Haematopoietic damage persists 1 year after autologous peripheral blood stem cell transplantation

In the present study we have used cell culture assays in order to assess th e damage in the haematopoietic system 1 year after peripheral blood stem ce ll transplantation (PBSCT), and to establish at what level, haematopoietic progenitor cells (HPC) or stroma, this damage occurs. Thirty-one patients, nine breast cancer (BC), 17 non-Hodgkin lymphoma (NHL) and five Hodgkin dis ease (HD), who had received autologous PBSCT were included. Forty-eight nor mal subjects who had given informed consent were used as controls. Results were also compared with a matched group of patients (25 cases) prior to PBS CT, Progenitor cells were analysed using CFU-GM and plastic adherent delta (P Delta) assays. Long-term bone marrow cultures (LTBMC) in one and two sta ges were established. One year after transplant both the number of committe d progenitor cells and the CFU-GM production in LTBMC were significantly re duced in the three groups of patients when compared with controls (P<0.05 o r P<0.01). Two-stage LTBMC experiments showed that the impairment in CFU-GM production was due to damage in both patients' stroma and haematopoietic p rogenitor cells (HPC). All patients, except those with HD, showed a decreas ed stromal layer confluence (P < 0.05), with significant differences in cel l composition as compared to normal bone marrow (P = 0.001). When all these variables were compared with pretransplant results, we observed that strom a formation was significantly lower after PBSCT (P < 0.05), while the numbe r of progenitor cells analysed by the P Delta assay was significantly incre ased (P < 0.05), We can conclude that even 1 year after PBSCT, both the com mitted HPC and BM stroma remain damaged.