Serum protein electrophoresis
Encyclopedia
Blood proteins
Blood proteins, also termed serum proteins or plasma proteins, are proteins found in blood plasma. Serum total protein in blood is 7g/dl...
called globulins. Blood
Blood
Blood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....
must first be collected, usually into an airtight vial or syringe
Syringe
A syringe is a simple pump consisting of a plunger that fits tightly in a tube. The plunger can be pulled and pushed along inside a cylindrical tube , allowing the syringe to take in and expel a liquid or gas through an orifice at the open end of the tube...
. Electrophoresis is a laboratory technique where the blood serum
Blood serum
In blood, the serum is the component that is neither a blood cell nor a clotting factor; it is the blood plasma with the fibrinogens removed...
(the fluid portion of the blood after the blood has clotted) is placed on special paper treated with agarose gel and exposed to an electric current
Electric current
Electric current is a flow of electric charge through a medium.This charge is typically carried by moving electrons in a conductor such as wire...
to separate the serum protein components into five classifications by size and electrical charge, those being serum albumin
Serum albumin
Serum albumin, often referred to simply as albumin is a protein that in humans is encoded by the ALB gene.Serum albumin is the most abundant plasma protein in mammals. Albumin is essential for maintaining the osmotic pressure needed for proper distribution of body fluids between intravascular...
, alpha-1 globulins, alpha-2 globulins, beta globulins, and gamma globulin
Gamma globulin
Gamma globulins are a class of globulins, identified by their position after serum protein electrophoresis. The most significant gamma globulins are immunoglobulins , more commonly known as antibodies, although some Igs are not gamma globulins, and some gamma globulins are not Igs.-Use as medical...
s.
Prealbumin
Prealbumin is the fraction migrating faster than albumin toward the anode. It is the same as transthyretinTransthyretin
Transthyretin is a serum and cerebrospinal fluid carrier of the thyroid hormone thyroxine and retinol binding protein bound to retinol. This is how transthyretin gained its name, transports thyroxine and retinol...
(TTR). Mutations in transthyretin is associated with hereditary amyloidosis. True prealbumin is generally below the limit of detection in serum protein electrophoresis, but may be detected in electrophoresis of concentrated CSF
CSF
-Biology and Medicine:* Cerebrospinal fluid* Colony-Stimulating Factor* Cancer slope factor* Classical swine fever* Certain safety factor-Military:* Central Security Forces , an Egyptian paramilitary force...
.
Albumin
A fall of 30% is necessary before the decrease shows on electrophoresis. Usually a single band is seen. Heterozygous individuals may produce bisalbuminaemia - two equally staining bands, the product of two genes. Some variants give rise to a wide band or two bands of unequal intensity but none of these variants is associated with disease. Increased mobility results from the binding of bilirubinBilirubin
Bilirubin is the yellow breakdown product of normal heme catabolism. Heme is found in hemoglobin, a principal component of red blood cells. Bilirubin is excreted in bile and urine, and elevated levels may indicate certain diseases...
, nonesterified fatty acids, penicillin
Penicillin
Penicillin is a group of antibiotics derived from Penicillium fungi. They include penicillin G, procaine penicillin, benzathine penicillin, and penicillin V....
and acetylsalicylic acid, and occasionally from tryptic digestion in acute pancreatitis
Pancreatitis
Pancreatitis is inflammation of the pancreas. It occurs when pancreatic enzymes that digest food are activated in the pancreas instead of the small intestine. It may be acute – beginning suddenly and lasting a few days, or chronic – occurring over many years...
.
Absence of albumin, known as analbuminaemia
Analbuminaemia
Analbuminaemia or analbuminemia is a genetically inherited metabolic defect characterised by an impaired synthesis of serum albumin. Despite the fact that albumin is the most common serum protein, analbuminaemia is a benign condition....
, is rare. A decreased level of albumin, however, is common in many diseases, including liver disease
Liver disease
Liver disease is a broad term describing any single number of diseases affecting the liver.-Diseases:* Hepatitis, inflammation of the liver, caused mainly by various viruses but also by some poisons , autoimmunity or hereditary conditions...
, malnutrition
Malnutrition
Malnutrition is the condition that results from taking an unbalanced diet in which certain nutrients are lacking, in excess , or in the wrong proportions....
, malabsorption, protein-losing nephropathy and enteropathy.
Albumin - Alpha-1 Interzone
Even staining in this zone is due to alpha-1 lipoprotein (High density lipoproteinHigh density lipoprotein
High-density lipoprotein is one of the five major groups of lipoproteins, which, in order of sizes, largest to smallest, are chylomicrons, VLDL, IDL, LDL, and HDL, which enable lipids like cholesterol and triglycerides to be transported within the water-based bloodstream...
- HDL). Decrease occurs in severe inflammation, acute hepatitis
Hepatitis
Hepatitis is a medical condition defined by the inflammation of the liver and characterized by the presence of inflammatory cells in the tissue of the organ. The name is from the Greek hepar , the root being hepat- , meaning liver, and suffix -itis, meaning "inflammation"...
, and cirrhosis
Cirrhosis
Cirrhosis is a consequence of chronic liver disease characterized by replacement of liver tissue by fibrosis, scar tissue and regenerative nodules , leading to loss of liver function...
. Also, 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....
can lead to decrease in albumin level; due to its loss in the urine through a damaged leaky 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...
.
An increase appears in severe alcoholics and in women during pregnancy and in puberty.
The high levels of AFP that may occur in hepatocellular carcinoma
Hepatocellular carcinoma
Hepatocellular carcinoma is the most common type of liver cancer. Most cases of HCC are secondary to either a viral hepatitide infection or cirrhosis .Compared to other cancers, HCC is quite a rare tumor in the United States...
may result in a sharp band between the albumin and the alpha-1 zone.
