A new tool in white blood cell reduction for packed red cells: 5 log depletion.

The recent development of new filters used for leucocyte reduction aims at restricting the number of leucocytes to a threshold where their undesirable effects can be minimized or excluded. In this paper we describe the performance of a new filter named BIO R01 MAX and claimed by the manufacturer to perform 5 Log10 depletion. The results show that the efficiency of the filter reached 5 Log10 depletion and the absolute number of white blood cells in the post-filtration units is always less than 2 x 10(4) with considerable safety in the prevention of transfusion reactions.