UNOS DonateLife

June 2, 2008

UNOS Researchers Present Studies at American Transplant Congress

Toronto -- Researchers from the United Network for Organ Sharing (UNOS) authored and will present several studies at the American Transplant Congress (ATC), a joint meeting of the American Society of Transplant Surgeons and the American Society of Transplantation held at the Metropolitan Toronto Convention Center May 30 through June 4. UNOS staff researchers are authors in a total of 10 papers being presented at ATC.

Below is a listing of studies to be presented orally in which UNOS researchers are primary authors. UNOS staff researchers are indicated with an asterisk.

NOTE: This work was supported wholly or in part by Health Resources and Services Administration contract 234-2005-370011C. The content is the responsibility of the authors alone and does not necessarily reflect the views or policies of the Department of Health and Human Services, nor does mention of trade names, commercial products, or organizations imply endorsement by the U.S. Government.

Longer Term Results for Hepatocellular Carcinoma Liver Transplant Recipients: Down-Staging Has Benefit

Embargo until Monday, June 2 -- 4:24 p.m. EDT
Authors: Ann M. Harper*, Erick B. Edwards, Ph.D.*, Richard B. Freeman, M.D.

The researchers studied the outcomes of people with hepatocellular carcinoma (HCC) who received liver transplants over a period of more than four years. Recipients whose HCC tumors were larger than three centimeters at the time of transplantation had poor three-year survival compared to recipients with smaller tumors. Those with micro or macrovascular invasion, and/or an AFP greater than 500, also had significantly lower post-transplant survival. Recipients who received pre-transplant ablation treatment to "down-stage" tumor size had better results, suggesting that this therapy is emerging as a potentially effective treatment to improve outcomes for recipients with HCC.

The Effect of Sirolimus on De Novo Cancer after Kidney Transplantation: An OPTN Database Analysis

Embargo until Monday, June 2 -- 4:36 p.m. EDT
Authors: Wida S. Cherikh, Ph.D.*, Douglas W. Hanto, M.D., Allan D. Kirk, M.D., Ph.D.

Previous analysis has demonstrated an increased risk of post-transplant lymphoproliferative disease (PTLD) in kidney recipients associated with use of the immunosuppressive drug sirolimus. The researchers analyzed data on adult kidney recipients over a five-year period to determine the association of sirolimus with non-PTLD, de novo (newly detected) solid and skin cancers. The risk of cancer occurrence was compared to a different immunosuppressive drug, tacrolimus. The researchers found a 55 percent decreased risk of skin cancer, with statistical significance, when sirolimus and cyclosporine were used together as compared to tacrolimus. The sirolimus-cyclosporine combination was also associated with a 32 percent decreased risk of de novo solid cancer, but this finding was not statistically significant. The researchers caution that the reduced cancer risk may not be uniquely due to sirolimus but may reflect practice patterns or patient selection.

The Effect of Pre-Transplant Ablation Therapy on Post-Transplant Outcome in Liver Recipients with Hepatocellular Carcinoma

Embargo until Tuesday, June 3 -- 9:00 a.m. EDT
Authors: Erick B. Edwards, Ph.D.*, Ann M. Harper*, Richard B. Freeman, M.D.

Under existing liver allocation policy, candidates with hepatocellular carcinoma (HCC) may receive extra allocation priority. The researchers studied adult liver recipients over a more than three-year period who had received pre-transplant ablation. Both of the most common ablation therapies were associated with a statistically significant lower risk of post-transplant graft failure. Further study is needed to determine how much of the effect is due to the therapy itself and how much is due to careful selection of patients to receive ablation.

Short-Term Complications in Recent Living Kidney Donors

Embargo until Tuesday, June 3 -- 3:25 p.m. EDT
Authors: Jennifer L. Wainright, Ph.D.*, Connie L. Davis, M.D.

The researchers studied reports of serious adverse events on registration forms for each of the 13,000 living kidney donors in the U.S. in 2005 and 2006. In the six weeks following donation, 512 donors (3.9 percent) had at least one serious adverse event. This included one reported death and 220 donors readmitted to the hospital following initial discharge. Since more than half of the forms were submitted prior to six weeks from the donation, the complication rates should be considered minimum estimates. There was a significant correlation between the number of living donor kidney transplants performed and the percentage of repeat admissions of living donors; complication rates were lower, on average, at hospitals that performed a higher volume of transplants.

Prior Living Kidney Donors Who Were Subsequently Placed on the Waiting List: An Updated OPTN Analysis

Embargo until Tuesday, June 3 -- 4:20 p.m. EDT
Authors: Wida S. Cherikh, Ph.D.*, Pang-Yen Fan, M.D., Sarah E. Taranto*, Henry B. Randall, M.D., Carlton J. Young, M.D.

The researchers identified and studied 148 previous living kidney donors who were wait-listed for a kidney transplant from January 1996 through March 2007; most had received a kidney transplant by the time of the data analysis. The overall median time between donation and listing was calculated at 20 years, so the number and rate of those listed within five years of donation were small. However, the rate of African-Americans being listed within five years of donation was higher, a finding that warrants further study.

U.S. Results of Mismatching Donor and Recipient Age after Kidney Transplantation

Embargo until Tuesday, June 3 -- 4:30 p.m. EDT
Authors: Maureen A. McBride, Ph.D.*, Ciara J. Gould, M.P.H.*, Wida S. Cherikh, Ph.D.*, Francis L. Delmonico, M.D., Timothy L. Pruett, M.D.

Current discussion in the transplant community has focused on the effect of kidney transplants from older deceased donors going to younger recipients and kidneys from younger deceased donors going to older recipients. The researchers studied the three-year outcomes of deceased donor kidney transplants occurring between 2002 and 2004. Of recipients who died within three years with a functioning kidney, the majority of deaths occurred among recipients age 50 or older; of these older recipients, nearly 29 percent had received a kidney from a donor aged less than 34. Conversely, among recipients aged 18-34 who received a kidney from a deceased donor older than 50, about 22 percent of the kidneys had stopped functioning within three years. The researchers conclude that these findings appear to exceed desired results, and that they justify consideration of changes to allocation policy to allow more age-appropriate matching.

Liver Graft Outcomes in Recipients with and without Combined Kidney Transplantation: A Propensity Analysis

Embargo until Wednesday, June 4 -- 11:05 a.m. EDT Authors: Erick B. Edwards, Ph.D.*, Ann M. Harper*, Richard B. Freeman, M.D.

One of the key components of the MELD score, used to determine medical urgency for a liver transplant, is serum creatinine (a measure of the kidneys' ability to eliminate waste). Since higher creatinine results (indicating lesser kidney function) tend to increase the MELD score, a growing number of candidates with kidney dysfunction have received either a liver or a combined liver-kidney transplant. The researchers examined variables affecting outcomes for recipients of liver-only and liver-kidney transplants over a period of more than four years. After statistical adjustment for the effect of several variables, the relative risk of liver graft failure was lower for combined liver-kidney transplants than liver-only. It is possible that the difference in outcomes is caused by factors not observed and/or data not currently collected by the OPTN.

The Organ Procurement and Transplantation Network (OPTN) is operated under contract with the U.S. Department of Health and Human Services, Health Resources and Services Administration, Division of Transplantation by the United Network for Organ Sharing (UNOS). The OPTN brings together medical professionals, transplant recipients and donor families to develop organ transplantation policy.