Search PubMedSearch

PubMed · 8347248

[Filtration technology].

Abstract

The leukocyte removal technology of platelet and red blood cell concentrates is now based on the only method: the filtration. In order to perfectly control this technology, it is necessary to know the different parameters that interfere in the quality of the leukocyte removal. These different parameters are studied here. They are classified in two types: the parameters that are related to the concentrate to filtrate: method used for the preparation, age, state (temperature, aggregates), concentration of red blood cells, platelets and leukocytes; the parameters that are related to the leukocyte removal technology and to the different steps of its carrying out: filter type (composition, size, geometry), prefilter, priming of the filter, flow rate during the filtration, rinsing and centrifugation after the filtration, elimination of the air inside the filter and the filtered concentrate, sterile connections, and finally good behavior in front of the difficulties and hitchs that could occur during the filtration procedure.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

C Hellot. 1993. [Filtration technology].. https://doi.org/10.1016/s1140-4639(05)80183-2

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

Type I (CD64) and type II (CD32) Fc gamma receptor-mediated phagocytosis by human blood dendritic cells.

Three classes of Fc receptors for IgG, Fc gamma RI (CD64), Fc gamma RII (CD32), and Fc gamma RIII (CD16), are expressed on blood leukocytes. Although Fc gamma R are important phagocytic receptors on phagocytes, most reports suggest that dendritic cells lack Fc gamma R-mediated phagocytosis and express significant levels of only CD32. We now report that phagocytically active forms of both CD64 and CD32 are expressed significantly on at least one subset of human blood dendritic cells. Countercurrent elutriation and magnetic bead selection were used to rapidly enrich subsets of blood dendritic cells (CD33brightCD14-HLA-DRbrightCD83-) and monocytes (CD33brightCD14brightHLA-DRdimCD83-). Upon culture for 2 days, dendritic cells became CD83-positive and markedly increased HLA-DR expression, whereas monocytes did not express CD83 and exhibited reduced levels of HLA-DR. Constitutive CD64 expression was identified on this circulating dendritic cell population, but at a lower level than on monocytes. CD64 expression by dendritic cells and monocytes did not decrease during 2 days in culture, and was up-regulated on both cell types following incubation with IFN-gamma. Freshly isolated blood dendritic cells performed CD64- and CD32-mediated phagocytosis, although at a lower level than monocytes. Dendritic cells generated by culture of adherent mononuclear cells in granulocyte-macrophage CSF and IL-4 also up-regulated CD64 following IFN-gamma stimulation, and mediated CD64-dependent phagocytosis. These results indicate that both CD64 and CD32 expressed on blood dendritic cells may play a role in uptake of foreign particles and macromolecules through a phagocytic mechanism before trafficking to T cell-reactive areas.

Cell Separation

[Thrombocyte concentrates prepared from the buffy coat. A modified method].

Since 1992 in the Institute of Haematology and Blood Transfusion thrombocyte concentrates are prepared from buffy coat by the method of Pietersz. The advantages of the above procedure include in particular improvement of the quality of thrombocyte concentrates with regard to their low contamination with leucocytes and erythrocytes. Contemporary resuspended erythrocyte concentrates are devoid of the buffy coat and have a very low leucocyte content. Administration of preparations of this type probably reduces the risk of alloimmunization and leads to a reduced incidence of post-transfusion febrile reactions in recipients. The objective of the submitted work was the implementation and evaluation or several centrifugation procedures for preparation of thrombocyte concentrates from buffy coat with the aim to increase the yield of thrombocytes and to obtain thrombocyte concentrates with a higher number of thrombocytes. From the four mentioned centrifuging procedures for the thrombocyte preparation it is apparent that centrifuging whole blood at 3500 g for 11 minutes with slow acceleration and subsequent spinning of the buffy coat at 555 g for 3 minutes leads to the highest thrombocyte content per transfusion unit of the preparation. Also leucocyte and erythrocyte values present in the preparation were favourable, close to recommendations of the European Council as regards the quality of thrombocyte concentrates.

Cell Separation