EVALUATION OF A NEW PRESTORAGE LEUKOREDUCTION FILTER FOR RED-BLOOD-CELL UNITS

Background and objectives: Prestorage leukoreduction offers a variety of potential benefits and is becoming more commonly practiced. The Leu koNet(TM) prestorage leukoreduction filtration system is intended for leukoreduction of red blood cells and uses a vent to allow automatic d rainage of red cells from the filter. Materials and methods: We studie d the functional characteristics and the in vivo and in-vitro properti es of leukoreduced AS-1 Red Blood Cells prepared with this new system. Units of AS-1 Red Blood Cells were filtered at 4 degrees C through th e LeukoNet(TM) filter 24-48 h after collection and stored under usual conditions for 42 days. Residual leukocytes were enumerated using a Na geotte chamber or with a polymerase chain reaction (PCR) technique. In the clinical trial (phase one), 21 donors had units stored with and w ithout leukoreduction for 42 days; biochemical assays were done before and after storage, and Cr-51/Tc-99m red cell recovery studies at the end of the storage period. Results: Leukocyte content after filtration was 3.2+/-2.6x10(4)/unit (n = 21), and all units had <1x10(5) leukocy tes (median: 3.8x10(4)). In-vivo paired studies showed no difference i n 24-hour recovery (control: 82.1+/-5.8%; test: 82.9+/-6.0%). Hemolysi s was halved with leukoreduction (0.59+/-0.30 vs. 0.29+/-0.11%; p<0.05 ), and glucose consumption was reduced by 5% compared to control units (p = < 0.05). Other biochemical parameters showed no differences. In the practical trial (phase two), filtration time was 41+/-23 min. With a residual leukocyte content of 6.6+/-4.9 x 10(4)/unit and 14+/-3% re d cell loss (n = 84). Six additional units underwent leukocyte enumera tion by PCR and had 2.6+/-1.1x10(4) residual leukocytes. Conclusions: Under the conditions studied, the LeukoNet(TM) leukoreduction filtrati on system produces about 4-5 log(10) leukocyte content reduction.