Transcription:
Examining the Long-term Health of Living Kidney Donors

Melanie Cole (Host):  In recent years, there’s been a great deal of progress in the field of kidney transplants including advances in treatment and faster recovery time for both donors and recipients. Dr. Aneesha Shetty, Assistant Professor in the Division of Nephrology and Hypertension and Organ Transplantation at Northwestern Medicine and Dr. John Friedewald, Professor in the Division of Nephrology and Hypertension and Organ Transplantation and the Medical Director of the Kidney Transplant Program at Northwestern Medicine are joining me today to share more about their work on the long term health of living kidney donors and advancements in treatment for kidney donor recipients. Doctors, thank you so much for joining us today. this is such an interesting topic. Dr. Friedewald, I’d like to start with you. You recently published a study examining the association between living kidney donation, hypertension and long term EGFR. Can you tell us more about this study and what you sought to find? Is kidney donation independently associated with a higher risk of hypertension? Give us a broad overview of your research.

John Friedewald, MD (Guest):  Sure. And thank you for having us on today. It’s a very important topic and just to give the background, we’ve been doing living donor kidney transplants meaning healthy people donating a kidney to a loved one now for about 60 years in the world, not just the US. And the question always remains is it safe to donate a kidney if you are a healthy person. And the answer although it seems would be obvious, or easy to figure out; it’s actually quite hard to do because the things we worry about in healthy people don’t develop right away. They often take years, decades to develop medical problems that maybe fairly subtle but related to donating a single kidney.

And so, there have been a number of different investigations trying to figure out is it safe to donate a kidney for a healthy person? Much of the early work came from the group at the University of Minnesota who did a lot of the early transplants in this country. And that was fantastic because they followed kidney donors for a long period of time. Unfortunately, for answering big questions, most of those donors were white and of northern European descent. And so, the long term health of that group of donors wasn’t necessarily applicable to many of the donors in the US who donate today who are other ethnic groups.

And so, what we did for this study was to take a collaborative approach, although we are a big transplant center, to get large numbers, we have to collaborate with multiple other transplant centers and so six transplant centers got together all that do a lot of living donor transplants and then have a diverse makeup of ethnicity for donors and followed up donors and reached out to donors who had given kidneys in the past to see how they are doing. And that was a big undertaking. Believe it or not, that’s a lot of effort to track down all these people and get information about them. And we asked some simple questions. How are they doing? How is their kidney function? And did they develop high blood pressure?

We know that from previous studies, that kidney donation can be associated with an increased risk of high blood pressure. But it’s very hard to isolate the effect of just donating a kidney compared to others. Ideally, we would have two identical twins, one would donate a kidney, the other one wouldn’t, and we could follow them and see how they do. But those studies are of course impossible to do. And so, what the approach has been and the approach we took was to find otherwise healthy and similar people who didn’t donate a kidney because again, kidney donors are selected to be quite healthy people to begin with. And then follow them over a long periods of time and in this study, we were able to do that by drawing from two other large what are called cohort studies. One called Aric, A-R-I-C and the other one called Cardia where tens of thousands of healthy people had been followed for decades to see what their long term health is.

And we were able to draw from those studies in collaboration a comparison group of healthy people who were young and similar to the donors here who donated kidneys and at the other five centers and we were able to follow and compare their outcomes, their rates of high blood pressure, their kidney function compared to the people that donated.

Host:  And what were your findings? Help us to understand that association between the living kidney donation.

Dr. Friedewald:  Yes, thank you. So, the first question and this study is ongoing, so we are continuing to glean new information from what we have gathered from these donors who have thankfully participated in this very important study. But the first thing we found when we asked a very simple question is does donation increase your risk of developing high blood pressure. We know that high blood pressure is a very common condition in the United States, but does donation affect that risk and number one and number two is does your ethnicity affect that risk.

