A new cellulose acetate filter to remove leukocytes from buffy-coat-poor red cell concentrates

Transfusion of leukocyte-free red cell concentrates (RCC) prevents or delays HLA immunization in multitransfused patients. We investigated a new cellulose acetate filter which was recently introduced to remove leukocytes from buffy-coat-poor RCC. It was found that the filtration time was only 10 min with buffy-coat-poor RCC in saline-adenine-glucose-mannitol (SAG M; n = 23), hematocrit being 62 +/- 2% (SD). The red cell loss was 13.5 +/- 2.6% and leukocyte removal was more than 99%. Routine filtration in SAG M (n = 179) showed again that more than 99% of the leukocytes were removed from buffy-coat-poor RCC with an original leukocyte content of 804 +/- (SD)458 x 10(6). The red cell loss (12 +/- 8.6%) was not diminished by increasing the amount of saline (0.9% NaCl) from 100 to 300 ml in an attempt to remove the retained red cells from the filter. We conclude that the new filter is reliable in rapidly removing more than 99% of the leukocytes from buffy-coat-poor RCC in SAG M solution.