nephrotic syndrome


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Related to nephrotic syndrome: nephritic syndrome

Nephrotic Syndrome

 

Definition

Nephrotic syndrome is a collection of symptoms which occur because the tiny blood vessels (the glomeruli) in the kidney become leaky. This allows protein (normally never passed out in the urine) to leave the body in large amounts.

Description

The glomeruli (a single one is called a glomerulus) are tiny tufts of capillaries (the smallest type of blood vessels). Glomeruli are located in the kidneys, where they allow a certain amount of water and waste products to leave the blood, ultimately to be passed out of the body in the form of urine. Normally, proteins are unable to pass through the glomerular filter. Nephrotic syndrome, however, occurs when this filter becomes defective, allowing large quantities of protein to leave the blood circulation, and pass out or the body in the urine.
Patients with nephrotic syndrome are from all age groups, although in children there is an increased risk of the disorder between the ages of 18 months and four years. In children, boys are more frequently affected; in adults, the ratio of men to women is closer to equal.

Causes and symptoms

Nephrotic syndrome can be caused by a number of different diseases. The common mechanism which seems to cause damage involves the immune system. For some reason, the immune system seems to become directed against the person's own kidney. The glomeruli become increasingly leaky as various substances from the immune system are deposited within the kidney.
A number of different kidney disorders are associated with nephrotic syndrome, including:
  • minimal change disease or MCD (responsible for about 80% of nephrotic syndrome in children, and about 20% in adults) MCD is a disorder of the glomeruli
  • focal glomerulosclerosis
  • membranous glomerulopathy
  • membranoproliferative glomerulonephropathy
Other types of diseases can also result in nephrotic syndrome. These include diabetes, sickle-cell anemia, amyloidosis, systemic lupus erythematosus, sarcoidosis, leukemia, lymphoma, cancer of the breast, colon, and stomach, reactions to drugs (including nonsteroidal anti-inflammatory drugs, lithium, and street heroine), allergic reactions (to insect stings, snake venom, and poison ivy), infections (malaria, various bacteria, hepatitis B, herpes zoster, and the virus which causes AIDS), and severe high blood pressure.
The first symptom of nephrotic syndrome is often foamy urine. As the syndrome progresses, swelling (edema) is noticed in the eyelids, hands, feet, knees, scrotum, and abdomen. The patient feels increasingly weak and fatigued. Appetite is greatly decreased. Over time, the loss of protein causes the muscles to become weak and small (called muscle wasting). The patient may note abdominal pain and difficulty breathing. Because the kidneys are involved in blood pressure regulation, abnormally low or abnormally high blood pressure may develop.
Over time, the protein loss occurring in nephrotic syndrome will result in a generally malnourished state. Hair and nails become brittle, and growth is stunted. Bone becomes weak, and the body begins to lose other important nutrients (sugar, potassium, calcium). Infection is a serious and frequent complication, as are disorders of blood clotting. Acute kidney failure may develop.

Diagnosis

Diagnosis is based first on the laboratory examination of the urine and the blood. While the urine will reveal significant quantities of protein, the blood will reveal abnormally low amounts of circulating proteins. Blood tests will also reveal a high level of cholesterol. In order to diagnose one of the kidney disorders which cause nephrotic syndrome, a small sample of the kidney (biopsy) will need to be removed for examination. This biopsy can be done with a long, very thin needle which is inserted through the skin under the ribs.

Treatment

Treatment depends on the underlying disorder which has caused nephrotic syndrome. Medications which dampen down the immune system are a mainstay of treatment. The first choice is usually a steroid drug (such as prednisone). Some conditions may require even more potent medications, such as cyclophosphamide or cyclosporine. Treating the underlying conditions (lymphoma, cancers, heroine use, infections) which have led to nephrotic syndrome will often improve the symptoms of nephrotic syndrome as well. Some patients will require the use of specific medications to control high blood pressure. Occasionally, the quantity of fluid a patient is allowed to drink is restricted. Some patients benefit from the use of diuretics (which allow the kidney to produce more urine) to decrease swelling.