And so for this study, we looked simply at people who are of Caucasian descent or of African American descent and to see if there was a difference. Now we know at baseline that people of African descent have higher rates of high blood pressure than Caucasians. So, that was known. But the question was would donation affect that differently. By taking out a kidney we know that the remaining kidney that’s left in the donor compensates and increases the work it does. And that may affect blood pressure. So, what we found was in fact that both Caucasians and African American donors both had higher rates of high blood pressure that could be attributed to donation. So, they had a 19% increased rate of high blood pressure at some point after donation that could be attributed to being a donor.

And that was compared to healthy – what we call healthy non donors. But the one thing we found that was interesting is that in the general population, we know that being African American does increase your risk of getting high blood pressure compared to other ethnicities. In the donor population, it was irrelevant. So, both Caucasian and African American donors had the same increase in risk of developing high blood pressure. It was similar between the two groups. There wasn’t an excess risk for African American donors. So, that was the primary finding of blood pressure.

The second question we asked was kidney function. And one just unfortunate facts about life is as we all age, we lose kidney function. That kidney function – kidney doctors refer to that as glomerular filtration rate or GFR and we can measure how that decreases over time. And everyone loses GFR as we age naturally. What’s interesting about donors is as we give up one kidney, the remaining kidney actually from the time you donate increases the work it does to compensate for the kidney that’s lost. And so actually the GFR in donors tends to go up steadily over time compared to healthy non donors who are losing kidney function.

And we found that in fact, looking at the healthy donors that they all lost kidney function at a predictable rate and all the kidney donors had increasing kidney function at a predictable rate. The rates are slightly different for African Americans and Caucasians but it’s similar in that sense. But what we found is that people who developed high blood pressure, kidney donors particularly who developed high blood pressure their increase in GFR leveled off. So, they didn’t continue to gain kidney function over time.

That’s an important finding because potentially obviously the amount of kidney function you have over time relates to your overall health and so, detecting people who have donated kidneys if they detect if they have high blood pressure getting treated and managed for that high blood pressure carefully may be an important way to protect kidney function over time. And so that was an important finding in the study is that increase in GFR is blunted or stopped in kidney donors who develop high blood pressure. And it’s not a trivial number. And when we looked at the two populations African American kidney donors had up to a 40% rate of high blood pressure by 15 years after donation. Whereas in Caucasians it was just above 20%. And so, a significant group of donors who may develop this and so it’s important that they understand how necessary it is to be followed up over time. Kidney donors tend to be healthy people and they feel often I’m healthy, I feel fine, I don’t need to see a doctor. And we remind kidney donors how important it is to maintain long term medical follow up to detect things like high blood pressure that can be treated.

Host:  Wow, that is absolutely fascinating Dr. Friedewald. Are there any implications coming out of this study that may affect patient care? You mentioned that they need to be followed up after donation and so post operation that living donors, what would you really like them to know? Expand a little on the follow up. What are they supposed to do?

Dr. Friedewald:  Yeah, that’s a great important question. And again, the way it works generally is that UNOS the United Network for Organ Sharing has set forth guidelines whereas transplant centers tend to follow up kidney donors for two years following donation. And we report on their outcomes and so actually UNOS keeps records about the outcomes of donors. But beyond two years, typically, kidney donors are asked to follow up with a primary care doctor. And again, it’s important to remind them that even though they may feel fine, hypertension or high blood pressure is known as the silent killer. You don’t necessarily know you have it unless you are checking. And so, it’s really, I think the study if anything, underscores the importance of having both your blood pressure and kidney function checked on an annual basis forever if you are a prior kidney donor.

Host:  It’s really great advice. Dr. Shetty, could you tell us about the patient education initiatives that you’ve been involved in?

