GSTP1 rs1695 and rs1871042, and SOD2 rs4880 as molecular markers of lipid peroxidation in blood storage

Abstract

Background - Red blood cells (RBC) are subject to oxidative stress by reactive oxygen species (ROS) during storage. Molecular characterisation of oxidative stress in stored RBC, which may also occur in other blood components during long periods of storage, is rare.
Materials and methods - Our study included 45 healthy RBC donors recruited in Brazil. Blood was collected into standard Grifols® Triple Bags containing CPD SAG-M. Haematological values, biochemical data, and oxidative stress markers were assessed weekly during storage until 42 days after collection. GSTM1 and GSTT1 were determined by multiplex-polymerase chain reaction (PCR), while GSTP1 rs1695 and rs1871042, CAT rs1001179, and SOD2 rs4880 were evaluated by real-time PCR.
Results - A direct proportional relationship was found between storage time and levels of ROS and thiobarbituric acid reactive substances (TBARS, indicators of lipid peroxidation) (p<0.001). These parameters were indirectly proportional to ABTS values (p<0.001). The plasma concentration of TBARS was associated with GSTP1 303^AG/GG, GSTP1 -16^CT/TT, and SOD2 47^CT/TT genotypes. Single-nucleotide polymorphisms at the CAT C-262T gene were not associated with TBARS, nor were oxidative markers of ROS.
Discussion - Prolonged storage may result in the onset of erythrocyte deterioration. Our results clearly indicate that erythrocytes are capable of attenuating ROS for 2 weeks of storage. We observed an association between elevated TBARS levels and the presence of GSTP1 and SOD2 variants in stored RBC. Although notable for heterozygous variants, this association was even stronger for the homozygous variants GSTP1 rs1695 (303^GG), GSTP1 rs1871042 (-16^TT), and SOD2 rs4880 (47^TT). These findings accentuate the importance of genetic factors in storage lesions and will expand our understanding and consideration of endogenous and exogenous causes in improving clinical treatment with blood transfusions.