Platelet Count before Peripheral Blood Stem Cell Mobilization Is Associated with the Need for Plerixafor But Not with the Collection Result.

Background: A low platelet count before mobilization has recurrently been identified as risk factor for poor mobilization.

Methods: To determine the relevance of this finding for peripheral blood stem cell (PBSC) mobilization, including pre-emptive or rescue plerixafor in the case of poor mobilization, we retrospectively analyzed all patients undergoing PBSC collection at our institution between January 2014 and December 2015 (n = 380).

Results: In total, 99% of the patients (377/380) successfully collected a minimum of 2 × 106 CD34+ cells/kg body weight sufficient for a single transplant. Rescue or pre-emptive plerixafor was administered to 11% of the patients (42/380). No correlations between the platelet count before mobilization and the number of peripheral blood CD34+ cells or the CD34+ cell collection result were detected in the entire population or the subgroups according to diagnosis (newly diagnosed multiple myeloma, relapsed multiple myeloma, lymphoma, amyloid light-chain amyloidosis, sarcoma, or germ cell tumor). However, patients requiring pre-emptive or rescue plerixafor had a significantly lower platelet count before mobilization (217/nl vs. 245/nl; p = 0.004).

Conclusion: With the current state of the art PBSC mobilization strategies, the platelet count before mobilization was not associated with the CD34+ cell collection result but was associated with the need for pre-emptive or rescue application of plerixafor.