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Transplanting Between Different Blood Types, Desensitization and Hepatitis C Transplants

Keith Melancon, MD, FACS discusses how ABO incompatible kidney transplant can now allow transplants between some individuals with different blood types. He shares the importance of the immunology of transplantation. and how desensitization, a process in which antibodies are removed from the blood through plasma exchange, can help to prevent antibodies from coming back. Additionally, he highlights hepatitis C transplantation and when to refer to the specialists at The George Washington University Hospital.
Transplanting Between Different Blood Types, Desensitization and Hepatitis C Transplants
Keith Melancon, MD
Dr. Keith Melancon is a general surgeon at The GW Medical Faculty Associates and a Professor of Surgery at The George Washington University School of Medicine and Health Sciences. Dr. Melancon received his medical degree from Tulane Medical School.  He completed his internship and residency at Tulane Medical Center. 

Learn more about Keith Melancon, MD

Andrew Wilner, MD (Host): Welcome to GW Doc Pod, a peer to peer podcast for medical professionals with The George Washington University Hospital. I'm your host, Dr. Andrew Wilner. I invite you to listen in, as we discuss advances in liver transplantation at The George Washington University Hospital. My guest today is Dr. Keith Melancon, Professor of Surgery at The George Washington University School of Medicine and Health Sciences. He's affiliated with The George Washington University Hospital. Welcome, Dr. Melancon.

Dr. Keith Melancon: Thank you for having me. So happy to be here.

Andrew Wilner, MD (Host): Yeah, thanks for joining us. Well, to get started, would you tell us a little bit about yourself and how you became involved in organ transplantation?

Dr. Keith Melancon: Well, I'm originally from Louisiana. I grew up in Louisiana and my mother was a surgical nurse there in Lafayette, Louisiana. So since the time I was a child, I was interested in becoming a surgeon. I was a fan of the sitcom M*A*S*H and I wanted to be Hawkeye Pierce from M*A*S*H. So for my entire life growing up through grade school and whatnot, I knew I wanted to be a surgeon. Eventually, I matriculated into medical school at Tulane University. And while I was there as a medical student, I did research with a transplant surgeon and that pretty much was it for me. I also had a very good friend who needed to receive a kidney and pancreas transplant while I was a medical student. And I got to scrub in on the case when he was transplanted.

So I became a transplant surgeon by doing a fellowship after my residency. My residency was at Tulane University as well. And then, I did a fellowship in organ transplantation at the University of Minnesota in multiorgan transplant, which means liver transplantation, kidney transplantation, and pancreas transplantation. So since 2004, I have been a board-certified multiorgan transplant surgeon.

Andrew Wilner, MD (Host): Wow. Okay. Well, you answered my question. That's a great background. Now, what I understand about transplant surgery is there's the technical aspect of removing the organs that are not functioning and connecting the new ones properly. And then, there's sort of the medical aspect of compatibility. We always hear that patients have to have a match. What's that all about?

Dr. Keith Melancon: Very good question. So the immunology of transplantation is much more important than even the technical aspects of sewing the organ in because if the patients don't match correctly, you are going to have rejection of the organ. So in liver transplantation, it's a little bit easier than say kidney transplantation because, in liver transplantation, we really just match people by blood type and size. So if the person is within a reasonable amount of facsimile to the size of the person that's getting the liver and if they're the same blood type or compatible blood type, you know, i.e., If you're a blood type O, you can give your organs to someone that's another blood type, because O is the universal donor or you need to match A going to A so forth.

But for a kidney transplantation, there's an additional hurdle because we also match people by these proteins that we have in our bodies that are really there to help us fight off infection. These proteins are called the human leukocyte antigens, and we all have them. It's incompatible with life If you don't have them. So we try to match those in kidney transplantation, because the better matched you are with those HLA proteins, the better the outcomes. So it's a little bit more complicated with kidney than with liver, but matching, usually you start with blood type matching.

Andrew Wilner, MD (Host): Okay. So in addition to matching, it would seem to me that the organs that you're transplanting from the donor have to be in good health. So how do you define that?

