Chimerism (engraftment) analysis- pro
Chimerism (engraftment) analysis, post transplantation specimen.
This test is used to asssess engraftment after an allogeneic transplant. When matched but allogeneic (from another individual) cells are infused the often co-exist with native cells. The situation in which two different populations exist side by side is called chimerism, from the Greek “Chimera”, a mythical creature that was made of different animals. If over time the proportion of native cells increases and transplanted cells decreases, the transplant is being rejected and failing and vice versa, if the allogeneic cells progressively constitute a larger percentage of bone marrow cells, the transplant is “taking”. In order to proceed with engraftment analysis, a pre-transplant specimen is obtained from the recipient and from the donor. DNA from each pre-transplant specimen is extracted and stored for future comparison with post-transplant specimens from the recipient. Engraftment studies are then sequentially performed post-transplant to monitor the level of donor and recipient cell chimerism. Donor and recipient cells are distinguished by PCR amplifying highly polymorphic Short Tandem Repeat (STR) markers, and analyzing the resulting products by capillary electrophoresis. The chimerism analysis is also often performed on flow-sorted purified T cells (often CD3+) and myeloid cells (often CD33+).
The test is standard for post-transplant monitoring.
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Van Deerlin V.M., Reshef R. (2016) Chimerism Testing in Allogeneic Hematopoietic Stem Cell Transplantation. In: Leonard D. (eds) Molecular Pathology in Clinical Practice. Springer
Jordan R. Clark et al, Monitoring of chimerism following allogeneic haematopoietic stem cell transplantation (HSCT): Technical recommendations for the use of Short Tandem Repeat (STR) based techniques, on behalf of the United Kingdom National External Quality Assessment Service for Leucocyte Immunophenotyping Chimerism Working Group BJH Volume 168, Issue 1
January 2015 Pages 26–37
P. Tozzo et al, Chimerism Monitoring Techniques after Hematopoietic Stem Cell Transplantation: An Overview of the Last 15 Years
of Innovations. Diagnostics 2021, 11, 621