Patient selection: recipient of a HSCT from a donor, including umbilical cord blood
Presentation:
(1) acute leukemia
(2) pancytopenia with myelodysplasia
Differential diagnosis:
(1) existing leukemia or myelodysplasia in the donor transferred to the recipient (which may be detected by studying the donor)
(2) leukemia or myelodysplasia in the recipient arising from residual stem cells, especially after chemotherapy
(3) leukemia or myelodysplasia arising in the donor cells following transplant to the recipient, possibly due to an adverse bone marrow micro-environment
Donor and recipient cells can be differentiated:
(1) using the Y chromosome if the transplant was not sex-matched
(2) using PCR amplification of short tandem repeats (STRs) as is used in forensic identification, which is more sensitive than use of the Y chromosome
The period between HSCT and diagnosis of donor cell disorder ranged from 1 to 193 months in the study of Wang et al, with a median interval of 24 months. Risk factors for a shorter interval:
(1) HSCT performed for malignancy in the recipient
(2) development of a T-cell large granular lymphocyte leukemia
(3) stem cells derived from the umbilical cord
