Blood stem cell mobilization and collection in patients with chronic lymphocytic leukaemia: a nationwide analysis

Some reports suggest that blood stem cell mobilization is difficult in a proportion of patients with CLL. We evaluated this issue in a large cohort of CLL patients. One hundred and twenty-eight patients with CLL underwent blood stem cell mobilization during 1995-2005 in Finland. Ninety-five percent of the patients had received fludarabine. The most common mobilization regimen was intermediate-dose CY plus G-CSF (90 patients, 70%). At least 2 x 10(6)/kg CD34+ cells were collected after the first mobilization attempt in 83 patients (65%), whereas 45 patients (35%) failed to reach this collection target. No differences were observed between these patient groups with regard to age, time from the diagnosis to mobilization, number of previous treatment lines, number of fludarabine courses, time from the last fludarabine-containing chemotherapy to mobilization, disease status or degree of marrow infiltration. Patients who failed collection had platelets <100 x 10(9)/l more commonly at the time of mobilization (30 vs 4%, P<0.001). A significant proportion of patients with CLL were difficult to mobilize. Adequate marrow function including platelet counts >100 x 10(9)/l seem to be important factors in terms of successful blood stem cell collection.