Long-term sustained mixed chimerism after allogeneic stem cell transplantation in a patient with severe aplastic anemia.
Mixed chimerism in a post-transplant patient with severe aplastic anemia (SAA) is generally considered to be a status preceding donor-cell rejection and bone marrow failure. Here, we report on a rare, prolonged mixed chimerism in a patient with SAA who showed a full recovery in hematological and immunological status after transplantation. The analysis in this patient showed about 20% and 80% recipient-type cells of total blood cells and T cells, respectively, at two years post-transplantation, and 14% and 25% of total blood cells and T cells, respectively, at four years post-transplantation. This report describes the most comprehensive case study known to date.