Dr. Keith Melancon: Yes. So, in order to determine if the organs are in good health, anyone that is being worked up to be a donor, and you can be a donor in two different ways, either after death or you can be a live donor. For a liver transplant, that would mean giving a portion of your liver. And for kidney transplantation, that would mean giving up one of your two kidneys. But in either scenario, the donor has to be in very good health and the organ that is going to be transplanted needs to be perfectly functioning. It's easier to find people that are really good donors earlier in life, but it's not a disqualification to be a donor even very late in life. So there are people that are in their 80s that are still in very good health and can donate their organs for transplantation. The way we determine this is usually through blood work. And every now and again, we will do some diagnostic tests. But through analysis of people's blood, you can determine the function of their kidney, the function of their liver and the function of many other organs, including the pancreas and others. So blood work tests usually done serially in people that are prospective donors is usually the ideal way to test if someone has good organ function and then the diagnostic test like a CT scan can determine if the anatomy would be appropriate for organ donation.

Andrew Wilner, MD (Host): Well, that's great to know. So even if it's a 75-year-old used liver, it still might be worth transplanting and could save somebody's life.

Dr. Keith Melancon: Absolutely. And a big part of knowing if people would pass muster to be an organ donor is going to be the social history. So you could be 75 years old, but you've never been a heavy drinker, you've never had hepatitis, things of that nature, your blood work looks good, diagnostic tests look good, you may not have a lot of miles on your liver even though you're 75 years old. So I always tell the people in organ transplantation that it's not about the chronologic age, it's about the physiologic age. So you could have patients that are in their 70s and 80s, but their organs are really much, much younger because of the way they've lived their lives.

Andrew Wilner, MD (Host): Now, I understand that you are transplanting livers that are actually infected with hepatitis. On the face of it, that doesn't sound like a very good idea. Can you enlighten us?

Dr. Keith Melancon: It's a very good point. So, you know, hepatitis, although it sounds like it's one disease is really a group of diseases. There are lots of different things that can cause hepatitis, including drugs and different types of viral infections. In this country, the most common type of hepatitis had been hepatitis C. So hepatitis A is a self-limiting infection that someone gets usually from infected shellfish or from water. And it basically does not cause much problems. So you get sick, you get better, hepatitis A never causes a problem again. However, hepatitis B can cause liver disease and hepatitis C can cause liver disease.

We are now taking people that have hepatitis C and allowing them to donate their livers because although hepatitis C can cause serious liver disease, it really takes decades of the indolent virus to be causing problems unknown to the patient before it really rears its ugly head, like I said, many decades later. So if you find someone that has hepatitis C, like let's say they were to die in a car accident and they're hepatitis C positive, but their liver through the tests that I told you about earlier is still in good shape, we can now successfully transplant that liver because of the invention of this whole new class of medicines called direct-acting antiviral medications. So these direct-acting antiviral medicines kill the virus. So you can take the organ, transplant it, give the recipient of the transplant these new drugs, and the virus is eradicated from the body and it will not live any longer to cause a problem down the road after transplantion. This is very different than what we used to be able to do in the past, because one of the things that used to happen with people that got an organ when they had hepatitis C, is that the medicines you would give the person to prevent rejection would actually make the hepatitis C virus come alive and go crazy in the recipient and cause them to maybe even die. This does no longer occur because of this fantastic new class of medications.

Andrew Wilner, MD (Host): Right. So ideally, the patient who ends up in a car accident would have had that treatment for their hepatitis before, but maybe they didn't know they had hepatitis C and now you find it post-mortem, but you can actually treat it once that organ is functioning again in a new person.

Dr. Keith Melancon: Absolutely correct. That is exactly the scenario.

Andrew Wilner, MD (Host): Cool. All right. Let's change gears a little bit. And I heard something about kidney pumps. Tell me about kidney pumps.

