UC receives grant to better understand how "microparticles" in blood contribute to inflammation, injury

A University of Cincinnati (UC) trauma and critical care researcher has received a National Institutes of Health grant to better understand how "microparticles" in stored blood can contribute to inflammation and injury after resuscitation from traumatic injury.

Timothy Pritts, MD, PhD, UC associate professor of surgery and UC Health trauma surgeon, received a five-year, $1.5 million R01 research award to investigate the nature of microparticles, or small vesicles, that bud off of damaged or active blood cells during storage.

UC researchers have been studying resuscitation with blood products for several years as part of their work with UC's Institute for Military Medicine.

"Hemorrhagic shock is the most common cause of potentially preventable death after traumatic injury," says Pritts. "With recent studies showing the benefits of giving traumatically injured patients blood products instead of the previously standard saline solution, many trauma centers are now using stored red blood cells and plasma for resuscitation. But there's some data to indicate stored blood products may have unforeseen effects on severe injury."

During storage, packed red blood cells (pRBC) undergo biochemical changes known as the "RBC storage lesion." Transfusion with aged pRBC units is associated with worsened outcomes in patients receiving these units, including increased risk of multisystem organ failure, pneumonia, renal failure, sepsis and death.

Originally thought to be harmless cellular debris, microparticles have now been shown to actively contribute to the RBC storage legion.

But Pritts says researchers know little about when and how microparticles form in stored pRBC, as well as how they may lead to cellular inflammation and worsening injury.

"Our preliminary data also show that the number of microparticles increases rapidly during storage and then plateaus, suggesting microparticles may continually form and breakdown in the pRBC units," he says. "We also have data that shows microparticles increase lung inflammation after hemorrhage."

He adds, "Our long-term goal is to understand the mechanisms by which transfusion of older pRBC units worsens patient outcomes. While there's no substitute for blood during resuscitation, we hope to find a way to lessen or prevent the effects of microparticles in the body afterward."