Nephritic syndrome
Encyclopedia
- Not to be confused with nephrotic syndromeNephrotic syndromeNephrotic syndrome is a nonspecific disorder in which the kidneys are damaged, causing them to leak large amounts of protein from the blood into the urine....
Nephritic syndrome (or acute nephritic syndrome) is a collection of signs (known as a syndrome
Syndrome
In medicine and psychology, a syndrome is the association of several clinically recognizable features, signs , symptoms , phenomena or characteristics that often occur together, so that the presence of one or more features alerts the physician to the possible presence of the others...
) associated with disorders affecting the kidney
Kidney
The kidneys, organs with several functions, serve essential regulatory roles in most animals, including vertebrates and some invertebrates. They are essential in the urinary system and also serve homeostatic functions such as the regulation of electrolytes, maintenance of acid–base balance, and...
s, more specifically glomerular disorders. It is characterized by having small pores in the podocyte
Podocyte
Podocytes are cells in the Bowman's capsule in the kidneys that wrap around the capillaries of the glomerulus...
s of the glomerulus
Glomerulus
A glomerulus is a capillary tuft that is involved in the first step of filtering blood to form urine.A glomerulus is surrounded by Bowman's capsule, the beginning component of nephrons in the vertebrate kidney. A glomerulus receives its blood supply from an afferent arteriole of the renal...
, large enough to permit proteins (proteinuria
Proteinuria
Proteinuria means the presence of anexcess of serum proteins in the urine. The protein in the urine often causes the urine to become foamy, although foamy urine may also be caused by bilirubin in the urine , retrograde ejaculation, pneumaturia due to a fistula, or drugs such as pyridium.- Causes...
) and red blood cell
Red blood cell
Red blood cells are the most common type of blood cell and the vertebrate organism's principal means of delivering oxygen to the body tissues via the blood flow through the circulatory system...
s (hematuria
Hematuria
In medicine, hematuria, or haematuria, is the presence of red blood cells in the urine. It may be idiopathic and/or benign, or it can be a sign that there is a kidney stone or a tumor in the urinary tract , ranging from trivial to lethal...
) to pass into the urine. By contrast, nephrotic syndrome
Nephrotic syndrome
Nephrotic syndrome is a nonspecific disorder in which the kidneys are damaged, causing them to leak large amounts of protein from the blood into the urine....
is characterized by only proteins (proteinuria
Proteinuria
Proteinuria means the presence of anexcess of serum proteins in the urine. The protein in the urine often causes the urine to become foamy, although foamy urine may also be caused by bilirubin in the urine , retrograde ejaculation, pneumaturia due to a fistula, or drugs such as pyridium.- Causes...
) moving into the urine. Both nephritic syndrome and nephrotic syndrome
Nephrotic syndrome
Nephrotic syndrome is a nonspecific disorder in which the kidneys are damaged, causing them to leak large amounts of protein from the blood into the urine....
result in hypoalbuminemia
Hypoalbuminemia
Hypoalbuminemia is a medical condition where levels of albumin in blood serum are abnormally low. It is a specific form of hypoproteinemia.Albumin is a major protein in the human body, making up about 60% of total human plasma protein by mass...
due to protein albumin
Albumin
Albumin refers generally to any protein that is water soluble, which is moderately soluble in concentrated salt solutions, and experiences heat denaturation. They are commonly found in blood plasma, and are unique to other blood proteins in that they are not glycosylated...
moving from the blood to the urine.
Hematuria can be caused by bleeding anywhere in the urinary tract, but if the RBCs are trapped in urinary casts, it is more likely that the bleeding originated in the nephron
Nephron
The renal tubule is the portion of the nephron containing the tubular fluid filtered through the glomerulus. After passing through the renal tubule, the filtrate continues to the collecting duct system, which is not part of the nephron....
, and nephritic syndrome becomes more probable.
It is usually distinguished from nephrotic syndrome, but sometimes the two are described as associated in a minority of cases (occasionally--and confusingly--referred to as "nephritic/nephrotic", though this is considered a progression of a nephritic syndrome, and categorically not a nephrotic syndrome). Some conditions can cause either syndrome
Syndrome
In medicine and psychology, a syndrome is the association of several clinically recognizable features, signs , symptoms , phenomena or characteristics that often occur together, so that the presence of one or more features alerts the physician to the possible presence of the others...
