Morphofunctional changes in red blood cells during storage in PAGGSM solution

Abstract

Background. Packed red blood cell (pRBC) components come from donor blood and are among the most commonly used transfusion products in clinical settings. They play a key role in treating anemia, blood cancers, severe bleeding, trauma, and other conditions that cause low tissue oxygenation. Therefore, the quality of RBC components and the preservation of their functional properties are fundamental to the efficacy and safety of transfusion therapy. The success of a blood transfusion depends on keeping the shape and function of RBCs intact. Prolonged storage leads to metabolic, membrane, and mechanical alterations in RBCs, potentially compromising their functional integrity. Additive solutions such as SAGM help reduce storage-related damage but do not fully prevent destructive changes during prolonged storage. The additive solution PAGGSM extends RBCs storage to 49 days while maintaining a low level of hemolysis. However, the effects on the structural and functional properties of RBCs remain insufficiently studied.
Aim. Comprehensive assessment of the morphofunctional properties of pRBCs during 49 days of storage in PAGGSM solution using atomic force microscopy and biochemical analysis.
Materials and Methods. A pRBC unit derived from four donors was analyzed following 49 days of storage at +4°C. Morphofunctional characteristics, such as nanostructure and Young’s modulus, along with various hematological parameters, were evaluated on days 1, 29, and 49. These time points mark the start, middle, and end of the storage period. Biochemical parameters and hemogram indices were assessed using the ABL800 Basic and Sysmex XN-350 hematology analyzers. Morphofunctional properties were assessed using the NTEGRA Prima and NTEGRA BIO atomic force microscopes. The percentage of hemoglobin derivatives was determined with a Unico 2800 spectrophotometer.
Results. During storage, characteristic metabolic changes occurred, including progressive acidification of the medium, glucose depletion, and changes in electrolyte balance. Although hematological parameters remained stable and hemolysis levels did not exceed the standard limit (<0.8%), atomic force microscopy identified distinct morphofunctional alterations. However, the proportion of discocytes decreased from 93% to 40% by day 49, indicating shape transformation, with increased numbers of echinocytes and microspherocytes seen in parallel. Young’s modulus increased twofold, reaching 11.1 kPa by day 49 of storage. Nanostructural parameters (h1 and L1) also increased significantly, further evidencing structural changes. In contrast, the percentage content of hemoglobin components remained stable throughout storage, indicating the retention of hemoglobin composition despite the other changes.
Conclusion. PAGGSM solution maintains membrane integrity and shows low hemolysis for up to 49 days. However, it does not prevent storage-related damage. Instead, it delays the onset of damage to later time points compared with the standard SAGM solution. The pattern of changes remains similar between the two solutions. By day 49, critical morphofunctional alterations accumulate in erythrocytes. This shows that membrane integrity and low hemolysis do not guarantee that cells remain functional or that transfusion effectiveness is ensured.