James C. Zimring has published a wonderful perspectives article in the April 2, 2015 issue of Blood (abstract) that nicely summarizes what is known about the red cell storage lesion from clinical and experimental studies. However, recent RCTs (ARIPI abstract, RECESS abstract, and ABLE presentation) have failed to show in clinically significant difference between groups receiving fresher versus older blood. So why should we bother about the red cell storage lesion when there doesn't appear to be any clinically relevant differences in outcome whether a patient is transfused with "older" blood?
Dr. Zimring's article answers this by framing the question in terms of precisely what is known about the storage lesion, but more importantly, what is not known. There is myriad studies describing various aspects of the storage lesion but there hasn't been that "unified theory" that really condenses all that has been described about the storage lesion into a discrete "lesion." Perhaps there isn't one. But the author concisely outlines the limitations of clinical studies, biological studies of RBCs, and animal models of the storage lesion to build the argument that the broad question, "Is older blood bad for you?," seeks an answer that would be an oversimplification and is neither testable nor applicable. What is needed, Dr. Zimring concludes, are more focused questions.
There are many important insights and informed in this article and I highly recommend it!