The Nebraska experience.

Autologous peripheral stem cell transplantation was initiated at the University of Nebraska Medical Center to provide hematopoietic rescue for patients who were candidates for high-dose therapy but had marrows that were unfit for autografting. From 1984 until 1991, the cells were collected during steady state without mobilization. These cells restored hematopoietic function at a rate similar to that of autologous marrow in patients not treated with total body irradiation. Patients who received total body irradiation experienced slower hematopoietic recovery. When growth factors became generally available in the United States in 1991, mobilization with cytokines became standard at Nebraska. In recent years, the function of cells other than hematopoietic progenitors contained in a peripheral stem cell apheresis product has been studied. Detection of tumor cells using cell culture, immunocytochemical and polymerase chain reaction techniques has revealed that such collections are less likely to contain, or contain fewer, tumor cells than autologous bone marrow harvests. More antitumor cytotoxic activity was found in cells in peripheral stem cell collections than in marrow cell collections. The immunocompetent lymphocyte population is larger in peripheral stem cell collection than in marrow harvests, and immunologic recovery after peripheral stem cell transplant has differed compared to recovery following bone marrow transplantation. The future of peripheral stem cell transplantation is likely to include engineering of the graft products specific for the patient and disease being treated. Determining the function of accessory cells in a peripheral stem cell collection will be important to provide the best engineered product for the patient.