Nephrotic Syndrome (Kidney Disease) Symptoms & Causes

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Contact the Division of Nephrology

We understand that you may have a lot of questions when your child is diagnosed with nephrotic syndrome:

  • What is it?
  • How serious is it?
  • What’s the long-term outlook for a child with nephrotic syndrome?

We’ve provided some answers to those questions here, and when you meet with our experts, we can explain your child’s condition and options fully.

What is nephrotic syndrome?

Nephrotic syndrome is the name given to a collection of kidney-related findings. These include:

  • proteinuria—high levels of protein in the urine (based on your child’s age and size)

  • hypoalbuminemia—low levels of protein in your child’s blood, since it’s being passed out of his body in his urine

  • edema—swelling. This happens because the proteins in your child’s blood act as a sponge to keep fluid in the blood. With fewer proteins to do this, the fluid may leak out of the blood into your child’s tissues, causing them to swell, especially around the stomach area.

  • high cholesterol (blood fat) levels—low levels of protein in the blood stimulate the body to overproduce certain kinds of blood fats

Why is nephrotic syndrome a concern?

Aside from the risk of kidney damage, nephrotic syndrome carries two main risks:

  • Infection—Fluid that escapes the blood and enters the tissues, as happens in edema, is susceptible to serious infection by bacteria such as E. coli.
  • Blood clots—When a child loses lots of blood protein, it’s harder for his body to form blood clots in the right way. This can lead to both minor and major problems, including pulmonary embolism, in which a blood clot cuts off blood supply to the lungs.

 
What are the different types of nephrotic syndrome?

One way to categorize types of nephrotic syndrome is by what’s causing them.

Idiopathic nephrotic syndrome—the kind most children have—occurs for a reason that is unknown.

Secondary nephrotic syndrome is caused by another medical condition or treatment for another condition, such as

It’s another way to look at nephrotic syndrome is in terms of how the affected tissue appears under a microscope, since this often correlates with treatment and outcome. There are two main categories: minimal change disease (MCD) and focal sclerosis (FSGS).

Minimal change disease (MCD) is so named because if you were to look at a kidney biopsy under a microscope, you’d see that the cells look relatively normal, and only have minimal changes. MCD:

  • affects between 85 and 95 percent of children with NS in the United States
  • is generally associated with the most positive outcomes among children with NS
  • usually responds to steroids
  • tends to relapse less and less frequently as the child grows older
  • is often outgrown by the time the child is a young adult
  • usually doesn’t affect kidney function
  • rarely results in a child needing dialysis or kidney transplant

Focal sclerosis (FSGS)

Focal sclerosis:

  • affects around 10 percent of children with NS in the United States
  • tends to be a more aggressive form of nephrotic syndrome
  • usually doesn’t respond to steroid therapy
  • may require multiple biopsies to diagnose
  • appears to disproportionately affect African-American and Hispanic populations in the U.S.
  • often result in the child needing kidney dialysis and/or kidney transplant

Researchers aren’t yet sure whether MCD and FSGS lie on an opposite ends of a continuum of the same disease, or are, in fact, fundamentally different diseases.

Congenital nephrotic syndrome

What is congenital nephrotic syndrome?

While “congenital” means present at birth, congenital nephrotic syndrome is usually discovered when a baby is a few months old, although it may take up to a year. Babies with congenital nephrotic syndrome show the same kinds of symptoms as children with nephrotic symptoms.

How common is it?

Congenital nephrotic syndrome is extremely rare. Less than one percent of children with nephrotic syndrome have this type.

Can it be diagnosed before birth?

While there’s no prenatal test for congenital nephrotic syndrome, information gained from other prenatal tests can provide clues as to whether the fetus might be leaking protein in his urine. So prenatal testing can give indicate that a child might have the condition, but it’s not conclusive.
What causes congenital nephrotic syndrome?

Congenital nephrotic syndrome may be caused by a genetic abnormality in one or more proteins and your baby’s doctors usually screen for them. It probably won’t change the treatment that your child receives, but it may suggest genetic counseling and prenatal screening in future pregnancies. It may also give doctors a clue as to how quickly your child will need a kidney transplantation

Much more rarely, congenital nephrotic syndrome may result if a pregnant mother has an infection that’s transmitted to her baby, such as herpes, toxoplasmosis or syphilis. In these cases, treating the infection usually treats the nephrotic syndrome, too.

Is congenital nephrotic syndrome serious?

