Reliability of tube-based quality assessment of packed red blood cells: Insights from FTIR and Raman spectroscopic analyses

The quality of red blood cells (RBCs) is crucial in transfusion efficacy and safety, particularly in high-risk patients. In this study, age-related biochemical alterations in stored pRBCs were investigated using a systematic, paired comparison of samples collected from pilot tubes and the main storage bags. The analyses were based on spectroscopic measurements of the isolated supernatant mixture containing RBC-derived metabolites and hemolysis products, instead of intact red blood cells. This proof-of-concept demonstrates that pilot tube samples may not reliably reflect the biochemical state of pRBCs stored in the main bag. Our findings revealed that RBCs stored in pilot tubes undergo accelerated degradation, as indicated by elevated hemoglobin concentration, increased lactate levels, reduced glucose content, and a higher lipid-to-protein ratio. Semiquantitative analysis showed that these markers were elevated by approximately 20-100% by the seventh week of storage compared to those observed in the main blood bags. These consistent trends underscore that pilot tube samples do not reliably reflect the true biochemical quality of pRBCs intended for transfusion. Notably, the study highlights the high diagnostic potential of FTIR and Raman spectroscopies in assessing blood quality in a rapid, non-destructive manner. These techniques offer a promising tool for point-of-care evaluation of RBC integrity directly through the storage bag, enabling improved transfusion decision-making, especially in critical care settings. By directly comparing pilot tube and main bag samples, this study reveals systematic differences in their biochemical profiles and proposes a spectroscopic framework for representative, non-invasive evaluation of pRBC quality.