PURPOSE: In an attempt to avoid GVHD, reduce earlier infection rate and decrease regimen-related toxicity while maintaining better engraftment, this study is to evaluate the effectiveness and safety of patient's own adipose-derived mesenchymal stem cell (AD-MSC) or AD-MSC transdifferentiated HSC (AD-HSC) transplant after an immunosuppressive regimen in treating patients who have severe aplastic anemia.