Urticaria and autoimmunity: where are we now?

Common autoimmune diseases and urticaria: the causal relationship from a bidirectional two-sample mendelian randomization study

Objective

The immune response assumes a pivotal role in the underlying mechanisms of urticaria pathogenesis. The present study delves into an investigation of the genetic causal connections between urticaria and prevalent autoimmune afflictions, notably rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), ulcerative colitis (UC), and Crohn's disease (CD).

Methods

A bidirectional two-sample Mendelian randomization (MR) analysis was conducted to investigate the causal relationships involving four autoimmune diseases and urticaria. The genome-wide association study (GWAS) summary data of four autoimmune disease were sourced from the IEU OpenGWAS database. The GWAS summary data for urticaria were derived from the Finnish consortium dataset. The principal analytical approach employed in this study was the random-effects inverse variance weighted (IVW) method. Subsequently, a series of sensitivity analyses were performed, encompassing assessments of heterogeneity, horizontal pleiotropy, outliers, "Leave-one-out" analyses, and tests for adherence to the assumption of normal distribution.

Results

The random-effects IVW analysis indicate a positive genetic causal association between RA and urticaria (P < 0.001, OR 95% CI = 1.091 [1.051-1.133]). Conversely, SLE, UC, and CD do not exhibit a significant genetic causal relationship with urticaria. The reverse MR analysis reveals a positive genetic causal linkage between urticaria and SLE (P = 0.026, OR 95% CI = 1.289 [1.031-1.612]). However, the analysis demonstrates no substantial genetic causal relationship between urticaria and RA, UC, or CD. Importantly, the genetic causal assessment absence of heterogeneity, horizontal pleiotropy, and outliers. Furthermore, it remains unaffected by any individual single nucleotide polymorphism (SNP), demonstrating adherence to a normal distribution.

Conclusion

This investigation establishing RA as a predisposing factor for urticaria. Moreover, urticaria as a plausible risk determinant for SLE. Heightened vigilance is recommended among RA patients to monitor the manifestation of urticaria within clinical settings. Similarly, individuals afflicted by urticaria should duly acknowledge the prospective susceptibility to SLE.

Do Antinuclear Antibodies Influence the Clinical Features of Chronic Spontaneous Urticaria?: A Retrospective Cohort Study

Background

Antinuclear antibody (ANA) is often used as a screening test for autoimmune comorbidities in patients with chronic spontaneous urticaria (CSU). However, the relationship of ANA status and the clinical course of the disease have not been fully described.

Objectives

To compare clinical features of CSU patients who are positive and negative for ANA.

Methods

This was a retrospective cohort study that enrolled CSU patients attending the Urticaria Clinic at Siriraj Hospital from 2013 to 2019. Demographics, clinical characteristics, laboratory investigations, and treatments were collected until July 2021. All patients were investigated for ANA. Clinical feature data was compared between CSU patients with positive ANA and negative ANA groups using the 2-sample t-test and the Mann-Whitney U test for quantitative variables. The chi-squared test or Fisher's exact test was conducted to explore the association of qualitative variables. Disease relapse and remission were analysed via Kaplan-Meier survival analysis.

Results

Of 323 CSU patients, 31% had positive ANA. There were no significant differences in disease severity or impairment in quality of life. Patients with a positive ANA test had significantly lower prevalence of allergic rhinitis (p = .048) and significantly higher level of erythrocyte sedimentation rate (p = 0.007). Kaplan-Meier survival analysis showed that 2% of ANA positive CSU patients achieved remission status after one year and 28% did so after five years. There was no statistically significant difference in time to remission and time to relapse between ANA-positive and negative groups.

Conclusion

Positive ANA in CSU patients could not indicate the differences in main disease characteristics from the ANA-negative CSU patients. Investigation for ANA may be useful in CSU patients who are suspected of having autoimmune diseases.

Rationale for the autologous serum skin test in acute versus chronic urticaria

Introduction

Autologous serum skin test (ASST) is a rapid, in-vivo clinical test to detect functional autoantibodies in patients with chronic spontaneous urticaria (CSU), but the rationale for its use in acute urticaria (AU) is unknown.

