Survival of renal allografts from living donors and the importance of being the mother of the organ donor

Most parous women have progenitor cells of offspring origin in their peripheral blood for various time periods after giving birth [1,2]. Artlett and colleagues have shown a rate of microchimerism in parous women of 28% [3]. Postpartum women may be microchimeric to offspring hematopoietic cells up to 27 years [1]. However, little is known about the effects of microchimerism in a normal person, but the appearance and persistence of allogeneic white blood cells in a recipient after transplantation, transfusion, or pregnancy has the potential for far-reaching biologic ramification [4]. Microchimerism and HLA-relationships of host and non-host cells may be involved in autoimmune disease [2]. On the other hand, it has been suggested that cellular microchimerism is a physiologic phenomenon in parous women [5]. Starzl et al. described the development of tolerance in five patients who received kidney allografts