[Animal models for intractable hematologic disorders]

We describe here characteristics of animal models for intractable hematologic disorders and discuss the concept of "stem cell disorders." Using these animal models, we have found that bone marrow transplantation can be used to treat both systemic and organ-specific autoimmune diseases, and that transplantation of hematopoietic stem cells from autoimmune-prone mice induces autoimmune diseases in normal mice. Based on these findings, we have proposed that autoimmune diseases are stem cell disorders. It has recently been reported that bone marrow transplantation can be used to treat autoimmune diseases such as rheumatoid arthritis and ulcerative colitis, also in humans.