Should microchimerism turn into rejection prophylactics?

Abstract

Non-self cells can circulate in the body of an individual after any sort of contact with an allogeneic source of cells, thus creating a situation of chimerism that can be transient or prolonged over time. This situation may appear after stem cell transplantation, pregnancy, transfusion or transplantation. Concerning transplantation, many hypotheses have been formulated regarding the existence, persistence and role of these circulating cells in the host. We will review the principal hypotheses that have been formulated for years since the first description of non-self circulating cells in mammals to the utilization of artificially induced chimerism protocols for the achievement of tolerance.

Five-year clinical effects of donor bone marrow cells infusions in kidney allograft recipients

“…3 Accordingly, several reports suggest that bone marrow augmentation in renal transplant recipients is associated with reasonable patient and when death (not related to rejection) was censored (100% vs. 77.8%, p = 0.03, Fig. 1B).…”

“…1,2 Microchimerism is defined as the presence of small quantity of non-self cells representing less than 1% of circulating cells in the host blood. 3,4 This phenomenon may be a prerequisite for the maintenance of induced clonal deletion, a critical mechanism for acquired tolerance following transplantation. [5][6][7] Since the pioneering study by Starzl et al evaluating persistent systemic microchimerism in long-term allograft recipients, many clinical trials have been performed to confirm whether DBMC infusion can promote donor specific hyporesponsiveness thus improving long-term allograft survival.…”

The role and potential of umbilical cord blood in an era of new therapies: a review

“…It is estimated that, as recently as 2012, about 115,000 solid organ transplants were performed worldwide [ 37 ]. Thus, alternative strategies to minimize maintenance immunosuppression in organ transplant recipients, including the use of regulatory cells [ 38 ] or induced tolerance by mixed chimerism [ 39 ], are evaluated. In terms of immunogenicity, some UCB-derived cell populations show inherent ‘immunoprivileged’ properties because they exhibit class I HLA antigens, and class II HLA antigens are seen only in response to interferon-gamma [ 40 – 42 ].…”

Fetal-maternal interface: A chronicle of allogeneic coexistence

“…Its existence has clearly been demonstrated in multiple fields such as hematopoietic stem cell 2 or solid organ transplantation, 3 non-depleted blood transfusions 4 and the most common form which is bidirectional maternal-fetal cell trafficking whereby cells from the fetus pass through the placenta and establish durable cell lineages within the mother. By delving a little deeper into this last topic, one can notice that normal fetal development directly correlates with previous and concomitant growth of the placenta.…”