Aim

To evaluate the efficacy of ASST among patients with AU or CSU.

Material and methods

Treatment-naïve adult (age ≥ 18 years) patients with a diagnosis of AU (< 6 weeks’ duration) and CSU were enrolled prospectively in a cross-sectional study. Healthy age- and sex-matched subjects served as controls. Besides a detailed history and physical examination, ASST, total immunoglobulin E (IgE), freeT3 (fT3), freeT4 (fT4), anti-thyroglobulin, and anti-TPO levels were assessed in all subjects.

Results

Of 101 subjects, mean age was 34.35 ±12.68 years and the study comprised 58.4% of females with no difference between AU (n = 27), CSU (n = 46), and control groups (n = 28). The ratio of positivity in ASST was similar between AU (25.9%) and CSU groups (21.7%), but higher than in controls (10.7%, p = 0.33 for all). The ratio of patients with high total IgE levels (> 100 IU/ml) in AU (85.2%) and CSU (65.2%) groups was similar (p = 0.06), but significantly higher than in the control group (10.7%) (p< 0.001 and p< 0.001). The CSU group had significantly higher abnormal thyroid test results (45.7%) than AU (14.8%) and control groups (3.6%) (p = 0.01 and p< 0.001), whereas patients with clinically diagnosed thyroiditis were only in the CSU group (6.5%). In logistic regression analysis, there was no relation found among the possible risk factors for ASST, even if analysed separately as AU, CSU and control groups.

Conclusions

Even though thyroid function test levels were found to be related with CSU, and total IgE was associated with urticaria, ASST was found to be of importance. This study confirms that ASST was insufficient to demonstrate autoimmunity and acute-chronic urticaria nature. Further tests indicating auto-antibodies in AU and CSU are needed.

FACTORS CONTRIBUTING TO CHRONIC URTICARIA/ANGIOEDEMA AND NUMMULAR ECZEMA RESOLUTION - WHICH FINDINGS ARE CRUCIAL?

When working with dermatology patients, the question sometimes arises which diagnostic tests and tools should be used for workup, particularly in cases of chronic urticaria (CU) and discoid nummular eczema, where the treatment of associated systemic diseases and infections may be crucial for patient outcome. The aim was to investigate retrospectively the influence of associated diseases on skin disease outcomes based on medical records of CU and nummular eczema patients in comparison to controls. We included patients admitted to our Dermatology Department over a 6-year period and analyzed their laboratory findings, related factors and outcomes recorded after two years of workup and treatment. Compared to controls, CU patients had a significantly higher prevalence of positive Helicobacter (H.) pylori findings (p=0.020), confirmed allergies (p=0.006), increased IgE (p=0.011) and pathologic thyroid findings (p=0.049), whereas nummular eczema patients only had significantly higher positive H. pylori findings (p=0.046). Meaningful regression of both dermatoses was recorded after treatment of associated diseases, with significant benefit from H. pylori treatment. This indicated that the diagnosis of associated infections (particularly H. pylori and urogenital infections), confirmed allergies, endocrine disorders (particularly of thyroid gland in CU patients) and serum malignancy markers could play a crucial role, as their treatment may improve disease outcomes.

Thyroid Autoimmunity and Autoimmunity in Chronic Spontaneous Urticaria Linked to Disease Severity, Therapeutic Response, and Time to Remission in Patients with Chronic Spontaneous Urticaria

Background

Chronic spontaneous urticaria (CSU) is autoimmune in nature and associated with thyroid autoimmunity (TA), but evidence on autoimmunity in relation to CSU progression and prognosis is limited. We evaluated whether TA and autoimmunity in CSU are correlated with disease severity, therapeutic response, and time to remission and establish an association between CSU characteristics linked to thyroid autoantibody.

Methods

Medical records of patients diagnosed with urticaria attending outpatient dermatology clinic at a university-based hospital from 2013 to 2017 were retrospectively reviewed. Data on the clinical characteristics, laboratory investigations particularly thyroid antibody titers, autologous serum skin test (ASST) and autologous plasma skin test (APST) results and their link to disease severity, treatments, and time to remission of CSU patients were analyzed.

