Preparation of Leukocyte-Free Platelets for Transfusion by Filtration through Cotton Wool

Abstract

Filtration through Imugard filters of random platelet concentrates or platelets obtained by plateletpheresis allow the preparation of leukocyte-free platelets for transfusion. The procedure is simple and determines only a small platelet loss (less than 10%). Filtered platelets seem to function normally in vivo. The use of leukocyte-free red cell and platelet transfusions for the support of patients suffering from leukemia or aplastic anemia could prevent major complications, such as refractoriness to platelet transfusion and to bone marrow transplantation.

Comparison of Three Different Methods Used in the Preparation of Leukocyte-Poor Platelet Concentrates

“…Similar changes were also observed by Sirchia et al [7]; but there was no significant difference in the hypotonic shock response before or after filtration. The in vitro function and integrity of the filtered apheresis plate lets were not affected as tested by hypotonic shock response, change in morphologic score or electron-micro scopic morphology [25].…”

“…The in vitro function and integrity of the filtered apheresis plate lets were not affected as tested by hypotonic shock response, change in morphologic score or electron-micro scopic morphology [25]. In vivo increments and function of the filtered platelets have been shown to function normally in vivo [7].…”

“…Then the pooled PC was passed through the filter without pressure in about 10 min. The filter was rinsed with 100 ml of saline to wash out the trapped platelets [7],…”

“…Therefore some patients become refractory to further treatment with random platelet con centrates. There is evidence that HLA alloimmunization by platelet transfusions is induced by contaminating leu kocytes [1], Some studies have shown that the incidence of HLA alloimmunization is reduced by the use of leuko cyte-poor red cell and platelet concentrates [2][3][4], Leuko cyte-poor platelet concentrates can be prepared by differ ential centrifugation [2,5,6] or by filtration [7,8]. We compared the standard method of centrifugation with a new cotton-wool filter type, Immugard TFIG 500 Y and a newly designed blood bag for preparing leukocyte-poor platelet concentrates (PC): the Cutter Leukotrap platelet pooling system.…”

Amount and Type of Leukocytes in ‘Leukocyte-Free’ Red Cell and Platelet Concentrates

“…The most effective removal of leukocytes from red cells is a combination of buffy coat removal with filtration [1], Recently, cotton wool filtration has also been shown to be highly efficient in reducing leukocyte contamination in platelet concen trates [4], The best leukocyte-poor red cell and platelet concen trates are usually said to contain less than 1-2% of the original number of leukocytes. The products are often called 'leukocyte-free' to distinguish them from the leu kocyte-poor cell concentrates with about 10-fold greater leukocyte contamination.…”