New cellular therapy could reduce dependency on life long drugs after transplants

Medicine has brought about many great changes in our society and nowhere is this more apparent than when it comes to the ability to perform human tissue transplants. Where things like heart and kidney transplants were consider the operation of last resort they are now common place.

The only thing that hasn’t changed is the need for transplant recipients to spend the rest of their life on drugs meant to fight organ rejection. These immunosuppressant drugs work wonders when it comes to stopping our bodies from rejecting new organs but they have their own dangers as well, among which things like increased risk of heart disease or cancer are top of the list.

So it has been a kind of holy grail of medical research that alternatives to these expensive immunosuppressants be found, and if the news out of Stanford University in California is any indication, that holy grail may be within reach.

The way it works is that Samuel Strober and his team have found that immediately following the transplant surgery that while still giving the patient the standard immunosuppressant drugs they apply a mild radiation to the lymph nodes, spleen, and thymus which further weakens the patient’s immune system by killing some of the white blood cells.

At the same time they also inject the patient with antibodies that are targeted directly against the ‘naive T-cells’. It is these cells that are a subset of the white blood cells that are responsible for rejecting grafts. Then ten days after the operation Strober injects the patient with millions of white blood cells from the organ donor. These include the CD34+ stems cells which will multiple and become a part of the recipient’s immune system.

It is this mixing of blood cells that allows for the possible ‘negative selection’ to be negated by bypassing the “do you recognize this material” question that can lead to tissue rejection.

In early trials this regime has proven to be successful in eight out of the twelve test subjects, with one of the twelve dying from an unrelated heart attack and the remainder still on the immunosuppressant drugs but still with an opportunity to be moved to the success column.

via New Scientist