Factors Affecting The Effect Of Leukocyte Filtration
(1)The effect of leukocyte removal depends on the type of Leukocyte Filter used.
(2) The effect of leukocyte filtration is related to the preparation methods and types of blood preparations.
Royer et al. reported that the ratio of platelets to white blood cells in erythrocyte components had an effect on the filtration of white blood cells. The effect of erythrocyte preparations prepared by mild and severe centrifugation on the filtration of white blood cells was observed. The erythrocyte preparations prepared by mild centrifugation contained more than 1 *106 residual white blood cells (up to the French standard upper limit); and the erythrocyte preparations prepared by severe centrifugation were used. The dosage contained leucocytes below this limit. The results showed that the removal efficiency of white blood cells depended on sufficient platelet-to-white blood cell ratio in erythrocyte preparations, which might facilitate the capture of white blood cells by filters. In fact, this ratio is higher in the preparation of erythrocyte preparations by severe centrifugation. Therefore, the filtering effect of white blood cells also depends on the preparation of red blood cells by RBCs filters.
(3) The effect of leukocyte removal is related to the time of leukocyte removal.
Studies have confirmed that with the increase of storage time, the removal effect of white blood cells in blood decreases . Leukocyte removal before storage and by bedside at 7 days can reduce leucocyte to less than 0.5 *106, and leucocyte removal at 21 or 35 days can reduce to 32.0 or 52.2 *106, respectively. Therefore, pre-storage leukocyte removal is superior to bedside leukocyte removal.