Bidirectional passage of cells through the placenta and the persistence of this cells postnatally (feto-maternal microchimerism) is a well described phenomenon^1-4, as well as the potential for this to translate in a long-lasting tollerance allowing the transplant of stem cells form mother to offspring and viceversa^5-9. In this setting a GvM effect has also been observed^10-12.

The use of the mother as stem cell donor has the potential advantage of not requiring costly cell purification procedures that are generally employed in the context of partially matched family donor transplantation (e.g. T-cell depletion through magnetic cell-sorting). Moreover, this type of study may extend this life-saving procedure to countries with ethnic groups less represented in international donor registries and/or stringent economical limitations.

References

1. Lo YM, Lo ES, Watson N, et al. Two-way cell traffic between mother and fetus: biologic and clinical implications. Blood. 1996;88:4390-4395.
2. Scaradavou A, Carrier C, Mollen N, Stevens C, Rubinstein P. Detection of maternal DNA in placental/umbilical cord blood by locus-specific amplification of the noninherited maternal HLA gene. Blood. 1996;88:1494-1500.
3. Maloney S, Smith A, Furst DE, et al. Microchimerism of maternal origin persists into adult life. J Clin Invest. 1999;104:41-47.
4. Evans PC, Lambert N, Maloney S, Furst DE, Moore JM, Nelson JL. Long-term fetal microchimerism in peripheral blood mononuclear cell subsets in healthy women and women with scleroderma. Blood. 1999;93:2033-2037.
5. Tamaki S, Ichinohe T, Matsuo K, Hamajima N, Hirabayashi N, Dohy H. Superior survival of blood and marrow stem cell recipients given maternal grafts over recipients given paternal grafts. Bone Marrow Transplant. 2001;28:375-380.
6. Ochiai N, Shimazaki C, Fuchida S, et al. Successful non-T cell-depleted HLA haplo-identical three-loci mismatched hematopoietic stem cell transplantation from mother to son based on the feto-maternal microchimerism in chronic myelogenous leukemia. Bone Marrow Transplant. 2002;30:793-796.
7. van Rood JJ, Loberiza FR, Jr., Zhang MJ, et al. Effect of tolerance to noninherited maternal antigens on the occurrence of graft-versus-host disease after bone marrow transplantation from a parent or an HLA-haploidentical sibling. Blood. 2002;99:1572-1577.
8. Lucarelli G. 2004. (GENERIC)
   Ref Type: Personal Communication
9. Shimazaki C, Ochiai N, Uchida R, et al. Non-T-cell-depleted HLA haploidentical stem cell transplantation in advanced hematologic malignancies based on the feto-maternal michrochimerism. Blood. 2003;101:3334-3336.
10. Tokita K, Terasaki P, Maruya E, Saji H. Tumour regression following stem cell infusion from daughter to microchimeric mother. Lancet. 2001;358:2047-2048.
11. Dolgopolov I, et al. Evidence of ''graft-versus-tumour'' effect following haploidentical transplantation in a patient with metastatic relapse of Ewing's sarcoma [abstract]. Bone Marrow Transplant. 2004;33:p464.
12. Lacitignola L, Tintori V, Bambi F, et al. Possible graft versus neuroblastoma effect after partially matched related haematopoietic transplantation [abstract]. Bone Marrow Transplant. 2004;33:p461.