[Leukocyte depletion, a comparison of the "Leukotrap in-line" filter system with a sterile added 4-bag Speacell-R-500-A filter system].

Leukocytes in RBC preparations have a variety of immunologic effects in transfused patients. Not only their elimination at time of transfusion but before storage seems to be advantageous. Filtration with the Leukotrap system at the day of preparation led to an overall reduction of leukocytes of 82.2%, i.e. an average of 5.4 x 10(8) leukocytes/RBC concentrate. Filtration with a Sepacell R 500 A eliminated 99.0% of leukocytes, 3.4 x 10(7) cells remained per blood unit. The determination of lymphocyte subpopulations by flow cytometry after filtration with the Leukotrap system showed a more effective adsorption of B cells than of T and natural killer cells.