Circulating γ/δ T lymphocytes from systemic sclerosis (SSc) patients display a T helper (Th) 1 polarization

Systemic sclerosis (SSc) is a connective tissue disease in which immune system activation is evidenced by high levels of different cytokines in the sera and/or in the supernatants of cultured peripheral blood mononuclear cells (PBMC) and by the presence of specific autoantibodies. γ/δ T cells accumulate in the lung and the skin of SSc patients suggesting their potential role in the development and maintenance of the disease. The aim of this study was to assess cytokine production and cytotoxic activity of circulating γ/δ T lymphocytes obtained from SSc patients and to evaluate their potential role during this disorder. Our results showed that both the proportion and the absolute number of IFN‐γγ/δ‐producing cells (i.e. displaying a Th1 polarization) in SSc was significantly higher than either the proportion and the absolute number of IL‐4 γ/δ‐producing cells in SSc or the proportion and the absolute number of IFN‐γγ/δ‐producing cells in healthy controls (P