Immunomodulatory approaches to the management of chronic urticaria: an immune-mediated inflammatory disease

Burden of and Trends in Urticaria Globally, Regionally, and Nationally from 1990 to 2019: Systematic Analysis

BACKGROUND

Urticaria presents a significant global health challenge due to its sudden onset and potential for severe allergic reactions. Past data on worldwide prevalence and incidence is inconsistent due to differing study methodologies, regional differences, and evolving diagnostic criteria. Past studies have often provided broad ranges instead of specific figures, underscoring the necessity for a cohesive global perspective to inform public health strategies.

OBJECTIVE

We aimed to assess the global burden of urticaria using the 2019 Global Burden of Disease (GBD) study data and systematically analyze urticaria prevalence, incidence, and disability-adjusted life years (DALYs) at global, regional, and national levels, thereby informing more effective prevention and treatment strategies.

METHODS

We analyzed the global, regional, and national burden of urticaria from 1990 to 2019 using the 2019 GBD study coordinated by the Institute for Health Metrics and Evaluation. Estimations of urticaria prevalence, incidence, and DALYs were derived using DisMod-MR 2.1, a Bayesian meta-regression tool. The Socio-demographic Index (SDI) was used to correlate development status with health outcomes. The GBD's division of the world into 21 regions and 204 countries and territories facilitated a comprehensive assessment. Age-standardized estimated annual percentage changes were generated for urticaria metrics to quantify temporal trends, with age standardization adjusting for potential confounding from age structure.

RESULTS

From 1990 to 2019, the global age-standardized prevalence, incidence, and DALY rates of urticaria showed marginal changes. In 2019, 65.14 million individuals were affected, with a prevalence rate of 841.88 per 100,000 population. The DALY rate was 50.39 per 100,000 population. Compared to 1990, the global age-standardized prevalence, incidence, and DALY rates saw increases of 2.92, 4.84, and 0.31 per 100,000 population, respectively. Women persistently had higher rates than men. At a regional level in 2019, low-middle SDI regions exhibited the highest age-standardized metrics, whereas high SDI regions reported the lowest. Central Europe showed the highest rates, contrasting with Western Europe's lowest rates. Nationally, urticaria prevalence in 2019 varied dramatically, from a low of 27.1 per 100,000 population in Portugal to a high of 92.0 per 100,000 population in Nepal. India reported the most DALYs at 749,495.9, followed by China, Pakistan, and the United States. Agewise data showed higher rates in younger age groups, which diminished with age and then experienced a slight resurgence in the oldest populations. This pattern was pronounced in women and younger populations, with the largest rises seen in those aged less than 40 years and the smallest in those aged more than 70 years.

CONCLUSIONS

Urticaria remains a significant global health issue, with considerable variation across regions, countries, and territories. The increased burden among women, the rising burden in younger populations, and the regional differences in disease burden call for tailored interventions and policies to tackle this emerging public health issue.

Exacerbation of Chronic Spontaneous Urticaria Symptoms in COVID-19 Patients, Case Report

Chronic spontaneous urticaria (CSU) is characterized by wheals lasting more than 6 weeks and can be accompanied by angioedema. Treatment of the disease varies depending on the severity and includes first-line therapeutics such as non-sedative antihistamines. Second- and third-line treatments are used in severe and uncontrolled form of CSU. Environmental exposure and infections could trigger worsening symptoms. The goal of this study is to assess the effect of SARS-CoV-2 infection on CSU symptoms and the efficacy of the second- and third-line therapeutics for CSU management in COVID-19 patients. Our findings show that SARS-CoV-2 infection exacerbates CSU symptoms. Worsening of disease was indicated by decreased Urticaria Control Test (UCT) and increased Urticaria Activity Score (UAS). Treatment management was modified by switching to second- and third-line therapeutics; however, therapeutic control was achieved only in one patient. Our data demonstrates that SARS-CoV-2 infection contributes to the severity of CSU. Symptoms of CSU are more challenging to manage and require changes in treatment protocol, including second- and third-line therapeutics. We believe that severe inflammation triggered by SARS-CoV-2 infection contributes to the worsening of CSU symptoms.

OSMR gene effect on the pathogenesis of chronic autoimmune Urticaria via the JAK/STAT3 pathway

Background

Chronic autoimmune urticaria (CAU) is a common skin disease and remains unclear understanding of pathogenesis in the vast majority of cases. In order to explore a new therapy for CAU, the current study was performed to investigate the possible functioning of the Oncostatin M receptor (OSMR) gene in the autoimmunity of CAU via regulation of the JAK/STAT3 signaling pathway.

