What is Nephrotic Syndrome?
Nephrotic syndrome occurs when the filters in the kidney leak an excessive amount of protein. The level of protein in the blood then falls and this allows fluid to leak across very small blood vessels into the tissues. Swelling around the eyes, abdomen and legs is then noted. Protein in the body is normally made by the liver and the liver then responds by producing extra protein. Nephrotic syndrome is a combination of proteinuria (excessive protein in the urine), low blood protein and oedema (swelling in the tissues).
What causes Nephrotic Syndrome?
Most cases of nephrotic syndrome are caused by changes in the immune system. Certain types of white cells produce a substance that acts on the filters in the kidney to produce a change in the filters. This allows protein to leak into the urine. Other forms of nephrotic syndrome are caused by swelling and increased cell numbers in the filters. In some instances this may result in permanent damage to the filters.
Types of Nephrotic Syndrome
The commonest type of nephrotic syndrome in children is called “minimal change” and occurs in 80% of cases. In this type, the kidney function remains normal. A small percentage of children may have partial scarring involving some of their filters, while others may have a significant increase in the number of cells in the filters. A kidney biopsy is sometimes necessary to differentiate the particular type of nephrotic syndrome, and this assists in the type of treatment to be given and advice on the long-term outlook. If a minimal change lesion is suspected then renal biopsy is usually not necessary. A renal biopsy is a procedure where a small needle is inserted into the kidney from the back and a small sample is taken. This procedure has little risk and is usually performed using ultrasound to locate the kidney. Sedation is given to younger children.
Treatment
As the child is losing excessive protein in the urine a good diet is necessary. A normal or high protein diet is encouraged. Mild reduction of fluid intake will assist in preventing excess swelling of the tissues. Salt reduction should be encouraged by not adding salt to the food. Most children can continue with normal activities. The majority of children with nephrotic syndrome respond to drug therapy. Prednisolone (a steroid medication) is the initial drug used with “minimal change” nephrotic syndrome. The urine usually becomes clear of protein within 2-3 weeks. Prednisolone can cause a large appetite. When there is no response to prednisolone or when the nephrotic syndrome recurs frequently, other medications may be indicated from time to time, and these include cyclophosphamide, levamisole and cyclosporin.
Are there any Complications?
Certain complications can arise while the child has swelling. Infections are infrequent but the child should see their doctor with any fevers or tummy pain. Clotting of a blood vessel is a rare complication, but should be suspected if a child develops severe tummy pain with frank blood in the urine. With the low blood protein, the circulating blood volume may become reduced and the kidneys respond by producing less urine. This is more likely to occur if a child becomes ill with vomiting or diarrhoea. This complication is easily treated by infusion of protein into a vein.
Is Nephrotic Syndrome likely to recur?
Approximately 70% of children with minimal change lesion have recurrences of oedema. This is more likely to occur at the same time as a common cold. The urine can be tested at home. The first sign of recurrence is an excessive amount of protein on the dip stick. Swelling does not occur until excessive protein has been present in the urine for some days. If either occurs the parent should contact their doctor and drug management can be started. When relapses become frequent the child may remain on prednisolone for some months or years depending on the recurrence rate. Side effects from the prednisolone can occur and include obesity, roundness in the face, a decrease in growth rate and small cataracts. The other medications listed above are given at certain times to prevent these complications. The majority of children who have relapses stop relapsing by the age of 16 years.
If the nephrotic syndrome does not respond to the prednisolone a renal biopsy is usually performed. A small percentage of children with other forms of nephrotic syndrome do not respond to drug therapy and they may develop kidney failure. In these patients medications that act on the kidney to increase urine output will decrease the amount of oedema. If high blood pressure is present then it is important that this be well controlled and smoking should be strongly discouraged.
Summary
Nephrotic syndrome in childhood is a condition that most children outgrow. Relapses are common and are more likely to occur with the common cold. Prednisolone is very effective in controlling the urine protein leak in the majority of cases. Every effort should be made so that the child continues to lead a normal school life.
Courtesy of the Renal Resource Centre Sydney - Nephrotic Syndrome brochure.
