Chimerism in women with end stage renal diseases: Who's who?

Abstract

Many sources of foreign or semi foreign cells, known as microchimerism (Mc), can be found in healthy individuals. We have recently shown in women with end stage renal disease (ESRD) that Mc frequencies and levels are exacerbated prior to kidney transplantation. Is Mc arising from pregnancy a protective factor for renal diseases explaining lower incidence in women? Is Mc helpful in slowing down disease progression? However, natural Mc is not the only actor as post blood transfusion Mc is also found at high levels in women with ESRD. The difficulty is therefore to distinguish the different types of Mc and this is made even more complicated when the recipient receives a potentially chimeric organ. What part does each source of chimerism play in disease and transplant fate, and can one decipher each role knowing that one chimerism may hide another?

Figure 1. Diagram representing the possibilities for kidney transplantations and their associated chimerism sources. To make Mc transfer easier to understand, we have arbitrarily represented a gravid woman when the donor or the recipient is a woman, although the woman may be nulligravid and would then be identical to a man in terms of chimerism sources. Furthermore, to avoid complicating the diagram, we have not represented fraternal/gemellar and/or post transfusion Mc. In cases (A and B) the recipient is a woman, in cases (C and D) the recipient is a man. In cases (A and C) the donor is a woman, in cases (B and D) the donor is a man.