[Fetal cells and the pathogenesis of scleroderma--microchimerism and mechanisms of alloimmunity]

Fetal cells can be detected during and after pregnancy in the maternal blood circulation. Since the majority of patients suffering from autoimmune diseases are female, and scleroderma (a systemic autoimmune disease) and chronic graft-versus-host disease appear to have similar symptoms, the theory emerged that these fetal cells could have some role in the pathogenesis of scleroderma. These cells could drive an aggressive immune reaction against the tissues of the patient, wherein not only auto- but alloimmune mechanisms could participate. In this brief review we try to make a short synopsis of the most important aspects of this fascinating theory.