By Dwayne Henry, MD, and Vikas R. Dharnidharka, MD

Introduction
When the kidneys stop working they cannot remove the toxic wastes from the blood, which with time accumulate and can make you sick. If irreversible, this condition is called renal failure or chronic kidney disease (CKD). CKD is defined as kidney function less than 75 percent of normal (or 75 ml/min/1.73 m2, with normal being greater than 100 ml/min/1.73m2). In children, the measure of kidney function used is ml/min/1.73 m2, not ml/min, adjusted for the smaller body size.

Chronic Kidney Disease (CKD) in Children
There are many causes of CKD in children, but these causes are quite different from those in adults. In adults, high blood pressure and diabetes are by far the most common causes of CKD. However, in children, the common causes of CKD are:
1. birth defects of the kidneys or urinary tract;
2. genetic/inherited diseases; or
3. acquired diseases later in childhood, usually due to some immune system abnormalities.

As the stages of CKD progress, children will require different medications to stay healthy and prolong the life of their kidneys. If children with moderate to severe CKD progress to end-stage renal disease (ESRD), then they will need dialysis and eventually a kidney transplant. Dialysis or transplant is usually needed when the kidney function is less than 15 ml/minute/1.73m2 (less than 15 percent of normal). The time to reach this stage varies with the individual child and the cause of their kidney disease. For children, dialysis is considered to be more of a temporary bridge until a kidney transplant is available. For most, though not all children, transplantation offers a better long-term quality of life, better growth and less lifestyle restrictions. Some children are transplanted before they need dialysis. This is known as pre-emptive transplantation. Some children are not transplant candidates due to other medical conditions. Your doctor should discuss this with you.

Evaluation for Kidney Transplant
The evaluation is performed by a transplant team. This team consists of a transplant coordinator, pediatric nephrologist, transplant surgeon, social worker, financial counselor as well as other medical specialties if there are coexisting medical concerns. Much of the evaluation is similar to that in adults. Before the surgery the transplant coordinator will schedule a series of tests. These involve blood type testing, human leukocyte antigens (HLA) matching, cross match with possible donors and serology (the study of blood serum) for previous transmissible diseases. After all this, the child is prepared for a living donor transplant, if available, or placed on a transplant list for a deceased donor. Living donation is much more common in children than in adults since parents are often available and willing to donate. The transplanted kidney is not placed at the site of the original kidneys but is placed in the lower belly. A child can receive an adult kidney, since by a certain age (usually older than 2 years) there is enough space in the belly to fit the new kidney.

Living Donors
These donors are usually family or friends of the child. They must be in excellent health to be considered. They will meet with the transplant coordinator to discuss the risk of donating a kidney. If you are a match, then the planning for a transplant date is set. The person donating his/her kidney should have a good understanding of the risk with surgery and changes to their life post-transplant.

Deceased Donors
To receive a deceased donor transplant your child is placed on a waiting list. Once a kidney is available the transplant team will determine if it is a match by blood type and HLA matching. If this happens, your transplant coordinator makes arrangement for the transplant. If you are on the deceased donor transplant list you should be prepared to travel to the transplant site. This means you must be available to be contacted by phone or pager at all times. You must be prepared to arrive at the transplant site as soon as possible after being notified of a match. The longer the kidney stays preserved outside the body, the poorer the results.

Transplant Day
The surgery typically takes between two to four hours, generally a little longer in children than in adults. In children, the surgeons have to be extra careful about preventing blood clots and blockage of the blood vessels, so they pay careful attention to fluid management and blood pressure. After the transplant, your child is taken to a recovery room then to the intensive care unit or hospital room, where the rest of his/her immediate post-operative care will occur. At some time before the transplant and during the surgery, your child is given anti-rejection medication (immunosuppressants) to prevent the immune system from attacking the foreign kidney. These medications, or ones similar, are continued and adjusted to keep your child’s immune system suppressed enough to prevent rejection but strong enough to prevent infection. The typical hospital stay after kidney transplant in children is four to five days, though in some cases it could be longer.

After Transplant
Immediately after transplant and throughout the life of the transplanted kidney many tests are used to determine your child’s health status, transplant function and to look for rejection or infection. This involves frequent blood samples to check medication levels as well as determine the function of the transplant.

Now that your child has a new kidney he or she will require many medications. These include anti-rejection medications, antibiotics, anti-viral medicines and others that are specific for the individual child. It is essential your child receives these medications to prevent rejection of the new kidney or becoming infected. The doses of these medications may change as your child grows. Many of these medications need to be made in liquid form for smaller children. Not all pharmacies can make medications into liquid form, however. Your transplant coordinator is available to work with you to find the pharmacy convenient for you. Children often degrade the medicines faster than adults and may need more frequent dosing.

Infection
Children are more prone to certain infections than adults because they have not been exposed to and developed immunity to those germs. During the first few weeks after transplant, known as the induction phase, your child is at highest risk for infection. This is due to the amount of immune suppression to keep them from rejecting the new kidney. You may be asked to avoid crowds, people with other infections as well as practice good oral hygiene and frequent hand washing. As time progresses the immune suppression medication is decreased to what is called maintenance therapy. This period usually occurs four to six months from the date of the transplant, but is unique to each child. When on maintenance therapy the type of infection your child is at risk for will change. Signs and symptoms of infection can be similar to those of rejection and are just as important. Your doctor should be notified with any concerns.

Rejection
A rejection episode can occur at anytime after transplant. A rejection episode means the child’s immune system is fighting the transplant kidney; this fighting can be reduced with medication and the kidney is not automatically lost with a rejection episode. Signs and symptoms of rejection are often similar to those of infection and include flu-like symptoms but can also involve decreased urine output and pain when pressing on the new kidney. Very often there are few symptoms, but blood tests show changes in the kidney function that lead your doctor to check for rejection. So regular blood test monitoring is very important. In young children who receive an adult kidney, the blood test changes may be late markers of rejection. A kidney biopsy is often needed to check for rejection episodes. Currently, the frequency for rejection in the first year post-transplant is about 15-20 percent.

Long-term care
In children with a kidney transplant, doctors keep a close watch on body growth. Most children with kidney failure are short in stature. A transplant often leads to some catch-up growth but growth hormone injections may also be needed. The overall life of a transplant kidney in a child is equal to that in adults. In fact, the very small infants who receive a kidney transplant have the best long-term transplant retention rates. In contrast, adolescents seem to do worse than other age groups. Adolescents need careful supervision to make sure they really are taking their medications. Adolescents also need to prepare to take over their own care as they become adults. Currently, most children and adults eventually wear out the transplant kidney in about 10-14 years. However, a repeat kidney transplant is not only possible but has been performed successfully in many people. Thus, children can potentially receive more than one kidney transplant in their lifetime.

Additional Resources
The American Society of Transplantation (www.a-s-t.org) has prepared a series of patient education brochures on kidney transplantation, including a pediatric kidney transplant brochure (this brochure is also available in Spanish).

Dwayne Henry, MD, is a Fellow in Pediatric Nephrology at the University of Florida in Gainesville, Fla.

Vikas Dharnidharka, MD, is an Associate Professor in the Division of Pediatric Nephrology at the University of Florida in Gainesville, Fla. He is also the current chair of the Pediatric Committee of the American Society of Transplantation.

This article originally appeared in the July 2008 issue of aakpRENALIFE.

Close Window