Effects of 3‐5 log10 pre‐storage leucocyte depletion on red cell storage and metabolism

Abstract

SUMMARY. A new, in‐line high‐efficiency 3‐5 log₁₀ leucodepletion filter system (Leukotrap° RC system) was used to investigate the effect of pre‐storage white cell removal on the quality of AS‐3 red cell concentrates stored for 42 d at 4°. Median residual white cell content was 4 × 10⁵ when filtration was performed at 22° within 8 h of phlebotomy (n= 20) and 3.2 × 10⁴ when filtration was performed at 4° 12‐24 h after phlebotomy (n= 24). None exceeded 1 × 10⁶ WBC per red cell product. Filtration was rapid (median 28 min), and red cell loss averaged (mean ± 1 SD) 6.4 ± 0.7%. In a paired study design, post‐transfusion recoveries of 42 d stored red cells in the filtered units averaged 84 ± 6% v 82 ± 8% for unfiltered units (P < 0.05) and post‐storage haemolysis, ATP, osmotic fragility, K+ and pH were significantly (P < 0.05) better in the filtered units. Reduced glycolytic activity was also observed in the filtered units, and there was a correlation between osmotic fragility, glucose consumption, and lactate produced in standard units that was not present in leucodepleted units. In conclusion, this study suggests that leucodepletion of AS‐3 red cell concentrates prior to storage results in better maintenance of the integrity of the red cell membrane with reduced glycolytic activity. There was a modest improvement in post‐infusion viability sufficient to offset the filtration‐induced loss and to result in an equivalent red cell product.