Peripheral blood stem cell mobilization following CHOP plus rituximab therapy combined with G-CSF in patients with B-cell non-Hodgkin's lymphoma.

We mobilized peripheral blood stem cells (PBSC) following CHOP plus rituximab (CHOP-R) therapy, and compared with the findings following CHOP therapy without rituximab. All patients were given G-CSF starting from day 11 after CHOP therapy. Patients in the CHOP-R group (n=8) were given rituximab on day 12. Target CD34(+) cells number was collected in a single leukapheresis on day 14, from all the eight patients in the CHOP-R group. PBSC mobilization kinetics, CD34(+) cells yield and colony-forming ability in the graft collection, toxicity during mobilization, and engraftment after transplantation of CHOP-R group were not significantly different from those in the CHOP group (n=8). In all patients given CHOP-R therapy, CD20(+) cells and immunoglobulin heavy chain (IgH) rearrangement in the graft collection were undetectable by flow-cytometric analysis and Southern blot analysis, respectively, but with PCR analysis two of eight grafts were positive for IgH rearrangement. While further studies are needed to evaluate the efficacy of purging and the outcome of patients undergoing autologous transplantation, CHOP-R therapy can be safely and effectively used in the mobilization phase of PBSC collection, without excess clinical toxicity or deleterious effect on PBSC mobilization kinetics or engraftment time.