Subscribe to Newsletter
Subspecialties Microbiology and immunology

A Closer Look at Chimerism

A vital organ transplant may seem like the end of a long journey through illness, treatment, and weeks, months, or years of waiting. But, in many cases, a new organ is only the beginning of another lifelong journey of immunosuppression and the constant risk of rejection. The immediate concern after transplant is to avoid acute rejection, a condition that places both the patient and the graft at risk. And though immunosuppressive therapy is an effective treatment for acute rejection, it carries its own set of disadvantages, including nephrotoxicity and the risk of opportunistic infections. What can be done to balance these two competing interests?

Ideally, patients will achieve tolerance – a state in which immunosuppression is not required to prevent rejection of the donor organ. In some cases, it’s possible to induce tolerance in patients; for example, by infusing bone marrow cells from the organ donor into the recipient to establish persistent donor chimerism – the coexistence of immune cells from both donor and recipient in the recipient’s body. What makes this an effective method? Researchers from Northwestern University and the University of Virginia investigated patients with this type of induced tolerance to find out the mechanisms involved (1). Gene expression analysis indicated that, in control patients, T- and B-cell-mediated rejection pathways were upregulated at the molecular level – whereas in tolerant patients, no upregulation was seen. Further analysis revealed the induction of regulatory elements known to downregulate inflammation and maintain tissue homeostasis.

It is the first time the molecular mechanisms of chimeric tolerance have been shown, and the researchers are hopeful that it will improve future patient care. Lead author Lorenzo Gallon believes that the data generated could not only help in the longitudinal monitoring of tolerant patients, but also aid in the identification of patients whose chronic immunosuppression could be minimized (2).

Receive content, products, events as well as relevant industry updates from The Pathologist and its sponsors.
Stay up to date with our other newsletters and sponsors information, tailored specifically to the fields you are interested in

When you click “Subscribe” we will email you a link, which you must click to verify the email address above and activate your subscription. If you do not receive this email, please contact us at [email protected].
If you wish to unsubscribe, you can update your preferences at any point.

  1. L Gallon et al., “Intragraft molecular pathways associated with tolerance induction in renal transplantation”, J Am Soc Nephrol, [Epub ahead of print] (2017). PMID: 29191961.
  2. American Society of Nephrology, “Study identifies genes involved in tolerance following kidney transplantation” (2017). Available at: Accessed 11 January, 2018.
About the Author
Michael Schubert

While obtaining degrees in biology from the University of Alberta and biochemistry from Penn State College of Medicine, I worked as a freelance science and medical writer. I was able to hone my skills in research, presentation and scientific writing by assembling grants and journal articles, speaking at international conferences, and consulting on topics ranging from medical education to comic book science. As much as I’ve enjoyed designing new bacteria and plausible superheroes, though, I’m more pleased than ever to be at Texere, using my writing and editing skills to create great content for a professional audience.

Most Popular
Register to The Pathologist

Register to access our FREE online portfolio, request the magazine in print and manage your preferences.

You will benefit from:
  • Unlimited access to ALL articles
  • News, interviews & opinions from leading industry experts
  • Receive print (and PDF) copies of The Pathologist magazine