Results

Of 1,096 patients with urticaria, 60.2% had CSU. Three-hundred patients fulfilled the inclusion criteria for CSU with complete thyroid antibody testing. Positive TA was significantly associated with female gender and age > 35 years (p = 0.008). Antithyroid peroxidase (anti-TPO)-positive patients suffered from CSU longer than 12 and 18 months compared to anti-TPO-negative patients (100.0% vs. 82.6%, p = 0.042, and 100.0% vs. 75.9% p = 0.020, respectively). The presence of urticarial attacks > 4 days/week was significantly seen in ASST and APST-positive patients compared to those without (84.6% vs. 61.3%, p = 0.011, and 85.3% vs. 61.8%, p = 0.006, respectively). Positive APST patients were more difficult to treat than those with negative results (61.2% vs. 37.8%, p = 0.017).

Conclusions

Antithyroid peroxidase is a predictor of time to remission, while autologous skin testing is linked to disease severity (ASST and APST) and therapeutic response (APST) in CSU patients.

Pathogenic mechanisms of IgE-mediated inflammation in self-destructive autoimmune responses

Autoantibodies of the IgG subclass are pathogenic in a number of autoimmune disorders such as systemic lupus erythomatosus. The presence of circulating IgE autoantibodies in autoimmune patients has also been known for almost 40 years. Despite their role in allergies, IgE autoantibodies are not associated with a higher rate of atopy in these patients. However, recently they have been recognized as active drivers of autoimmunity through mechanisms involving the secretion of Type I interferons by plasmacytoid dendritic cells (pDC), the recruitment of basophils to lymph nodes, and the activation of adaptive immune responses through B and T cells. Here, we will review the formation, prevalence, affinity, and roles of the IgE autoantibodies that have been described in autoimmunity. We also present novel evidence supporting that triggering of IgE receptors in pDC induces LC3-associated phagocytosis, a cellular process also known as LAP that is associated with interferon responses. The activation of pDC with immune complexes formed by DNA-specific IgE antibodies also induce potent B-cell differentiation and plasma cell formation, which further define IgE's role in autoimmune humoral responses.

Urticaria: "You're Probably Just Allergic to Something"

Urticaria is a common symptom seen in pediatric patients, and it has multiple allergic and nonallergic causes. Unfortunately, it is far too common that when children present acutely for urticaria, they are told that it is an "allergy." This statement often leads to increased anxiety while the patient waits to be evaluated by an allergist/immunologist. This article discusses the frequency that allergic reactions are involved in urticaria and provides examples of potential nonallergic causes. Additionally, the article discusses approaches to treatment that may be appropriate to initiate in the pediatrician's office or acute setting. This article is intended to provide a broader understanding of urticaria and its management in the outpatient or emergency setting so that we are able to tell our patients more than"you're probably just allergic to something." [Pediatr Ann. 2016;45(11):e399-e402.].

Comorbidity and pathogenic links of chronic spontaneous urticaria and systemic lupus erythematosus--a systematic review

Chronic spontaneous urticaria (CSU) is a common mast cell-driven disease characterized by the development of wheals (hives), angioedema (AE), or both for > 6 weeks. It is thought that autoimmunity is a common cause of CSU, which is often associated with autoimmune thyroiditis, whereas the link to other autoimmune disorders such as systemic lupus erythematosus (SLE) has not been carefully explored. Here, we systematically reviewed the existing literature for information on the prevalence of CSU in SLE (and vice versa) and we examined the possible clinical and pathogenetic relationship between CSU and SLE. The prevalence of CSU and CSU-like rash in SLE was investigated by 42 independent studies and comorbidity in adult patients reportedly ranged from 0% to 21.9% and 0.4% to 27.5%, respectively (urticarial vasculitis: 0-20%). In children with SLE, CSU was reported in 0-1.2% and CSU-like rash in 4.5-12% (urticarial vasculitis: 0-2.2%). In contrast, little information is available on the prevalence of SLE in patients with CSU, and more studies are needed to determine the rate of comorbidity. Recent insights on IgG- and IgE-mediated autoreactivity suggest similarities in the pathogenesis of CSU and SLE linking inflammation and autoimmunity with the activation of the complement and coagulation system. Future studies of patients with either or both conditions could help to better define common pathomechanisms in CSU and SLE and to develop novel targeted treatment options for patients with CSU and SLE.

