LONG-TERM BONE-MARROW CULTURES ESTABLISHED FROM BONE-MARROW TRANSPLANT RECIPIENTS

Following bone marrow transplantation (BMT), the stroma remains host-d erived, and has therefore been exposed to the high doses of chemoradio therapy used in BMT conditioning. We have used long term bone marrow c ulture (LTBMC) to study the effect of this conditioning therapy on the stroma. Twenty-five BMT recipients were studied, comprising 13 allogr afts and 12 autografts. Marrow was aspirated prior to transplant (6 ca ses) and at 3, 6 or 12 months post-BMT. Fifteen haematologically norma l subjects were studied in parallel. The stromal layer of LTBMC was vi sually assessed at weekly intervals and supematant cells counted and a ssayed for colony forming unit-granulocyte/macrophage (CFU-GM). Five o f the six cases studied both before and after BMT formed less confluen t stroma following the procedure. A successive improvement in the prop ortion of patients forming good stroma was observed with increasing ti me from BMT. Supematant cell and CFU-GM counts were not significantly different from normal following BMT. No clear relationship was observe d between stromal confluence and any of the following: supematant cell and CFU-GM counts, transplant type, underlying disease, conditioning regime or time to engraftment. These data support the view that BMT co nditioning regimes cause stromal damage, and that this damage graduall y improves with time.