BONE-MARROW PURGING WITH MONOCLONAL-ANTIBODIES PLUS COMPLEMENT - USEFULNESS OF LONG-TERM BONE-MARROW CULTURES AS A CONTROL IN-VITRO

Treatment with monoclonal antibodies in vitro is a common therapy for purging leukaemic cells in autologous bone marrow transplantation. How ever, an increase in graft failures has been reported in patients who received treated cells. Successful engraftment depends on functional h aemopietic stem cells being present in the bone marrow infused and on the capacity of the microenvironment to receive these stem cells. Long -term bone marrow cultures indirectly provide knowledge about the pers istence of both haemopoietic stem cells and supportive accessory cells in bone marrow. 37 bone marrows were analysed in long-term cultures b efore and after treatment with monoclonal antibodies plus complement i n vitro. Several parameters from long-term marrow cultures were measur ed over 6 weeks. 76% of cultures initiated after monoclonal antibody t reatment showed abnormalities in adherent cell layer development. More over, in most of these cultures there was a premature loss of haemopoi etic precursors in the supernatant.