Peripheral blood mononuclear cell collection from patients undergoing adoptive immunotherapy or peripheral blood-derived stem cell transplantation and from healthy donors

The demand for collection of mononuclear cells from the peripheral blood of patients for therapeutic purposes is rapidly increasing. Automated blood cell separators are usually designed for collection of blood components from healthy donors. We reviewed safety and efficiency of collection data of a new procedure for the Fenwal CS 3000 blood cell separator in 125 collections from normal donors and 101 collections from patients after IL‐2 pretreatment or chemotherapy. The new procedure set red blood cell spillovers to occur at 3.5 minute intervals, using procedure 1 with the interface detector set at 1,000 and the standard granulocyte and collection chambers. Despite significant anemia and thrombocytopenia in a large number of patients no serious procedure‐related side effects occurred. The lymphocyte yield was 4.74 ± 1.6 × 109 per 5 liters of blood processed in normal donors and 24.2 ± 12.0 × 109 per 10 liters of blood processed after IL‐2 treatment. After chemotherapy the lymphocyte yield was 4.5 ± 3.1 × 109 per 10 liters of blood processed; the collection efficiency was found to be significantly lower in this group. The main problem was the platelet loss of 35.6 ± 12% of the initial count in normal donors, 40.3 ± 14.1% after IL‐2 treatment, and 42.1 ± 18.0% after chemotherapy. The platelet loss is, however, closely related to the preapheresis platelet count; patients with thrombocytopenia lose fewer platelets than normal donors. Therefore the procedure was found to be safe for patients with a platelet count as low as 20/nl.