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

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.

Novel Application of Immunochromatographic Assay for Measurement of Total Tear Immunoglobulin E

PURPOSE

The aim of this study was to evaluate the efficacy of a new immunochromatographic assay (Aifeice) in the diagnosis of allergic conjunctivitis diseases (ACDs) and to explore the relationship between Aifeice testing results and the severity of ACDs.

METHODS

A multicenter prospective cross-sectional study (390 patients diagnosed with ACDs and 619 healthy controls) was conducted. Patients with ACDs were scored based on clinical symptoms. All participants received the Aifeice test. The positive testing results were further divided into 3 immunoglobulin E (IgE) grades. Statistical analysis was performed to evaluate the indexes associated with the testing results.

RESULTS

The sensitivity, specificity, positive predictive value, negative predictive value, and total coincidence rate of the Aifeice test were 96.15%, 98.87%, 98.17%, 97.61%, and 97.82%, respectively. The total clinical score was significantly correlated with the IgE grade. The factors that affected the IgE score were conjunctival hyperemia, conjunctival swelling, conjunctival papillae, and Horner-Trantas dots.

CONCLUSIONS

The high sensitivity and specificity of Aifeice in the diagnosis of ACD was confirmed. This new immunochromatographic assay could be used to assess the severity of ACD.

A comparative study of chronic spontaneous urticaria and chronic mast cell mediated angioedema

Background: Mast cell-mediated angioedema (MC-AE) is considered a form of chronic spontaneous urticaria (CSU). Objective: To investigate the clinical and laboratory features that distinguish MC-AE from antihistamine-responsive CSU (CSU), and antihistamine-resistant CSU (R-CSU) with and without concomitant AE. Methods: A retrospective observational study using the electronic patient record data base of patients with MC-AE, CSU, R-CSU, and sex- and age-matched control group (control), with a case-control ratio of 1:2. Results: A total of 986 subjects in the CSU group, 148 in the R-CSU group, 64 in the MC-AE group, and 1198 in the control group were compared. The R-CSU group without AE was characterized by lower total IgE levels (118.5 ± 84.7 IU/mL) and higher High sensitivity-C reactive protein (hs-CRP) levels (138.9 ± 94.2 IU/mL, p = 0.027; and 7.4 ± 6.9 mg/L versus 5.1 ± 6.8 mg/L, p = 0.001) than the CSU without AE group. The R-CSU group with AE was characterized by lower total IgE levels (112.1 ± 81.3 IU/mL) than the CSU group with AE (141.7 ± 89.5 IU/mL; p < 0.001), higher hs-CRP levels (7.1 ± 6.1 mg/L versus 4.7 ± 5.9 mg/L; p < 0.001). There were fewer female subjects in the MC-AE group (31 [48.4%]) than in the CSU with AE and in the R-CSU with AE 223 (67.8%) and 18 (66.7%), respectively; p = 0.012). MC-AE group was characterized by less eyelid/perioral/facial involvement and more limb involvement than in the CSU with AE and R-CSU with AE groups (p < 0.001). Conclusion: Low IgE in MC-AE and higher IgE in CSU may signify two distinct types of immune dysregulation. Due to clinical and laboratory differences between MC-AE and CSU, we suggest questioning the assumption that MC-AE is a form of CSU.

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.