Platelet Loss and Collection Efficiency During Autologous PBSC Collection: A Retrospective Comparison of Two Apheresis Platforms

Hematopoietic stem cell transplantation is a standard treatment for hematologic malignancies, and peripheral blood stem cell (PBSC) collection by leukapheresis is the preferred harvesting method. Platelet loss is a common procedure-related complication. This study compared platelet loss and product characteristics between two PBSC apheresis systems and evaluated the pre-collection platelet baseline needed to avoid procedure-related thrombocytopenia. This retrospective cohort study was conducted at a tertiary care hospital from March 2024 to October 2025. We reviewed 158 autologous PBSC collections in 110 patients using Spectra Optia in continuous mononuclear cell mode and 63 collections in 55 patients using Amicus in Mononuclear Cell mode. Platelet loss, hemoglobin, hematocrit, white blood cell count, granulocyte percentage, and CD34⁺ product characteristics were evaluated. Platelet loss was lower with Amicus than with Spectra Optia (median [IQR] 19.28% [10.94%-31.43%] vs. 33.33% [24.40%-42.50%]; p < 0.001). Spectra Optia had higher collection efficiency (48.30% [37.03%-63.64%] vs. 37.23% [27.26%-48.58%]; p < 0.001), higher product volume (257 [238-283] vs. 177 [155-202] mL; p < 0.001), and higher platelet concentration (515 [390-680] vs. 340 [240-480] × 10³/μL; p < 0.001). A pre-collection platelet threshold of 35 000/μL was proposed to maintain post-collection counts ≥ 20 000/μL. Both systems were effective for autologous PBSC collection. Spectra Optia provided higher collection efficiency, whereas Amicus was associated with lower platelet loss. Appropriate pre-apheresis assessment of CD34⁺ cells and platelet count may help optimize collection and reduce procedure-related thrombocytopenia.