Search for additional criteria for evaluating the health status of donors for plateletapheresis (PA) was carried out. The effects of PA on blood biochemistry, erythropoiesis, and rheology were carried out by Density-specific distribution of erythrocytes (DSDE) method and the clotting system status was evaluated by endogenous thrombin potential (ETP) registration. Platelet donors exhibited folic acid deficit, associated with increase of homocysteine level, associated with liability to thrombophilia. Study of blood rheology by ETP registration showed that repeated PA procedures did not impair the barrier characteristics of erythrocyte membrane. Studies of hemostasis with ETP evaluation showed no appreciable shifts, while the detected trend to hypocoagulation (5.7% decrease) after PA was caused by the anticoagulant. Studies of platelet reduction after PA detected the reserve potentials of donors (platelet counts reduced to 184.7 ± 7.7 • 10 9/l). Conclusion. Substantial inspection of donors for repeated PA for identification latent anemias and a throm-bophilia is necessary.

Search for additional criteria for evaluating the health status of donors for plateletapheresis (PA) was carried out. The effects of PA on blood biochemistry, erythropoiesis, and rheology were carried out by Density-specific distribution of erythrocytes (DSDE) method and the clotting system status was evaluated by endogenous thrombin potential (ETP) registration. Platelet donors exhibited folic acid deficit, associated with increase of homocysteine level, associated with liability to thrombophilia. Study of blood rheology by ETP registration showed that repeated PA procedures did not impair the barrier characteristics of erythrocyte membrane. Studies of hemostasis with ETP evaluation showed no appreciable shifts, while the detected trend to hypocoagulation (5.7% decrease) after PA was caused by the anticoagulant. Studies of platelet reduction after PA detected the reserve potentials of donors (platelet counts reduced to 184.7 +/- 7.7 center dot 10(9)/I). Conclusion. Substantial inspection of donors for repeated PA for identification latent anemias and a thrombophilia is necessary.

Aim. To evaluate the effect of pathogen-inactivated platelet concentrates (PIPC) on posttransfusion platelet increments, hemorrhagic syndrome relief, and transfusion intervals.Subjects and methods. This prospective study included 29 hemoblastosis patients (13 women, 16 men), median age 38 years (20-66 years). Pathogens were inactivated by the photodynamic method using the Intecept system. Each patient received two PC transfusions: one PIPC transfusion and one control one. Posttransfusion platelet increments one hour and one day after PC transfusion, the course of hemorrhagic syndrome, and the time to next platelet transfusion were analyzed.Results. Pathogen inactivation with amotosalen and ultraviolet irradiation reduced posttransfusion platelet increments in recipients by 24% after one hour and by 29% after one day after PIPC transfusion versus control ones.Conclusion. The clinical efficiency of transfusions of amotosalen-induced PIPC was comparable with that of untreated platelet concentrates. Despite a reduction in post-transfusion platelet increment with the use of PIPC, this caused no significant increase in the frequency,of transfusions.

The clotting activity of factor VIII (FVIII) was evaluated in 203 samples of fresh frozen plasma (FFP) obtained from whole blood of each donor collected in settings outside of hospital and in 54 FFP samples from blood collected in hospital (control). The time of blood storage from phlebotomy till FFP isolation was 4-6 h under field conditions and 0.5 h in hospital settings. The mean FVIII activity was similar in FFP specimens from donor blood collected in settings outside of hospital and in the control group. The activity of FVIII below 0.7 Unit/ml (70% activity) was detected in FFP specimens from the control group and from each outside of hospital session, but the incidence of these specimens was no higher than 25% in both groups. Thus, the quality of FFP from blood collected in settings outside of hospital met the requirements of Technological Regulations of the Russian Federation and the foreign norm-setting regulations.

The clotting activity of factor VIII (FVIII) was evaluated in 203 samples of fresh frozen plasma (FFP) obtained from whole blood of each donor collected in settings outside of hospital and in 54 FFP samples from blood collected in hospital (control). The time of blood storage from phlebotomy till FFP isolation was 4-6 h under field conditions and 0.5 h in hospital settings. The mean FVIII activity was similar in FFP specimens from donor blood collected in settings outside of hospital and in the control group. The activity of FVIII below 0.7 Unit/ml (70% activity) was detected in FFP specimens from the control group and from each outside of hospital session, but the incidence of these specimens was no higher than 25% in both groups. Thus, the quality of FFP from blood collected in settings outside of hospital met the requirements of Technological Regulations of the Russian Federation and the foreign norm-setting regulations.

The aim of the study was evaluation of the effects of amotosalen photodynamic inactivation of pathogens in platelet concentrates (PC) on the platelet function. Three groups of PC were analyzed: 1) native PC on the day of donation; 2) native PC after 20-24 h storage; and 3) PC after pathogen inactivation (PI) by the Intercept system 20-24 h after donation. Platelet counts, large and immature platelet fractions, phosphatidylserine (PS) and P-selection expression on inactivated platelet membranes and after their target stimulation were studied in all samples. Pathogen inactivation was associated with a significant reduction of platelet concentrations in PC. Studies of PS and P-selectin expression showed that PI suppressed spontaneous stimulation of platelets during storage. However, direct stimulation of platelets was associated with a significant reduction of PS expression in PC subjected to PI. The PI method used in our study led to reduction of cell concentrations in PC and modulated platelet function.

Summary T. he aim of the study was evaluation of the eff ects of amotosalen photodynamic inactivation of pathogens in platelet concentrates (PC) on the platelet function. Three groups of PC were analyzed: 1) native PC on the day of donation; 2) native PC after 20—24 h storage; and 3) PC after pathogen inactivation (PI) by the Intercept system 20—24 h after donation. Platelet counts, large and immature platelet fractions, phosphatidylserine (PS) and P-selection expression on inactivated platelet membranes and after their target stimulation were studied in all samples. Pathogen inactivation was associated with a signifi cant reduction of platelet concentrations in PC. Studies of PS and P-selectin expression showed that PI suppressed spontaneous stimulation of platelets during storage. However, direct stimulation of platelets was associated with a signifi cant reduction of PS expression in PC subjected to PI. The PI method used in our study led to reduction of cell concentrations in PC and modulated platelet function.Key words: platelet concentrate, pathogen inactivation. amotosalen, P-selectin, phosphatidylserine