University Tulane UniversityA new study reveals how kidneys rebuild immune defenses after injury. But when those organs are damaged by illness or injury, a specialized group of immune cells helps determine whether the kidneys recover or sustain lasting damage. Acute kidney injury is a common complication of severe infections, surgery, trauma, dehydration, or reduced blood flow to the kidneys, accounting for roughly 1 in 5 hospitalized adults. The research focused on kidney-resident macrophages, immune cells that serve as the kidney’s first responders. Together, the research provides an increasingly detailed picture of how these specialized immune cells maintain kidney health before, during, and after injury.