Does Getting a Kidney Transplant Affect Your Immune System?

Matt Ronin, VP of Research & CMC Operations

Kidney transplants are life-changing procedures that can significantly improve the health and well-being of individuals with kidney disease. For many people experiencing kidney failure, a kidney transplant is the best option.

However, people considering a kidney transplant may wonder whether getting a kidney transplant has any impact on the immune system. The bottom line is, getting a kidney transplant does affect the immune system, mainly due to the use of immunosuppressant medications.

Here’s what you need to know about how a kidney transplant affects the immune system.

How the Immune System Works

Your immune system is like a protective shield, defending your body against dangers such as bacteria, viruses, toxins, and other foreign substances.

In a kidney transplant, a kidney from a deceased or living donor is introduced into the recipient’s body. If the immune system identifies the organ as foreign (i.e., not matching the recipient’s own tissue), it may treat it as a potentially harmful invader and launch an attack against it.

If the immune system attacks the organ, the organ becomes damaged and is likely to stop functioning. When this occurs relatively soon after the transplant, typically within a few months, it is called acute organ rejection. If this takes place slowly and/or repeatedly over time, it is called chronic organ rejection.

The more closely matched a donor organ is to the recipient, the less likely the recipient’s immune system is to attack it, which is one reason a good donor–recipient match is so important. However, no matter how close the match, most transplant recipients experience some degree of immune reaction to the new organ.

To prevent the immune system from causing organ rejection, doctors prescribe medications called immunosuppressants.

The Role of Immunosuppressants

Immunosuppressants are a category of drugs that help reduce the immune response. Immunosuppressant drugs are used in a wide variety of diseases and conditions that involve the immune system, including autoimmune diseases such as rheumatoid arthritis, lupus, multiple sclerosis, psoriasis, and Crohn’s disease. They are also sometimes used to combat severe asthma, allergies, and other conditions.

In organ transplants, immunosuppressants are used to prevent the immune system from attacking the donor organ, which minimizes the risk of organ rejection. However, there is currently no way to selectively prevent the immune system from attacking the new organ while still allowing it to attack other harmful invaders, such as germs and viruses. Immunosuppressants suppress the immune system across the board, making it less effective against all foreign pathogens.

To use an analogy, if your body is a castle and the immune system is the guards, immunosuppressants effectively tie up the guards so they can’t prevent anyone from entering the castle. While this stops the guards from attacking friendly visitors (the organ), it also prevents them from attacking any unfriendly visitors (germs, viruses). Basically, with no guards, anyone can get into the castle.

This means that anyone who is taking immunosuppressants to prevent organ rejection (or for any other reason) is at higher risk of contracting other illnesses, infections, and diseases because the immune system is “compromised” and unable to fight them off as it usually would.

For transplant recipients, doctors must carefully monitor and adjust immunosuppressive medications to strike a balance between ensuring the transplanted kidney is accepted by the body and still protecting against potential infections.

A New Approach

Most people who have organ transplants must take immunosuppressants for the rest of their lives. In addition to suppressing the immune system, these drugs can have serious side effects.

ImmunoFree is a new initiative that aims to eliminate the need for immunosuppressive medications for transplant recipients, enabling them to live a longer, healthier life free from the side effects of immunosuppressive medications and without fear of organ rejection. Learn more at