Researchers from the University of Colorado in the United States have identified a biochemical marker linked to how long donated blood stays viable for transfusion. Their findings center on the kynurenine metabolite, which appears at higher levels in some blood samples and is associated with a faster loss of essential transfusion properties. The study was summarized for Blood magazine readers, highlighting the potential impact on storage and use of donor blood.
Blood transfusion remains one of the most frequent procedures in hospitals, and the current understanding is that donor blood can be stored for roughly 42 days before transfusion is needed. However, the efficiency of red blood cells, the erythrocytes responsible for carrying hemoglobin and supporting tissue metabolism, declines as storage time extends. This decline can influence how effectively a transfusion meets a patient’s needs and can affect overall outcomes, particularly in patients with complex or urgent medical conditions.
In their pursuit of reliable indicators of blood quality, the research team sought biomarkers that correlate with longer shelf life and better performance after storage. They also examined how donor characteristics such as age, gender, and body mass index might modulate these quality markers. The analysis drew on data involving about 13,000 donors from the US General Biobank and the Recipient Epidemiology and Donor Evaluation Database, providing a large sample to test associations and trends across diverse donor populations.
The investigators found that elevated levels of kynurenine in donor blood signal a tendency toward cellular fragility. Kynurenine is a metabolite produced during normal metabolic processing and can reflect how well cells will tolerate extended storage. Higher concentrations were observed more frequently in the blood of male donors, older female donors, and individuals with higher body mass index. When kynurenine is abundant, red blood cells may degrade more rapidly, reducing transfusion effectiveness and shortening the usable shelf life of the sample.
These results offer a path toward more personalized transfusion strategies, potentially guiding how blood is allocated and prepared for patients with specific needs. The researchers suggest that measuring kynurenine and related metabolic markers could help clinicians anticipate how a given donor unit will perform after storage, leading to better matching of blood quality with patient requirements. Such insights also pave the way for future work to identify additional metabolic properties that contribute to longer-lasting donor blood and more reliable transfusion outcomes for diverse patient groups.
Beyond transfusion practices, these findings contribute to a broader understanding of how metabolic profiles influence blood component quality. The study underscores the importance of integrating donor biology into storage and transfusion decision-making, moving toward a more data-driven approach that considers individual variability rather than treating all donor units as interchangeable. The ultimate goal is to optimize blood use for patient safety, efficacy, and efficiency in healthcare systems across North America.
In related research, scientists have previously identified specific proteins that may play protective roles against certain diseases, illustrating how metabolic and molecular insights can drive advances in medicine and public health. While this study focuses on kynurenine as a marker of blood quality, it also highlights the ongoing importance of comprehensive biobanking, standardized data collection, and large-scale analyses to improve transfusion medicine for patients in Canada, the United States, and beyond. The findings are presented with careful consideration of potential confounders and emphasize the need for further validation in diverse populations and real-world settings to ensure robust clinical applicability.