Donor Factors Affect Success of Liver Transplantation

Donor Factors Affect Success of Liver Transplantation

By Todd Neale, Staff Writer, MedPage Today
Published: May 29, 2009
Reviewed by Dori F. Zaleznik, MD; Associate Clinical Professor of Medicine, Harvard Medical School, Boston and
Dorothy Caputo, MA,RN,BC-ADM,CDE, Nurse Planner Earn CME/CE credit
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LITTLE FALLS, N.J., May 29 -- A donor's age and other identifiable characteristics appear to worsen outcomes for liver transplant recipients, particularly those who are hepatitis C virus (HCV)-positive. But steatosis alone in a donor's liver should not be a disqualifier, according to two new studies.
Action Points
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■Explain to interested patients that these studies identified characteristics that modified outcomes following liver transplantation.

■Point out that donor steatosis was not associated with transplantation outcome, even in patients who were HCV-positive.
In the first study, higher scores on an index predicting the risk of graft failure based on donor factors were associated with poorer outcomes in all liver transplant recipients, although the relationship was amplified in HCV-positive patients, according to Daniel Maluf, M.D., of Virginia Commonwealth University in Richmond, and colleagues.

The second study indicated that steatosis in the donor liver had no effect on the progression of liver disease or three-year survival among transplant recipients, regardless of HCV status, according to Patrizia Burra, M.D., Ph.D., of the University of Padova in Italy, and colleagues.

They did find, however, that recipient age older than 50, diabetes, and impaired liver function shortly after transplantation were independent predictors of mortality.

Both studies were published in the June issue of Liver Transplantation.

Despite increases in the number of liver transplants over the years, about 15% of patients awaiting a new liver will die before receiving one.

To address the organ shortage, researchers have searched for ways to increase the supply of donor organs, including using less-than-perfect livers.

It had been unclear whether using mildly or moderately fatty livers would be associated with worse outcomes, so Dr. Burra and colleagues analyzed the results of 116 consecutive liver transplants at a single center. A total of 56 recipients were HCV-positive.

About half (50.9%) of the donor livers showed no signs of steatosis, while 39.6% had mild steatosis, and 9.5% had moderate or severe steatosis.

As expected, through three years, HCV-positive patients had significantly worse progression of fibrosis (P=0.001), with nearly a quarter having pre-cirrhosis or cirrhosis.

However, there was no association between donor liver steatosis and the progression of liver disease.

In addition, three-year survival was not affected by recipients' HCV status (P=0.4) or by the degree of donor steatosis (P=0.7).

"Judging from the data presented here, albeit with the limits imposed by the relatively small number of patients considered, we would like to support the use of grafts with steatosis, even in HCV," Dr. Burra and colleagues said.

In the second study, Dr. Maluf and colleagues performed a retrospective analysis of 16,678 patients who received liver transplants over a six-and-a-half year period using the Organ Procurement and Transplantation Network Database.

Nearly half of the patients (46%) were HCV-positive.

A donor risk index was calculated using the following variables: age older than 40, black race, shorter height, donation after cardiac death, death by cerebrovascular accident, and death other than trauma, stroke or anoxia, and transplantation using a split or partial graft.

Increasing scores on the index were associated with greater chances of graft failure and death for both HCV-positive and HCV-negative patients.

However, the risk was significantly greater in HCV-positive patients for both graft failure (P=0.004) and death (P=0.0002).

Donor age accounted for 70% of the relationship between the donor risk index and adverse outcomes.

Beyond the donor risk index, the researchers said, "other risk factors such as graft steatosis, high vasopressor drug requirement, and other clinical attributes of the donor must also be carefully considered by the transplant physician and balanced against the risk of recipient mortality while the patient continues on the waiting list in the event that the offer of a graft is declined."

They acknowledged that the study was limited by possible misclassification bias and by the determination of HCV status by serology only.

Sandy Feng, M.D., Ph.D., of the University of California San Francisco, wrote in an accompanying editorial that there is a severe shortage of organs and that transplantation remains the best hope of survival for many.

Considering the organ shortage, she said, "we must vow to take advantage of every available opportunity to realize reasonable survival benefit through transplantation."

Creating "an allocation algorithm that can systematically and objectively account for the variable impact of donor characteristics on liver transplant outcomes within the context of recipient diagnosis and disease severity . . . would be the most equitable and transparent way to distribute the differential risk posed by the donor pool to individual transplant candidates," she said.

The study authors and the editorialist made no financial disclosures.

Primary source: Liver Transplantation
Source reference:
Burra P, et al "Donor livers with steatosis are safe to use in hepatitis C virus-positive recipients" Liver Transpl 2009; 15: 619-28.

Additional source: Liver Transplantation
Source reference:
Maluf D, et al "Impact of the donor risk index on the outcome of hepatitis C virus-positive liver transplant recipients" Liver Transpl 2009; 15: 592-99.

Additional source: Liver Transplantation
Source reference:
Feng S "Increased donor risk: who should bear the burden?" Liver Transpl 2009; 15: 570-73.