HYDROXYETHYLSTARCH SEDIMENTATION BY GRAVITY EX-VIVO FOR RED-CELL REDUCTION OF GRANULOCYTE APHERESIS COMPONENTS

BACKGROUND: When selecting only leukocyte compatible donors, the requi rement of ABO compatibility limits the investigation and application o f granulocyte transfusion therapy by reducing the pool of potential do nors. Ex vivo hetastarch (HES) sedimentation was evaluated as a method of red blood cell (RBC) reduction of granulocyte components. The obje ctive was to determine if this procedure consistently resulted in redu ction of component packed RBC (PRBC) volume to < 5 ml, the range accep table for infusion of ABO incompatible blood components based on guide lines set forth by the American Association of Blood Banks (AABB). STU DY DESIGN AND METHODS: HLA-matched, ABO-compatible sibling marrow dono rs were selected to donate granulocyte components, which were transfus ed into the allogeneic bone marrow transplant (BMT) recipient as proph ylaxis against infection. Three granulocyte components were collected from each of 5 donors receiving G-CSF (daily x 5). Leukapheresis (LA) began 1 day after the first G-CSF dose (Day 1), and was repeated on Da ys 3 and 5. LA were performed using a continuous-flow blood cell separ ator, with 7L, blood processed during each procedure. RBC sedimentatio n was facilitated by administration of a 6% HES solution to the donor line. The 5 granulocyte components collected on Day 1 were not manipul ated after collection. The 10 components collected on Days 3 and 5 wer e manipulated by ex vivo gravity sedimentation for 60 minutes followed by transfer of the buffy coat (red cell poor [RCP] fraction) to a tra nsfer bag with residual RBCs retained in the collection bag (red cell rich [RCR] fraction). The PRBC volume and cellular composition of the components and fractions were determined. RESULTS: When data for the 1 0 manipulated components were combined, the fraction of the components with < 5 mi PRBC was 0.4 in the RCP and 0.1 in the RCR fractions. All unmanipulated components contained > 5 mi PRBC. The mean PRBC volume (ml) of the RCP and RCR fractions were 6.3 and 16.4, respectively (P = .06). The mean number of RBC (x10(11)) in the RCP and the RCR fractio ns were .41 and 1.73, respectively (P = .03). The average proportion o f cells in the manipulated components lost to the RCR fraction was 19. 2% of granulocytes and 18.6% of platelets. CONCLUSION: Ex vivo HES sed imentation, as performed, significantly reduced the number of RBCs fro m granulocyte components, but did not consistently result in PRBC volu mes in the RCP fraction within the range acceptable for infusion of AB O incompatible blood components based on the AABB guidelines. Moreover , significant numbers of granulocytes were lost to the RCR fraction. J . Clin. Apheresis 13:56-61, 1998. (C) 1998 Wiley-Liss, Inc.