High-dose methotrexate in the mobilization of hematopoietic stem cells for patients with non-Hodgkin's lymphoma: a twelve-year study in a single center.

BACKGROUND: High-dose chemotherapy followed by autologous hematopoietic stem cell transplantation (auto-HSCT) is a promising approach for non-Hodgkin's lymphoma (NHL). Higher cell doses have been associated with a faster blood count recovery and a reduction in transfusion requirements, infection rates, and hospitalization times. Mobilization failure constitutes one of the main reasons for avoiding auto-HSCT. The role of high-dose methotrexate (MTX) as mobilization regimen is still unclear. STUDY DESIGN AND METHODS: The effect of high-dose MTX as a mobilization regimen for 67 adult patients with NHL who received auto-HSCT was studied between January 2001 and October 2012. The stem cells were mobilized using combination chemotherapy including MTX plus granulocyte-colony-stimulating factor (G-CSF) in 33 patients (Group A), and the stem cells of the other 34 patients were mobilized using the same combination chemotherapy plus G-CSF without MTX (Group B). RESULTS: All of the patients were successfully mobilized in Group A; however, two patients failed in Group B. The median numbers of CD34+ cells collected were 14.36 × 10(6) and 5.3 × 10(6) cells/kg for Groups A and B, respectively (p < 0.05). All of the patients experienced a stable neutrophil and platelet (PLT) engraftment. The times to white blood cell engraftment were 8.0 days in Group A and 11.0 days in Group B, and the times to PLT engraftment were 12.0 days in Group A and 13.0 days in Group B (p < 0.05 for both variables). CONCLUSION: High-dose MTX is a powerful regimen component for stem cell mobilization in adult patients with NHL.