Nephrotic syndrome is a disorder of the kidneys which is characterized by high protein levels in the urine, high lipid (cholesterol and triglyceride) levels in the blood, low albumin (a blood protein) levels in the blood, and generalized edema (swelling). This clinical state can occur as a primary disease, as a secondary disorder resulting from damage to the glomeruli of the kidney, or as a congenital disorder resulting from an inherited gene.
Etiology or Causes
Nephrotic syndrome is characterized by increased glomerular membrane permeability to blood proteins. This means that the large protein molecules are able to pass thru the membrane and spill into the urine. The nephrons,are tiny organs that are responsible for filtering the blood to form urine. Inside each nephron is the glomerulus. The glomerulus is a network of capillaries that form the first step of the filtering process. With nephrotic syndrome, that membrane becomes damaged. Proteins leak into the urine, which results in generalized swelling and this causes weight gain. There are a number of conditions that cause that damage. However, in children, the most common condition is known as minimal change disease. Other conditions that may lead to nephrotic syndrome are diseases like diabetes, some cancers, genetic disorders, immune disorders, infections, certain drugs, and even certain kidney disorders.
Signs and Symptoms
The most common symptom related to this disorder is generalized edema or swelling. You will see puffiness of the face, particularly around the eyes. It tends to be more obvious in the morning when the child wakes up, but it may subside as the day progresses. Other areas of the body that have a tendency to swell are the abdomen (ascites), genitals, legs, ankles and feet. Edema of the lining of the intestine, a more covert symptom, can lead to diarrhea, loss of appetite, and malabsorption of nutrients in the intestines. You may also notice your child experience weight gain, become more easily fatigued, lethargic, and irritable. Their urine output will decreased in amount and frequency, and may appear frothy and darker.
A physical examination is the first step in making a definitive diagnosis. After the exam, your doctor will order lab tests (blood and urine) to determine how well the kidneys are functioning. The urinalysis will show high levels of protein. The blood work will show elevated cholesterol and triglyceride levels and low albumin levels. Serum (blood) creatinine level and creatinine clearance (a urine test) are routinely ordered. A kidney biopsy may be ordered to find out the cause of the disorder. There are other tests your doctor may also order to make the diagnosis or to rule out other disorders.
The goal for managing nephrotic syndrome is fourfold. It includes 1) reducing the excretion of urine protein, 2) preventing infection, 3) reducing the swelling which is a result of fluid retention and lastly, 4) minimizing the complications secondary to the treatment. A low salt diet is highly recommended as well as restricting the amount of fluid your child drinks. Medication such as Prednisone, (a corticosteroids),is the first line of therapy in treating this disorder. If your child does not respond to steroids or if the side effects outweigh the benefits, then other immunosuppressant medications will be considered. Since these drugs suppress the immune system you will need to monitor your child for signs of infection. These kids are particularly vulnerable to upper respiratory infections. Some symptoms to be looking for are frequent cough, sore or reddened throat, runny nose, and fever. Diuretics are used to get rid of excess fluids and reduce swelling. The diuretics can be an adjunct therapy to albumin infusions. It is wise to closely monitor their intake and output because the use of diuretics can lead to dehydration. Some diuretics are known to deplete the blood potassium levels because potassium is excreted in the urine. For that reason, a potassium supplement should be ordered by your doctor. Some children experience high blood pressure with this disorder, so blood pressure medication may be necessary. Checking your child’s urine for protein (by using dipsticks) is taught to the parents.
The silver lining with this disease is that it is self-limiting and complete recovery is possible. It is estimated that as many as 80% of those affected have a favorable prognosis. However, it is dependent upon the underlying cause of the disease, the age of the person, and their response to treatment. For children under the age of five, the prognosis is poorer than for the prepubescent child. For some children, dialysis or kidney transplantation may be necessary. When detected early and treated promptly, damage to the kidney is minimized. Although your child may experience periods where they relapse and have to resume treatment over time, the tendency to relapse will decrease. Once any relapses have occurred and been treated, in time your child may well outgrow this condition and kidney function may return to normal or to near normal.