Most forms of congenital nephrotic syndrome are aggressive and require significant medical intervention. It’s not uncommon that babies born with congenital nephrotic syndrome require a kidney transplant within the first few years of life, and many babies need one even sooner.

What is the outlook for a baby with congenital nephrotic syndrome?

Babies with congenital nephrotic syndrome need blood protein infusions, often every day, through an IV. Some children come into the hospital for this treatment, and some can receive infusions at home. They may also need hormones and boosters to their immune systems to keep their bodies healthy until they’re about six months old.

Then, doctors usually operate to remove the child’s kidneys. Without kidneys, the problems caused by leaking protein are gone, but the child’s body still needs to have done what the kidneys were doing. So the baby’s healthcare team will put him on dialysis while awaiting a transplant. This usually happens when a child weighs about 15 lbs., which is usually when he’s around 1 year old.

Here at Children’s, our specialists have lots of experience caring for babies with congenital nephrotic syndrome, seeing them through dialysis and kidney transplantation. In fact, we’re able to perform transplants on smaller babies than many other centers, so children we treat don’t have to wait as long to get their new kidneys.

Causes

What causes nephrotic syndrome in children?
Most children have idiopathic nephrotic syndrome, which means that there is no clear cause. Researchers have identified a few genetic associations, but not strongly enough that it can be characterized as a genetic syndrome. In other parts of the world, where children are more likely to be affected by focal sclerosis (FSGS) than by minimal change disease (MCD), FSGS seems to have more clearly defined genetic causes.

In rare cases, nephrotic syndrome may develop from a viral disease, such a hepatitis or HIV, and relapses may also be triggered by viruses. Certain medications may cause nephrotic syndrome, too.
Signs and symptoms

What are the signs and symptoms of nephrotic syndrome in children?

Signs of nephrotic syndrome may vary significantly from child to child, but you or your child may notice:

  • fatigue and malaise
  • decreased appetite
  • weight gain and facial swelling
  • abdominal swelling or pain
  • foamy urine
  • edema (fluid accumulation in the body spaces)
  • pale fingernail beds
  • dull hair
  • ears cartilage may feel less firm
  • food intolerances or allergies

FAQ

Q: Can nephrotic syndrome be cured?

A: The vast majority of kids in the United States with nephrotic syndrome outgrow it by the time they reach early adulthood. Until that time, they may experience relapses, but these can most often be anticipated and quickly brought under control with medication. A smaller percentage have a more aggressive form of the syndrome, and may require lifelong medical follow-up.

Q: What’s the long-term outlook for a child with nephrotic syndrome?

A: For between 85 and 90 percent of kids with nephrotic syndrome—those with minimal change disease—the outlook is quite good. Their nephrotic syndrome can be brought under control with steroids. Relapses are common, but they can be brought into remission with medication, and kids with this type of NS usually outgrow it by early adulthood.

If your child has focal sclerosis (FSGS), nephrotic syndrome is harder to treat. It often doesn’t respond to steroids, and in about 50 percent of children, FSGS may progress to end-stage renal disease. When this happens, dialysis or kidney transplantation can be an option.

Q: Are my other children more at risk for nephrotic syndrome?

A:Probably not. There do seem to be some types of FSGS that run in families, but in the vast majority of cases, only one child in a family is affected by nephrotic syndrome.

Q: Should my child stay away from certain physical activities?

A:Most likely not, but your child’s doctor will be able to tell you for sure. Here at Children’s, we recommend that children continue to go to school and participate in normal activities. If your child is taking high doses of steroids or other medicines that suppress her immune system, it’s important to try to avoid exposing her to someone who is ill.
Questions to ask your doctor

After your child is diagnosed with nephrotic syndrome, you may feel overwhelmed with information. It can be easy to lose track of the questions that occur to you.

Lots of parents find it helpful to jot down questions as they arise–that way, when you talk to your child’s doctors, you can be sure that all of your concerns are addressed. If your child is old enough, you might encourage him to write down questions as well.

Here are some questions to get you started:

  • How did you arrive at this diagnosis?
  • What does this diagnosis mean for my child’s kidneys?
  • Are there any other conditions my child might have in addition to nephrotic syndrome?
  • What might be causing my child’s nephrotic syndrome?
  • How did you come to that conclusion?
  • What treatment is best for my child right now, and why?
  • What kind of improvement should I be noticing, and how soon?
  • Are any restrictions or changes in exercise, diet or other daily activities necessary?
  • When and how will you follow up with my child?
  • What resources are available to help my family cope?
  • Is there anything else I should know right now?
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