A prospective ten-year follow-up of patients with chronic urticaria

BACKGROUND

Chronic urticaria can be the initial clinical presentation of a number of different diseases. The objective of the present study was to report the associated diseases during a ten-year clinical-laboratory follow-up in patients with an initial diagnosis of chronic spontaneous urticaria (CSU) of unknown cause.

METHODS

A prospective, longitudinal cohort study with a ten-year clinical-laboratory follow-up was conducted. Patients with a history of urticarial plaques of over six weeks presenting as the only clinical symptom were selected. Individuals with other clinical conditions, urticaria of known causes or chronic physical urticaria were excluded. The following tests were initially performed: haemogram, urine type I, stool parasite exam and sedimentation rate. The following exams were ordered during follow-up: PPD; urine culture; serology tests; antithyroid and antinuclear antibodies, rheumatoid factor, lupus anticoagulant; thyroid hormones; serum immunoglobulin; paranasal sinus and thorax radiographs; testing for BK and Helicobacter pylori; and prick tests.

RESULTS

Infections were diagnosed in 29% of patients (syphilis, parasitosis, H. pylori, urinary infection, tuberculosis, hepatitis B and C); autoimmune diseases in 21% (thyroiditis, rheumatoid arthritis and antiphospholipid antibody syndrome); primary immunodeficiencies in 4% (IgA and IgG2 deficiencies); and chronic myeloid leukaemia in 1%. At ten-years of follow-up, the urticaria diagnosis was CSU of unknown cause in 45% of the cases.

CONCLUSION

This ten-year clinical-laboratory follow-up of 100 individuals with chronic urticaria as the initial diagnosis revealed the presence of associated diseases in over half of the cases. The most prevalent diseases were infections and autoimmune diseases besides primary immunodeficiencies and blood diseases.

Role of IgE in autoimmunity

There is accumulating evidence to suggest that IgE plays a significant role in autoimmunity. The presence of circulating self-reactive IgE in patients with autoimmune disorders has been long known but, at the same time, largely understudied. However, studies have shown that the increased IgE concentration is not associated with higher prevalence for atopy and allergy in patients with autoimmune diseases, such as systemic lupus erythematosus. IgE-mediated mechanisms are conventionally known to facilitate degranulation of mast cells and basophils and promote TH2 immunity, mechanisms that are not only central to mounting an appropriate defense against parasitic worms, noxious substances, toxins, venoms, and environmental irritants but that also trigger exuberant allergic reactions in patients with allergies. More recently, IgE autoantibodies have been recognized to participate in the self-inflicted damaging immune responses that characterize autoimmunity. Such autoimmune responses include direct damage on tissue-containing autoantigens, activation and migration of basophils to lymph nodes, and, as observed most recently, induction of type 1 interferon responses from plasmacytoid dendritic cells. The importance of IgE as a central pathogenic mechanism in autoimmunity has now been clinically validated by the approval of omalizumab, an anti-IgE mAb, for patients with chronic spontaneous urticaria and for the clinical benefit of patients with bullous pemphigoid. In this review we summarize recent reports describing the prevalence of self-reactive IgE and discuss novel findings that incriminate IgE as central in the pathogenesis of inflammatory autoimmune disorders.

Effect of Levothyroxine Treatment on Clinical Symptoms in Hypothyroid Patients with Chronic Urticaria and Thyroid Autoimmunity

BACKGROUND

Thyroid autoimmunity has been increasingly reported to be associated with chronic urticaria (CU), and the possible clinical benefit of thyroid hormone or anti-thyroid drugs in some CU patients with autoimmune thyroid disease has been studied. However, the effect of thyroid hormone or anti-thyroid drugs on clinical symptoms of CU remains unclear.