, and both syndromes can have a similar appearance upon biopsy. Neither term represents a definitive diagnosis, but both terms can be useful in the early stages of a differential diagnosis
Differential diagnosis
A differential diagnosis is a systematic diagnostic method used to identify the presence of an entity where multiple alternatives are possible , and may also refer to any of the included candidate alternatives A differential diagnosis (sometimes abbreviated DDx, ddx, DD, D/Dx, or ΔΔ) is a...
.
Signs and symptoms
Nephritic syndrome is characterized by;- hematuriaHematuriaIn medicine, hematuria, or haematuria, is the presence of red blood cells in the urine. It may be idiopathic and/or benign, or it can be a sign that there is a kidney stone or a tumor in the urinary tract , ranging from trivial to lethal...
(blood in the urine), with red blood cell (RBC) casts present in the urine - proteinuriaProteinuriaProteinuria means the presence of anexcess of serum proteins in the urine. The protein in the urine often causes the urine to become foamy, although foamy urine may also be caused by bilirubin in the urine , retrograde ejaculation, pneumaturia due to a fistula, or drugs such as pyridium.- Causes...
(protein in the urine) - small amounts of protein are lost in the urine, but this is usually trivial (<3.5 g/day) - hypertensionHypertensionHypertension or high blood pressure is a cardiac chronic medical condition in which the systemic arterial blood pressure is elevated. What that means is that the heart is having to work harder than it should to pump the blood around the body. Blood pressure involves two measurements, systolic and...
(high blood pressure)- mild - uremiaUremiaUremia or uraemia is a term used to loosely describe the illness accompanying kidney failure , in particular the nitrogenous waste products associated with the failure of this organ....
- due to retention of waste products
and variable renal insufficiency
Renal failure
Renal failure or kidney failure describes a medical condition in which the kidneys fail to adequately filter toxins and waste products from the blood...
, with;
- azotemiaAzotemiaAzotemia is a medical condition characterized by abnormally high levels of nitrogen-containing compounds, such as urea, creatinine, various body waste compounds, and other nitrogen-rich compounds in the blood...
(elevated blood nitrogen) - oliguriaOliguriaOliguria is the low output of urine, It is clinically classified as an output below 300-500ml/day. The decreased output of urine may be a sign of dehydration, renal failure, hypovolemic shock, HHNS Hyperosmolar Hyperglycemic Nonketotic Syndrome, multiple organ dysfunction syndrome, urinary...
(low urine output <400 mL/day)
The main features are hypertension and RBC casts. The proteinuria in nephritic syndrome is not usually severe, but may occasionally be heavy enough to be in the range usually found in nephrotic syndrome
Nephrotic syndrome
Nephrotic syndrome is a nonspecific disorder in which the kidneys are damaged, causing them to leak large amounts of protein from the blood into the urine....
.
Mnemonic
Mnemonic
A mnemonic , or mnemonic device, is any learning technique that aids memory. To improve long term memory, mnemonic systems are used to make memorization easier. Commonly encountered mnemonics are often verbal, such as a very short poem or a special word used to help a person remember something,...
: PHARAOH = Proteinuria, Hematuria, Azotemia, RBC casts, Anti-strep titres (if post-strep), Oliguria, Hypertension
Diagnosis
Nephritic syndrome is not a specific diagnosis. It is a clinical syndrome and characterized by the above signs.An anti-streptolysin O titre (or ASOT) is typically done to test for exposure to streptococci. This test however has very poor specificity.
Pathophysiology
The exact pathophysiologyPathophysiology
Pathophysiology is the study of the changes of normal mechanical, physical, and biochemical functions, either caused by a disease, or resulting from an abnormal syndrome...
is dependent on the specific diagnosis. However, the common features are an inflammation
Inflammation
Inflammation is part of the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Inflammation is a protective attempt by the organism to remove the injurious stimuli and to initiate the healing process...
of the glomeruli
Glomerulus
A glomerulus is a capillary tuft that is involved in the first step of filtering blood to form urine.A glomerulus is surrounded by Bowman's capsule, the beginning component of nephrons in the vertebrate kidney. A glomerulus receives its blood supply from an afferent arteriole of the renal...
, leading to salt and water retention (causing hypertension) and a reduction in the kidney function.
