Factors which predict unsuccessful mobilisation of peripheral blood progenitor cells following G-CSF alone in patients with non-Hodgkin's lymphoma

Introduction: High-dose therapy with haematopoietic progenitor cell support has increasingly been utilised for patients with haematological malignancies. Peripheral blood is the stem cell source of choice, however, various mobilisation strategies are used by different centres. Patients and methods: Over a 2-year period, 52 patients with non-Hodgkin's lymphoma (median age 47 years, range 16-64 years) underwent peripheral blood progenitor cell mobilisation using G-CSF alone (16 μg/kg/day). The harvest was considered successful if ≥ 1 × 10⁶ CD34⁺ cells/kg were collected by leukapheresis. The histological subtypes of non-Hodgkin's lymphoma comprised: follicular (24 patients), diffuse large B-cell (14 patients), lymphoplasmacytoid (four patients), mantle cell (three patients), lymphoblastic lymphoma (one patient) and small lymphocytic lymphoma/chronic lymphocytic leukaemia (six patients). The median interval from diagnosis of non-Hodgkin's lymphoma to mobilisation was 27 months (range 2 months to 17 years). The median number of prior treatment episodes was 2 (range 1-5); 26 patients had received fludarabine alone or in combination. At the time of peripheral blood progenitor cell mobilisation, 20 patients were in 1st remission and 32 were in ≥ 2nd remission; 30 patients were in partial remission and 22 were in complete remission; the bone marrow was involved in nine patients. Results: Peripheral blood progenitor cell mobilisation/harvest was unsuccessful in 19 out of 52 (37%) patients (mobilisation: 18, harvest: 1). The factors associated with unsuccessful mobilisation or harvest were: prior fludarabine therapy (P=0.002), bone marrow involvement at diagnosis (P=0.002), bone marrow involvement anytime prior to mobilisation (P=0.02), histological diagnosis of follicular, mantle cell, or lymphoplasmacytoid lymphoma, or small lymphocytic lymphoma/chronic lymphocytic leukaemia (P=0.03) and female gender (P=0.04). Conclusion: Although peripheral blood progenitor cells can be successfully mobilised and harvested from the majority of patients with non-Hodgkin's lymphoma after treatment with G-CSF alone, the latter is unsuccessful in approximately one-third of patients. These factors should be taken into account when patients are being considered for high-dose treatment.