Collection, cryopreservation and subsequent viability of haemopoietic stem cells intended for treatment of chronic granulocytic leukaemia in blast-cell transformation.

We have stored at -196 degrees C peripheral blood buffy coat (BC) and bone marrow (BM) cells collected from 47 patients with chronic granulocytic leukaemia in the chronic phase. Dimethyl sulphoxide (DMSO) 10% was used as cryoprotective agent. As these cells include CFUc and probably pluripotential stem cells they may be transfused as part of the management of patients who enter blast cell transformation. The mean numbers of nucleated cells collected and stored per procedure was about 9 times greater for BC collections than for BM harvests (106 +/- 49 (SD) X 10(9) versus 11.9 +/- 6.6 X 10(9) respectively). Agar CFUc assay showed that stored cells may remain viable for up to 5 years. Since in vitro studies showed that CFUc proliferation is not inhibited by low concentrations of DMSO the removal of all DMSO during cell reconstitution before transfusion may not be necessary. If autologous BC cells are capable of repopulating the BM of patients treated for CGL in blast cell transformation the routine collection and storage of BC rather than BM cells may be desirable for all newly diagnosed patients.