The historical concentration of thrombocytes is an average of three subsequent concentrations of thrombocytes before donation (during two years) in blood of donors. The evaluation was applied to characteristics of historical concentration of thrombocytes concerning concentration of thrombocytes in blood of 99 regular donors before every donation of apheresis thrombocytes. It is established that less than 20% dispersion between historical concentration of thrombocytes and value obtained in day of donation is observed in 96% of regular donors. The average concentration of thrombocytes before three subsequent donations of apparatus apheresis in males is statistically higher than in females: 235,2±6,7 and 222,1±11,0 (× 109 cells/l) correspondingly (p < 0,05). The concentration of thrombocytes has no relationship with intervals between donations. There is no statistically significant differences between historical concentration of thrombocytes and concentration of thrombocytes before fourth donation and in general and between separate donations both in males and females. It is appropriate to analyze quality of concentrates of thrombocytes received through program accounting historical concentration of thrombocytes.
Keywords: concentrate; concentration of thrombocytes; donation; donor; regular; thrombocytes; transfusion.