サイトスピン法: 白血球除去濃厚血小板中の残存白血球数の新しい確認法

抄録

As methods for depleting leukocytes from platelet concentrates (PC) have been developed to prevent or delay alloimmunization, it has become increasingly necessary to accurately determine the number of leukocytes which still contaminate leukocyte-depleted platelet concentrates (LDPC). Leukocytes in PC can be removed by newly developed filters, such as Pall PL100 and Sepacell PL, and the residual leukocytes in LDPC are so few that they cannot be counted by automated electronic cell counters or manual counting using hemocytometers. Flow cytometric count may be better for that purpose, but its accuracy and sensitivity are still uncertain.
We have applied a cytocentrifuge method to count the residual leukocytes in LDPC using a Shandon Cytospin 2. Optimal conditions of cytocentrifugation were investigated for the centrifugation speed and period, for the volume of the sample, for the effects of red cell and platelet concentrations, etc.
Under the optimal conditions, there was a good correlation between the number of cells attached to the slide glass after cytocentrifugation (y) and that of cells put into the sample chambers (x), expressed as the following regression line: y=0.75x-3.41 (r=0.99). When pooled PC (20-unit pool, 1-day-old) were filtered through a Pall PL100 filter, neither the automated electronic cell counter (Coulter Counter model S Plus IV) nor manual counting could detect leukocytes in these LDPC, but the cytocentrifuge method could detect an average of 1×10⁴ lymphocytes still contained in them.