Nephrotic syndrome

What is Nephrotic syndrome?

Nephrotic syndrome is a collection of symptoms that result when damage to the glomeruli (the filtering units in the kidney) causes a loss of protein from the blood into the urine. This loss of plasma proteins into the urine can cause massive edema (fluid retention). Fluid can collect in the chest cavity (pleural effusion) and abdomen (ascites), causing shortness of breath or abdominal pain. The most common cause of nephrotic syndrome is glomerular disease including idiopathic or membranous glomerulonephritis (inflammation of the glomeruli). Certain systemic diseases are also associated with nephrotic syndrome including diabetes mellitus, amyloidosis (a condition in which an abnormal protein, amyloid, collects in the tissues and organs), and systemic lupus erythematosus (an inflammatory autoimmune disease). Other causes of nephrotic syndrome include high blood pressure (hypertension), cancer (malignant neoplasms), hepatitis B, exposure to heavy metals (such as lead), reactions to carbon tetrachloride, poison ivy, or other toxins, and adverse drug reactions.

How is it diagnosed?

History: Symptoms of Nephrotic syndrome include persistent, worsening edema affecting the legs and face, loss of appetite, fatigue, headaches, and irritability. The individual may complain of blood in the urine, change in urinary frequency or consistency, and may note the appearance of foam in the toilet after urinating (caused by the high protein content of the urine). A bloated or tight feeling in the abdomen may be present as a result fluid retention in the abdomen (ascites).

Physical exam: may reveal marked edema in legs and face. Exertion may cause shortness of breath (dyspnea) due to fluid retention in the chest (pleural effusion, pulmonary edema).

Tests: Urinalysis shows proteinuria (abnormally high level of protein). Microscopic examination of urine sediment can detect a glomerular disease. Renal function can be determined by a 24-hour urine collection, creatinine clearance, and glomerular filtration rate. Blood chemistries demonstrate decreases in serum protein due to decreases in serum albumin. Other blood chemistries (sodium, calcium, potassium, cholesterol, and lipid levels) are useful. A kidney biopsy (sample of tissue removed for microscopic examination) is essential in identifying the renal disease underlying the nephrotic syndrome. Exclusion of non-kidney causes may require further diagnostic testing including fasting blood sugar, ANA, serum complement, HIV, VDRL, hepatitis B and C, serum and urine protein electrophoresis, PT, PTT, platelet count, and total protein.

How is nephrotic syndrome treated?

Treatment depends on the underlying condition causing the nephrotic syndrome. However, some therapies are common to nephrotic syndrome regardless of the underlying cause. Dietary changes may include a low-sodium, low-fat diet, with increased protein. If the blood protein level is particularly low, protein may need to be given intravenously. Diuretic drugs that increase urination are given to reduce edema. High blood pressure may be treated with antihypertensive medication. Loss of proteins involved with clotting functions may increase the risk of blood clots. This may necessitate the use of anticoagulants. Other drugs shown to be effective in the treatment of nephrotic syndrome include corticosteroids, cytotoxic, angiotensin converting enzyme inhibitors, and HMG CoA reductase inhibitors.

Medications

Information

Brand

Generic

Label

Deltasone

Prednisone

Activity

• Stay in bed (except for trips to the bathroom) until the edema (fluid retention) improves. After the swelling decreases, be as mildly active as your strength allows.
• Avoid excess sunlight and insect bites.

Diet

• Eat a low-fat, low-salt diet. Avoid prepared foods that contain salt. Protein levels may need to be restricted.
• You may need to restrict fluid intake.

What might complicate it?

Complications include progression to end-stage renal disease, increased risk of coronary artery disease and heart attacks, thrombosis (blood clots), pulmonary edema (excessive amount of fluid in the lungs), infections, and high blood pressure.

Predicted outcome

Many individuals with nephrotic syndrome will have remission (period of time during which symptoms lessen or disappear), either spontaneous or after months of therapy. However, relapses after remission are common. A few individuals (those with membranoproliferative glomerulonephritis and immunotactoid glomerulopathy) will progress to end-stage renal disease.

Alternatives

Conditions with similar symptoms include congestive heart disease, diabetes, collagen vascular disease (SLE, SS), and cancer.

Appropriate specialists

Nephrologist and urologist.

Last updated 6 April 2018