Key terms

Glomeruli — Tiny tufts of capillaries which carry blood within the kidneys. The blood is filtered by the glomeruli. The blood then continues through the circulatory system, but a certain amount of fluid and specific waste products are filtered out of the blood, to be removed from the body in the form of urine.
Immune system — The complex system within the body which serves to fight off harmful invaders, such as bacteria, viruses, fungi.
Kidney failure — The inability of the kidney to excrete toxic substances from the body.

Prognosis

Prognosis depends on the underlying disorder. Minimal change disease has the best prognosis of all the kidney disorders, with 90% of all patients responding to treatment. Other types of kidney diseases have less favorable outcomes, with high rates of progression to kidney failure. When nephrotic syndrome is caused by another, treatable disorder (infection, allergic or drug reaction), the prognosis is very good.

Resources

Organizations

American Kidney Fund (AKF). Suite 1010, 6110 Executive Boulevard, Rockville, MD 20852. (800) 638-8299. http://216.248.130.102/Default.htm.
National Kidney Foundation. 30 East 33rd St., New York, NY 10016. (800) 622-9010. http://www.kidney.org.

nephrotic syndrome

 [nĕ-frot´ik]
any of several conditions marked by massive edema, heavy proteinuria, hypoalbuminemia, and unusual susceptibility to intercurrent infections. See also nephrosis.

neph·rot·ic syn·drome

a clinical state characterized by edema, albuminuria, decreased plasma albumin, doubly refractile bodies in the urine, and usually increased blood cholesterol; lipid droplets may be present in the cells of the renal tubules, but the basic lesion is increased permeability of the glomerular capillary basement membranes, of unknown cause or resulting from glomerulonephritis, diabetic glomerulosclerosis, systemic lupus erythematosus, amyloidosis, renal vein thrombosis, or hypersensitivity to various toxic agents.
Synonym(s): nephrosis (3)

nephrotic syndrome

[nəfrot′ik]
Etymology: Gk, nephros + L, icus, like
an abnormal condition of the kidney characterized by marked proteinuria, hypoalbuminemia, and edema. It occurs in glomerular disease and thrombosis of a renal vein and as a complication of many systemic diseases, diabetes mellitus, amyloidosis, systemic lupus erythematosus, and multiple myeloma. The nephrotic syndrome occurs in a severe primary form. The presenting symptoms include anorexia, weakness, proteinuria, hypoalbuminuria, and edema. Treatment and prognosis depend on the underlying cause of disease. Patients with primary nephrotic syndrome usually respond favorably to corticosteroids. Loop diuretics are used to control symptomatic edema, and dialysis may be necessary. Also called nephrosis. nephrotic, adj.

nephrotic syndrome

A non-inflammatory derangement of glomerular function, characterised by increased glomerular leakage with loss of albumin and other macromolecules. Nephrotic syndrome is characterised by the triad of oedema, proteinuria (> 3.5 g protein/1.73 m2/24 hours) and hypoalbuminaemia (< 30 g/L) related to damage to the glomerular basement membrane and podocyte.
 
Clinical findings
Common to all nephrotic syndromes are oedema, proteinuria and hypoalbuminaemia; because various conditions can lead to nephrotic syndrome, the symptoms reflect the cause.

Aetiology
Amyloidosis, diabetes (diabetic nephropathy), primary glomerular disease (e.g., focal segmental glomerulosclerosis), IgA nephropathy, light-chain disease, mesangiocapillary, membranous glomerulonephritis (may by linked to neoplasia), myeloma, amyloidosis, diabetes, infection, SLE, toxins (e.g., colloidal gold, “street” heroin, penicillamine). Rarely, HIV, pre-eclampsia.
 
Lab
Increased alpha2-globulin, increased beta-globulin, decreased albumin, increased cholesterol, increased TGs, increased phospholipids; these increases are confined to lipoproteins containing apoB (chylomicrons and LDL-C), due to increased production of apoB. Also, decreased HDL2 and increased VLDL.
 
