Rapid and sustained hematopoietic reconstitution by peripheral blood stem cell infusion alone following high-dose chemotherapy.

We utilized mobilized peripheral blood stem cells (PBSC) as sole support for hematologic reconstitution following high-dose chemotherapy in 52 patients with advanced solid tumors and lymphoma. PBSC were collected by large scale leukapheresis after mobilization with chemotherapy. Each apheresis product was analysed for total nucleated cells, CFU-GM and CD34+ content. Disease-specific high-dose chemotherapy regimens were administered followed by thawed PBSC. Colony-stimulating factors were not administered. The median time to an absolute neutrophil count > 0.5 x 10(9)/l was 13 days (range 9-26 days) and median time to a sustained platelet count > 20 x 10(9)/l without transfusion support was 10 days (range 5-43 + days). There was no difference in time to recovery by dose-intensive regimen or underlying disease. The times to recover ANC and platelets both correlated significantly with increasing doses of PBSC as assayed by CD34+ cells and CFU-GM. All four patients with prolonged platelet recovery times received < 20 x 10(4) CFU-GM/kg, establishing this as a threshold value for PBSC infusion. There were no late transient or sustained graft failures. For 26 patients alive 1 year after infusion, the mean total leukocyte count is 6.3 x 10(9)/l, mean hematocrit 35.5% and mean platelet count 182 x 10(9)/l. Thirteen patients followed at least 24 months after PBSC infusion have essentially normal blood counts. Mobilized peripheral blood progenitors are an effective source of stem cells which afford rapid and complete hematopoietic engraftment after myelo-suppressive chemotherapy regimens. Engraftment appears sustained with no late failures.(ABSTRACT TRUNCATED AT 250 WORDS)