[The influence of initial values of donor platelets count on the efficiency of plateletpheresis with the cell separator Fenval Baxter Amicus s.v.2.51].

INTRODUCTION The collection of platelets by apheresis is considered as a very great progress in transfusional medicine. A larger yield (total number of collected platelets) is obtained if the donor has a greater number of initial platelets and if the separation is done in a shorter time. One of the parameters is also the efficiency of the platelet collection (expressed in percentage) on the value of which different factors may have direct or indirect influence. AIMS To calculate the efficiency of platelet collection with the separator Fenval Baxter AMICUS s.v.2.51 and to compare the efficiency of platelet collection with this separator in relation to the initial value of donor platelets. DONORS AND METHODS The donors who participated in this study were divided into groups according to the value of the donors' number of platelets before separation. Group A consisted of donors whose initial value of the platelet number was higher than 200 but lower than 300 x 109/L Group B consisted of donors whose initial platelet number was higher than 300 but less than 450 x 109/L. The process was carried out on Fenval Baxter Amicus s.v.2.51. The expected efficiency of the collection was obtained by dividing the total number of collected cells by the expected total number of processed cells, i.e., the total number of cells passed through the equipment. RESULTS In the 258 separations which satisfied the fixed criteria the donors were men in 226 cases (87.6%) and women in 32 (12.4%). The efficiency of platelet collection in our material gave 64.14 +/- 7.92 in the range of minimal and maximal value from 36.65 to 85.22. There is no relation in the correlation between the efficiency of the initial value of the number of platelets. There is no statistical significance in the difference in efficiency of the collection of platelets in the groups A and B. The separations lasted for 44.72 (+/- 9.35) minutes, in group A 49.40 (7.30) minutes and (+/- 8.27) in group B. There is a significant statistical difference (p 0.050; Equal Variance Test P = 0.527). DISCUSSION The values we have obtained from our material are similar to results from other studies of this procedure with one important difference which is that our results were obtained from a larger number of samples. We did not find any relation in the correlation in the variables, the efficiency of platelet separation or in the value of initial number of platelets. The efficiency of platelet collection is almost the same in groups A and B (64.65 +/- 7.99 in group A and 63.50 +/- 7.83 in group B and there is no statistically significant difference). The difference in time of the separation is statistically significant in the groups A and B. CONCLUSION The initial value of the number of the donor's platelets has no effect on the efficiency of platelet collection by apheresis but they have effect on the duration of the separation and the value of the yield. With a higher number of the value of platelets we can cut the time of the separation and obtain a greater yield. It is preferable to choose donors with a greater value of the initial number of platelets. In this way it is possible to obtain a greater yield, cut the time of separation and improve the efficiency of platelet collection. This is beneficial both from the medical point of view because of the greater yield and from the financial point of view because of the shorter time of separation and greater efficiency.