The role of CD8 Granzyme B T cells in the pathogenesis of Takayasu's arteritis.

Objective: T cell-mediated immune response plays a key role in Takayasu arteritis (TAK). Although previous studies have showed the roles of CD4T cell and its subsets in TAK, the change of CD8 T cell subsets remains unclear. This study investigated the role of CD8 T cell subsets in TAK.

Methods: The study consisted of 56 TA patients and 51 healthy controls. The percentages of CD8T cells, CD8GranzymeB T cells, CD8Perforin T cells, and CD8IFN-γ T cells in blood samples were analyzed by flow cytometry.

Results: We found that the percentages of CD8GranzymeB T cells (P = 0.030), CD8Perforin T cells (P = 0.000), and CD8IFN-γ T cells (P = 0.002) in CD8T cells were higher in TAK patients compared to control group. After 6 months of treatment, the proportion of CD8T cells in lymphocytes were significantly lower in TAK patients than the baseline assessment (P = 0.033). A lower ratio of CD8GranzymeB T cells/CD8 T cells were showed in TAK patents after treatment compared with TAK patients before treatments (P = 0.011). The change of CD8GranzymeB T cells/CD8 T cells ratio was positively correlated with the change of ITAS (r = 0.721, P = 0.002) and ITAS-A (r = 0.637, P = 0.008). Finally, the immunofluorescence staining showed the infiltration of CD8 Granzyme B cells in the aortic tissue of TAK patients.

Conclusion: Our results disclose that the CD8 T lymphocytes may play a role in TAK pathogenesis. Targeting CD8GranzymeB T lymphocytes or Granzyme B inhibitors could be a potential therapeutic approach for the treatment of TAK. Key Points • Our study investigated role the of CD8 T cell subsets in TAK. • We found the percentages of CD8GranzymeB T cells, CD8Perforin T cells, and CD8IFN-γ T cells in CD3CD8T cells were higher in TAK patients. • The proportion of CD8T cells in lymphocytes and the ratio of CD8GranzymeB T cells/CD8 T cells were significantly lower in TAK patients after treatment.