Kidney Exchange Program Digram
Paired kidney exchange, beginning with a non-directed, altruistic donor and resulting in the initiation of a subsequent, unrelated chain by a “bridge” donor.

The Penn Transplant Institute is a leading center for paired kidney exchange for kidney transplantation, a practice that depends largely upon the benevolence of anonymous, altruistic donors.

A common perception of paired kidney exchange is that the process involves single, two-way exchanges between recipients and altruistic donors within their circle of acquaintance or relation. In fact, this is rarely the case. Almost always, despite friends and family members who were evaluated as live kidney donors, the recipient has failed to find an appropriate match. Incompatibility between donor/recipient pairs can come about not only because of blood type, but because the recipient has been sensitized by previous blood transfusions, previous organ transplants or previous pregnancies.

More often, paired kidney exchanges occur as chains initiated between a “non-directed,” non-directed anonymous, altruistic donor and a matched recipient and continued when a friend or relative of this recipient repeats the process by donating to a second matched anonymous recipient. If this person, too, is linked to an unmatched donor, that donor may be enlisted to continue the chain as a donor to another anonymous recipient. Donors in the chain who do not immediately find a matched recipient may choose to begin a separate chain as “bridge” donors from the original chain (see Figure).

At Penn, recipients and donors who are willing to participate in paired kidney exchange must undergo a comprehensive medical evaluation. During this stage, the kidney transplant and living donor transplant teams complete a series of evaluations to determine if the procedures are safe and appropriate for the respective recipients and living donors. Only when the team feels it is safe to proceed are the donor and recipient surgeries scheduled.

The benefit of paired kidney exchange is that it offers kidney recipient and donor pairs who aren’t blood and/or tissue-type compatible an alternative to deceased donor transplantation, thus increasing the number of kidney donors while diminishing competition for deceased donor kidneys.

Paired kidney exchanges also play a critical role in expediting transplants and thereby improving outcomes. According to the United States Department of Health and Human Services, the median waiting time among patients aged 18 to 65 in the US for a deceased-donor kidney in 2014 was 4.5 years, versus 185 days for patients participating in paired kidney exchange. The estimated six-month graft survival rate for patients having paired kidney exchange was 98.8%, compared to 95.1% for deceased donor kidney transplants. [1]

Case Study

Upon learning that 32-year-old Mr. B had end-stage kidney disease, his uncle, Mr. C, volunteered to donate a kidney to him. However, tests at the Penn Transplant Institute showed that Mr. C and Mr. B were not a compatible match. Subsequently, Mr. B entered the home dialysis program at Penn and was placed on the waiting list for a deceased kidney.

Several months later, a transplant coordinator at Penn contacted Mr. C and Mr. B to ask if they would be interested in participating in a paired kidney exchange. She explained that an anonymous altruistic donor, Mr. A, had been found compatible with Mr. B and had agreed to donate a kidney to him. The coordinator asked if Mr. C would consider becoming a kidney donor for an anonymous recipient for whom he was compatible.

Mr. C agreed to become a donor, and at Penn, was paired with Mrs. D. The chain would thus involve Mr. A donating a kidney to Mr. B, and Mr. C donating a kidney to Mrs. D. All four participants in the resulting exchange were found to be physically and psychologically prepared for transplant surgery. The four surgeries were scheduled to take place at Penn Medicine on the same day in separate operating rooms.

On the morning of the kidney exchange, Mr. A had surgery first, and his kidney was transplanted into Mr. B. Later that day, a similar exchange took place. This time, Mr. C’s kidney was transplanted into Mrs. D.

All four patients recovered without incident. In the days after surgery, Mr. C and Mr. B decided to meet the pair with whom they had been matched. All donors currently have functioning transplants, due in large part to the initial intervention of Mr. A, the initiating altruistic donor.

Adding to the success of this exchange, Mr. E, the husband of Mrs. D, initiated a second chain of paired exchange kidney transplants two months later by donating a kidney to Mr. F, thus becoming an altruistic “bridge” donor to this new chain.


Penn Transplant Institute
Kidney Transplant Program
The Perelman Center for Advanced Medicine
2 West Pavilion
3400 Civic Center Boulevard
Philadelphia, PA 19104

Renal Electrolyte and Hypertension
Perelman Center for Advanced Medicine
South Pavilion, 1st Floor
3400 Civic Center Boulevard
Philadelphia, PA 19104

Patients also evaluated at:

Penn Medicine Radnor
250 King of Prussia Road
Radnor, PA 19087

Penn Medicine Bucks County
777 Township Line Road
Yardley, PA 19067

Penn Medicine Cherry Hill
1400 East Route 70
Cherry Hill, NJ 08034

Penn Medicine Woodbury Heights
1006 Mantua Pike
Woodbury Heights, NJ 08097

Lancaster General Health Downtown Campus
Comprehensive Care Center, 3rd Floor
554 N. Duke Street
Lancaster, PA 17602

The contact number for recipients and donors is 215.662.6200.

Published on: September 5, 2017


1. State of the OPTN/UNOS KPD Pilot Program, DHHS 2014.

About the Penn Transplant Institute

The Penn Transplant Institute is home to kidney, liver, lung, heart, pancreas and hand transplantation programs, and is ranked among the top 10 multi-organ transplant centers in the country. Paired Kidney Exchange at Penn Medicine Penn performed the first successful kidney transplant in 1966, and the Penn Transplant Institute is now a leader in the effort to increase paired kidney exchanges for kidney transplantation. In partnership with the National Kidney Registry (NKR), a consortium of 72 transplant centers nationwide, the Penn Transplant Institute recently took part in the largest kidney exchange to be concluded in under 40 days and the second largest in history (ultimately involving 28 donors and 28 recipients).

In 2012, the US Department of Health and Human Services awarded the Penn Transplant Institute’s Kidney Transplant program a Silver Level Award. Penn is the only transplant center in the region and one of a select group of programs in the nation to receive this distinction. In addition to its partnership with the NKR, the largest and most successful kidney transplant matching program in the US, the Penn Transplant Institute is a member of the United Network for Organ Sharing (UNOS). Outside of its participation with these organizations, the Transplant Institute has a large enough waiting list to initiate donor chains within its own programs.

Performing Kidney Transplantation at Penn Medicine

Penn Faculty Team

Ali Naji, MD, PhD

Vice Chair, Research, Department of Surgery

J. William White Professor of Surgical Research

Peter L. Abt, MD

Associate Professor of Surgery at the Hospital of the University of Pennsylvania and the Children's Hospital of Philadelphia

Melissa B. Bleicher, MD

Assistant Medical Director, Penn Kidney Transplant Program, Post-Transplant Operations, University of Pennsylvania

Director, Transplant Adolescent Transition Program, University of Pennsylvania

Associate Professor of Clinical Medicine

Roy D. Bloom, MD

Medical Director, Kidney/Pancreas Transplant Program, Hospital of the University of Pennsylvania

Professor of Medicine at the Hospital of the University of Pennsylvania

Simin Goral, MD

Director, Polycystic Kidney Disease Clinic

Transplant Nephrology Fellowship Director

Professor of Medicine at the Hospital of the University of Pennsylvania

Matthew H. Levine, MD, PhD

Associate Professor of Surgery

Mary Ann C. Lim, MD

Assistant Professor of Clinical Medicine

Paige M. Porrett, MD, PhD

Assistant Professor of Surgery

Deirdre L. Sawinski, MD

Assistant Medical Director, Kidney Pancreas Transplantation

Assistant Professor of Medicine at the Hospital of the University of Pennsylvania

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