Nephrotic syndrome (NS) is a condition that is often caused by any of a group of diseases that damage the kidneys’ filtering system, the glomeruli. The structure of the glomeruli prevents most protein from getting filtered through into the urine. Normally, a person loses less than 150mg of protein in the urine in a 24-hour period. Proteinuria is the primary indicator of NS.
There are a number of different disorders that can cause NS. Diabetes and, to a lesser extent, hypertension can cause diffuse damage to the glomeruli and can ultimately lead to NS. The following diseases can cause specific damage to the glomeruli and often result in the development of heavy proteinuria and in many instances NS:
- Amyloidosis (the stiffening and subsequent malfunction of the kidney due to fibrous protein deposit in the tissue)
- Congenital nephrosis
- Focal segmental glomerular sclerosis (FSGS) (creates scar tissue in the glomerulus, damaging its protein-repellant membrane)
- Glomerulonephritis
- Diffuse mesangial proliferative GN (affecting the messangium)
- Membranous (damages the protein-repellant membrane)
- Postinfectious
- IgA nephropathy (Berger’s disease) (deposit of specific immunoglobulin A causing an inflammatory reaction and leading to glomerulonephritis)
- Minimal change disease (Nil’s disease)
- Pre-eclampsia, though rarely resulting in NS, is more often limited to heavy proteinuria
Diagnosis of this condition will include a physical examination and the assessment of family health history, along with blood tests, urinalysis and likely a kidney biopsy. A closed kidney biopsy may be used to determine the underlying cause and extent of disease with the exception of the following cases.
The outcome of NS varies and is largely dependent on the underlying cause. Some patients may have a spontaneous recovery not requiring any specific therapy, while others worsen despite aggressive, specific therapy.
Conditions that suggest Nephrotic Syndrome (NS)
Hypercoagulation (Thickened Blood)
A hypercoaguable state, in which the blood abnormally overclots, is also seen in some patients with NS. This means that they are at risk for developing a blood clot in the legs or in the renal veins that transport blood from the kidney. Some patients take blood thinners to prevent this complication.
Hypertension
Hypertension can be both a cause and the result of NS. This hypertension must be treated aggressively to prevent further damage to the kidneys.
Atherosclerosis
Complications that can arise during treatment for NS include atherosclerosis “hardening of the arteries” and adverse reaction to medications such as steroids.
Hypoalbuminemia (A low albumin level)
Blood analysis often shows high cholesterol levels and low albumin. Evaluation of the urine by a simple urine dipstick in the office can give preliminary information on the amount of protein in the urine. However, this test is a qualitative test. In order to determine the actual amount of protein in the urine, a 24-hour quantitative test must be done, which indicates levels of protein and creatinine in the urine. Often, a comparison of protein to creatinine based on a single sample is used to determine 24-hour protein loss. This is helpful for quicker results or when the patient cannot collect urine over 24 hours.
Kidney Failure
Nephrotic syndrome is associated with renal failure. The disease that causes NS can damage the glomeruli and can interfere with their ability to clean the blood. The edema that is present in the legs may also be occurring in the kidney tissue itself and can interfere with the kidneys’ ability to clean the blood. Renal failure can either be gradual (CRF) or acute (ARF).
BUN and creatinine may or may not be elevated in NS. If bun and creatinine are elevated the patient has renal failure and the prognosis is worse.
Risk factors for Nephrotic Syndrome (NS)
Nephrotic Syndrome (NS) can lead to
Hypertension
Hypertension can be both a cause and the result of NS. This hypertension must be treated aggressively to prevent further damage to the kidneys.
Atherosclerosis
Complications that can arise during treatment for NS include atherosclerosis “hardening of the arteries” and adverse reaction to medications such as steroids.
Recommendations for Nephrotic Syndrome (NS)
High/Increased Protein Diet
In NS, one gram of protein in the diet daily for every kilogram of body weight is considered sufficient, but may be varied by the doctor based upon need.
Conventional Drugs / Information
People with NS may be at risk for developing a blood clot in the legs or in the renal veins that transport blood from the kidney. Some patients take blood thinners to prevent this complication.
Controlling hypertension is essential in reducing proteinuria in NS. This is accomplished with angiotensin converting enzyme (ACE-1) inhibitors. ACE-1 inhibitors are the preferred blood pressure lowering medication because they provided added protection to the kidneys.
ACE-1 inhibitors cause a dry cough in approximately 8% of patients who take them. ACE-1 inhibitors are given in the highest dose tolerable to ensure kidney protection. If a patient develops a cough, a new class of drugs may be used, known as angiotensin receptor blockers (ARB). ARBs work by blocking angiotensin receptors, which blocks the effects of angiotensin after it is produced. They offer the same kidney protection as ACE-1 inhibitors without causing cough. If tolerable, ARBs may be combined with an ACE-1 inhibitor for added benefit.
Fibrinolytic Enzymes
Nattokinase is a naturally occurring agent with a good track record which can thin the blood if excess clotting is an issue for a particular NS patient.
Key
| Weak or unproven link |
| Strong or generally accepted link |
| Likely to help |
| Highly recommended |
Glossary
Protein
Compounds composed of hydrogen, oxygen, and nitrogen present in the body and in foods that form complex combinations of amino acids. Protein is essential for life and is used for growth and repair. Foods that supply the body with protein include animal products, grains, legumes, and vegetables. Proteins from animal sources contain the essential amino acids. Proteins are changed to amino acids in the body.
Milligram
(mg): 1/1,000 of a gram by weight.
Diabetes Mellitus
A disease with increased blood glucose levels due to lack or ineffectiveness of insulin. Diabetes is found in two forms; insulin-dependent diabetes (juvenile-onset) and non-insulin-dependent (adult-onset). Symptoms include increased thirst; increased urination; weight loss in spite of increased appetite; fatigue; nausea; vomiting; frequent infections including bladder, vaginal, and skin; blurred vision; impotence in men; bad breath; cessation of menses; diminished skin fullness. Other symptoms include bleeding gums; ear noise/buzzing; diarrhea; depression; confusion.
Hypertension
High blood pressure. Hypertension increases the risk of heart attack, stroke, and kidney failure because it adds to the workload of the heart, causing it to enlarge and, over time, to weaken; in addition, it may damage the walls of the arteries.
Scar Tissue
Fibrous tissue replacing normal tissues destroyed by injury or disease.
Glomerulonephritis
Inflammation of glomerulus. The glomerulus is part of a nephron, which in turn is the basic functional (working) unit of a kidney. Millions of nephrons acting together filter the blood to produce urine.
IgA
Immunoglobulin A. Supports mucosal immunity.
Biopsy
Excision of tissue from a living being for diagnosis.
Atherosclerosis
Common form of arteriosclerosis associated with the formation of atheromas which are deposits of yellow plaques containing cholesterol, lipids, and lipophages within the intima and inner media of arteries. This results in a narrowing of the arteries, which reduces the blood and oxygen flow to the heart and brain as well as to other parts of the body and can lead to a heart attack, stroke, or loss of function or gangrene of other tissues.
Steroid
Any of a large number of hormonal substances with a similar basic chemical structure containing a 17-carbon 14-ring system and including the sterols and various hormones and glycosides.
Cholesterol
A waxy, fat-like substance manufactured in the liver and found in all tissues, it facilitates the transport and absorption of fatty acids. In foods, only animal products contain cholesterol. An excess of cholesterol in the bloodstream can contribute to the development of atherosclerosis.
Edema
Abnormal accumulation of fluids within tissues resulting in swelling.
Acute
An illness or symptom of sudden onset, which generally has a short duration.