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.

Stored red blood cell susceptibility to in vitro transfusion-associated stress conditions is higher after longer storage and increased by storage in saline-adenine-glucose-mannitol compared to AS-1.

BACKGROUND: Biochemical changes induced in red blood cells (RBCs) during storage may impair their function upon transfusion. Transfusion-associated stresses may further amplify storage lesion effects including increased phosphatidylserine (PS) exposure at the RBC membrane, microparticle (MP) release, and adhesion to endothelial cells (ECs). RBC stress susceptibility in vitro was investigated in relation to storage time and additive solution. STUDY DESIGN AND METHODS: Leukoreduced whole blood donations (n = 18) were paired, mixed, and resplit before separating the RBCs for storage in saline-adenine-glucose-mannitol (SAGM) or AS-1. Samples were taken after 3, 21, or 35 days. For oxidative stress treatment, RBCs were exposed to 0.5 mmol/L tert-butylhydroperoxide. Transfusion-associated stress was simulated by overnight culture at 37 °C with plasma containing inflammatory mediators. PS exposure and MPs were measured by flow cytometry and adhesion to ECs was tested under flow conditions. PS specificity of adhesion was tested by blocking with PS-containing lipid vesicles. RESULTS: Oxidative stress induced significantly higher PS exposure and adhesion to ECs in RBCs stored for 35 days compared to 3 days (p < 0.04). PS-containing vesicles blocked RBC-EC adhesion. After overnight culture with or without plasma, PS exposure and EC adhesion were significantly increased (p < 0.05). MP numbers increased with longer RBC storage and after RBC culture with plasma. Culture conditions influenced MP numbers from Day 35 RBCs. RBCs stored in SAGM had significantly higher PS exposure after stress treatment than AS-1 RBCs (p < 0.02). CONCLUSION: Storage for 35 days significantly increased RBC susceptibility to oxidative and in vitro transfusion-associated stresses and was higher for RBCs stored in SAGM compared to AS-1.

In vitro measures of membrane changes reveal differences between red blood cells stored in saline-adenine-glucose-mannitol and AS-1 additive solutions: a paired study.

BACKGROUND: Saline-adenine-glucose-mannitol (SAGM) and a variant solution, AS-1, have been used for more than 30 years to preserve red blood cells (RBCs). Reputedly these RBC components have similar quality, although no paired study has been reported. To determine whether differences exist, a paired study of SAGM RBCs and AS-1 RBCs was conducted to identify membrane changes, including microparticle (MP) quantitation and in vitro RBC-endothelial cell (EC) interaction. STUDY DESIGN AND METHODS: Two whole blood packs were pooled and split and RBCs were prepared (n=6 pairs). One pack was suspended in SAGM and one in AS-1. Samples were collected during 42 days of refrigerated storage. RBC shape and size and glycophorin A (GPA)(+) and phosphatidylserine (PS)(+) MPs were measured by flow cytometry. RBC adhesion to ECs was determined by an in vitro flow perfusion assay. Routine variables (pH, hemolysis) were also measured. RESULTS: Compared to SAGM RBCs, AS-1 RBCs had lower hemolysis (p<0.04), lower GPA(+) MPs (p<0.03), and lower PS(+) MPs (p<0.03) from Day 14 onward. AS-1 RBCs had higher (p<0.02) side scatter from Day 28 onward compared to SAGM RBCs. SAGM RBCs were more adherent to ECs on Day 28 of storage compared to AS-1 RBCs (p=0.04), but reversed on Day 42 (p=0.02). CONCLUSION: SAGM RBCs lose more membrane during storage. SAGM RBCs had increased adherence to ECs on Day 28 of storage, while AS-1 RBCs were more adherent on Day 42. The effect of these differences on the function and survival of SAGM RBCs and AS-1 RBCs after transfusion remains to be determined.