DETECTION OF DONOR CELL-DERIVED ACUTE MYELOGENOUS LEUKEMIA IN A PATIENT TRANSPLANTED FOR CHRONIC MYELOGENOUS LEUKEMIA USING FLUORESCENCE IN-SITU HYBRIDIZATION

The recurrence of leukaemia following allogeneic bone marrow transplan tation appears to develop rarely in donor cells. However, the standard method for assigning the origin of recurrence, metaphase analysis, ca n be unreliable. We have applied the technique of fluorescence in situ hybridization (FISH) directly on archival Wright stained bone marrow slides obtained from a patient who developed acute myelogenous leukaem ia (AML) following allogeneic bone marrow transplantation (BMT) for ch ronic myelogenous leukaemia (CML). Using a chromosome-specific DNA pro be we linked a chromosomal aberration, previously detected by conventi onal metaphase analysis, directly to morphologically identifiable blas t cells. In this way we were able to assess cell-lineage involvement o f the secondary leukaemia and assign a donor origin.