UNOS DonateLife

July 24, 2006

UNOS Researchers Present Studies at World Transplant Congress

Boston, Mass. -- Researchers from the United Network for Organ Sharing (UNOS) authored and will present several studies at the World Transplant Congress (WTC), a joint meeting of the American Society of Transplant Surgeons, American Society of Transplantation and The Transplantation Society held at the Hynes Convention Center in Boston, Mass., July 22-27. UNOS staff researchers are authors in a total of 21 papers being presented at WTC. Below is a listing of studies to be presented in which UNOS researchers are primary authors. UNOS staff researchers are indicated with an asterisk.

Dissociation of Depletion and PTLD in Kidney Recipients Treated with Alemtuzumab Induction Therapy

Embargo until Tuesday, July 25 - 11:40 a.m. EST
Authors: Wida S. Cherikh, Ph.D.*, Michael Ring, M.D., H. Myron Kauffman, M.D.*, George Burke, M.D., Dixon Kaufman, M.D., Stuart Knechtle, M.D., Santosh Potdar, M.D., Ron Shapiro, M.D., Vikas Dharnidharka, M.D. and Allan Kirk, M.D., Ph.D.

Post-transplant lymphoproliferative disorder (PTLD) is a well recognized, relatively uncommon, complication of organ transplants associated with Epstein-Barr virus (EBV) infection of B cells. An analysis of 46,690 primary kidney transplant recipients was performed to examine the association of various types of induction therapies with PTLD within 730 days of the kidney transplant. For recipients on alemtuzumab, the actual rate of PTLD within 730 days of the transplant was 0.12 percent, the smallest risk of PTLD of any induction strategy including no induction. Multivariate Cox regression analysis also showed that alemtuzumab was not associated with an increased risk of PTLD development within 730 days of the transplant. Further studies are needed to evaluate whether this is related to alemtuzumab's effects on B cells studied or if it is a factor of the maintenance regimens associated with its use.

Trends in Acceptance Rates Among Liver Transplant Programs in the U.S.

Embargo until Tuesday, July 25 - 12:30 p.m. EST
Authors: Erick B. Edwards, Ph.D.* and Sarah E. Taranto*

Organ acceptance practices among liver transplant programs during 2004 were examined along with other indicators of liver program performance. Only programs with 30 or more liver offers were included in the study. Data on actual transplant rates and waiting list deaths by transplant programs were obtained from the Scientific Registry of Transplant Recipients. The median acceptance rate among the 111 liver transplant programs in the study was 37 percent. The study concluded that acceptance rates varied substantially among liver transplant programs in 2004. While the acceptance rates were moderately associated with transplant rates, there was no relationship with waiting list death rates, indicating other factors are responsible for the differences in this performance measure among programs. Since many factors can affect organ acceptance, risk-adjusted models are needed to provide an adequate assessment of a liver program's performance.

What Determines Post Transplant Survival for HCC Recipients 

Embargo until Tuesday, July 25 - 5:40 p.m. EST
Authors: Ann M. Harper*, Erick B. Edwards, Ph.D.*, Abigail Mithoefer, P.A., Anthony Schore, M.D. and Richard B. Freeman, M.D.

The study analyzed 3,426 patients transplanted with a hepatocellular carcinoma (HCC) exception between February 27, 2002 and September 30, 2005 to find what factors influenced post transplant survival for HCC liver recipients. The mean follow up time was 534 days with many predictors analyzed, including tumor size. The study concluded that post transplant HCC survival under current U.S. allocation priority remains excellent, and factors reported in the OPTN database used to predict the outcome in single transplant center studies are associated with survival.

Deceased Donors with Primary CNS Malignancies: An Underused Organ Source

Embargo until Wednesday, July 26 - 12:00 p.m. EST
Authors: H. Myron Kauffman, M.D.*, Wida S. Cherikh, Ph.D.*, Maureen A. McBride, Ph.D.*, Yulin Cheng* and Douglas W. Hanto, M.D., Ph.D.

Though there are over 13,000 central nervous system (CNS) tumor deaths each year in the U.S., the OPTN records an average of only 24.3 CNS tumor donors per year. One reason could be early reports of high CNS donor tumor transmission rates, although a Medline literature search revealed only one case reported since 1992.

A review of CNS tumor transmissions reported to the OPTN from 1994 to 2004 on the recorded 65,930 deceased donors and 202,233 deceased donor transplants, found only one donor with a CNS tumor transmission. The number of deceased donors with CNS tumors, 267, resulted in 819 organ transplants and a subset of 128 donors with malignant CNS tumors resulted in 385 transplants with 81 percent of the recipients still living at a median survival time of 3.2 years. The study concluded that the risk of dying from a donor transmitted CNS tumor should be seriously considered against the risk of dying on the wait list. And deceased donors with CNS tumors are an underused organ source that could provide acceptable organs with a low risk of tumor transmission.

Broader Geographic Sharing Through Accurate Prediction of Crossmatch Results

Embargo until Wednesday, July 26 - 4:10 p.m. EST
Authors: Wida S. Cherikh, Ph.D.*, Timothy Baker*, Karen Nelson, Ph.D., Geoffrey Land, Ph.D., Mary Leffell, Ph.D., and Afzal Nikaein, Ph.D.

The OPTN/UNOS Histocompatibility Committee designed a multi-center study to evaluate the accuracy of predicting crossmatch results using unacceptable HLA antigens (UHA). This information may be used to facilitate transplanting highly sensitized patients. Fourteen labs submitted crossmatch data for 6,620 crossmatches of 225 patients. Results suggest that solid phase immunoassays for detecting UHA may accurately predict crossmatch results. The study shows that highly sensitized patients may have a large number of potential compatible donors nationwide, thus broadening the geographic sharing of organs. The authors recognize that crossmatch standardization and antibody screening techniques are needed for a successful strategy.

Association of Most Commonly Used Antibody Induction and Graft Survival in High Immunologic Risk Kidney Transplant Recipients

Embargo until Thursday, July 27 - 12:10 p.m. EST
Authors: Wida S. Cherikh, Ph.D. *, Sandy Feng, M.D., Ph.D., Carlton Young, M.D., H. Myron Kauffman, M.D.*, and Allan Kirk, M.D., Ph.D.

Antibody induction therapies after kidney transplants have substantially increased from 39 percent in 1998 to 70 percent in 2005. This study compares the impact of no induction versus induction using the three most widely used therapies (basilixumab, daclizumab and thymoglobulin) on graft survival after deceased donor kidney transplants, specifically in three separate high immunologic risk recipient groups: those undergoing repeat transplants, peak PRA of 80 percent or greater, and African-American recipients. The study cohort included 28,496 deceased donor kidney transplant recipients from the OPTN database from 1999 to 2003 with at least eight days of graft survival and one of the previously mentioned therapies or no induction. Compared to no induction therapy, results of the multivariate analysis showed that daclizumab was associated with a significantly improved graft survival rate within 900 days of kidney transplants in low risk recipients and in all high immunologic risk recipients, except repeat transplants. Detailed analyses evaluating a combination of induction and maintenance regimens as well as a combination of various high risk immunologic groups are needed to further expand the current results.

A private, nonprofit organization, UNOS manages the nation's organ transplant system and oversees the world's most comprehensive database of clinical transplant information under contract with the federal government. UNOS operates the 24-hour computerized organ sharing system, matching donated organs to patients registered on the national organ transplant waiting list. UNOS seeks to increase organ donation through education and improve transplant success rates through outcomes-based research and policymaking. The strength of the transplant database relies on the conscientious reporting of 412 UNOS member institutions.