Nephrotic Syndrome

Symptoms and Diagnosis

• Nephrotic syndrome can occur at any age but is most common between the ages of 2 to 8 years. It affects boys more often than girls.

• The first sign of nephrotic syndrome in children is usually puffiness or swelling around the eyes and swelling of the face. Because of puffiness around the eyes, the patient is likely to consult an ophthalmologist (eye doctor) first.
• In nephrotic syndrome swelling of the eyes and the face is most noticeable in the morning and is less marked in the evening.
• With time, the swelling develops in the feet, hands, abdomen and all over the body and is associated with increase in weight.
• Swelling may occur after a respiratory tract infection and fever in many patients.
• Excluding swelling, the patient is usually well, active and does not seem sick.
• A decreased urine output compared to normal is common.
• Frothy urine and white stain on tiles due to albumin in urine may be a revealing feature.
• Red urine, breathlessness and high blood pressure are less common in nephrotic syndrome.

Possible complications of nephrotic syndrome include an increased risk of developing infections, blood clots in the veins (deep vein thrombosis), malnutrition, anemia, heart disease due to high cholesterol and triglycerides, kidney failure and different treatment-related complications.

In patients with swelling the first step is to establish a diagnosis of nephrotic syndrome. Laboratory tests should confirm (1) heavy loss of protein in the urine, (2) low blood protein levels, and (3) high cholesterol levels.

• Urine examination is the first test used in the diagnosis of nephrotic syndrome. Normally, routine examination of urine will show negative or trace protein (albumin). The presence of 3+ or 4+ protein in a random urine sample is suggestive of nephrotic syndrome. Remember though that the presence of albumin in urine is not a specific diagnostic confirmation of nephrotic syndrome. It only suggests urinary loss of protein. Further investigations are necessary to determine the exact cause of urine protein loss.
• After starting treatment, urine is tested regularly to assess its response to treatment. The absence of protein in urine tests suggests a positive response to treatment. For self monitoring, protein in urine can be estimated by using a urine dipstick at home.
• In microscopic examination of urine, red blood cells and white blood cells are usually absent.
• In nephrotic syndrome, the loss of protein in urine is more than 3.5 grams in a day. The amount of protein lost in 24 hours can be estimated by a 24-hour urine collection or more conveniently by a spot urine protein/creatinine ratio. These tests provide precise measurements of the amount of protein lost and identify whether protein loss is mild, moderate or heavy. In addition to its diagnostic value, estimation of urine protein loss in 24 hours is useful for monitoring response to treatment.

• The characteristic findings of nephrotic syndrome that accompany the high urine protein levels are low blood albumin level (less than 3 g/dL) and elevated cholesterol (hypercholesterolemia) in blood tests.
• The value of serum creatinine is normal in nephrotic syndrome due to minimal change disease, but may be increased in patients with more severe kidney damage from other forms of nephrotic syndrome like focal segmental glomerulosclerosis. Serum creatinine is measured to assess overall kidney function.
• Complete blood count is a routine blood test performed in most of the patients.

Once the diagnosis of nephrotic syndrome has been established, additional tests are performed selectively. These tests determine whether the nephrotic syndrome is primary (idiopathic) or secondary to a systemic disorder; and to detect the presence of associated problems or complications.

• Blood sugar, serum electrolytes, calcium and phosphorus.
• Testing for HIV, hepatitis B and C and VDRL test.
• Complement studies (C3, C4) and ASO titer.
• Antinuclear antibody (ANA), anti–double-stranded DNA antibody, rheumatoid factor and cryoglobulins.

• An ultrasound of the abdomen is performed to determine the size and shape of the kidney, and to detect mass, kidney stone, cyst or other obstruction or abnormality.
• X-ray of the chest is done to rule out infections.

The kidney biopsy is the most important test used to determine the exact underlying type or cause of nephrotic syndrome. In a kidney biopsy, a small sample of kidney tissue is taken and examined in a laboratory. (for further information read Chapter 4).