Abstract

Chronic urticaria is a prevalent disabling dermatological disease. About 90%, are considered idiopathic and referred to as chronic spontaneous urticaria (CSU), and nearly half of them are likely to have autoimmune mechanisms.  Regulatory T cells play a substantial role to prevent autoimmune diseases. Subsets of Tregs expressing the CD4⁺CD25^high and forkhead-box-P3 (FOXP3) transcription factor, crucial for their development and function, are best characterized in maintenance of self-tolerance. The objective of this study was the analysis of peripheral CD4⁺CD25^highFOXP3⁺(T regs) frequency in chronic spontaneous urticaria; and its possible association with  autologous serum skin test (ASST). Fifty chronic spontaneous urticaria patients (25 with positive ASST and 25 with negative ASST) and 20 healthy controls were enrolled in this study. The frequency of CD4⁺CD25^highFOXP3⁺ (T regs) was analyzed by flow cytometry. A Significant decrease in peripheral blood CD4⁺CD25^highFOXP3⁺ T regs% was detected in CSU patients in comparison to healthy individuals (median [IQR], 1.47% [0.71–3.12] vs 1.79% [1.15–4.00]; P = 0.05). When ASST positive patients were compared with ASST negative patients, no significant difference was found in percentage of T regs, (P=0.112). In conclusion our data provided further insights into CSU pathogenesis. Reduced frequency of CD4⁺CD25^highFOXP3⁺(Tregs) in patients with urticaria, support the notion that CSU is an immune mediated disease and may help researchers to develop a novel immunotherapy strategy.

Keywords: Regulatory T cells: T regs, CD25, Forkhead-box-P3: FOXP3, chronic spontaneous urticaria: CSU, Autologous Serum Skin Test: ASST.

Date received: 23 March 2021; accepted: 22 July 2021

PMID: 34453789