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-γ, IL-2, and TNF-α, 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-α was increased in ASST+ compared to HG; however, with respect to the amount of TNF-α, 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.


CONCLUSIONS
Our data suggest a probable involvement of cytotoxic T cells, mainly the Tc1 and Tc17 subsets, in chronic urticaria, particularly in the ASST+ group.
Blood and Transplantation Center of Coimbra, Portuguese Institute of Blood and Transplantation, Coimbra, Portugal.
Ana
A
Lopes
Daniel
D
Machado
Susana
S
Pedreiro
Ana
A
Henriques
Isabel
I
Silva
Beatriz
B
Tavares
Maria Jesus
MJ
Inácio
Celso
C
Chieira
António
A
Martinho
Maria Luísa
ML
Pais
Celso
C
Pereira
Artur
A
Paiva
D000328:Adult; D016207:Cytokines / Q000235:genetics / Q000276:immunology; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000276:immunology; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000737:chemistry / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D013602:T-Lymphocytes, Cytotoxic / Q000166:cytology / Q000276:immunology*; D018417:Th1 Cells / Q000166:cytology / Q000276:immunology*; D058504:Th17 Cells / Q000166:cytology / Q000276:immunology*; D014581:Urticaria / Q000097:blood / Q000276:immunology*
D016207:Cytokines; D012333:RNA, Messenger