Lipid peroxidation in platelet concentrates: effects of leukocyte removal by filtration

Increased lipid peroxidation (LP) occurs in the presence of various transition, metal ions, including copper and iron, as well as various heme moieties. In addition, irradiation significantly increases LP. The degree of LP, as determined by the liquid chromatographic measurement of plasma malondialdehyde (MDA), can be significantly reduced by the addition of various metal chelating agents and other antioxidants to both stored red blood cells and platelet concentrates. They are also effective in reducing the degree of LP following irradiation. In the current study, leukocytes were effectively removed by filtration from platelet concentrates prepared by standard methods (mean +/- SD before filtration, 460 +/- 286 per microL vs 0.3 +/- 0.2 per microL after filtration). The removal of the white blood cells significantly reduced the plasma MDA levels in the leukocyte-free platelet concentrates compared with concentrates containing leukocytes after storage for 4, 7, and 11 days (P < 0.001; P < 0.02; P < 0.05, respectively). In addition, plasma potassium levels were also significantly reduced in the leukocyte-free platelet concentrates (P < 0.001). Our results suggest that the early removal of leukocytes from platelet concentrates may be helpful in prolonging platelet viability and longevity.