The CD19+ B-cell counts at peripheral blood stem cell mobilization determine different levels of tumour contamination and autograft purgability in low-grade lymphoma

Responsiveness to G-CSF before leukopenia predicts defense to infection in high-dose chemotherapy recipients

An active assessment of the host capacity to prevent infection during myelosuppression should be beneficial in patients receiving high-dose chemotherapy. A single dose of granulocyte colony-stimulating factor (G-CSF) (5 μg/kg) was given to 57 patients with multiple myeloma early after the completion of 85 high-dose chemotherapy (melphalan 200 mg/m2) courses. This provoked a highly variable white blood cell (WBC) peak after 12 to 14 hours. The median WBC count was 21 000/μL (range, 6400-60 600/μL) after a first high-dose therapy (n = 50) and 13 500/μL (range, 4700-24 800/μL) after a second high-dose therapy (n = 35). The responsiveness to single G-CSF was associated with the risk of infection during subsequent cytopenia (P = .003). This association was significant after adjustment for neutropenia duration. Notably, the result of testing G-CSF responsiveness was opportunely available before the onset of leukopenia, and G-CSF responsiveness was more informative than neutropenia duration regarding the risk of infection. Furthermore, there was an association between the responsiveness to G-CSF and stem cell engraftment (P < .005), which remained significant after adjustment for the number of transplanted CD34+ cells. Our results show for the first time that G-CSF potentially could be used for an early in vivo assessment of defense to infection in recipients of high-dose chemotherapy.

A model of in vivo purging with Rituximab and high-dose AraC in follicular and mantle cell lymphoma

We studied a model of in vivo purging with Rituximab and high-dose (HD) cytarabine in 14 patients with relapsed/refractory follicular lymphoma and two with refractory mantle cell lymphoma enrolled in a program of HD chemotherapy and autotransplant. After two courses of debulking immunochemotherapy with Rituximab, Vincristine and Cyclophosphamide, we used a combination of Rituximab, HD cytarabine and granulocyte colony-stimulating factor for peripheral blood stem cells (PBSC) mobilization. The median number of CD34+ cells collected was 14.69 x 10(6)/kg (range 5.74-73.2). Monitoring of peripheral CD19+ and CD20+ B cells prior to and throughout the purging period showed that a treatment with Rituximab, Vincristine and Cyclophosphamide results in a profound depletion of B cells in peripheral blood. B-cell depletion persists during mobilization with Rituximab and HD cytarabine allowing a collection of PBSC free of B cells (median CD19+ and CD20+ cells counts 0%). Of nine patients PCR positive for bcl-2 or bcl-1 in blood and marrow at the start of immunochemotherapy, all showed PCR-negative PBSC. In conclusion, in patients with indolent lymphoma, the concurrent administration of Rituximab and HD cytarabine is a safe and efficient method to obtain in vivo purged PBSC. Immunochemotherapy prior to mobilization produces B-cell depletion and seems to be a useful preparative step.