Circulating CD34⁺ cells to predict the adequate harvest of peripheral blood progenitor cells in platinum-based chemotherapy

Abstract  

Objective: The aim of this study was to clarify the appropriate timing for peripheral blood progenitor cells (PBPC) harvesting after platinum-based mobilization chemotherapy by measurement of the circulating CD34⁺ cell concentrations. Patients and Methods: PBPC were collected for autotransplantation via a total of 68 leukaphereses in 16 patients with gynecological cancer. Circulating CD34⁺ cell concentrations were measured by CD34-side scatter parameter analysis. Results: Data could be fitted into a linear regression line described by the equation y=0.33+4.14×x (R ²=0.256), where y=the number of harvested colony-forming unit granulocyte macrophage (CFU-GM (×10⁵/kg) and x=the percentage of circulating CD34⁺ cells and y=1.747+44.53×x (R²= 0.475), where y=the number of harvested CD34⁺ cells (×10⁶/kg) and x=the percentage of circulating CD34⁺ cells. Failure to mobilize sufficient CFU-GM numbers (>1×10⁵/kg) occurred in 29 of 31 leukaphereses when the percentage of circulating CD34⁺ cells was less than 0.10%. Conclusions: Harvesting procedure may be avoided when circulating CD34⁺ cells showed less than 0.10% after platinum-based mobilization chemotherapy.