COMPARISON OF 4 FILTERS FOR LEUKOCYTE DEPLETION OF SINGLE DONOR PLATELETAPHERESIS PRODUCTS

Removal of leukocytes from platelet suspensions is important in preven ting the development of alloimmunization to HLA antigens in repeatedly transfused patients. Several types of filters have recently become av ailable to remove leukocytes from platelet suspensions. We have compar ed the results obtained with Pall PL100S, Pall PL50S, Sepacell PL-10N and Sepacell PL-5N filters. Platelets were obtained by plateletapheres is using the Haemonetics V-50 TSPP surge procedure. A total of 160 pla telet suspensions were studied, 40 for each type of filter used. The m edian number of leukocytes pre-filtration was 321 x 10(6) (range: 16-4 068). The median number of leukocytes post-filtration was 2 x 10(6) (< 1-521) and was dependent on the number of leukocytes present prefiltra tion but not on the type of filter used. All filters tested showed app roximately a 2 log10 reduction of leukocytes. When the number of leuko cytes was below 500 x 10(6) pre-filtration, the number of leukocytes p ost-filtration did not exceed 10 x 10(6). Overall platelet loss was 11 +/- 7% and was lowest with the Pall PL50S filters (7 +/- 7%). Mean pl atelet volumes post-filtration were decreased with all types of filter s used.