Differential diagnosis
The two classic diagnoses of nephritic syndrome are:- post-streptococcal glomerulonephritis
- crescentic glomerulonephritis (also called rapidly progressive glomerulonephritis)
Nephritic syndrome causes are usually grouped into 'focal proliferative' and 'diffuse proliferative' on the basis of histology
Histology
Histology is the study of the microscopic anatomy of cells and tissues of plants and animals. It is performed by examining cells and tissues commonly by sectioning and staining; followed by examination under a light microscope or electron microscope...
(obtained by a renal biopsy
Renal biopsy
A renal biopsy is a procedure in which a sample of kidney tissue is obtained. Microscopic examination of the tissue can provide information needed to diagnose, monitor or treat a renal disorder.-Indications:...
).
Focal proliferative
- IgA nephropathyIgA nephropathyIgA nephropathy is a form of glomerulonephritis...
- chronic liver failure
- Celiac sprue
- dermatitis herpetiformisDermatitis herpetiformisDermatitis herpetiformis , or Duhring's disease,Freedberg, et al. . Fitzpatrick's Dermatology in General Medicine. . McGraw-Hill. ISBN 0-07-138076-0. is a chronic blistering skin condition, characterised by blisters filled with a watery fluid...
- Henoch-Schoenlein purpura
- Alport syndromeAlport syndromeAlport syndrome or hereditary nephritis is a genetic disorder characterized by glomerulonephritis, endstage kidney disease, and hearing loss. Alport syndrome can also affect the eyes . The presence of blood in the urine is almost always found in this condition.It was first identified in a British...
- SLELupus erythematosusLupus erythematosus is a category for a collection of diseases with similar underlying problems with immunity . Symptoms of these diseases can affect many different body systems, including joints, skin, kidneys, blood cells, heart, and lungs...
Diffuse proliferative
- membranoproliferative glomerulonephritisMembranoproliferative glomerulonephritisMembranoproliferative glomerulonephritis , also known as mesangiocapillary glomerulonephritis, is a type of glomerulonephritis caused by deposits in the kidney glomerular mesangium and basement membrane thickening, activating complement and damaging the glomeruli.MPGN accounts for approximately 4%...
(malariaMalariaMalaria is a mosquito-borne infectious disease of humans and other animals caused by eukaryotic protists of the genus Plasmodium. The disease results from the multiplication of Plasmodium parasites within red blood cells, causing symptoms that typically include fever and headache, in severe cases...
, hepatitis B, hepatitis CHepatitis CHepatitis C is an infectious disease primarily affecting the liver, caused by the hepatitis C virus . The infection is often asymptomatic, but chronic infection can lead to scarring of the liver and ultimately to cirrhosis, which is generally apparent after many years...
, chronic infection, sickle-cell diseaseSickle-cell diseaseSickle-cell disease , or sickle-cell anaemia or drepanocytosis, is an autosomal recessive genetic blood disorder with overdominance, characterized by red blood cells that assume an abnormal, rigid, sickle shape. Sickling decreases the cells' flexibility and results in a risk of various...
, SLELupus erythematosusLupus erythematosus is a category for a collection of diseases with similar underlying problems with immunity . Symptoms of these diseases can affect many different body systems, including joints, skin, kidneys, blood cells, heart, and lungs...
, hemolytic uremic syndrome/thrombotic thrombocytopenic purpuraThrombotic thrombocytopenic purpuraThrombotic thrombocytopenic purpura is a rare disorder of the blood-coagulation system, causing extensive microscopic thromboses to form in small blood vessels throughout the body...
) - cryoglobulinemiaCryoglobulinemiaCryoglobulinemia is a medical condition in which the blood contains large amounts of cryoglobulins - proteins that become insoluble at reduced temperatures. Cryoglobulins typically precipitate at temperatures below normal body temperature and will dissolve again if the blood is heated...
- SLELupus erythematosusLupus erythematosus is a category for a collection of diseases with similar underlying problems with immunity . Symptoms of these diseases can affect many different body systems, including joints, skin, kidneys, blood cells, heart, and lungs...
- rapidly progressing glomerulonephritis (RPGNs) - several.
Treatment
Treatment is dependent on the underlying etiologyEtiology
Etiology is the study of causation, or origination. The word is derived from the Greek , aitiologia, "giving a reason for" ....
(cause) and the degree of kidney dysfunction.
Prognosis
Because nephritic syndrome is not a disease, just a collection of symptoms, the prognosis depends on the underlying etiology.External links
- Acute nephritic syndrome - medlineplus.org
- Nephritic syndrome - A to Z topics.
- Nephritic syndrome - Merck Manual.