Graft-versus-host disease

Since 1957, when the first bone marrow transplantation was performed by Thomas et al., hematopoietic stem cell transplantation (HSCT) has been used for the treatment of several hematologic and autoimmune disorders. With the discovery of the human leukocyte antigen system in 1958 and the subsequent better understanding of histocompatibility, allogeneic and autologous stem cell transplantations became standard practice. In the 1970s the number of bone marrow transplantations was low and the 1-year patient survival was less than 50%. Currently, nearly 20, 000 HSCTs are performed in the United States and 5-year survival approaches 50%. Thus long-term complications of HSCT were almost unknown in early 1970s but today, with an increase in life expectancy of patients, they are significant.