Successfull autologous peripheral blood stem cells collection by a single dose of pegfilgrastim in combination with chemotherapy in patients with malignant lymphomas

Granulocyte colony-stimulating factors (G-CSF) alone or in combination with CHT are standard procedures for mobilization of peripheral blood stem cells (PBSC). Recently the pegylated form of G-CSF has been introduced, that leads to a larger molecule with an increased half-life. While pegfilgrastim is equivalent to daily filgrastim in enhancing neutrophil recovery, its efficacy in PBSC collection is still under evaluation. From January 2006 to October 2008 37 patients (pts) with malignant lymphoma were eligible for stem cell mobilization and ASCT. They were relapsed or progressive disease or mantle-cell, T-cell lymphoma at diagnosis. Pts received DHAP-modified schedule (ESHAP) as cytoreductive and mobilizing regimen. Twenty-four hours after the chemotherapy they received a dose of 6 mg of pegfilgrastim. For the characteristics of pts see Table 1. Peripheral CD34+ cell evaluation started from the increase of WBC above 1x[10.sup.9]/L. PBSC were collected using a Cobe Spectra separator. Leukapheresis started when the number of circulating CD34+ cells was >7microL and performed daily until target number of PBSC ≥2x[10.sup.6] was reached. All pts were considered for time to neutrophil and CD34+ cells recovery, as for the engrafment after high dose CHT. Thirty-five pts (94%) performed successfully PBSC collection, that was completed after a single apheresis in 33 pts. The median time to a sufficient number of CD34+ was 10 days (8-12 days). Two pts required an additional procedure, despite the satisfactory number of CD34+ circulating. At the time of harvest the median peak of absolute CD34+ cells in the PBL was 68 microL (range 7-252) and the median CD34+ cells collected for single patient were 9,4 x [10.sup.6]/Kg (range 2,447,6). No failure at collection was recorded and 28 pts obtained an optimal harvest (>5,0x[10.sup.6]/Kg). Up to now 23 pts evaluable for engrafment after BEAM regimen engrafted. The median time of grade 4 neutropenia was 8 days (range 6-10 days) and the recovery of platelet ≥ 20 x [10.sup.9]/L was recorded in median 12 days after the reinfusion (range 8-21 days). Our experience showed that a single injection of pegfilgrastim in combination with CHT is a valid procedure for mobilization of CD34+ cells into the PBL in pts with malignant lymphoma. Besides, a high percentage of pts (82%) obtained an optimal collection just with a single leukapheresis. Finally, the pegfilgrastim-mobilized CD34+ cells induced rapid and sustained engrafment after myel