without CSU, matched 1:2 for age and sex with patients with CSU. Results: Twenty-seven patients were included in the relapsed CSU group, 32 patients in the new-onset CSU group, 179 patients in the CSU control group, and 476 subjects in the healthy control group. The relapsed CSU and new-onset CSU groups had more allergic comorbidities overall (19 [70.4%] and 13 [40.6%], respectively) than the CSU control group and the healthy control group (50 [27.9%] and 110 [23.1%], respectively; p < 0.001). Multiple logistic regression analysis showed that a positive autologous serum skin test result, overall allergic comorbidities, and basopenia were positively associated with the probability of CSU relapse within 3 months after BNT162b2 mRNA vaccination (odds ratio [OR] 5.54 [95% confidence interval {CI}, 2.36-13.02], p < 0.001); OR 6.13 [95% CI, 2.52-14.89], p = 0.001; and OR 2.81 [95% CI, 1.17-6.72, p = 0.020, respectively). Conclusion: It is possible that BNT162b2 mRNA vaccination serves as a provoking and/or relapsing factor of CSU in individuals with allergic diseases and/or predisposed autoimmunity.

Genome-Wide DNA Methylation Profile in Whole Blood of Patients With Chronic Spontaneous Urticaria

Background

Chronic spontaneous urticaria (CSU) is a common autoimmune skin disease. Little is known about the role of epigenetics in the pathogenesis of CSU. This study aimed to investigate genome-wide DNA methylation profile in whole blood of patients with CSU.

Patients and Methods

Genome-wide DNA methylation levels in whole blood samples of 95 Chinese Han ethnicity adult CSU patients and 95 ethnicity-, age- and sex-matched healthy controls were analyzed using Illumina 850K methylation chip. The differentially methylated genes (DMGs) were screened out and then functionally annotated by the gene ontology and the Kyoto encyclopedia of genes and genomes databases.

Results

A total of 439 differentially methylated positions (DMPs) (p < 0.01 and |Δβ| ≥ 0.06) were identified with 380 hypomethylated and 59 hypermethylated. The average global DNA methylation levels of the 439 DMPs in the CSU patients were significantly lower than those in the healthy controls (p < 0.001). The distribution of the 439 DMPs was wide on chromosome 1 to 22 and chromosome X. Chromosome 6 embodied the largest number of DMPs (n = 51) and their annotated genes were predominantly related to autoimmunity. The 304 annotated DMGs were mainly enriched in autoimmune disease- and immune-related pathways. A total of 41 DMPs annotated to 28 DMGs were identified when p < 0.01 and |Δβ| ≥ 0.1. Of the 28 DMGs, HLA-DPB2, HLA-DRB1, PPP2R5C, and LTF were associated with autoimmunity. CSU cases with elevated total IgE, positive anti-thyroid peroxidase IgG autoantibodies, positive anti-thyroglobulin IgG autoantibodies, angioedema, UASday > 4, or recurrent CSU showed phenotype-specific DMPs as compared with cases with normal total IgE, negative anti-thyroid peroxidase IgG autoantibodies, negative anti-thyroglobulin IgG autoantibodies, no angioedema, UASday ≤ 4, or non-recurrent CSU respectively.

Conclusion

This study shows a distinct genome-wide DNA methylation profile in Chinese Han ethnicity adult CSU patients and indicates a role of epigenetics in the pathogenesis of CSU. The predominant enrichment of the CSU-associated DMGs in immunological pathways provides supportive evidence for the immunopathogenesis of CSU. Future research on the CSU-associated DMPs and DMGs will help discover potential therapeutic targets for CSU.

Autoimmune Chronic Spontaneous Urticaria Detection with IgG Anti-TPO and Total IgE

BACKGROUND

Autoimmune chronic spontaneous urticaria (aiCSU) comes with high disease activity and poor response to treatment. Recently, elevated levels of IgG anti-thyroid peroxidase (aTPO) and low levels of total IgE were reported to be common in aiCSU.

OBJECTIVE

To investigate how high aTPO and low IgE individually and combined are linked to features of aiCSU, including treatment responses.

METHODS

We analyzed records of patients with CSU from 2 independent cohorts (n = 1120) for demographic, clinical, and laboratory parameters and treatment responses. Total IgE and aTPO were measured, and 4 markers of aiCSU were analyzed: autologous serum skin test, basophil activation test (BAT), and blood eosinophil and basophil counts. Cutoff values were greater than or equal to 34 kU/L (high aTPO) and less than 40 IU/mL (low total IgE).

RESULTS

One of 10 patients with CSU had both high aTPO and low IgE (aTPO↑IgE↓, 11%, n = 123). aTPO↑IgE↓ was linked to higher age at CSU onset, being female, angioedema, and shorter CSU duration. aTPO↑IgE↓ was associated with markers of aiCSU, that is, BAT and autologous serum skin test positivity, basopenia, and eosinopenia (P < .01 for all). Almost half the patients with aTPO↑IgE↓ (44%, 19 of 43) had a positive BAT result, the best single marker for aiCSU, versus 12% (43 of 344) of patients without aTPO↑IgE↓ (P < .001). Relative risk of showing BAT positivity for a patient with aTPO↑IgE↓ is 3.636 (95% CI, 2.382-5.551). Patients with aTPO↑IgE↓ showed low response rates to antihistamine treatment as compared with patients without aTPO↑IgE↓ (30% vs 47%; P = .01).

CONCLUSIONS

Our findings suggest that aTPO↑IgE↓ is a useful diagnostic marker for aiCSU in everyday clinical practice.

The Diagnostic Workup in Chronic Spontaneous Urticaria-What to Test and Why

BACKGROUND

In chronic spontaneous urticaria (CSU), the guidelines recommend very limited diagnostic procedures during the routine workup, although additional investigations might be indicated in some patients with CSU. For physicians treating patients with CSU, it is often difficult to decide which diagnostic tests are useful.

OBJECTIVE

To provide recommendations on what diagnostic tests should be performed on which patients with CSU.

METHODS

We performed an extensive literature search on the respective topics and identified relevant questions that should prompt diagnostic procedures based on the published evidence and expert consensus among all authors.

RESULTS

We provide questions, diagnostic testing, where appropriate, and recommendation that should be included when assessing the history of a patient with CSU, to explore and rule out differential diagnoses, to assess patients for underlying causes and modifying conditions, to explore patients for comorbid diseases and consequences of having CSU, and to assess patients for CSU components that can help to predict their disease course and response to treatment.

CONCLUSIONS

Here, we provide physicians treating patients with CSU with information about which clues should lead to which tests and why.