Basophil CD63 expression in chronic spontaneous urticaria: correlation with allergic sensitization, serum autoreactivity and basophil reactivity

Atopy in chronic urticaria: an important yet overlooked issue

Chronic urticaria (CU) is one of the most common dermatological diseases and has a significant impact on the quality of life of patients. However, the pathogenesis of this disease remains unclear. Autoimmunity in chronic spontaneous urticaria (CSU) has received considerable attention and has been studied previously. Atopy is an important characteristic of CU; however, it has not been fully recognized. Atopy predisposes individuals to immune responses to allergens, leading to type 2 inflammation and immunoglobulin E (IgE) overproduction. Compared with healthy individuals, patients with CU have a higher proportion of atopy, and an atopic background is correlated with the clinical characteristics of CU. The total IgE levels in patients with CU is significantly higher than those in healthy individuals. Although its level is not higher than that in classic allergic diseases, it is closely related to CU. Exogenous allergens, auto-allergens, and specific IgEs, which are closely related to atopy, have been reported, and their roles in CU pathogenesis are also being studied. Local and systemic atopic inflammation is present in patients with CU. This review summarizes the current knowledge regarding atopy and CU, speculating that there are CU subtypes, such as atopic CSU or atopic chronic inducible urticaria (CIndU) and that atopy may be involved in the pathogenesis of CU. These findings provide a new perspective for a comprehensive understanding of the clinical features of CU and further research regarding its pathogenesis.

Evaluation of Pediatric Chronic Urticaria with Emphasis on Clinical and Laboratory Characteristics and Treatment Response to Omalizumab: A Real-Life Experience from a Tertiary Allergy Center

Pediatric data on the clinical and etiologic features, treatment response, and use of omalizumab for chronic urticaria (CU) are quite limited. The aim of this study was to evaluate the clinical and demographic characteristics, laboratory findings, and response to treatment of CU in children. Children with a diagnosis of CU between 2019 and 2023 were included in the study. Information on demographic characteristics, clinical features, laboratory tests, provocation tests for inducible urticaria, urticaria activity scores (UAS7), and treatment responses were obtained from patients' medical records. A total of 150 children (50.7% male) with CU were enrolled in the study. A total of 14 (9.3%) patients had autoimmune diseases of which 11 (7.3%) had autoimmune thyroiditis. Overall, 97 (64.7%) patients had chronic spontaneous urticaria (CSU) and 53 (35.3%) had chronic inducible urticaria. A total of 16 patients who remained symptomatic despite high-dose antihistamines were treated with omalizumab, with a good response in 13 (81.3%) and a partial response in 3 (18.7%) patients. CSU accounts for the majority of pediatric CU, with the etiology being in part related to an autoimmune background. This study provides an overview of CU in children and demonstrates the safety and efficacy of treatment with omalizumab.

Positive Basophil Tests Are Linked to High Disease Activity and Other Features of Autoimmune Chronic Spontaneous Urticaria: A Systematic Review

BACKGROUND

Chronic spontaneous urticaria (CSU) is believed to be Autoimmune (aiCSU) (type IIb CSU) in at least 8% of patients, associated with mast cell-activating IgG autoantibodies. Basophil tests such as the basophil activation test (BAT) and basophil histamine release assay (BHRA) are considered the best single tests for an aiCSU diagnosis. To date, the strength of associations among a positive BAT and/or BHRA (BAT/BHRA+) and CSU features, patient demographics, and response to treatment remains poorly characterized.

OBJECTIVE

To evaluate the strength of current evidence on basophil tests as parameters for CSU characteristics.

METHODS

We performed a systematic literature search and review to assess the relationship between BAT/BHRA+ and clinical and laboratory parameters of CSU. Of 1,058 records found in the search, 94 studies were reviewed by experts in urticaria and 42 were included in the analysis.

RESULTS

In CSU patients, BAT/BHRA+ showed a strong level of evidence for an association with high disease activity and low levels of total IgE. A weak level of evidence was shown for the association of BAT/BHRA+ and the presence of angioedema, and basopenia.

CONCLUSIONS

Our results suggest that aiCSU defined by BAT/BHRA+ is more active or severe and is linked to other aiCSU markers such as low total IgE/basopenia. Basophil tests should be standardized and implemented in routine clinical care to improve the diagnosis and treatment of patients with aiCSU.

Noninvasive and simultaneous quantitative analysis of multiple human blood components based on the grey analysis system

Noninvasive detection of human blood components is the dream of human beings and the goal of clinical detection. From the perspective of mathematical analysis, based on the grey analysis system, the principle of spectral chemical quantitative analysis and the solution method of multivariate linear equation, this paper pioneers the spectrum elimination method, and obtains a complete, high-precision, synchronous and noninvasive detection system for a variety of human blood components. The spectral elimination method applies the principle of elimination method in mathematics to the noninvasive quantitative analysis of human blood components by spectral method, reduces the influence of non-target components on the detection of target components, and improves the accuracy of noninvasive quantitative analysis of human blood components. To demonstrate the effectiveness of the method, taking the analysis of the contents of seven blood components (hemoglobin, red blood cell count, neutrophils, lymphocytes, monocytes, eosinophils and basophils) in blood as an example, fourteen models were established by two different methods. From the comparison of modeling results, it can be concluded that when the seven models established by spectral elimination method predict the corresponding seven components of all samples, the predicted correlation coefficients are more than 0.9500. The experimental results show that the spectral elimination method and non-invasive detection system proposed can predict the content of human blood components with high accuracy. This paper studies a high-precision, simultaneous and noninvasive quantitative analysis system of multiple human blood components for the first time, which not only makes great progress in the non-invasive chemical quantitative analysis of human blood components by spectroscopy, but also has great application value for clinical medical treatment and disease diagnosis.

