CD8+ T cells in systemic sclerosis.

Systemic sclerosis (SSc) is a progressive and highly debilitating autoimmune disorder characterized by inflammation, fibrosis, and vascular damage of the connective tissue. T cell-derived cytokines have been implicated in the induction of fibrosis. We found that high levels of the profibrotic type-2 cytokine IL-13 are produced by peripheral blood effector CD8(+) T cells from SSc patients compared to normal controls. This abnormality correlates with increased expression of the transcription factor GATA-3 and the extent of skin fibrosis. Together, the data provide new insights into SSc pathogenesis and identify a specific T cell phenotype that can be used as a biomarker of immune dysfunction in patients with SSc and as a novel therapeutic target for this currently incurable disease.