Microchimerism: A new concept

Abstract

Microchimerism is the presence of cells from one individual in another genetically distinct individual. Pregnancy is the main cause of natural microchimerism through transplacental bi-directional cell trafficking between mother and fetus. In addition to a variety of cell-free substances, it is now well-recognized that some cells are also exchanged in pregnancy. Furthermore, it is now known that microchimerism persists decades later both in mother and in her progeny. The consequences of pregnancy-related microchimerism are under active investigation. However, many authors have suggested a close relationship linking fetal microchimerism and the development of autoimmune diseases. Fetal microchimerism is emerging as a potential contributing factor in certain diseases, including cancer. Parallel studies in animal and human pregnancy suggest that microchimeric fetal cells play a role in wound healing. Role of these microchimeric cells in human health and disease is discussed here.

Keywords: Autoimmune disease; fetal-maternal trafficking; microchimerism; pregnancy.

Figure 1

Chimera: An individual organ

Figure 2

Types of microchimerism

Figure 3

The bidirectional fetomaternal trafficking of cells across the placenta

Figure 4

Elective abortion increases the degree of fetal microchimerism which favors the development of autoimmune disease in the postabortion women

Figure 5

Role of maternal microchimeric cells on fetal immunity

Figure 6

Organs affected by autoimmunity diseases caused by microchimeric cells