Pediatric Glomerular Filtration Disorders

Your child may show no symptoms of some glomerular diseases or may show symptoms related to the type of substances the kidneys are failing to filter out. For example, if your child has a condition called hematuria, your child’s urine may have blood in it and appear as pink or rust colored.

Often, a condition called edema, or swelling from the body’s retention of fluids, is a symptom of glomerular disease. Your child also might have foamy, pink or cola-colored urine. Symptoms of  glomerulonephritis may include:

• Blood in the urine, which may appear pink or the color of cola
• Decreased output of urine
• Difficulty breathing
• Fatigue
• Headache
• Joint pain or muscle aches
• Paleness
• Rash, especially on the legs and buttocks
• Seizures, caused by high blood pressure
• Sore throat
• Swelling in the hands, ankles, feet, and around the eyes
• Urine that appears foamy
• Weight loss
• Yellow or brown appearance to the skin

Many diseases can affect how well your child’s kidneys function, and it’s possible that the glomeruli, the tiny vessels in kidneys that filter the body’s blood, can stop working correctly.

When the glomeruli stop filtering as they should, your child may have no symptoms at first. Eventually, though, the disorder in the glomeruli begins causing problems in the kidneys and around the body.

Your child’s doctor may detect signs of glomerulonephritis and other glomerular diseases as part of your child’s routine checkup. But if you notice symptoms in your child, your child’s doctor will take a complete medical history and perform a thorough examination.

Your doctor will order one or more tests to diagnose a glomerular filtration disorder, such as:

• Urine tests - determines whether there is blood or excess protein in the urine, and to gather information about kidney function
• Blood tests - such as glomerular filtration rate, which calculate how kidneys are functioning
• A chest X-ray
• An electrocardiogram - which measures the electrical activity of the heart and can reveal abnormal rhythms or muscle damage in your child’s heart
• A renal (kidney) ultrasound - provides the doctor with information about the size and shape of the kidney and helps detect cysts, stones, obstructions, masses and other problems in the kidney. The test is painless and noninvasive. A technologist moves a probe over the kidney or bladder, creating sound waves that bounce back, forming an image on a video screen.
• A renal (kidney) biopsy -  allows the doctor to take a sample of kidney tissue to be analyzed. The sample determines the nature and extent of the specific disease causing glomerular damage. Your child will receive a light sedative and local anesthesia, and the doctor will direct a biopsy needle into the kidneys, guided either by images from an ultrasound or a computed tomography (CT) scan. The kidney tissue will be examined in a laboratory.

An accurate and timely diagnosis of glomerular filtration disease is important.

A frequent cause of glomerulonephritis in children is streptococcal infection, for example, an upper respiratory infection or strep throat. In these cases, glomerulonephritis typically occurs at least a week after your child’s infection. This acute, or sudden, type of glomerulonephritis is most common in children between 3 and 7 years old, but it can occur at any age. It affects boys more often than girls.

Other diseases that may cause glomerulonephritis include

• Alport syndrome - an inherited form of glomerular disease
• Henoch-Schonlein purpura - usually affecting children and causing purple lesions on the skin and the organs in the body
• Polyarteritis nodosa - an inflammatory disease affecting the arteries
• Systemic lupus erythematosus (lupus or SLE) - a systemic immune disease
• Wegener vasculitis - a disease that results in inflammation of all the body’s organs

The scarring that causes glomerulosclerosis can come from use of medications or be caused by kidney diseases. Glomerulonephritis can cause the scarring that leads to glomerulosclerosis.

Glomerular filtration disorders affect the glomeruli, the millions of tiny vessels in the kidneys that filter blood. If they become damaged, the kidneys don’t work as they should.

It’s important to seek treatment for your child’s glomerulonephritis, inflammation of the glomeruli, or other glomerular disorder right away to prevent more damage to the kidneys or other complications from the disease.

Usually, a pediatric kidney disease specialist, or nephrologist, treats these disorders, often with

• Medications - which might include diuretics, blood pressure drugs, steroids, immunosuppressive drugs (drugs that stop your child’s natural immune responses), or phosphate binders that reduce the amount of the mineral phosphorous in the blood
• Dialysis - a treatment that filters waste and excess fluid from the blood when the kidneys become unable to do it themselves. Dialysis may be necessary on a short-term or long-term basis.
• Dietary measures - such as fluid restrictions, and a diet low in salt, protein and potassium.

Usually, these treatments can help control problems with glomerular filtration. Sometimes, though, the disorders lead to kidney failure and even dialysis fails to stop the kidneys’ decline.