Marrow function reconstitution by fraction 3 of Percoll-density-gradient-separated cells

Eight children with advanced tumors or acute myeloid leukemia were treated either with very-high-dose multi-agent chemotherapy (4) or marrow ablative high-dose melphalan (4) followed by autologous marrow rescue, using only fraction 3 from a Percoll-discontinuous density gradient separation of bone marrow buffy coats. Each patient received less than 20% of the number of cells usually reinfused from the buffy coat. The yield of CFU-c in Percoll gradient 3 was similar to the yield obtained from whole buffy coats of bone marrow. Reconstitution of marrow function with a neutrophil count greater than 0.5 X 10(9)/L and platelet count greater than 50 X 10(9)/L occurred in 7 patients in a medium time of 15 and 16 days, respectively--a time comparable to that following infusion of whole buffy coat in 20 other patients. In one patient, hemopoietic recovery was considerably delayed, suggesting that fraction 3 from the Percoll gradient had been relatively ineffective in marrow reconstitution. We conclude that fraction 3 from marrow separated on Percoll gradients has the advantages of small volume and good recovery of marrow stem cells and can promptly reconstitute marrow function in the majority of children treated with very-high-dose chemotherapy or marrow ablative doses of melphalan.