PCR amplification of minisatellite DNA for the detection of mixed chimerism after bone marrow transplantation

Allogeneic bone marrow transplantation (BMT) has become a recognized therapy for the treatment of patients with leukemia, severe combined immune deficiency (SCID) and severe aplastic anemia (SAA). It was originally assumed that complete donor chimerism was essential for sustained engraftment. However, despite high dose chemoradiotherapy given as preconditioning, the persistence of host hematopoietic cells (mixed chimerism) has commonly been observed after BMT and the relationships between mixed chimerism, engraftment and relapse have remained controversial (1-4). To evaluate the clinical relevance of mixed chimerism after BMT, we developed a method based on the amplification of minisatellite DNA regions by the polymerase chain reaction (PCR) (5,6).