Methods

CAU skin tissues from 24 CAU patients and normal skin tissues from normal subjects were collected. Hematoxylin-eosin (HE) staining was conducted to count eosinophils, and immunohistochemistry was carried out to detect the positive rate of OSMR expression in two kinds of skin tissues. A total of 72 Kunming (KM) mice were selected, and 60 mice were used for establishing CAU models and later transfected with different plasmids. The expression of inflammatory factors was evaluated by enzyme-linked immunosorbent assays (ELISA). Expressions of janus kinase (JAK), signal transducer and activator of transcription 3 (STAT3), interferon-stimulated gene 15 (ISG15), CT10-regulated kinase (CRK), and interferon regulatory factor 9 (IRF9) were identified using Western blot assay and reverse transcription quantitative polymerase chain reaction (RT-qPCR). Epithelial cell proliferation was assessed by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay, and cell cycle distribution and cell apoptosis were assessed using flow cytometry.

Results

The findings confirm that OSMR protein expression and histamine release rate are highly elevated in human CAU skin tissues, and the expression of the JAK/STAT3 signaling pathway-related genes (OSMR, JAK2, STAT3, ISG15, CRK and IRF9) was up-regulated. OSMR gene silencing in CAU mice significantly decreases the content of inflammatory factors (IL-1, IL-6, IFN-γ, and IgE), the number of eosinophils, and reduces the expression of the JAK/STAT3 signaling pathway related genes, and further enhances cell proliferation, promotes cell cycle entry and inhibits apoptosis of epithelial cells.

Conclusion

All aforementioned results indicate that OSMR gene silencing inhibits the activation of the JAK/STAT3 signaling pathway, thereby suppressing the development of CAU.

Treatment of chronic spontaneous urticaria: Immunomodulatory approaches

This paper summarizes and reviews the mechanisms of action and data concerning efficacy of recommended treatments as well as other treatments that have been tested, independently of the outcomes, in the management of chronic spontaneous urticaria. Due to the central role of mast cells, basophils and histamine in the pathophysiology of this disease, H₁-antihistamines remain the first-line treatment. However, current knowledge about this complex disease, also recognizes an important role for T lymphocytes, B lymphocytes, and autoantibodies. Implications of these others mediators thus provide further targets for treatment. Indeed, agents previously used to treat other autoimmune and inflammatory diseases, have demonstrated efficacy in chronic spontaneous urticaria and are therefore potential therapeutic alternatives for antihistamine unresponsive patients.

Mediators of Inflammation and Angiogenesis in Chronic Spontaneous Urticaria: Are They Potential Biomarkers of the Disease?

In chronic spontaneous urticaria (CSU), different pathophysiological mechanisms, potentially responsible for the development of the disease, have been recently described. It is likely that the activation of skin mast cells with consequent release of histamine and other proinflammatory mediators is responsible for vasodilation in the lesional skin of CSU. However, the underlying causes of mast cell activation in the disease are largely unknown and remain to be identified. Thus, in this review, we discuss new insights in the pathogenesis of CSU, focusing on inflammation and angiogenesis. The understanding of these mechanisms will enable the identification of biomarkers useful for the diagnosis, follow-up, and management of CSU and will allow the development of novel, more specific, and patient-tailored therapies.

Association between chronic idiopathic urticaria and hypertension: A population-based retrospective cohort study

BACKGROUND

Chronic idiopathic urticaria (CIU) is defined as urticaria that is not caused by external triggers. The pathogenesis of CIU remains unknown. A previous study investigated whether hypertension is associated with extended duration of CIU.

OBJECTIVE

To investigate the possible association between CIU and hypertension.

METHODS

We performed a population-based retrospective cohort study of 2,460 patients with CIU and 9,840 age-, sex-, and index year-matched comparison patients, using the National Health Insurance of Taiwan database. The median follow-up periods were 7.13 years for the CIU cohort and 7.20 years for the non-CIU cohort. The distributions by sex and age were similar for both cohorts.

RESULTS

The CIU cohort had a 1.37-fold (95% CI, 1.22-1.53) greater risk of developing subsequent hypertension than the non-CIU cohort after adjusting for sex, age, comorbidities, and nonsedating antihistamine use.

