New perspectives on the etiology of systemic sclerosis

Systemic sclerosis (SSc) is a disease of unknown origin. Although SSc is co nsidered to be an autoimmune disease, recent studies have implicated cellul ar microchimerism in its pathogenesis. Microchimerism results from the pers istence of fetal cells, from prior pregnancies, in the maternal circulation . The demonstration of the presence of fetal CD3(+) T cells in the maternal circulation and of fetal cells in affected SSc tissues suggests that micro chimerism might cause SSc in certain patients by initiating a graft-versus- host like response.