why do successful transplants fail



If someone has a successful lung/ kidney transplant, they are expected to fail after 5-10 years even if they take care of their bodies.
Why? Is there anything that can be done to increase this?

In: Biology

There are SO many variables. For those that have experienced the process, it’s amazing that they happen at all.
But, since your asking, the transplant centres can have almost 100% control over the receiver, insuring that they are as healthy as possible.
At the other end, there is zero control over the donor. If a person dies and donates, there is no way of knowing a comprehensive medical background. The organs have a “shelf life” and are harvested quickly. The organ is then assigned to a receiver based on rudimentary marching of sine variables. The receiver begins prep to get the organ and while the organ is in transit, it is tested further. If a problem such as disease is detected but is deemed still treatable once in the host, the host is made aware and has final say if they want want the risk. So, they fail because there will always be holes in the system.
That’s a nutshell for you.

Your body knows (most of the time) what is you and what is not. It tries to defend you from things in you that are not you. Transplants are a constant fight between you and the part you want to be a new part of you. But it is a fight you cannot win in the long run.


Because the body is very effective at identifying and attacking foreign objects, organisms, viral agents and other intruders. The only reason transplants are successful in the first place is the discovery of powerful immunosuppressive pharmaceuticals, drugs that cause the immune system to stop working.

However, over time the body will still reject the organ even from a relative. Perhaps monozygotic/single egg twins wouldn’t have this problem since their DNA is or is almost identical, but I don’t know enough about that to make any statement.

>Is there anything that can be done to increase this?

There is significant research going on into extracting stem cells from the patients themselves and growing organs in a laboratory. This could potentially make the organs as functional as the ‘original’.

In case you don’t know, stem cells are a sort of *cell factory* that can divide almost indefinitely – and will adapt to their surroundings to produce the appropriate type of structures. Thus, they can be ‘convinced’ to make organs that are in near all respects identical to the individual they’re extracted from.

You are on life long immunosuppresion so that your body doesnt take out your new organ because it doesnt look like the other cells in your body.

Moreoever, because they suppress your immune system you are more prone to dying of infections that normal people can handle.

The biggest problem with an organ transplant in the immune system reaction to the organ. Your immune system will identify the new organ as a foreign object and will attack it causing rejection which will destroy the organ.

Now, rejection can be avoided by immunosuppressions medications : They lower the activity of the immune system and thus it will attack less the transplanted organ.

Problem tho is that you can’t completely prevent the immune system from attacking the transplant, even with good medication. And immunosupressors can induce long term complications on other organs and increase the overall risk of getting cancer. So usually after a few years, the transplant will start to get rejected.

However, everyone is different and some people are luckier than others. While a heart transplant give you an average life expectancy of 9 years, some people have managed to live with a transplanted heart for more than 25 years.

In addition to what everyone else has said, sometimes the disease which necessitated the transplant in the first place reoccurs and affects new the organ also.

I’m going to go a bit beyond 5 years old here, but I think you may appreciate it.

Our organs are made of cells, but it’s important for our cells to communicate with each other but also self identify as being part of a larger whole, because otherwise our bodies immune system will destroy any “foreign” cell. To communicate between cells (and therefore organs) we have tiny little signaling “antennae” called glycoproteins and glycolipids and these have their own unique fingerprint for everyone.

So the surgery could go right, but the organ could still be rejected by the recipients immune system targeting a “foreign” group of cells.