Chimerism analysis on mononuclear cells in the CSF after allogeneic bone marrow transplantation

To evaluate the chimeric status of mononuclear cells in the CSF after allogeneic BMT, cells were analyzed by FISH using satellite DNA probes for human X and Y chromosomes. CSF cells were obtained from five pediatric ALL patients who received BMT from sex-mismatched donors. All patients received TBI-containing conditioning regimens. We found that CSF cells showed complete donor type in 19-97 days after BMT, when complete donor type hematopoiesis was observed. The rapid entry of the donor leukocytes into the brain may exert beneficial effects to eradicate the residual CNS leukemic cells and prevent a CNS relapse in ALL patients after BMT.