OBJECTIVE

We investigated the clinical response of urticaria to the treatment of thyroid dysfunction.

METHODS

Medical records of patients with CU evaluated for thyroid autoimmunity and thyroid function were collected and reviewed.

RESULTS

Of 184 patients with CU, 43 patients (23.4%) had thyroid autoantibodies and 26 patients (14.1%) had thyroid dysfunction. While none of the five patients with Graves' disease showed any improvement of urticaria after treatment with anti-thyroid drugs, two of the 10 patients with Hashimoto's thyroiditis showed improved urticaria after being treated with levothyroxine.

CONCLUSION

Although levothyroxine treatment was effective in a minority of patients with CU, there may be a causal relationship between CU and thyroid autoimmunity.

Chronic spontaneous urticaria: latest developments in aetiology, diagnosis and therapy

Chronic urticaria is a debilitating disease characterized by itching and hives with or without angioedema lasting for more than 6 weeks. The disease carries a significant emotional and economic burden for the patient and often results in an odyssey between doctors of different specialities. Patients suffering from chronic urticaria are considered more difficult to satisfy, treat and to have a bigger emotional burden than the average patient in dermatology, paediatric and general practice settings. A joint initiative under the Dermatology section of the European Academy of Allergy and Clinical immunology (EAACI), the Global Allergy and Asthma European Network (GA(2)LEN), the European Dermatology Forum (EDF) and the World Allergy Organization (WAO) has resulted in recently published guidelines for the diagnosis, classification and treatment of chronic urticarial: these guidelines are clinically useful and have a high success rate when followed in daily clinical practice. The treatment of choice for chronic urticaria is still nonsedating antihistamines although other treatments are available, with omalizumab (humanized IgG anti IgE antibodies) as the newest therapy. The pathogenesis of urticaria is poorly understood but autoimmunity is considered as one of the major underlying causes for this disease, although other theories exist.

The potential role of omalizumab in the treatment of chronic urticaria

Treatment of chronic urticaria refractory to antihistamines presents a challenge to both people affected with the disease as well as the physicians who treat them. Omalizumab, a monoclonal antibody against IgE, has emerged as one potential solution to this challenge. In several clinical trials published between 2011 and 2013, omalizumab significantly reduced or eliminated symptoms of chronic urticaria. The optimal dose for chronic urticaria is 300 mg administered every 4 weeks, a dose that differs from those used in asthma, which are based on the patient's weight and IgE level. Omalizumab does not appear to cause lasting symptom remission, and the ideal duration of treatment for chronic urticaria has not been defined.

Update on rupatadine in the management of allergic disorders

In a review of rupatadine published in 2008, the primary focus was on its role as an antihistamine, with a thorough evaluation of its pharmacology and interaction with histamine H1 -receptors. At the time, however, evidence was already emerging of a broader mechanism of action for rupatadine involving other mediators implicated in the inflammatory cascade. Over the past few years, the role of platelet-activating factor (PAF) as a potent mediator involved in the hypersensitivity-type allergic reaction has gained greater recognition. Rupatadine has dual affinity for histamine H1 -receptors and PAF receptors. In view of the Allergic Rhinitis and its Impact on Asthma group's call for oral antihistamines to exhibit additive anti-allergic/anti-inflammatory properties, further exploration of rupatadine's anti-PAF effects was a logical step forward. New studies have demonstrated that rupatadine inhibits PAF effects in nasal airways and produces a greater reduction in nasal symptoms than levocetirizine. A meta-analysis involving more than 2500 patients has consolidated the clinical evidence for rupatadine in allergic rhinoconjunctivitis in adults and children (level of evidence Ia, recommendation A). Other recent advances include observational studies of rupatadine in everyday clinical practice situations and approval of a new formulation (1 mg/ml oral solution) for use in children. In this reappraisal, we revisit some key properties and pivotal clinical studies of rupatadine and examine new clinical data in more detail including studies that measured health-related quality of life and studies that investigated the efficacy and safety of rupatadine in other indications such as acquired cold urticaria, mosquito bite allergy and mastocytosis.