Dec.1, 1999 (Chicago) -- Every year, 5,000 Americans receive new livers and a new lease on life. But for every person with end-stage liver disease, who is the lucky recipient of a new liver, three more are left waiting on the transplant list, and many of them will die waiting. Now an experimental technique being tested at several centers in the U.S. may offer hope those who wait for the gift of life: liver cell transplant.
Doctors at the Medical College of Virginia/Virginia Commonwealth University and the University of Nebraska Medical Center are using cells gathered from donor livers as either a bridge to transplant or bridge to recovery in patients with end-stage liver disease. The papers were presented at the 85th Scientific Assembly and Annual Meeting of the Radiological Society of North America.
Jaime Tisnado, MD, professor of cardiovascular and interventional radiology and surgery, Medical College of Virginia/Virginia Commonwealth University, Richmond, says his team has used the experimental procedure in 12 patients.
"One of the patients recovered with the infused cells alone and seven are alive awaiting whole organ transplant," Tisnado tells WebMD. The woman who recovered with just a cell transplant was in her mid-30s and had traumatic liver damage, probably from a drug reaction. "When we transplanted her she was bleeding out. The next morning, I went to check on her and she was up eating breakfast. I couldn't believe it was the same woman." However, this was an atypical case because the woman "had a healthy liver before the acute injury to it, so we could infuse directly into the liver."
At Nebraska, William C. Culp, MD, assistant professor of radiology, and colleagues have concentrated their efforts on pediatric patients. An 11-year-old girl who had a liver disease that caused excess amounts of bilirubin, a substance produced by the liver, to accumulate in her blood was required to spend 12 to 15 hours a day under ultraviolet lights as treatment, a process called phototherapy. After the cell transplant, her bilirubin level dropped dramatically, and now, "two years later, she is alive and functioning although she still has to spend about four to six hours in phototherapy," says Culp. Moreover, he says, "she came into the hospital, had the transplant, and was discharged the next day. That's not a transplant scenario, that's a tonsillectomy." His team has used liver cell transplants in five patients, two of whom are still alive; three have died. His other surviving patient was an infant who received an infusion at birth. "He was sustained for five months until he could receive an organ transplant," says Culp. The baby is now 1 year old.
Although the results are encouraging, Culp and Tisnado caution that their work is still experimental. At Virginia, Tisnado is developing a technique to freeze and bank the liver cells while the Nebraska team is "using cells harvested from excess liver tissue [from a] transplant." Livers, Culp and Tisnado explain, sometimes need to be pared down to "fit" the recipient.
In other instances, cells are harvested from livers that may be damaged from trauma and thus are not suitable for transplant but could be used as a source for liver cells. Importantly, Tisnado says that a single liver used as a source for transplantable cells could provide enough cells "for 20 people or maybe more." That is significant considering the mathematics of liver transplantation: about 5,000 patients receive liver transplants each year, but 15,000 are waiting for donor organs. Many of those who are waiting for livers will die while waiting, says Tisnado.
The cell transplant procedure is a work in progress. For example, patients who receive cell transplants need to receive immunosuppressive medications to keep the body from rejecting the cells. In adults, it appears that full immunosuppression is necessary, but in children it appears that the level of suppression can be scaled down, says Culp.
Currently, there are about five U.S. centers working on perfecting the liver cell transplant procedure, says Tisnado. He says the technique was developed in Europe by a team of German researchers but adds that U.S. researchers have been involved in animal studies of the technique "for about 10 years."
- Each year, only a fraction of end-stage liver disease patients who are awaiting a transplant will receive one, and many of the remaining patients will die.
- A new technique of transplanting liver cells into these patients can be either a bridge to recovery or a bridge to transplant.
- Donor liver cells can be collected from donated organs that are pared down or unsuitable for whole transplant.