Aged blood transfusions trigger dangerous inflammation via tiny vesicles, study finds

When medicine offers a lifeline, it sometimes carries hidden burdens. Researchers publishing in Nature have found that microscopic vesicles shed from aging red blood cells — particles so small they were long overlooked — can ignite dangerous inflammatory cascades in septic patients receiving transfusions, worsening the very crisis clinicians are trying to resolve. The discovery reframes a long-standing clinical mystery around why older blood transfusions correlate with poorer outcomes, and opens a path toward intervention through a compound called calpeptin, which may quiet the storm before it