Cytokine levels measured in WB and buffy-coat-poor RBCs result in levels which are unlikely to cause febrile reactions even in the case of massive transfusion. We conclude that, according to present knowledge, there is no reason for prestorage filtration of buffy-coat-poor RBCs or WB to avoid febrile transfusion reactions due to cytokine accumulation during storage.

One hundred and nine patients suffering from various malignancies underwent 285 apheresis procedures for PBPC collection. A median of two leukaphereses (range: 2-5) resulted in median numbers of 4.6 x 10(8) MNC/kg, 14.1 x 10(4) CFU-GM/kg, and 6.0 x 10(6) CD34+ cells/kg. Preleukapheresis peripheral blood CD34+ cells correlated significantly with collected CD34+ cells/kg (r = 0.94; p < 0.0001) and with CFU-GM/kg (r = 0.52; p < 0.0001). A value > 4 x 10(4) CD34+ cells/ml was highly predictive for a collection yield > 2.5 x 10(6) CD34+ cells/kg harvested by a single leukapheresis. Sixty patients were evaluated for hematologic reconstitution and engrafted in a median time of 10 days for WBC > 1.0 x 10(9)/l (range: 7-21 days), 10 days for ANC > 0.5 x 10(9)/l (7-20) and 11 days for PLT > 20 x 10(9)/l (7-62). Reinfused CD34+ cells/kg correlated significantly with hematologic engraftment (r = 0.44-0.52 and p < 0.006-0.001) as well as CFU-GM/kg (r = 0.36-0.44 and p < 0.007-0.001). A progenitor cell dose > 2.5 x 10(6) CD34+ cells/kg or > 8.0 x 10(4) CFU-GM/kg led to a significantly faster recovery for WBC, ANC, and PLT when compared with patients receiving < 2.5 x 10(6) CD34+ cells/kg or < 8.0 x 10(4) CFU-GM/kg. We conclude that rapid hematopoietic engraftment after high-dose therapy and PBPC reinfusion correlates well with a progenitor cell dose > 2.5 x 10(6) CD34+ cells/kg or > 8.0 x 10(4) CFU-GM/kg, and that above a preleukapheresis threshold of 4 x 10(4) CD34+ cells/ml a PBPC autograft containing > 2.5 x 10(6) CD34+ cells/kg can be collected by a single leukapheresis. We suggest that patients recovering from myelosuppression should be monitored for CD34+ cells in serial blood samples to determine the course of circulating hematopoietic progenitor cells. This issue will help to define the optimal time point to start apheresis and to predict a PBPC autograft harvested by a single leukapheresis, which will lead to rapid and stable hematopoietic reconstitution following transplantation.

While collecting peripheral blood derived stem cell ( PBSC concentrates for autografting, we investigated the applicability of the new, completely microprocessor controlled continuous flow cell separator Fresenius-AS 104 for PBSC-collection in patients. After correcting some small initial problems, we are working using the Leucollect program version 4.4. 32 separations carried out in 11 patients are evaluable. Due to venous problems, we had to stop one separation after processing 2863 ml. Therefore, a mean peripheral blood volume of 9101 ml ( f1391 per separation has been processed and PBSC concentrates of 276 ml ( +43 were collected. During the 215 min ( range: 97-252 ) separation time, no technical problems occured.As the absolute cell count in the concentrates depends on the patients preseparation count, we defined the program's efficiency as percentage of the collected mononuclear cells ( MNC and granulocyte-monocyte-colonyforming-units ( CFU-GM ) in relation to the cells that were theoretically available and obtained a mean MNC-efficiency of 47.2 O h and a mean CFU-GM-efficiency of 126.4 %.

(1) Collection and/or ex vivo processing can result in microbiological contamination of BM grafts predominantly with bacteria from the skin flora, and (2) only CNSC can be cultured at thawing from previously contaminated/cryopreserved BM. Since patients undergoing ABMT usually receive oral antibiotics from beginning of the conditioning regimen which are active against CNSC, no further administration of antibiotics is recommended for the reinfusion of bacterially contaminated BM grafts.

Introduction: An increasing demand for blood components is opposed by a decreasing donor availability for the collection of the required blood components. Furthermore, current stem cell transplantation regiments require the collection of more than one similar or different component from one donor or patient. One strategy for maintaining the patients' supply with the required blood components can be the concurrent collection of more than one component from one donor by apheresis, thus multicomponent apheresis.Scope of multicomponent combinations: Combinations are possible for nearly every kind of blood components. In one session it is possible -depending on the apheresis device -to collect up to four plasma units alone, one or more plasma units and one or two red blood cell (RBC) units, one or more plasma units and one or more platelet units, one or more plasma units and one or two RBC units and one or more platelet units, one or two RBC units and one or more platelet units, two RBC units alone, one or more platelet units.Also in leucocytapheresis the collection of more than one blood component has become a routine procedure. Performing allogeneic stem cell apheresis can lead to a cell dose for two transplantations or to one unit of PBSCs and concurrently collected and frozen mononuclear cells used for donor lymphocyte infusions therapy. Autologous mononuclear cell products (e.g. PBSCs or monocytes for dendritic cell generation) usually are cryoconserved before use and require additional plasmaproteins for cryoconservation. The latter can be obtained by the concurrent collection of plasma during leucocytapheresis. Thus, the combination of cell and plasma units or of cell units of different dose or for different purpose are further examples for the implementation of multicomponent apheresis in tumor therapy. Conclusions:The understanding of apheresis technologies facilitates the use of multicomponent apheresis in the vast application field for tailoring the kind, quantity, and quality of blood components for patient care.