Dr. Keith Melancon: Yes. Yes. We are so excited about the fact that we are utilizing these pumps in kidney transplantation, because what's happened recently in the field of kidney transplantation is that in order to give greater equity and access to kidney transplantation, we have really pushed the envelope in so far as allowing greater and greater distances to be called local for the purpose of increasing transplant in areas where people have historically not had good access or at least not had equitable access. To give an example, if you lived in New York City a few years ago, the problem is that there are so many people with kidney disease in New York City that even in such a large city, there's not enough donors to keep up with the need.

And therefore, the wait for a kidney transplant was, you know, greater than 12 years, whereas the same type of person needing a transplant in let's say Charlotte, North Carolina, would only have to wait about three years. So, because we had such a problem, what happened is we as an organization of, you know, transplant professionals, we decided that the right thing to do was to make the local area not be just New York City, but a circumferential area of about 250 miles. So now, Baltimore is considered local for New York City. And now, these kidneys can go from Baltimore all the way up to New York if those patients have been waiting longer.

Well, the problem with that is the longer the organ needs to travel, the longer it stays on ice without blood flow and you can get what's called delayed graft function, which basically means it just takes a little bit longer for the kidney to start working. They can still work fine, but this delay sometimes can be very problematic for the patient that you transplant because they become fluid overloaded and the treatment of fluid overload is more dialysis, but more dialysis hurts the new organ because it robs it of very important blood flow.

So the solution is to try not to have delayed graft function. And what we have found is we can markedly reduce the rate of delayed graft function if we take those kidneys that sit on ice longer and then, right before we transplant them, put them on a kidney perfusion pump, so that fluid is pumping through the kidney like blood, but it's not blood, it's preservation fluid, but because our organs are so programmed to have in a pulsatile fashion, pushing this fluid through the kidneys, it makes them work better when you transplant them. We started doing this at George Washington Hospital approximately two years ago and the outcomes have been fantastic. We saw our delayed graft function rate decrease, although the cold ischemia time, i.e., the time that the kidneys are on ice have increased. So this has been a very successful program and by decreasing the delayed graft function rate, we have decreased the rejection rate and increased the outcomes after transplantation. So we are very excited about this new area of being able to pump these kidneys prior to transplant.

Andrew Wilner, MD (Host): Kind of priming the pump as it were. That's kind of interesting because it sounds like a fairly low tech solution. In other words, you didn't really have to invent these new pumps, right? I mean, it's kind of off-the-shelf technology, but it was the idea to do it that was new. Is that right?

Dr. Keith Melancon: Well, the field of pumping kidneys has been around for decades, but what really I think has burned the increased use of these pumps is that the technology got progressively better. In the old days, and, by old days. I mean, more than a decade ago, the pumps at times actually used to cause some damage to the kidneys because the pressure was too high inside the vessels. So the technology had to evolve to us realizing that we did not have to pump at nearly the pressures that you would see inside the human body. And I think early on, the idea was to push the fluid through at around the same pressure as you would see inside the human body. We only now, because of research, push the fluid through at a pressure of about one-fourth of what you would see inside a human body, but this decreased pressure actually has had better results.

So then what happened is you had some people in industry that were able to create these portable pumps that have low pressure and uniform temperature, and these pumps which have now been out I would say around five to six years were really the beginning of the pump revolution. And like I said, we started doing this in the last few years because the other boon to this area has been these new allocation regions that have been organized by the United Network of Organ Sharing. So it was these two things, the technology and then the regulations has caused us to adapt this more readily for our patients.

Andrew Wilner, MD (Host): Thanks for explaining that, Dr. Melancon. That was great. And thank you for this great discussion of advances in liver and kidney transplantation that allow more patients to receive life-saving organs.

Dr. Keith Melancon: Thank you. I'm very happy to have been here because this information I think will be very informative and important for our patients.

That concludes this episode of GW Doc Pod, a peer to peer podcast for medical professionals with The George Washington University Hospital. To refer your patient please call 1-888-4GW-DOCS. If you have a question for one of our specialists please email This email address is being protected from spambots. You need JavaScript enabled to view it.

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