Overview of Kidney Diseases in Children

What are the kidneys, and what do they do?

The kidneys are two bean-shaped organs located near the middle of the back, just below the rib cage. When blood flows through the kidneys, waste products and extra water are removed from the blood and sent to the bladder as urine. The kidneys also regulate blood pressure, balance chemicals like sodium and potassium, and make hormones to help bones grow and keep the blood healthy by making new red blood cells.

Who is at risk?

In the general population, slightly more than 30 people in every 100,000 develop kidney failure each year. In the pediatric population-age 19 and under-the annual rate is only 1 or 2 new cases in every 100,000 children. In other words, adults are about 20 times more likely to develop kidney failure than children. The risk increases steadily with age.

African Americans in their late teens are three times more likely than Caucasians in the same age group to develop kidney failure. Diseases that damage the tiny blood vessels in the kidney are also more common in children of color. Moreover, boys are nearly twice as likely as girls to develop kidney failure from birth defects, polycystic kidney disease, or other hereditary diseases.

What are the causes of kidney failure in children?

Kidney failure may be acute or chronic. Acute diseases develop quickly and can be very serious. Although an acute disease may have long-lasting consequences, it usually lasts for only a short time and then goes away once the underlying cause has been treated. Chronic diseases, however, do not go away and tend to get worse over time. When the kidneys stop working, doctors use a treatment called dialysis to remove waste products and extra water from patients with chronic kidney failure.

Acute Kidney Diseases

Acute kidney disease may result from an injury or from poisoning. Any injury that results in loss of blood may reduce kidney function temporarily, but once the blood supply is replenished, the kidneys usually return to normal. Other kinds of acute kidney disease in children are

Chronic Kidney Diseases

Unfortunately, the conditions that lead to chronic kidney failure in children cannot be easily fixed. Often, the condition will develop so slowly that it goes unnoticed until the kidneys have been permanently damaged. Treatment may slow down the progression of some diseases, but in many cases the child will eventually need dialysis or transplantation.

From birth to age 4 years, birth defects and hereditary diseases are by far the leading causes of kidney failure. Between ages 5 and 14 years, hereditary diseases continue to be the most common causes, followed closely by glomerular diseases. In the 15- to 19-year-old age group, glomerular diseases are the leading cause, and hereditary diseases become rarer.

What are the treatments for kidney failure?

A child whose kidneys fail completely must receive treatment to replace the work the kidneys do. The two types of treatment are dialysis and transplantation.

Dialysis

Dialysis is a way to remove the waste products and extra water from the blood of patients with kidney failure. The two main types of dialysis are peritoneal dialysis and hemodialysis.

Transplantation

Transplantation provides the closest thing to a cure for kidney failure. In this procedure, a surgeon places a healthy kidney in the child's body. The kidney may come either from a living donor or from someone who has just died.

People who have transplants must take drugs to keep the body's immune system from rejecting the new organ. These immunosuppressive drugs can help maintain good function in the transplanted kidney for many years. However, they may have some undesirable side effects such as making a child vulnerable to infections.