The possibility of having a kidney transplant without spending a lifetime on immunosuppressive drugs has come a step or two closer with the announcement this week of two studies using two new techniques to discourage rejection of the donor organ.
The studies are published in today’s issue of the New England Journal of Medicine (NEJM), 24th January.
In the first study which was carried out by researchers at Massachusetts General Hospital and Harvard Medical School in Boston, five patients with end stage kidney disease received combined bone marrow and kidney transplants from relatives that did not match. This was done in three stages. First their immune system was partly inactivated, then they were given a bone marrow graft from the donor, and then they received the donor’s kidney.
All but one of the patients was able to stop taking immunosuppressive drugs 9 to 14 months after the transplants, and their kidney function has remained stable for between 2 to 5.3 years.
Dr David Sachs, co-leader of the study, who works in the Transplantation Biology Research Center at Massachusetts General and Harvard, said that while the study should be replicated with a larger patient population before it can be considered for clinical use:
“This is the first time that tolerance to a series of mismatched transplants has been intentionally and successfully induced.”
In the second study, conducted at Stanford University, a man was given his matched brother’s kidney and implanted with his brother’s blood cells, after his immune system was partly inactivated with radiation and antibodies. The result appears to have created a “hybrid” immune system that has not attempted to reject the donor organ and there have been no symptoms of graft versus host disease from the implanted blood cells.
Lead author Dr John Scandling, professor at Stanford’s Department of Medicine said:
“The idea of getting off drugs holds tremendous appeal for patients.”
However, he stressed there is still a long way to go before this method is available in clinical practice.
A third study in the same issue of the NEJM, reported the successful case of a 9 year old girl who received a liver transplant and was able to come off immunosuppressive drugs after the donor’s liver “seeded” stem cells in her own bone marrow. Like the man who received his brother’s blood cells, this also resultedd in a “hybrid” immune system, except in this little girl’s case it went as far as to change her blood type.
“HLA-Mismatched Renal Transplantation without Maintenance Immunosuppression.”
Kawai, Tatsuo, Cosimi, A. Benedict, Spitzer, Thomas R., Tolkoff-Rubin, Nina, Suthanthiran, Manikkam, Saidman, Susan L., Shaffer, Juanita, Preffer, Frederic I., Ding, Ruchuang, Sharma, Vijay, Fishman, Jay A., Dey, Bimalangshu, Ko, Dicken S.C., Hertl, Martin, Goes, Nelson B., Wong, Waichi, Williams, Winfred W., Jr., Colvin, Robert B., Sykes, Megan, Sachs, David H.
N Engl J Med 2008 358: 353-361.
Volume 358:353-361, January 24, 2008, Number 4.
“Tolerance and Chimerism after Renal and Hematopoietic-Cell Transplantation.”
Scandling, John D., Busque, Stephan, Dejbakhsh-Jones, Sussan, Benike, Claudia, Millan, Maria T., Shizuru, Judith A., Hoppe, Richard T., Lowsky, Robert, Engleman, Edgar G., Strober, Samuel.
N Engl J Med 2008 358: 362-368.
Volume 358:362-368, January 24, 2008, Number 4.
Sources: NEJM articles, BBC News, Reuters.
Written by: Catharine Paddock