Publication / Source: Infectious Diseases Hub
Authors: Whitney E. Harrington, MD PhD (University of Washington, WA, USA)
Microchimerism refers to the acquisition of foreign cells or DNA by an individual; maternal microchimerism (MMc) specifically refers to the in utero acquisition of maternal cells or DNA by the fetus . MMc is a part of normal human pregnancy, can be detected as early at the second trimester  and is distributed both in hematopoietic cells and in the organs of the body [1, 3–5]. Cross-sectional work has demonstrated that MMc is readily detectable for decades after birth , suggesting that maternal cells are maintained long-term in the offspring. In addition, the acquisition of MMc is associated with the development of maternal antigen-specific tolerance . The evolutionary benefit of maintaining these cells is unknown, although work from a mouse model suggests that they may confer protection from future pregnancy loss in the offspring .
Microchimerism has been studied within the context of solid organ and hematopoietic cell transplant [9–12], autoimmune disease [13–18], breast cancer [19–21] and abnormal pregnancy [22–24]. However, relatively little work has been done exploring the intersection of MMc and infectious disease.