OBJECTIVETo explore the impact of courses of intermediate-dose cytarabine (ID-Ara-C) chemotherapy on the efficiency of hematopoietic stem cell mobilization in acute myeloid leukemia (AML) patients with autologous hematopoietic stem cell transplantation (auto-HSCT).

METHODS90 patients with de novo AML undergoing auto-HSCT between August 1999 and November 2012 were enrolled. All patients received the mobilization regimen of cytarabine and etoposide chemotherapy in combination with recombinant human granulocyte-colony stimulating factor (rhG-CSF). Stem cell apheresis was scheduled when blood leukocyte count recovered greater than 4.0 × 10⁹/L or the proportion of CD34⁺ cells greater than 1% in peripheral blood. The impact of ID-Ara-C courses on the mobilization efficiency was analyzed retrospectively.

RESULTSAccording to the ID-Ara-C courses, patients were divided into group A (<2 courses), B (2 courses), and C (>2 courses). The median doses of CD34⁺ cells (×10⁶/kg) in three groups were 4.7, 2.7, 2.3, respectively (P=0.003). Of the available 87 patients who could be evaluated, 61 (70.1%) cases had CD34⁺ cells greater than 2.0 × 10⁶/kg, and 26 (29.9%) cases less than 2.0 × 10⁶/kg. Of the 26 patients without satisfactory mobilization efficiency, 7 (15.2%) were in group A, 10 (47.6%) in group B, and 9 (45.0%) in group C (χ²=10.05, P=0.007). In addition, patients with satisfactory mobilization efficiency (CD34⁺ cells ≥ 2.0×10⁶/kg) in groups C needed more times of collection, more volume of blood processed, and even high-dose and longer course of rhG-CSF (P<0.05). In univariate analysis. The ID-Ara-C courses and the cumulative dose were significant correlate with mobilization efficiency. In multivariate analysis, the ID-Ara-C courses was an independent correlation factor for mobilization efficiency (odd ratio=0.623, 95% confidence interval=0.418-0.926, P=0.019). The sex, age, cytogenetic risk, the standard chemotherapy courses did not correlate with mobilization efficiency.

CONCLUSIONThe number of ID-Ara-C courses was independent factor for the mobilization efficiency and should be taken seriously in AML patients with auto-HSCT.