Background: During the plateletpheresis procedure the number of thrombocytes in the donor’s blood significantly decreases, and the levels of the hematocrit, hemoglobin, and leukocyte diminish as well. Influence of the cell separator is one of the factors that affects the levels of HCT, Hgb and WBC. Objective: In this study, the goal was to determine the value difference of HCT, Hgb, WBC, and platelets after the platelet pheresis process between performance on Fenwal AMICUS and on COBE Spectra LRS Methods: The criteria for participation: male in the age range of 25-45. We have formed two groups: group I–180 separation were performed on 60 participants were the values of hematocrits, concentration of hemoglobin and number of leukocytes ware established before and after separation using the single-needle intermitent flow cell separation (SN-IFCS) on the Fenwal AMICUS device. Group II – presented 180 separation that were performed on 60 participants, were the values of hematocrits, concentration of hemoglobin and number of leukocytes ware established before and after separation using double-needle continuous flow cell separation (SN-IFCS) on the COBE Spectra LRS. device. To confirm the statistical differences we have used Student t-test for independent or dependent samples, as well as Mann-Whitney U test as non-parametric alternative. To compare differences between the values of four parameters (P1-P2) from two groups (using two devices–Fenwal AMICUS and Fresenius Com Tec) we have performed the ANOVA variance analyze. The possibility of errors were accepted for α<0,05, and the difference between groups as statistical relevant were accepted for p<0,05. Results Statistically significant lower values were noted for all researched parameters after separation on both devices (Fenwal AMICUS and COBE Spectra LRS). Comparing the parameters of hematocrit, leukocytes and hemoglobin’s, we found a statistical significant difference in the decrease of the parameter’s value after separation, there was a significant decrease change in using COBE Spectra LRS cell separator compared to using Fenwal AMICUS cell separator with the same procedure. For the platelets (Plt) there was no statistical significant difference (p> 0,05-α=0,05), between average level obtained using either Fenwal AMICUS or COBE Spectra LRS. Conclusion: The type of cell separator had the influence on the decrease value of the observed parameters.

INTRODUCTION During the plateletpheresis procedure the number of thrombocytes in the donor's blood significantly decreases, and the levels of the hematocrit (HCT), hemoglobin (Hgb), and leukocyte (WBC) diminish as well. Influence of the cell separator is one of the factors that affects the levels of HCT, Hgb and WBC. In this study, the goal was to determine the value difference of HCT, Hgb, WBC, and platelets after the platelet pheresis process between performance on Fenwal AMICUS and on Fresenius Com Tec. DONORS AND METHODS The criteria for participation: male in the age range of 25-45. We have formed two groups: for both groups - 180 separations were performed on 60 participants were the values of hematocrits, concentration of hemoglobin and number of leukocytes were established before and after separation using the double-needle continuous flow cell separation (DN-CFCS) on two different devices, Fenwal AMICUS device and the Fresenius Com Tec. device. To confirm the statistical differences we have used Student t-test for independent or dependent samples, as well as Mann-Whitney U test as non-parametric alternative. To compare differences between the values of four parameters (P1-P2) from two groups (using two devices - Fenwal AMICUS and Fresenius Com Tec) The possibility of errors were accepted for α<0.05, and the difference between groups as statistical relevant were accepted for p<0.05. RESULTS Statistically significant lower values were noted for all researched parameters after separation on both devices. The statistically significant average values for Hct, Hgb and WBC obtained between two devices, were less than 0.05 (p=0.05). For the platelets (Plt) there was no statistical significant difference (p>0.05 - α=0.05), between average level obtained using either Fenwal AMICUS or Frazenius Com Tec. CONCLUSION The type of cell separator had the influence on the decrease value of the observed parameters.

INTRODUCTION During the plateletpheresis procedure the number of trombocites in the donor's blood significantly decreases, and the levels of the other components of blood as hematocrit, hemoglobin, and leukocyte diminish as well. Influence of the type of procedure DN-CFCS and SN-ICFS it is one of the factors that affects the decrease of the levels of HCT, Hgb and WBC. In this study, our goal was to see the difference in the value of HCT, Hgb, WBC, and platelets after the plateletfphresis process between DN-CFCS and SN-IFCS on the same cell separator - Fenval AMICUS. DONORS AND METHODS The criteria for participation: men between age of 25-45. Two groups were formed. Group I 112 separation done with the method SN-ICFS and Group II 180 separation done with the method DN-CFCS. STATISTICAL ANALYSIS To confirm the statistical difference we used Student t-test for independent or dependent samples, as well as Mann-Whitney U test as non parametric alternative. The possibility of errors were accepted for α<0.05, and the difference between groups were accepted as statistical relevant for p<0.05. RESULTS Statistically significant lower values were observed of all researched parameters after separation for the donors on the equipement Amicus DN, and for donors on Amicus SN. A significant higher value of HCT before procedure was found in the AM DN group, in the researches of the other variables there were no significant differences. The resultst for the comparison of variables after procedure procedure for DN and SN procedure. A significant higher value of HCT and a significant higher level of Hgb, as well as a significant lower level of WBV after procedure in the AM DN group, while for the levels of PLT there were no significant differences. CONCLUSION On the decrease of the value of the observed parameters the type of procedure has an influence that means DN-CFCS or SN-IFCS, continuous or discontinuous flow.

CONFLICT OF INTEREST: NONE DECLARED Introduction The collection of platelets by apheresis is considered as a very great progress in transfusion 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 and to compare the efficiency of platelet collection with this separator in relation to the initial value of donor hematocrit. Donors and Methods The donors who participated in this study were divided into groups according to the value of the donor’s ‘hematocrit before separation. Group C consisted of donors whose initial value of the hematocrit was lower or equal to 46%. Group D consisted of donors whose initial value of the hematocrit was higher than 46%. The process was carried out on Fenval Baxter AMICUS. 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 were men in 226 cases (87.6%) and women in 32 (12.4%). There is a statically significant difference in the platelet value between the groups and this value is higher in group D than in group C. The average value of platelets before separation was 46.66. The range of minimal and maximal value is from 38.8 to 52.4 ±2.78. The initial value of hematocrits of the donor does not intervene in the length of the separation, but it has a significant effect on the efficiency of the platelet collection. Increases in the number of hematocrits significantly decrease the efficiency of platelet collection. In practice it means that we can base on this fact make a better selection of donors. In this kind selection, one should prefer a donor with a higher number of initial platelets and lower levels of hematocrits. In that way we can collect a more important yield, have a shorter length of separation and increase the efficiency of platelet collection. Its advantage is as well medical because of a more important yield but also financial because of the decrease of the length of the separation and the increase in efficiency. Key words: value of hematocrits, donors, apheresis, platelets, efficiency.

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.