OBJECTIVETo analyze the results and influential factors of mobilization and harvesting of autologous peripheral blood stem cell in patients with multiple myeloma (MM).

METHODSRetrospective analysis of peripheral blood stem cell collection data [CD34⁺ cells collected, successful mobilization rate (CD34⁺ cells≥2×10⁶/kg body weight), good mobilization rate (CD34⁺ cells≥5×10⁶/kg body weight)] of 149 multiple myeloma patients who were treated with cyclophosphamide (CTX) or E-CHOP (etoposide+ CTX+epirubicin+vindesine+prednisone) chemotherapy combined with G-CSF mobilization from January 1998 to March 2014. The relevance between gender, age, subtype, DS staging, ISS staging, treatment before mobilization, disease status at mobilization, regiment of mobilizationand the collection results was analyzed.

RESULTSA total of 177 stem cell mobilizations were performed in 149 MM patients, the median CD34⁺ cells harvested were 3.20 (0.13-22.34)×10⁶/kg body weight (BW), successful mobilization rate and good mobilization rate were 74.5% and 27.5%, respectively. The single logistic regression analysis showed that gender, age （>60 ys vs ≤60 ys）, subtype, DS staging (III vs II+I), ISS staging (III vs II+I) and regiment of mobilization (E-CHOP+G-CSF vs ID-CTX+G-CSF) were not correlated with the cell collection or successful mobilization rate (P>0.05). However, successful collection rate of single harvest in old patients (age>60 ys) was lower (P<0.05), andthe good mobilization rate in patients at ISS stage III was lower (P<0.05). The collection results of patients with fewer cycles of treatment (treatment before mobilization ≤6 cycles) and optimal disease status (disease status at mobilization ≥partial remission) were much better. Analysis of logistic factors revealed that treatment efficacy before mobilization affected success rate of collection (P=0.006). Risk of collection failure in patients who received more than 6 cycles of treatment before mobilization was high (OR 3.57, 95% CI 1.45-8.78).

CONCLUSIONGender, age, subtype, DS staging, ISS staging and mobilization regimen did not influence MM patients peripheral blood stem cell collection; but old patients may need twice mobilizations to collect sufficiently. Few cycles of treatment and stable disease status before mobilization is favorable to the mobilization and collection of peripheral blood stem cells.