Pre-emptive plerixafor injection increases blood neutrophil, lymphocyte and monocyte counts in addition to CD34+ counts in patients with non-Hodgkin lymphoma mobilizing poorly with chemotherapy plus G-CSF: potential implications for apheresis and graft composition

BackgroundCXCR4 receptor antagonist plerixafor is used to mobilize hematopoietic stem cells. No detailed data regarding the effects of plerixafor on other blood cell components have been published but may be of importance in regard to graft composition collected after plerixafor injection.Patients and methodsThe study included thirty-nine patients with non-Hodgkin lymphoma (NHL) mobilized with chemotherapy plus G-CSF. Plerixafor was given pre-emptively in twenty patients due to poor mobilization or low collection yield. Nineteen NHL patients served as controls. We evaluated CD34⁺ counts and WBC counts and differential from the morning of the first plerixafor injection and 8 h after the plerixafor injection. From the control patients the corresponding values were evaluated on the morning of the first apheresis and 24 h before it.ResultsThe first plerixafor dose increased CD34⁺ counts and number of leukocytes, neutrophils, lymphocytes, eosinophils and monocytes. Leukocyte, neutrophil, lymphocyte, monocyte and eosinophil counts were higher after plerixafor injection compared to the control group at the time of the first apheresis. Minimal graft (?2 × 10⁶/kg CD34⁺ cells) was collected in 85% of plerixafor treated patients, with a single apheresis in 45% of the patients.DiscussionPlerixafor significantly increases B-CD34⁺ cell counts on the next morning making effective blood stem cell collection possible in the majority of the patients mobilizing poorly. It also influences other blood cell components but impact of this observation in regard to graft content and post-transplant course needs to be assessed in further studies.