New technique offers successful bone marrow, organ transplant for patients with autoimmune diseases

University of MinnesotaMay 19 2011

New technique will give patients a better chance of having a successful bone marrow or organ transplant

University of Minnesota Medical School researchers have discovered a method to quickly and exponentially grow regulatory T-cells - also known as "suppressor cells." The new process enables replication of the cells by tens of millions in several weeks, a dramatic increase over previous duplication methods. Historically, regulatory T-cells have been difficult to replicate.

The new technique will give patients a better chance of having a successful bone marrow or organ transplant, and will have profound implications for patients with autoimmune diseases such as lupus, type 1 diabetes, Crohn's disease and multiple sclerosis.

The use of the new replication technique has already shown promising effects in the treatment of acute graft-versus-host disease; a post-transplant condition in which T-cells from the donor's bone marrow recognizes a recipient's body as foreign, and tries to attack.

"When regulatory T-cells don't respond to inflammation quickly enough to suppress an immune system response, the patient's own immune response can do considerable harm after a transplant, injuring organs, joints and other tissues of the body," said Dr. Bruce Blazar, senior author of the study and Director of the Clinical and Translational Science Institute at the U of M.

Compounding the challenge is that humans have a limited supply of regulatory T-cells, Blazar said. So even if the immune system's cells respond appropriately, there may not be enough suppressor cells to stop errant reactions in time before the immune response causes widespread tissue damage.

Researchers felt that by developing a way to replicate the cells - which have been historically challenging to coax into high rates of duplication - they could increase transplantation success rates.

Between 30-40 percent of all related bone marrow transplant patients experience graft-versus-host disease, and between 10-30 percent of kidney transplants and 60-80 percent of liver transplant recipients experience acute rejection, according to the National Institutes of Health.