Systemic sclerosis (SSc) is a connective tissue disease with unknown etiology characterized
by excessive deposition of collagen in the skin as well as various internal organs. One of the
characteristic histological features is the presence of infiltrating mononuclear cells in the
dermis in its early stage. As well as T cells, macrophages are implicated to play an important
role in the initial pathologic changes associated with SSc by releasing fibrogenic cytokines,
including transforming growth factor-β or platelet-derived growth factor. However, the …