CONCLUSION

This nationwide retrospective cohort study found that CIU is associated with a higher future risk of hypertension after adjusting for sex, age, comorbidities, and nonsedating antihistamine use. The detailed pathophysiologic mechanisms require further clarification in prospective studies.

Looking forward to new targeted treatments for chronic spontaneous urticaria

The introduction of omalizumab to the management of chronic spontaneous urticaria (CSU) has markedly improved the therapeutic possibilities for both, patients and physicians dealing with this disabling disease. But there is still a hard core of patients who do not tolerate or benefit from existing therapies and who require effective treatment. Novel approaches include the use of currently available drugs off-licence, investigational drugs currently undergoing clinical trials and exploring the potential for therapies directed at pathophysiological targets in CSU. Off-licence uses of currently available drugs include rituximab and tumour necrosis factor inhibitors. Ligelizumab (anti-IgE), canakinumab (anti-IL-1), AZD1981 (a PGD2 receptor antagonist) and GSK 2646264 (a selective Syk inhibitor) are currently in clinical trials for CSU. Examples of drugs that could target potential pathophysiological targets in CSU include substance P antagonists, designed ankyrin repeat proteins, C5a/C5a receptor inhibitors, anti-IL-4, anti-IL-5 and anti-IL-13 and drugs that target inhibitory mast cell receptors. Other mediators and receptors of likely pathogenic relevance should be explored in skin profiling and functional proof of concept studies. The exploration of novel therapeutic targets for their role and relevance in CSU should help to achieve a better understanding of its etiopathogenesis.

Diamine oxidase levels in different chronic urticaria phenotypes

BACKGROUND

Diamine oxidase (DAO) is a polyamine-degrading enzyme also implicated in histamine metabolism. Chronic urticaria (CU) has a wide spectrum of clinical presentations and causes. Anisakis sensitisation associated chronic urticaria (CU+) has been characterised as a phenotype with different clinical and immunological characteristics and possibly associated with previous acute parasitism. We aimed to analyse serum DAO levels in different CU phenotypes. We further analysed the possible association of DAO with fish eating habits.

METHODS

We studied 35 CU+ patients and 39 non-sensitised CU patients (CU-) as well as 19 controls. We analysed fish-eating frequency as well as fish intake associated exacerbation of CU (FIAE) or gastro-intestinal complaints (GI). DAO levels were further analysed with respect to lymphoproliferative responses, cytokine and specific IgE production.

RESULTS

DAO levels were not different between CU and controls, but were significantly higher in CU+ than in CU-. CU+ patients with FIAE had lower DAO levels, but no differences were detected in patients with GI. DAO levels correlated positively with oily and canned fish consumption in CU-. In CU+, DAO levels correlated positively with specific Anisakis IgE, percentages of proliferation in Anisakis stimulated peripheral blood lymphocytes, serum IL-2 and IL-6, but correlated negatively with mitogen stimulated TGF-β in supernatants.

CONCLUSIONS

DAO levels in CU depend on fish-eating habits and in CU+ on the amount of specific IgE production. In the CU+ phenotype, lower levels of DAO predispose to urticaria exacerbation after fish intake, probably due to a relative insufficient enteric availability of this enzyme.

Different fish-eating habits and cytokine production in chronic urticaria with and without sensitization against the fish-parasite Anisakis simplex

BACKGROUND

Anisakis simplex sensitization has been associated with acute, but also with chronic urticaria. The objective of this study is to characterize chronic urticaria with (CU+) and without sensitization (CU-) against the ubiquitous fish parasite A. simplex in a transversal and longitudinal evaluation.

METHODS

16 CU+ and 22 CU- patients were included and assessed for Urticaria activity score (UAS), fish-eating habits by standardized questionnaire and cytokine production (assessed by flow cytometric bead-based array) of peripheral blood mononuclear cells after stimulation with A. simplex extract or Concanavalin A (Con A). Patients were randomly put on a fish-free diet for three months and UAS, as well as cytokine production were again assessed. A difference of ≥1 in UAS was defined as improvement.

RESULTS

There was no difference in UAS in both groups. Anisakis induced IL-2, IL-4 and IFN-γ production was higher in CU+. Con A induced IL-6 and IL-10 production was higher in CU+. CU+ was associated with higher total fish intake, whereas CU- was associated with oily fish intake. The correlation of UAS was positive with oily fish, but negative with total fish intake. There was a better UAS-based prognosis in CU+ without diet. Improvement was associated with higher Con A induced IL-10/IFN-γ as well as IL-10/IL-6 ratios. Further, previous higher oily fish intake was associated with improvement.