Urinalysis
Maltese cross-shaped structures (cholesterol, oval fat bodies), renal tubular casts (fatty, waxy, cellular, granular).
 
Management
Loop diuretics (e.g., furosemide, thiazides and potassium-sparing diuretics); heparin and anticoagulants to reduce the risk of thromboembolism; extreme measures include hyperoncotic albumin, plasma ultrafiltration and bilateral nephrectomy (to avoid the complications of severe hypoproteinaemia and hypovolaemia); ex vivo adsorption of plasma on protein A Sephadex columns to reduce proteinuria.

nephrotic syndrome

Ellis type 2 nephrosis Nephrology A non-inflammatory derangement of glomerular function, characterized by ↑ glomerular leakage with loss of albumin and other macromolecules; NS is characterized by the triad of edema; proteinuria, > 3.5 g protein/1.73 m2/24 h; hypoalbuminemia, < 30 g/L Etiology Diabetic nephropathy, 1º glomerular disease; membranous glomerulonephritis may by linked to neoplasia, myeloma, amyloidosis, DM, infection, SLE, toxins–eg, colloidal gold, 'street' heroin, penicillamine, rarely, HIV, preeclampsia Clinical Various conditions may lead to NS; the Sx reflect the cause Management Loop diuretics–eg, furosemide, thiazides and potassium-sparing diuretics; heparin, anticoagulants to ↓ risk of thromboembolism; extreme measures include hyperoncotic albumin, plasma ultrafiltration, bilateral nephrectomy to avoid the complications of severe hypoproteinemia and hypovolemia; ex vivo adsorption of plasma on protein A Sephadex columns to ↓ proteinuria. See Diabetic nephropathy.

neph·rot·ic syn·drome

(nef-rot'ik sin'drōm)
A clinical state characterized by edema, albuminuria, decreased plasma albumin, doubly refractile bodies in the urine, and usually increased blood cholesterol; lipid droplets may be present in the cells of the renal tubules, but the basic lesion is increased permeability of the glomerular capillary basement membranes, of unknown cause or resulting from glomerulonephritis, diabetic glomerulosclerosis, systemic lupus erythematosus, amyloidosis, renal vein thrombosis, or hypersensitivity to various toxic agents.
Synonym(s): nephrosis (3) .

nephrotic syndrome

A kidney disorder in which protein, never normally found in the urine, is excreted in such quantities that blood levels may be depleted and the OSMOTIC PRESSURE of the blood reduced. This leads to accumulation of fluid in the body tissues (oedema). The nephrotic syndrome may follow kidney damage from GLOMERULONEPHRITIS or DIABETES or it may be caused by severe high blood pressure (HYPERTENSION), poisoning or adverse reactions from drugs. The condition is treated with DIURETIC drugs to get rid of the accumulated fluid in the tissues.

Epstein,

A.A., U.S. physician, 1880-1965.
Epstein syndrome - symptoms include edema, protein concentration in urine, low concentration of albumin in the blood, and hyperlipidemia. Synonym(s): nephrotic syndrome

neph·rot·ic syn·drome

(nef-rot'ik sin'drōm)
Clinical state characterized by edema, albuminuria, decreased plasma albumin, doubly refractile bodies in the urine, and usually increased blood cholesterol.

nephrotic syndrome

a condition marked by edema, marked proteinuria, hypoalbuminemia and hypercholesterolemia.

Patient discussion about nephrotic syndrome

Q. Q. I want to know about urine protein creatine ratio in diagnosing nephrotic syndrome. Please explain interms of unit such as mg/mg or mmol/mg. Normal range, nephrotic range with good referrence.

A. Nephrotic syndrome is defines as a damage to the kidneys, in which there is a leak of large amounts of protein (over 3.5 grams of protein / 24 hours urine output) from the blood to the urine. Protein loss causes low protein count in the blood (hypoalbuminemia) and edemas (excess fluid in the interstitial cavity which is between the cells, causes leg swelling most often, and also in the adbomen and around the eyes).

More discussions about nephrotic syndrome
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