Underestimation of recipient DNA in bone marrow by post-transplant chimerism analyses using DNA extracted from EDTA-collected aspirate samples in pediatric acute myeloid leukemia

Chimerism analysis (CA) is essential for post-transplant surveillance. DNA from bone marrow (BM) aspirates drawn into EDTA specimen tubes (EDTA-BM) is widely used for CA. Since EDTA-BM is subject to peripheral dilution, however, DNA from aspirate particle smears (PS-BM) might better represent BM chimerism status. In this regard, we evaluated the influence of BM sources on CA. Study subjects were consecutive pediatric AML patients who had experienced relapse after allogeneic stem cell transplantation with the interval between CA before relapse (pre-relapse) and at relapse