Peripheral Blood Mononuclear-Stem Cell (PBMSC) Collection in Two Continuous Flow Cell Separators: Yields and Crosscellular Contamination

Interest in PBMSC for autologous transplantation is emerging for patients who are candidates for high-dose chemotherapy and marrow rescue but whose marrow is either fíbrotic or infiltrated with malignant cells. Earlier work described mononu-clear cell concentrate collection from normal donors. Whether the same principles apply to patient who may be pancytopenic is not established. Objectives for collection of PBMSC included: (1) < 10 % granulocytes (PMN); (2) minimal red cells (RBC), and (3) minimal platelet (pit) loss in the patient. Collection was initiated early in the recovery phase from a single dose of Cytoxan, and continued on consecutive weekdays until 7 × 108 PBMnc/kg were collected for 16 multiple myeloma patients using the Spectra (S) or the CS-3000 (CS) for 150 procedures. Mean patient hematocrit was 28%. Mean absolute pre and postprocedure PBMnc was comparable for S and CS; 1.07 ± 9.4/0.9 ± 0.5 × 1071 S, and 1.0 ± 0.6/1.0 ± 0.5 × 109/1 CS: Mean pre/post pit counts differend in S and CS. For S pit were 135 ± 68/114 ± 55 × 109/1, a fall averaging 17%. For CS pit were 127 ± 53/81 ± 50 × 10Vl, a fall averaging 36%. Yields (Y) PBMSC were similar: 6.2 ± 1.8 for S and 6.6 ± 2.5 CS. Yields (Y) RBC and yields (Y) pit differed. For S, yields (Y) RBC and pit were significantly lower: 0.6 × 1011 RBC and 0.99 × 1011 pit. For CS yields (Y) RBC was 1.3 × 10u and yields (Y) pit 3.1 × 10π. Yields (Y) pit was reduced in CS to 2.2 × 10n when centrifugal speeds were reduced and linked to the whole blood processing rates. Collecting too deeply into the RBC and excess myeloma protein resulted in excess PMN contamination for both S and CS. Conclusion: Yields (Y) PBMSC cannot be predicted for either S or CS at this time, and procedural variables must be altered frequently to maintain low crosscellular PMN and RBC contamination for both S and CS. Yields (Y) pit and pit loss in the patient were always less in the S, even after modifying centrifugal speed in CS. Gewinnung peripherer mononuklearer Blutstammzellen (PBMSC) mit zwei Zellseparatoren mit kontinuierlichem Fluß: Ausbeute und Reinheit2 Das Interesse an PBMSC für autologe Transfusionen steigt für Patienten, die Anwärter auf hochdosierte Chemotherapie und Knochenmarkerhaltung sind, deren Knochenmark aber entweder fíbrotisch oder mit malignen Zellen durchsetzt ist. In frü-heren Arbeiten wurde die Gewinnung von mononukleären Zellkonzentraten von normalen Spendern beschrieben. Ob die gleichen Prinzipien auch auf panzytopenische Patienten zutref-fen, ist nicht gesichert. Fakten, auf die man bei Separation von PBMSC achten muß, sind: