Higher donor body mass index is associated with increased hemolysis of red blood cells at 42-days of storage: A retrospective analysis of routine quality control data.

BACKGROUND: For reasons unclear, some stored red blood cells (RBCs) have low hemolysis, while others have high hemolysis, which impacts quality consistency. To identify variables that influence hemolysis, routine quality control (QC) data for 42-days-stored RBCs with corresponding donor information were analyzed. STUDY DESIGN AND METHODS: RBC QC and donor data were obtained from a national blood supplier. Regression models and analyses were performed on total cohort stratified by donor sex and by high hemolysis (≥90th percentile) vs control (<90th percentile) samples, including matching. RESULTS: Data included 1734 leukoreduced RBCs (822 female, 912 male), processed by buffy coat-poor or whole blood filtration methods. Male RBCs had larger volume, hemoglobin content, and higher hemolysis than female RBCs (median hemolysis, 0.24% vs 0.21%; all P < .0001). Multivariable regression identified increased body mass index (BMI) and RBC variables were associated with higher hemolysis (P < .0001), along with older female age and buffy coat-poor processing method (P < .002). Logistic regression models comparing the high and control hemolysis subsets, matched for RBC component variables and processing method, identified overweight-obese BMI (>27 kg/m2 ) in males remained the single donor-related variable associated with higher hemolysis (P < .0001); odds ratio, 3 (95% confidence interval [CI], 1.3-6.7), increasing to 4 (95% CI, 1.8-8.6) for obese males (BMI > 30 kg/m2 ). Female donor obesity and older age trended toward higher hemolysis. CONCLUSION: Donor BMI, sex, and female age influence the level of hemolysis of 42-days-stored RBCs. Other factors, not identified in this study, also influence the level of hemolysis.

AS-7 improved in vitro quality of red blood cells prepared from whole blood held overnight at room temperature.

BACKGROUND: Extended room temperature (RT) hold of whole blood (WB) may affect the quality of red blood cell (RBC) components produced from these donations. The availability of better RBC additive solutions (ASs) may help reduce the effects. A new AS, AS-7 (SOLX, Haemonetics Corporation), was investigated for improved in vitro quality of RBCs prepared from WB held overnight at RT. STUDY DESIGN AND METHODS: Sixteen WB units were held for 21.4 hours ± 40 minutes at 22°C on cooling plates before processing. Each pair of ABO-matched WB units were pooled, divided into a WB filter pack containing saline-adenine-glucose-mannitol (control) and a LEUKOSEP WB-filter pack containing SOLX, and processed according to manufacturer's instructions. RBCs were stored at 2 to 6°C and sampled weekly until expiry. Glycophorin A (GPA+) and annexin V-binding microparticles (MPs) were quantitated using flow cytometry. Osmotic fragility, intracellular pH (pHi), adenosine triphosphate (ATP), 2,3-diphosphoglycerate (2,3-DPG), and routine quality variables were measured. Adhesion of RBCs to human endothelial cells (ECs) was evaluated by flow perfusion under low shear stress (0.5 dyne/cm(2) ), similar to low blood flow in microvessels. RESULTS: ATP and 2,3-DPG levels were improved for SOLX-RBCs. SOLX-RBCs maintained higher pHi, increased resistance to hypotonic stress, and reduced numbers of GPA+ MPs. No significant difference was observed between annexin V binding to MPs or adhesion of RBCs to ECs under shear stress. CONCLUSION: SOLX-stored RBCs showed increased osmotic resistance, pHi, and reduced GPA+ MPs and together with higher ATP and 2,3-DPG levels demonstrated improved in vitro RBC quality measures during 42 days of storage.

Proteomic analysis of supernatant from pooled buffy-coat platelet concentrates throughout 7-day storage.

BACKGROUND: The platelet (PLT) storage lesion remains incompletely understood. To gain a greater insight into the PLT storage lesion, a proteomic analysis of supernatant from leukofiltered pooled buffy-coat PLT concentrates (PCs) was undertaken. STUDY DESIGN AND METHODS: PCs were prepared in PLT additive solution and stored according to standard blood bank procedures. Supernatant samples were collected throughout 7 days of storage. Maps of supernatant proteins were generated by two-dimensional (2D) gel electrophoresis and mass spectrometry. Cytokine antibody microarrays and enzyme-linked immunosorbent assay were used to investigate bioactive molecules. RESULTS: The 2D gel maps of PC supernatant proteins displayed many features of plasma protein maps. Several storage-induced protein changes were identified including modifications to major plasma proteins. PLT-derived proteins were also identified, including tremlike transcript 1 and integrin-linked kinase, which may influence PLT-endothelium interactions. Cytokine antibody microarrays revealed a number of bioactive proteins that have not been previously associated with PCs produced for transfusion, such as brain-derived neurotrophic factor (BDNF). The concentration of PLT-derived cytokines including BDNF, CXCL7, epidermal growth factor, PLT-derived growth factor (PDGF), and CCL5 significantly increased during storage of PCs. Extended storage from Day 5 to Day 7 caused significantly increased levels of BDNF, PDGF, and CCL5 in PC supernatant. CONCLUSION: Proteomic techniques provide valuable new insight into the effects of storage on PCs and the contribution of soluble proteins to the development of the PLT storage lesion and recipient responses to PLT transfusion.

Red blood cell (RBC) age at collection and storage influences RBC membrane-associated carbohydrates and lectin binding.

BACKGROUND: Membrane-associated carbohydrate changes act as signals for removal of senescent and damaged red blood cells (RBCs) from the circulation and could play a role in the RBC storage lesion and RBC survival after transfusion. In this study, a panel of lectins was used to investigate the expression of carbohydrates on RBCs that had been separated before storage into young and old RBCs. STUDY DESIGN AND METHODS: Leukodepleted RBCs were separated before storage into young and old RBCs (n = 9 paired units) by centrifugation and sampled at nominated time points during 42 days of storage. Changes to carbohydrate expression at the RBC membrane during storage were determined by flow cytometry with a panel of fluorescein-labeled lectins. RESULTS: Old RBCs showed lower fluorescence intensity throughout storage, suggesting reduced binding of lectins compared to young RBCs. Progressively increased binding of lectins specific for galactose and N-acetylglucosamine residues was observed during storage of young and old RBCs. CONCLUSION: Changes to lectin binding during storage of RBCs suggest that significant changes occur to the carbohydrate structures at the RBC membrane. These findings provide further insight into the mechanisms of the RBC storage lesion and potential influence on RBC survival after transfusion.