Not to be confused with nephritic syndrome

Nephrotic syndrome is a disorder where the kidneys have been damaged, causing them to leak protein from the blood into the urine. It is characterised by proteinuria (>3.5g/ day) hypoalbuminemia, hyperlipidemia and edema. The International Statistical Classification of Diseases and Related Health Problems (most commonly known by the abbreviation ICD) provides codes to classify diseases and a wide variety of signs, symptoms, abnormal findings, complaints, social circumstances and external causes of injury or disease. ... The International Statistical Classification of Diseases and Related Health Problems 10th Revision (ICD-10) is a coding of diseases and signs, symptoms, abnormal findings, complaints, social circumstances and external causes of injury or diseases, as classified by the World Health Organization (WHO). ... // N00-N39 - Diseases of the genitourinary system: urinary system (N00-N08) Glomerular diseases Prefixes: .2 Diffuse membranous glomerulonephritis (N00) Acute nephritic syndrome (N01) Rapidly progressive nephritic syndrome (N02) Recurrent and persistent haematuria (N03) Chronic nephritic syndrome (N04) Nephrotic syndrome Lipoid nephrosis (N05) Unspecified nephritic syndrome (N06) Isolated proteinuria with specified... The International Statistical Classification of Diseases and Related Health Problems (most commonly known by the abbreviation ICD) provides codes to classify diseases and a wide variety of signs, symptoms, abnormal findings, complaints, social circumstances and external causes of injury or disease. ... The following is a list of codes for International Statistical Classification of Diseases and Related Health Problems. ... The Disease Bold textDatabase is a free website that provides information about the relationships between medical conditions, symptoms, and medications. ... eMedicine is an online clinical medical knowledge base that was founded in 1996. ... Medical Subject Headings (MeSH) is a huge controlled vocabulary (or metadata system) for the purpose of indexing journal articles and books in the life sciences. ... Nephritic syndrome is a collection of signs (known as a syndrome) associated with disorders affecting the kidneys, more specifically glomerular disorders. ... The kidneys are organs that filter wastes (such as urea) from the blood and excrete them, along with water, as urine. ... A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... Human blood smear: a - erythrocytes; b - neutrophil; c - eosinophil; d - lymphocyte. ... This article or section is in need of attention from an expert on the subject. ...

• The most common sign is excess fluid in the body. This may take several forms:
  • Puffiness around the eyes, characteristically in the morning.
  • Edema over the legs which is pitting (i.e. leaves a little pit when the fluid is pressed out, which resolves over a few seconds).
  • Fluid in the pleural cavity causing pleural effusion.
  • Fluid in the peritoneal cavity causing ascites.
• Hypertension (rarely)
• Some patients may notice foamy urine, due to a lowering of the specific gravity by the severe proteinuria. Actual urinary complaints such as hematuria or oliguria are uncommon, and are seen commonly in nephritic syndrome.
• May have features of underlying cause, such rash associated with SLE, or neuropathy with diabetes.
• Examination should also exclude other causes of gross edema- especially the cardiovascular and hepatic system.

Hypervolemia (or Fluid overload) is the medical condition where there is too much fluid in the blood. ... This article refers to the sight organ. ... This page is about the condition called edema. ... Diagram of an insect leg A leg is the part of an animals body that supports the rest of the animal above the ground and is used for locomotion. ... The lungs are surrounded by two membranes, the pleurae. ... Pleural effusion Chest x-ray of a pleural effusion. ... In higher vertebrates, the peritoneum is the membrane that forms the lining of the abdominal cavity - it covers most of the intra-abdominal organs. ... For other forms of hypertension, see Hypertension (disambiguation). ... This article or section is in need of attention from an expert on the subject. ... Relative density (also known as specific gravity) is a measure of the density of a material. ... Proteinuria (from protein and urine) means the presence of an excess of serum proteins in the urine. ... In medicine, hematuria (or haematuria) is the presence of blood in the urine. ... Oliguria and anuria are the decreased or absent production of urine, respectively. ... Nephritic syndrome is a collection of signs (known as a syndrome) associated with disorders affecting the kidneys, more specifically glomerular disorders. ...

Investigations

The following are baseline, essential investigations

• Urine sample shows proteinuria. It is also examined for active casts; which is more a feature of active nephritis.
• Hypoalbuminemia: albumin levels in blood < 30g/L
• High levels of cholesterol (hypercholesterolemia), specifically elevated LDL, usually with concomitantly elevated VLDL
• Electrolytes, urea and creatinine (EUCs): to evaluate renal function

Furher investigations are indicated if the cause is not clear Proteinuria (from protein and urine) means the presence of an excess of serum proteins in the urine. ... Cast can refer to: Cast: A UK band. ... This article is in need of attention. ... Cholesterol is a sterol (a combination steroid and alcohol), a lipid found in the cell membranes of all body tissues, and is transported in the blood plasma of all animals. ... Hypercholesterolemia (literally: high blood cholesterol) is the presence of high levels of cholesterol in the blood [1]. It is not a disease but a metabolic derangement that can be secondary to many diseases and can contribute to many forms of disease, most notably cardiovascular disease. ... Low-density lipoprotein (LDL) belongs to the lipoprotein particle family. ... Very Low Density Lipoprotein (VLDL) is a lipoprotein subclass. ...

• Biopsy of kidney (not usually done in children)
• Auto-immune markers (ANA, ASOT, C3, cryoglobulins, serum electrophoresis)

Pathogenesis

The glomeruli of the kidneys are the parts that normally filter the blood. They consist of capillaries that are fenestrated (leaky, due to little holes called fenestrae or windows) and that allow fluid, salts, and other small solutes to flow through, but normally not proteins. The glomerulus is a capillary bed found surrounded by the Bowmans capsule of the nephron in the vertebrate kidney. ... The word capillary is used to describe any very narrow tube or channel through which a fluid can pass. ...

