[Quality control in producing thrombocytapheresis preparations with minimal leukocyte contamination]

Passenger white blood cells (WBC) in platelet concentrates (PC) produced by apheresis can cause a variety of adverse effects in recipients after platelet transfusion. With new technologies (LRS, leukocyte reduction system), the preparation of PC with a low WBC contamination is possible without consecutive filtration. In a prospective examination, we compared the effect of LRS apheresis on the donor, the quality of the resulting PC (n = 120), and the platelet increment in the corresponding recipients with conventionally prepared PC (n = 27). In LSR apheresis, no serious adverse effects on the donors were observed, but the post-donation absolute numbers of lymphocytes were reduced from 1,787 +/- 505/microliter to 1,402 +/- 383/microliter (p < 0.001). Comparable results were observed in non-LRS donors. The collection efficiency of the LRS procedures was 50.0 +/- 7.6%, resulting in a yield of 4.25 +/- 1.03 x 10(11) platelets/PC. Flow cytometric examination concerning the expression of platelet glycoproteins in LRS PC showed no elevation in mean fluorescence of CD 62 (6 +/- 4) or CD 63 (9 +/- 3) in comparison to non-LRS PC (mean fluorescence CD 62: 7 +/- 4, CD 63: 8 +/- 3). Median leukocyte contamination of the LRS PC was 0.41 x 10(5) (range 0.06-8.5 x 10(5)) WBC/unit. In 43 recipients, the 24-hour corrected count increments (CCI) after transfusion of LRS PC (12,530 +/- 8,761) showed no significant differences when compared with the CCI in 20 recipients of non-LRS PC (13,133 +/- 9,812, p = 0.75). LRS apheresis seems to be safe procedure, resulting in PC with low WBC contamination, which causes adequate CCI values after transfusion.