CONCLUSIONS

Our data confirm the different clinical and immunological phenotype of CU+. Our results show a complex relationship between fish-eating habits, cytokine production and prognosis, which could have important consequences in dietary advice in patients with CU. When encountering A. simplex sensitization, patients should not be automatically put on a diet without fish in order to reduce contact with A. simplex products.

Increased mean platelet volume and C-reactive protein levels in patients with chronic urticaria with a positive autologous serum skin test

INTRODUCTION

Activation of the coagulation cascade resulting in thrombin production is a prominent feature of exacerbations in chronic spontaneous urticaria (CU). Autologous serum skin test (ASST) causes wheal-and-flare reactions in 30% to 50% of CU cases.

OBJECTIVE

The aim of this study was to evaluate the clinical and laboratory data in patients with CU with positive and negative ASST. To understand the role of platelets in CU, we investigated the relation between CU clinical severity, platelet count and their mean platelet volume (MPV).

METHODS

Clinical and laboratory data were prospectively collected from 373 patients with CU who attended our Allergy and Clinical immunology Clinic during the period 2003 to 2007. The laboratory data were compared with 46 healthy subjects.

RESULTS

There were no significant differences in platelet counts between the groups, nevertheless the platelets in ASST-positive CU patients were characterized by a higher MPV (9.12 +/- 1.25 fl), than that in ASST-negative patients (7.95 +/- 1.08 fl; P = 0.039) and control group (7.72 +/- 1.04 fl; P = 0.007). There was a significant positive correlation between CU severity score and MPV in ASST-positive patients (r = 0.44; P < 0.001) but not in ASST-negative patients. Higher levels of C-reactive protein (5.31 +/- 2.74 mg/L) were measured in the ASST-positive CU group compared with the ASST-negative CU group (2.53 +/- 1.27; P = 0.029) and the control group (2.34 +/- 1.38; P = 0.003).

CONCLUSION

CU with positive ASST is characterized with higher clinical severity, increased MPV and C-reactive protein.

Leukotriene receptor antagonists in monotherapy or in combination with antihistamines in the treatment of chronic urticaria: a systematic review

In vitro and in vivo clinical and experimental data have suggested that leukotrienes play a key role in inflammatory reactions of the skin. Antileukotriene drugs, ie, leukotriene receptor antagonists and synthesis inhibitors, are a class of anti-inflammatory drugs that have shown clinical efficacy in the management of asthma and in rhinitis with asthma. We searched MEDLINE database and carried out a manual search on journals specializing in allergy and dermatology for the use of antileukotriene drugs in urticaria. Montelukast might be effective in chronic urticaria associated with aspirin (ASA) or food additive hypersensitivity or with autoreactivity to intradermal serum injection (ASST) when taken with an antihistamine but not in mild or moderate chronic idiopathic urticaria [urticaria without any possible secondary causes (ie, food additive or ASA and other NSAID hypersensitivity, or ASST)]. Evidence for the effectiveness of zafirlukast and the 5-lipoxygenase inhibitor, zileuton, in chronic urticaria is mainly anecdotal. In addition, there is anecdotal evidence of effectiveness of antileukotrienes in primary cold urticaria, delayed pressure urticaria and dermographism. No evidence exists for other physical urticarias, including cholinergic, solar and aquagenic urticarias, vibratory angioedema, and exercise-induced anaphylaxis.

New concepts in chronic urticaria

Chronic urticaria is a common skin disease without a clear etiology in the vast majority of cases. The similarity of symptoms and lesion pathology to allergen-induced skin reactions supports the idea that skin mast cell and blood basophil IgE receptor activation is involved; however, no exogenous allergen trigger has been identified. The presence of serum IgG autoantibodies targeting IgE or the IgE receptor in approximately 40% of CIU cases supports the theory of an autoimmune basis for the disease. However, issues remain with the assays to detect autoantibodies among other serum factors, the relationship of autoantibodies to CIU disease activity, and the occurrence of autoantibodies in healthy subjects. Other studies have identified altered IgE receptor degranulation that reverts in disease remission and is accompanied by changes in signaling molecule expression and function in mast cells and basophils in active CIU subjects. The arrival of therapies targeting IgE and the IgE receptor pathway elements has potential use in CIU.