Different Frequencies of Tc17/Tc1 and Th17/Th1 Cells in Chronic Spontaneous Urticaria

Background: Chronic urticaria is associated with an immune dysregulation usually mediated by T lymphocytes. Recently, Th17 and Tc17 have been implicated in autoimmune diseases; however, their role in urticaria is not clear yet. Methods: For the study we recruited 20 patients [10 of them had autoreactive chronic spontaneous urticaria (positive autologous intradermal serum test response, ASST+), and the other 10 were nonautoreactive chronic spontaneous urticaria patients (ASST-)] and 17 healthy age-and gender-matched controls (HG). The frequency and functional activity of Th17/Tc17 and Th1/Tc1 cells were evaluated by flow cytometry and type 2 cytokine mRNA by real-time PCR. Results: Our results demonstrated a significant decrease in Th17 frequency in both chronic urticaria groups compared to HG; regarding the amount of IL-17, at the single cell level, it was reduced in ASST-compared to HG. Concerning the Th1 and Th17 cells producing IFN-gamma, IL-2, and TNF-alpha, a lower frequency was noted in chronic urticaria patients compared to HG. In contrast, a significantly increased frequency of Tc1 cells producing these cytokines was noted in ASST+ compared to HG and ASST-. Also, the frequency of Tc17 cells producing TNF-alpha was increased in ASST+ compared to HG; however, with respect to the amount of TNF-alpha, at the single cell level, we found a decrease in ASST+ compared to HG. Regarding type 2 cytokine mRNA, a higher expression was verified in ASST+ compared to HG. Conclusion: Our data suggest a probable involvement of cytotoxic T cells, mainly the Tc1 and Tc17 subsets, in chronic urticaria, particularly in the ASST+ group. Copyright (C) 2013 S. Karger AG, Basel