FISH analysis of native smears from bone marrow and blood for the monitoring of chimerism and clonal markers after stem cell transplantation in children.

After stem cell transplantation (SCT) close follow-up of chimerism and/or clonal disease markers is essential for early treatment of graft failure or relapse. We wanted to assess the sensitivity, clinical reliability and practicability of inter-phase FISH on untreated, native smears of BM or PB for this purpose. We investigated 23 children after SCT with sex mismatch (MM) and/or clone specific markers (monosomy 7, trisomy 8, MLL rearrangement, bcr-abl, TEL-AML-1).