[Leukocyte depletion by in-line-filtration]

Leukocyte depletion was tested in 30 red cell concentrates (RCC) using a new 450-ml triple U blood-bag system (Optipac, Baxter) with an integrated polyester filter (Sepacell R 2000). Centrifugation at 3,600 rpm was well tolerated by all filters. RCC were filtered 48 h after preparation (mean time 25-30 min). Filtration loss of red blood cells was about 7%. Prefiltration leukocyte concentration averaged 3 x 10(9) leukocytes/l (Coulter). After filtration 6 x 10(5) leukocytes/l (median) were counted in the Nageotte chamber (NC). 1.5 x 10(5)/RCC leukozytes (WBC) per filtered RCC were calculated (median). 29/30 (97%) RCC contained less than 5 x 10(6) WBC, in 4 cases no WBC were detectable in the NC, but 6.62 x 10(6) WBC remained in 1 RCC. The rate of hemolysis (8/30) averaged 0.4% on day 42. Handling was easy, allowing routine use. Quality controls are necessary.