Incomplete stroma formation after allogeneic marrow or autologous blood stem cell transplantation.

Long term and semi-solid culture techniques were used to evaluate the quality of stroma produced by bone marrow from 33 normal subjects and 57 patients (46 allogeneic bone marrow and 11 autologous blood stem cell transplant recipients). Bone marrow from transplant recipients was capable of sustained CFU-GM and nucleated cell production in long term culture. However, only 13% of the marrow investigated developed a complete, confluent stromal layer. These stromal abnormalities were observed in spite of complete hematopoietic reconstitution after transplantation and rarely improved with time. Our results suggest that the hematopoietic microenvironment is very fragile and susceptible to long term damage as a result of chemotherapy and the conditioning regimes used prior to transplantation.