Macrophages and Kidney Transplantation

SummaryMacrophages are present within the transplanted kidney in varying numbers throughout its lifespan. Because of their prominence during acute rejection episodes, macrophages traditionally have been viewed as contributors to T-cell–directed graft injury. With growing appreciation of macrophage biology, it has become evident that different types of macrophages exist within the kidney, subserving a range of functions that include promotion or attenuation of inflammation, participation in innate and adaptive immune responses, and mediation of tissue injury and fibrosis, as well as tissue repair. A deeper understanding of how macrophages accumulate within the kidney and of what factors control their differentiation and function may identify novel therapeutic targets in transplantation.