[Changes in thrombocytapheresis concentrations caused by leukocyte depletion with polyester filters]

We studied platelet loss, leukocyte depletion, T/B-cell-ratio, platelet morphology and platelet function (aggregation, hypotonic shock reaction, retention and retraction) prior to and after filtration through two different polyester filters (Sepacell PL-5A, Pall PL100) as well as the posttransfusional platelet increment 1 h after transfusion in 8 pairs of single donor platelet concentrates (Cobe Spectra, Fresenius AS 104). Leukocyte depletion was effective (greater than 99.9%) and platelet loss acceptable in both filters, all tests showing no indication of a diminished platelet function by filtration.