Aneesha Shetty, MD (Guest):  Yeah, and thank you for having me on this talk. Northwestern has been trying to start a lot of patient education initiatives that will help both potential transplant recipients and potential living kidney donors go through the process in an informed way. One of the initiatives we recently started is called the Living Donor Champion Program. Essentially this addresses the fact that it is really hard for somebody who needs a kidney transplant because they have advanced kidney dysfunction to walk up to a friend or family member and ask them for their kidney. It’s really hard to do that. And as a result of that and other reasons, a lot of recipients that we evaluate for transplant don’t have donors who are willing to donate a kidney to them. The Living Donor Champion Program addresses that deficit. What it does is it’s held at a certain frequency at Northwestern. It’s free of charge to attend. And it addresses one, education required to know about transplant and know about living donation. So, a recipient can talk to friends and family about this process. And two, we give potential recipients and their family members tips and tricks on how to open the conversation. What do you say when you want to talk about your kidney disease? How do you talk about your evaluation? How do you go about breaking this conversation that is so sensitive?

We give them tips about social media sharing. Tips about how to share in church. How to share in your friends circle. And all this is done not a by a physician or a nurse, but by a recipient who has had a transplant before or by donors who have donated their kidney before and now are part of this program. So, it’s much more relatable and the purpose of this it to make it so much easier for patients who need transplant to potentially find a donor for themselves.

Host:  What a great program and Dr. Shetty, what are some other projects that you are working on right now?

Dr. Shetty:  So, in the spirit of patient education, there are a few other things that we are working on at Northwestern with Dr. Friedewald’s leadership. We underwent this massive quality improvement process in our living donor program with the primary purpose of making the process of evaluation both for recipients and donors more efficient, more individualized to the patients and ultimately to decrease the time it would take for someone to go from the first point of contact with our division to the actual transplant. And as a part of that quality initiative, a few different things have resulted.

There are a lot more educational materials that are coming out of that initiative in the form of videos that educate patients about different aspects of transplant, one pagers that we can hand out to patients with sort of a quick review, the Donor Champion Program is another example. We are also trying to minimize the number of visits donors have to make down to the center. So, we are trying to respect their schedules because donors are taking this time out of their life to come get their blood testing, come meet the doctors and they all have lives and jobs and we want to be cognizant of that. So, we’re trying to make that more efficient.

The ultimate goal for this is for us to increase the number of living donor transplant programs and be able to help more recipients go through a living donor transplant.

Host:  Dr. Friedewald, how do you envision your research translating into patient care? You are speaking to other providers. What would you like to tell them about counseling their kidney patients on looking for that donor, whether or not they’ve started dialysis, about looking for that donor and discussing studies like this?

Dr. Friedewald:  That’s a great question. I think one of the things that this study does of the long term health of donors is reassures us that it is healthy and safe to donate a kidney. I think what we all are searching to do is to better define the risks involved in kidney donation so that we can better educate potential kidney donors about what they are going through. Obviously, kidney donors all start with the idea of trying to save someone’s life and that’s an incredibly noble thing. But we certainly are getting new ways and new tools to better evaluate what those long term risks really are so we can better educate our patients and our donors about that.

And I think that’s an important part of this is a bit of a reassurance that this is in fact safe to do but it’s important to know that you need to have regular follow up for particularly for blood pressure and then treating blood pressure may help prevent some of the potential lose of kidney function that may occur over time as a result of that.

Host:  And Dr. Shetty before we wrap up, is there anything else you’d like other providers to know about living kidney donation and the program at Northwestern Medicine?

Dr. Shetty:  Our program at Northwestern Medicine is very focused on providing recipients and donors the opportunity to get the transplant that they need for recipients and for donors to be able to donate a kidney safely to their loved ones. And we are constantly in the process of trying to improve our system and improve the way we deal with the recipients and donors. We are open to feedback for any providers out there if they think there’s ways that it can be done better. And overall, we just want to be able to have more patients get the transplant and live a longer and healthy life.

Host:  Thank you both so much. Absolutely fascinating topic and such great information. And that concludes this episode of Better Edge a Northwestern Medicine Podcast for physicians. To refer your patient or for more information on the latest advances in medicine please visit our website at www.nm.org to get connected with one of our providers. Please remember to subscribe, rate and review this podcast and all the other Northwestern Medicine podcasts. For more health tips and updates please follow us on your social channels. I’m Melanie Cole.