Thursday, November 25, 2010

Misc. kidney chains and exchanges

The UNOS National Kidney Paired Donation Pilot System is cautiously expanding its scope to include non-directed donor chains
"St. Louis: The OPTN/UNOS Board of Directors, meeting Nov. 8-9, approved a proposal to broaden potential participation in the recently established national pilot program for kidney paired donation (KPD) transplantation.

"The pilot program was initially approved for operation to match only two to three pairs of transplant candidates and their intended donors. All of these intended donors had meant to donate to a specific recipient before they were found to be medically incompatible with that person. (For additional resource information about the paired donation process, visit the OPTN website:

"Once the newly approved protocol is implemented, pairs can be matched with a "non-directed donor" - a person who chooses to be a living donor but does not come forward to help a specific patient. By including one non-directed donor and a series of other donor/candidate pairs, a chain of transplants can be performed that ends with the transplantation of a candidate who had been awaiting a deceased donor transplant. This is known as "donor chain."

"The pilot program is intended to determine whether having a national base for paired donation can result in more transplants," said OPTN/UNOS President Charles Alexander, RN, M.S.N., M.B.A. The transplant community asked us to take some extra time to study whether and how to add non-directed donors and chains; A number of transplant centers and paired donation organizations have been performing chains for years with good results, and the consensus is that this option should be part of the national pilot."

Here's the Washington Post story about the UNOS pilot: Pilot transplant project aims to spur kidney swaps

Here's a press release from Carnegie Mellon University highlighting the role of software in that effort: Organ Network Uses Carnegie Mellon Algorithm To Match Live Kidney Donors With Recipients, National Pilot Program Facilitates Kidney Paired-Donation Transplants  (no chains were allowed in this initial pilot...)

In the meantime, kidney exchange is also spreading regionally, as the following stories indicate.

Here's a video about a recent, large non-simultaneous chain at Georgetown, which accomplished 16 transplants.

Transplant exchanges allow more to benefit from donations : Oct 29, 2010: Sanford Health transplant leader once personally touched by donation when daughter received new liver

"Sanford Transplant Services, part of Sanford Health of Fargo, N.D., has been in place since 1989 and has completed more than 580 transplants. Dr. Bhargav Mistry has been an instrumental leader in the program and has completed more than 400 of those transplants. Hospital leaders and others say Mistry's commitment to the excellence and genuine care for his patients has built the program into what it is today - a nationally recognized transplant program offering the latest in surgery and technology.

"An example of that innovation occurred in July 2010, when an anonymous kidney donor set off a sequence of 10 surgeries involving 10 patients and resulting in five people receiving kidney transplants.

"The rare chain of surgeries - the first of its kind in North Dakota - was made possible using a unique paired exchange program involving multiple transplant centers based in Minneapolis. Under a transplant chain, or exchange, a potential recipient and her willing, but incompatible, donor family member, friend or other donor are listed in a waiting "pool," along with other mismatched pairs.

"Then, when any potential donor on the list is determined to be compatible for any potential recipient also on the list, the donor gives their organ anonymously if a donation match will also be made for his partner.
"In this case, a Minneapolis non-directed donor, or an anonymous donor who meets strict criteria to donate a kidney, was a match for a potential recipient in Fargo in the paired exchange pool.

"Therefore, the donor's kidney was recovered and flown to Fargo. Two surgeries later, a kidney from Fargo was driven to Minneapolis, extending the chain with four more transplants at Abbott Northwestern Hospital and University of Minnesota Medical Center, Fairview. In total, 10 people produced five successful kidney transplants.
"Mistry seems incredibly compassionate about his chosen career; in fact, he has been personally affected by the need for donation. His daughter, Karishma Mistry, was born without a gall bladder, and doctors told the Mistrys years ago that she would eventually need a new liver.

"I decided to go into transplantation a few months before she was born," Mistry said. "I didn't know we would be in this kind of situation. I think it was just fate."

"In October of 2005, Karishma was added to the transplant list, when complications with her condition arose. In May 2006, the Mistrys received a call that a donor had been found. Today, the teenage girl is doing well and lives a full life. "
(See also Transplant surgeon's daughter gets liver transplant after long wait )

Large non-simultaneous chain in San Antonio at Methodist Specialty and Transplant Hospital, includes 16 transplants: here's a video report from CNN.

And here's a paper on the virtual matching process...

Virtual Crossmatch Approach to Maximize Matching in Paired Kidney Donation.
Am J Transplant. 2010 Nov 10;
Authors: Ferrari P, Fidler S, Wright J, Woodroffe C, Slater P, Van Althuis-Jones A, Holdsworth R, Christiansen FT
Abstract: "We developed and tested a new computer program to match maximal sets of incompatible live donor/recipient pairs from a national paired kidney donation (PKD) registry. Data of 32 incompatible pairs included ABO and 4 digit-high-resolution donor and recipient HLA antigens and recipient’s HLA antibodies. Three test runs were compared, in which donors were excluded from matching to recipients with either donor-specific antibodies (DSA) >8000MFI (mean fluorescent intensity) at low-resolution (Run 1) or >8000MFI at high-resolution (Run 2) or >2000MFI and high-resolution (Run 3). Run 1 identified 22 703 possible combinations, with 20 pairs in the top ranked, Run 2 identified 24 113 combinations, with 19 pairs in the top ranked and Run 3 identified 8843 combinations, with 17 pairs in the top ranked. Review of DSA in Run 1 revealed that six recipients had DSA 2000-8000MFI causing a possible positive crossmatch resulting in breakdown of two 3-way and three 2-way chains. In Run 2, four recipients had DSA 2000-8000MFI, also potentially causing breakdown of three 2-way chains. The more prudent approach of excluding from matching recipients with DSA with >2000MFI reduces the probability of matched pairs having a positive crossmatch without significantly decreasing the number of possible transplants."

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