FACTORS FOR RAPID AND SUSTAINED HEMATOPOIETIC RECONSTITUTION BY CIRCULATING PROGENITOR-CELL TRANSPLANTATION IN NON-HODGKINS-LYMPHOMA

Circulating progenitor cells (CPCs) mobilized from bone marrow will re place the use of bone marrow transplantation because hematopoietic rec onstitution is more rapid using the former technique. We report on ear ly and late recovery of hematopoiesis after CPC transplantation in pat ients with non-Hodgkin's lymphoma (NHL) and analyze the role of variab les possibly influencing engraftment. From December 1992 through Septe mber 1995, 57 consecutive NHL patients were enrolled in this study. Pa tients could be divided into 2 groups: the first comprised 32 patients with untreated diffuse large-cell lymphoma and unfavorable prognostic factors; the second comprised 25 patients with resistant or relapsing NHL of low- and high-grade histology. All patients received high-dose chemotherapy (carmustine, cytarabine, etoposide, and melphalan; BEAM) followed by CPC transplantation. In all, 25 patients were treated wit h granulocyte colony-stimulating fatter (G-CSF) after CPC administrati on. The time to short- and long-term hematologic engraftment and varia bles correlating with multilineage long-term reconstitution were exami ned. The time to bilineage (neutrophils and platelets) hematopoietic r econstitution did not differ in G-CSF-treated and -untreated patients. In contrast, the time taken to reach a neutrophil count of 0.5 x 10(9 )/l and a WBC of 1 x 10(9)/l was significantly shorter in G-CSF-treate d patients. Overall, 33 patients achieved long-term, complete trilinea ge engraftment after a median of 117 days from CPC transplantation. Th e leukocyte count was the first parameter to reach full engraftment an d hemoglobin was the last. According to Kaplan-Meier analysis, 80% of the patients are projected to reconstitute fully at 12 months after tr ansplantation. Univariate and multivariate analyses showed that sustai ned, long-term hematopoiesis was significantly related to a younger ag e, an early bilineage reconstitution, and the quantity of CD34(+) cell s infused.