In nephrotic syndrome, the glomeruli become damaged due to inflammation and hyalinisation so that small proteins, such as albumins immunoglobulins and anti-thrombin can pass through the kidneys into urine. You may be looking for albumen, or egg white. ...

Albumin is the major protein in the blood which maintains colloid osmotic pressure- this prevents leakage of blood from vessels into tissue. However, experiments show that the edema formation in nephrotic syndrome is more so due to microvascular damage and intense salt and water retention by the damaged kidneys (due to increased angiotensin secretion). The mechanism is very complex and still not fully understood.

In response to leakage of albumin, the liver begins to make more of all its proteins, and levels of large proteins (such as alpha 2-macroglobulin and lipoproteins) increase. The excess lipoproteins end up in the urine filtrate, which is then rebsorbed by the tubular cells, which end up shedding and forming oval fat bodies or fatty casts. Alpha-2 macroglobulin is a large plasma protein found in the blood. ... When present on microscopic evaluation during urinalysis, urinary casts hold significance as diagnostic and prognostic indicators of kidney disease. ...

Causes of nephrotic syndrome

A) Primary renal diseases

Any of the glomerulonephritides can cause nephrotic syndrome; but in adults the most common ones are membranous, FSGS, and minimal change disease. In children 95% of cases are due to minimal change disease.

B) Secondary renal diseases

Many and varied. Causes include

• Diabetes
• SLE
• Amyloidosis

However, Idiopathic Nephritic syndrome, has no known causes.

Differential diagnosis of gross edema

When someone presents with generalised edema, the following causes should be excluded

1) Heart failure: The patient is older, with a history of heart disease.

Jugular venous pressure is elevated on examination, might hear heart murmurs

An echocardiogram is the gold standard investigation

2) Liver failure: History suggestive of hepatitis/ cirrhosis: alcoholic, IV drug user, some hereditary causes

Stigmata of liver disease are seen: dilated veins over umbilicus (caput medusae), scratch marks, enlarged spleen, spider angiomata, encephalopathy, bruising, nodular liver

3) Acute fluid overload in someone with kidney failure These people are known to have kidney failure, and have either drunk too much or missed their dialysis.

4) Metastatic cancer: When cancer seeds the lungs or abdomen it causes effusions and fluid accumulation due to obstruction of lymphatics and veins as well as serous exudation.

Treatment

Treatment includes: A) General measures (supportive)

Monitoring and maintaining euvolemia (the correct amount of fluid in the body)

- monitoring urine output, BP regularly

- fluid restrict to 1L

- diuretics (IV furosemide)

Monitoring kidney function

-do EUCs daily and calculating GFR

Prevent and treat any complications [see below]

Albumin infusions are generally not used because their effect lasts only transiently.

B) Specific treatment of underlying cause

Immunosupression for the glomerulonephritides (steroids, cyclosporin)

Achieving stricter blood glucose control if diabetic

BP control. ACE inhibitors are the drug of choice. Independent of their blood pressure lowering effect, they have been shown to decrease protein loss.

Complications

Venous thrombosis: due to leak of anti-thrombin 3, which helps prevent thrombosis. This often occurs in the renal veins. Treatment is with heparin.

Infection: due to leakage of immunoglobulins, encapsulated bacteria such as Haemophilus influenzae and Streptococcus pneumonia can cause infection.

Acute renal failure is due to hypovolemia. Despite the excess of fluid in the tissues, there is less fluid in the vasculature. Decreased blood flow to the kidneys causes them to shutdown. Thus it is a tricky task to get rid of excess fluid in the body while maintaining ciculalatory euvolemia.

Pulmonary edema: again due to fluid leak, sometimes it leaks into lungs causing hypoxia and dyspnoea.

Do not give diuretics.

Prognosis

The prognosis depends on the cause of nephrotic syndrome. It is usually good in children, because minimal change disease responds very well to steroids and does not cause chronic renal failure. However other causes such as focal segmental glomerulosclerosis frequently lead to end stage renal disease. Factors associated with a poorer prognosis in these cases include level of proteinuria, blood pressure control and kidney function (GFR). Minimal change disease or nil disease (lipoid nephrosis) is a disease of the kidney which causes nephrotic syndrome and usually affects children (peak incidence at 2-3 years of age). ... In chemistry and biology, Steroids are a type of lipid, characterized by a carbon skeleton with four fused rings. ... Focal segmental glomerulosclerosis (FSGS) is a cause of nephrotic syndrome in children and adolescents, as well as an important cause of kidney failure in adults. ... Chronic renal failure - Wikipedia /**/ @import /skins/monobook/IE50Fixes. ... Proteinuria (from protein and urine) means the presence of an excess of serum proteins in the urine. ... A sphygmomanometer, a device used for measuring arterial pressure. ... Glomerular filtration rate or GFR is the volume of fluid filtered from the renal glomerular capillaries into Bowmans capsule per unit time. ...

References

• Brenner, Barry M. (editor) (2004). Brenner & Rector's The Kidney, seventh edition. W.B. Saunders Company. ISBN 0-7216-0164-2. 
• www.emedicine.com

External links

• NephCure Foundation Only organization solely committed to support research seeking the cause of Nephrotic Syndrome and FSGS, improve treatment and find the cure.
• Childhood Nephrotic Syndrome - National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), NIH
• Adult Nephrotic Syndrome - National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), NIH
• KidComm - An online resource for parents dealing with childhood kidney diseases (FSGS, Nephrotic Syndrome and others). Features an email support group for parents plus an email support group for adults with kidney disease (YakTalk).