Mobilization of peripheral blood progenitor cells after DHAP regimen with or without rituximab: a large multicenter comparative study in patients with malignant lymphoma.

DHAP regimen is commonly used in patients with lymphoma. It is routinely used in combination with the monoclonal anti-CD20 antibody rituximab (R-DHAP), particularly for peripheral blood stem cell (PBSC) mobilization. The aim of this study was to assess the impact of rituximab on PBSC mobilization in patients with lymphoma receiving DHAP chemotherapy. We retrospectively reviewed the data of patients treated by DHAP or R-DHAP regimens as PBSC mobilization protocol between July 1998 and June 2005. Sixty-nine patients were included in the study: 21 in the DHAP group and 48 in the R-DHAP group. Both groups were not statistically different in term of clinical and biological presentation of the disease. The first cytapheresis was performed at day 10 in the R-DHAP group versus day 11 in the DHAP group. In contrast, the number of circulating CD34(+) cells was higher, but not significant, in the R-DHAP group than the DHAP group, namely 9.7x10(6) CD34(+) cells/kg and 6.1x10(6) CD34(+) cells/kg, respectively. Finally, the complete remission status at time of harvest was the only one factor associated with poor mobilization on multivariate analysis. In conclusion, our results show that rituximab does not impair PBSC collection.