Leukaphereses were performed on the intermittent flow cell separator (Haemonentics Model 30) using citrated dextran 150 as a macromolecular agent to improve separation of granulocytes. A mean of 1.77 X 10(10) granulocytes and 7.73 X 10(11) platelets were obtained without steroid stimulation and 2.65 X 10(10) granulocytes and 8.91 X 10(11) platelets were obtained with steroid stimulation of donors. There were no significant adverse reactions to dextran.

Cell Separation↗

PubMedDate not supplied

Comparison of two methods for concentrating stem cells for cryopreservation and transplantation.

Dextran sedimentation with centrifugation and semicontinuous flow centrifugation was used to concentrate marrow stem cells from collections of human bone marrow. With the dextran sedimentation method, recovery of the myeloid stem cells was 92 percent in 35 percent of the original volume, but contamination by mature cells was high. In the semicontinuous flow centrifugation method the recovery of myeloid stem cells was 82 percent in 15 percent of the original volume. Contamination with platelets, erythrocytes and neutrophils was reduced to 20.4, 29.6, and 38.6 percent respectively of the original values. It was concluded that semicontinuous flow centrifugation provides a comparatively convenient and efficient method for concentrating large collections of human bone marrow cells in a closed system.

Bone Marrow Cells↗

PubMedDate not supplied

Red cell alloantibodies produced after bone marrow transplantation.

This article describes the production of red cell alloantibodies in 13 of 150 patients after bone marrow transplantation. New alloantibodies appeared 12 days to 11 months after the transplantation. The specificities of these antibodies were anti-N, -Jka, -E-like, -Kell-like, -M, -Leb, -Hl, -H and -A1. The posttransplantation production of antibody could be due to either the transfusion of mature lymphocytes along with the marrow, the ability of the grafted immune system to produce alloantibodies, or the viable immunocompetent cells remaining despite high-dose chemotherapy and irradation.

Antibody Formation↗