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This next article is courtesy of the Children’s Hospital Boston USA.
What is nephrotic syndrome?
Nephrotic syndrome is characterised by the following symptoms that result from changes that occur to the small, functional structures in the kidneys, such as:
* Very high levels of protein in the urine
* Low levels of protein in the blood due to its loss in the urine
* Tissue swelling all over the body (oedema) especially in the abdomen (ascites)
* High cholesterol levels in the blood
What are the different types of nephrotic syndrome?
The type of nephrotic syndrome that is most common in children is called idiopathic nephrotic syndrome. Idiopathic means that a disease occurs with no known cause. The most common type of idiopathic nephrotic syndrome is called minimal-change nephrotic syndrome (MCNS). Idiopathic nephrotic syndrome is more common in boys than girls.
With MCNS, the child usually has relapses of the illness, but the disease can usually be managed and prognosis is good. In rare cases, a child may develop kidney failure that requires dialysis.
There is a rare nephrotic syndrome present in the first week of life called ‘congenital nephrotic syndrome’. Congenital nephrotic syndrome is inherited by an autosomal recessive gene, which means that males and females are equally affected, and the child inherited one copy of the gene from each parent, who are carriers. The chance for carrier parents to have a child with congenital nephrotic syndrome is one in four, or 25 percent, with each pregnancy. The outcome for this type of nephrotic syndrome is extremely poor.
What are the symptoms of nephrotic syndrome?
The following are the most common symptoms of nephrotic syndrome. However, each child may experience symptoms differently. Symptoms may include:
* Fatigue and malaise
* Decreased appetite
* Weight gain and facial swelling
* Abdominal swelling or pain
* Foamy urine
* Fluid accumulation in the body spaces (oedema)
* Pale fingernail beds
* Dull hair
* Ears cartilage may feel less firm
* Food intolerances or allergies
The symptoms of nephrotic syndrome may resemble other conditions and medical problems. Always consult your child’s physician for a diagnosis.
How is nephrotic syndrome diagnosed?
In addition to a thorough physical examination and complete medical history, your child’s physician may recommend the following diagnostic tests:
* Urine tests (to check for protein)
* Blood tests (to check the levels of cholesterol and a special blood protein called albumin)
* Renal ultrasound – a non-invasive test in which a transducer is passed over the kidney producing sound waves which bounce off of the kidney, transmitting a picture of the organ on a video screen. The test is used to determine the size and shape of the kidney, and to detect a mass, kidney stone, cyst, or other obstruction or abnormalities.
* Renal biopsy – a procedure where a small sample of tissue is taken from the kidney through a needle. The tissue is sent for special testing to determine the specific disease.
Treatment for nephrotic syndrome
Specific treatment for nephrotic syndrome will be determined by your child’s physician based on:
* Your child’s age, overall health, and medical history
* The extent of the disease
* Your child’s tolerance for specific medications, procedures, or therapies
* Expectations for the course of the disease
* Your opinion or preference
During the initial episode of nephrotic syndrome, your child may require hospitalisation. He/She may need to be monitored if the oedema is severe or if he/she has blood pressure and/or breathing problems.
Medications may be required to treat initial symptoms and during relapses, including:
* Corticosteroids
* Immunosuppressive drug therapy
* Diuretics (to reduce the oedema)
* Intravenous (IV) albumin – a blood protein that can be administered to replace the low levels.
* A special diet that restricts salt and has other specifications
The medications used to treat nephrotic syndrome weaken the immune system so your child should not receive live vaccines. If your child has been exposed to chickenpox and has not already had the vaccine, the vaccine may be recommended.
Long-term outlook for nephrotic syndrome
Relapses do occur throughout childhood. However, once a child reaches puberty, the disease usually stays in remission (complete or partial absence of symptoms). It is uncommon for symptoms to return during adulthood, however, it is possible.
Disclaimer: Articles are general comment, not advice. The information is believed to be accurate and reliable, but no responsibility is taken for any opinions expressed or for errors and omission. Readers should never act on the basis of the material without taking professional medical advice relating to their particular personal circumstances.
