Introduction
The long-term success of a kidney transplant involves several key steps. It is important to maintain regular appointments with the transplant team and adhere to their guidance. This includes taking anti-rejection or immunosuppressive medications at the correct doses and times to prevent one's body from rejecting the new kidney. Following the recommended schedule for laboratory tests and clinic visits helps ensure that the kidney is functioning well. This article deals with various aspects of induction therapy during a kidney transplant.
What Types of Medications Are Used to Prevent Rejection?
There are three groups of anti-rejection (immunosuppressant) medications:
- Induction Agents - Powerful anti-rejection medication used before the transplant in the operating room and immediately after the transplant surgery.
- Maintenance Agents - One must take anti-rejection medications on a daily basis for as long as they possess the transplanted kidney.
- Rejection Agents - Medications used for the treatment of rejection episodes.
What Is Induction Therapy for Kidney Transplant Recipients?
Induction therapy is a treatment given during kidney transplantation to lower the chances of the body rejecting the new kidney. Usually, there are two types of induction methods. One method uses strong doses of regular immunosuppressive drugs. The second method combines antibodies that either deplete T cells (a type of lymphocytes) or block the IL-2 receptor with lower doses of regular drugs and is more common.
What Are the Indications for Induction Therapy?
Most kidney transplant recipients need medicine to stop rejection and keep the new kidney healthy. Doctors usually recommend a treatment called induction therapy, which combines antibody therapy with regular medicine, instead of just regular medicine alone. The specific antibody therapy used depends on how likely the patient is to have rejection.
Some patients after kidney transplantation do not require antibody induction therapy. For example, those who receive kidneys from closely matched living relatives usually do not need them because they have a very low risk of rejection. So, doctors do not give them antibody therapy as part of their treatment in most cases.
What Are the Various Approaches Considered During Induction Therapy?
1. Induction Treatment for Transplants With a High Risk -
Induction therapy proves particularly advantageous for kidney transplant recipients facing a high risk of rejection. Research comparing two induction therapy types, rATG (rabbit anti-thymocyte globulin) and IL2RA ((interleukin 2 receptor subunit alpha), demonstrated that rATG notably decreased rejection rates compared to IL2RA among high-risk patients. One study revealed nearly a halved rejection rate at both the 1-year and 5-year marks with rATG.
Another study also found lower rejection rates with rATG compared to IL2RA. These results led to the recommendation to use rATG for patients at high risk of rejection. While both therapies showed similar long-term survival benefits, the significant reduction in rejection rates with rATG makes it a preferred choice for high-risk transplants.
2. Induction Treatment for Transplants With Standard Risk -
Induction therapy in standard-risk transplants has been studied through meta-analyses, but these studies mainly looked at data from the 1990s and early 2000s. At that time, the treatments used were different from what is commonly used now. For example, most patients received Cyclosporine instead of Tacrolimus, and only half received mycophenolic acid. Nowadays, Tacrolimus and Mycophenolic acid are more commonly used because they have shown to be better at preventing rejection. MPA has usually replaced the use of Azathioprine for similar reasons. Also, triple maintenance therapy with steroids, Tacrolimus, and Mycophenolic acid is now standard. This change has led to much lower rejection rates compared to before.
There has not been a big study comparing the effect of the usual induction treatments like IL2RA or ATG versus no induction in patients who are given Tacrolimus and MPA-based triple therapy. Most of the evidence comes from looking back at past data, which is not as strong. Some studies have shown that adding IL2RA induction did not really lower the chance of rejection or improve how long the graft or patient survived. Other studies compared different treatments and found mixed results, making it hard to say which induction treatment is best. Overall, for kidney transplant patients who are not at high risk, using IL2RA with Tacrolimus and MPA-based therapy does not seem to make much difference in preventing rejection or improving survival compared to not using induction therapy.
3. Induction Therapy for Assisting Steroid-Free Immunosuppressive Regimens -
Using induction therapy to support steroid-free immunosuppressive regimens has become more common in recent years. This approach, known as early steroid withdrawal or steroid avoidance, aims to reduce post-transplant complications while still keeping the new kidney safe. A recent study found that early steroid avoidance, when combined with induction therapy and maintenance therapy with Tacrolimus, was effective and safe in terms of graft and patient survival. Most patients in this study received IL2RA induction therapy, but it is unclear if this is better than other types of induction therapy like rATG or no induction at all.
Another study looked at patients who received Tacrolimus and MPA without induction therapy and found a high rate of rejection in the first six months after transplant compared to patients who received standard triple therapy with Tacrolimus, MPA, and steroids with induction therapy. This suggests that induction therapy may help prevent rejection in steroid-free regimens. Overall, while more research is needed, current data suggests that using rATG induction therapy may be more effective than IL2RA induction therapy in supporting steroid-free regimens.
What Are the Adverse Effects Associated With Induction Therapy?
Adverse effects related to anti-thymocyte globulin (ATG) are well-known.
- It can cause problems like cytokine release syndrome and serum sickness.
- It is also linked to higher chances of CMV (cytomegalovirus) infection.
- Other concerns like cancer or diabetes risk are not fully clear yet.
- So, for patients with a low risk of rejection or delayed graft function, using a different induction therapy like Basiliximab or even no induction might be a better choice.
Conclusion:
Induction therapy is really important for kidney transplants because it stops the body from rejecting the new kidney and helps it start working quickly. There have been a lot of improvements in the drugs used for induction therapy, which means better results for patients. Right now, doctors are working on making these drugs work even better and cause fewer side effects. They are also trying to tailor induction therapy to each patient's needs. More research is needed to make induction therapy even safer and more effective, which will help kidney transplants last longer and improve patient health in the long run.