Aeroallergens in Atopic Dermatitis and Chronic Urticaria

PURPOSE OF REVIEW

While aeroallergens are a well-established trigger of asthma and allergic rhinitis, their role in allergic skin diseases such as atopic dermatitis and chronic urticaria remains controversial. This paper reviews the pathophysiology and clinical evidence for aeroallergens in these allergic skin diseases and summarizes current strategies for evaluation and management.

RECENT FINDINGS

Current evidence implicates aeroallergens as triggers of cutaneous reactions in atopic dermatitis. Direct skin contact is the likely route of trigger. Aeroallergens may also trigger chronic urticaria, though mechanistic studies are limited. These allergens may cross the skin barrier and directly trigger neurons to release substance P, resulting in mast cell degranulation and dumping of histamine and prostaglandin D2. Many studies link aeroallergen sensitization to chronic urticaria, and case reports suggest the utility of avoidance strategies. The role of aeroallergens as a trigger is clear in atopic dermatitis and becoming emergent in chronic urticaria. Skin prick testing or serum-specific immunoglobulin E testing may be used to determine sensitivities. Management at this time centers on avoidance, and further studies are necessary to evaluate the efficacy of aeroallergen immunotherapy for both conditions.

Mast cell activation tests by flow cytometry: A new diagnostic asset?

Since the late nineties, evidence has accumulated that flow-assisted basophil activation test (BAT) might be an accessible and reliable method to explore the mechanisms governing basophil degranulation and diagnostic allowing correct prediction of the clinical outcome following exposure to the offending allergen(s) and cross-reactive structures for different IgE-dependent allergies and particular forms of autoimmune urticaria. Although the BAT offers many advantages over mediator release tests, it is left with some weaknesses that hinder a wider application. It is preferable to perform the BAT analysis within 4 h of collection, and the technique does not advance diagnosis in patients with non-responsive cells. Besides, the BAT is difficult to standardize mainly because of the difficulty to perform large batch analyses that might span over several days. This article reviews the status of flow cytometric mast cell activation test (MAT) using passively sensitized mast cells (MCs) with patients' sera or plasma (henceforth indicated as passive MAT; pMAT) using both MC lines and cultured MCs in the diagnosis of IgE-dependent allergies. In addition, this paper provides guidance for generating human MCs from peripheral blood CD34⁺ progenitor cells (PBCMCs) and correct interpretation of flow cytometric analyses of activated and/or degranulating cells. With the recent recognition of the mas-related G protein-coupled receptor X2 (MRGPRX2) occupation as a putative mechanism of immediate drug hypersensitivity reactions (IDHRs), we also speculate how direct activation of MCs (dMAT)-that is direct activation by MRGPRX2 agonists without prior passive sensitization-could advance paradigms for this novel endotype of IDHRs.

Predicting inadequate treatment response in children with chronic spontaneous urticaria

BACKGROUND

We aimed to investigate the treatment response and associated factors for loss of control in children with chronic spontaneous urticaria (CSU).

METHODS

A total of 240 CSU patients (aged 0-17 years) were enrolled in a single-center study in Korea from May 2014 to May 2019. We retrospectively reviewed the medical records and compared the duration of treatment and step of medications using the urticaria control test (UCT, range 0-16 points). Serum total immunoglobulin levels, eosinophil count, allergic sensitization, autologous serum skin test, antinuclear antibody, thyroid function test, erythrocyte sedimentation rate, and C-reactive protein were measured. The patients were divided into well-controlled (sustained UCT ≥12), partly controlled (fluctuating UCT around 12), and poorly controlled (sustained UCT <12) groups.

RESULTS

Of the 240 children, 150 (62.5%) achieved well-controlled status; 74 (30.8%), partly controlled; and 16 (6.7%), poorly controlled. Longer duration (adjusted odds ratio: 1.09, 95% confidence interval: 1.05-1.13, P < .001) and higher treatment steps (5.61, 2.82-11.14, P < .001) for reaching the initial 12 points or more of UCT score, initial urticaria activity score (UAS) score (1.06, 1.03-1.09, P < .001), and food sensitization (1.88, 1.03-3.46, P = .041) were associated with inadequate treatment response. The mean duration to symptom free for 1 month without medication was 14.6 months in the well-controlled group and 22.1 months in the partly controlled group (P = .002).

CONCLUSION

Children with CSU have a good treatment response. Longer duration and higher treatment step until the initial disease control, higher initial UAS7 score, and food sensitization can predict inadequate treatment response.