CD8(+) T lymphocyte is a main source of interferon-gamma production in Takayasu’s arteritis

Interferon-gamma (IFN-γ) is a cytokine involved in the pathogenesis of Takayasu’s arteritis (TAK). However, the source of IFN-γ in TAK patients is not fully clear. We aimed to investigate the source of IFN-γ in TAK. 60 TAK patients and 35 health controls were enrolled. The lymphocyte subsets of peripheral blood were detected by flow cytometry, cytokines were detected by Bio-plex. The correlation among lymphocyte subsets, cytokines and disease activity indexes was analyzed by person correlation. The level of serum IFN-γ in TAK patients was significantly increased (P < 0.05). The percentage of CD3(+)IFN-γ(+) cells in peripheral blood CD3(+) cells was significantly higher in TAK patients than that of healthy control group (P = 0.002). A higher proportion of CD3(+)CD8(+)IFN-γ(+) cells/CD3(+)IFN-γ(+) cells (40.23 ± 11.98% vs 35.12 ± 11.51%, P = 0.049), and a significantly lower CD3(+)CD4(+)IFN-γ(+)/ CD3(+)CD8(+)IFN-γ(+) ratio (1.34 ± 0.62% vs 1.80 ± 1.33%, P = 0.027) were showed in the TAK group than that of control group. The CD3(+)CD8(+)IFN-γ(+)/CD3(+)IFN-γ(+) ratio was positively correlated with CD3(+)IFN-γ(+)cells/ CD3(+)cells ratio (r = 0.430, P = 0.001), serum IFN-γ level (r = 0.318, P = 0.040) and IL-17 level (r = 0.326, P = 0.031). It was negatively correlated with CD3(+)CD4(+)IFN-γ(+)/CD3(+)IFN-γ(+) ratio (r = − 0.845, P < 0.001). IFN-γ secreted by CD3(+)CD8 (+) T cells is an important source of serum IFN-γ in TAK patients.