Alpha-1 Zone
OrosomucoidOrosomucoid
Orosomucoid or alpha-1-acid glycoprotein is an acute phase plasma alpha-globulin glycoprotein and is modulated by two polymorphic genes. It is synthesized primarily in hepatocytes and has a normal plasma concentration between 0.6-1.2 mg/mL...
and antitrypsin migrate together but orosmucoid stains poorly so alpha 1 antitrypsin (AAT) constitutes most of the alpha-1 band. Alpha-1 antitrypsin has an SG group and thiol compounds may be bound to the protein altering their mobility. A decreased band is seen in the deficiency state. It is decreased in the 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....
and absence could indicate possible alpha 1-antitrypsin deficiency. This eventually leads to emphysema
Emphysema
Emphysema is a long-term, progressive disease of the lungs that primarily causes shortness of breath. In people with emphysema, the tissues necessary to support the physical shape and function of the lungs are destroyed. It is included in a group of diseases called chronic obstructive pulmonary...
from unregulated lung elastase
Elastase
In molecular biology, elastase is an enzyme from the class of proteases that break down proteins.- Forms and classification:There exist eight human genes for elastase:Bacterial forms: Organisms such as P...
breakdown by neutrophils in the lung tissue. The alpha-1 fraction does not disappear in alpha 1-antitrypsin deficiency, however, because other proteins, including alpha-lipoprotein and alpha-1 acid glycoprotein, also migrate there. As a positive acute phase reactant, AAT is increased in acute inflammation.
Bence Jones protein
Bence Jones protein
A Bence Jones protein is a monoclonal globulin protein found in the blood or urine, with a molecular weight of 22-24 kDa.Finding this protein is often suggestive of multiple myeloma or Waldenstrom's macroglobulinemia....
may bind to and retard the alpha-1 band.
Alpha-1 - Alpha-2 Interzone
Two faint bands may be seen representing alpha-1 antichymotrypsin and vitamin DVitamin D
Vitamin D is a group of fat-soluble secosteroids. In humans, vitamin D is unique both because it functions as a prohormone and because the body can synthesize it when sun exposure is adequate ....
binding protein. These bands fuse and intensify in early inflammation due to an increase in alpha-1 antichymotrypsin, an acute phase protein
Acute phase protein
Acute-phase proteins are a class of proteins whose plasma concentrations increase or decrease in response to inflammation...
.
Alpha-2 Zone
This zone consists principally of alpha-2 macroglobulin (AMG) and haptoglobinHaptoglobin
Haptoglobin is a protein that in humans is encoded by the HP gene. In blood plasma, haptoglobin binds free hemoglobin released from erythrocytes with high affinity and thereby inhibits its oxidative activity. The haptoglobin-hemoglobin complex will then be removed by the reticuloendothelial system...
. There are typically low levels in haemolytic anaemia (haptoglobin is a suicide molecule which binds with free haemoglobin released from red blood cells and these complexes are rapidly removed by phagocytes). Haptoglobin is raised as part of the acute phase response, resulting in a typical elevation in the alpha-2 zone during inflammation. A normal alpha-2 and an elevated alpha-1 zone is a typical pattern in hepatic metastases and cirrhosis.
Haptoglobin/haemaglobin complexes migrate more cathodally than haptoglobin as seen in the alpha-2 - beta interzone. This is typically seen as a broadening of the alpha-2 zone.
Alpha-2 macroglobulin may be elevated in children and the elderly. This is seen as a sharp front to the alpha-2 band. AMG is markedly raised (10-fold increase or greater) in association with glomerular protein loss, as 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....
. Due to its large size, AMG cannot pass through glomeruli, while other lower-molecular weight proteins are lost. Enhanced synthesis of AMG accounts for its absolute increase in nephrotic syndrome.
AMG is mildly elevated early in the course of diabetic nephropathy
Diabetic nephropathy
Diabetic nephropathy , also known as Kimmelstiel-Wilson syndrome, or nodular diabetic glomerulosclerosis and intercapillary glomerulonephritis, is a progressive kidney disease caused by angiopathy of capillaries in the kidney glomeruli. It is characterized by nephrotic syndrome and diffuse...
.
Alpha-2 - Beta Interzone
Cold insoluble globulin forms a band here which is not seen in plasmaBlood plasma
Blood plasma is the straw-colored liquid component of blood in which the blood cells in whole blood are normally suspended. It makes up about 55% of the total blood volume. It is the intravascular fluid part of extracellular fluid...
because it is precipitated by heparin
Heparin
Heparin , also known as unfractionated heparin, a highly sulfated glycosaminoglycan, is widely used as an injectable anticoagulant, and has the highest negative charge density of any known biological molecule...
. There are low levels in inflammation and high levels in pregnancy.
B lipoprotein forms an irregular crenated band in this zone. High levels are seen in type II hypercholesterolaemia, hypertriglyceridemia
Hypertriglyceridemia
In medicine, hypertriglyceridemia denotes high blood levels of triglycerides, the most abundant fatty molecule in most organisms. It has been associated with atherosclerosis, even in the absence of hypercholesterolemia . It can also lead to pancreatitis in excessive concentrations In medicine,...
, and in the nephrotic syndrome.
Beta Zone
TransferrinTransferrin
Transferrins are iron-binding blood plasma glycoproteins that control the level of free iron in biological fluids. In humans, it is encoded by the TF gene.Transferrin is a glycoprotein that binds iron very tightly but reversibly...
and beta lipoprotein (LDL) comprises the beta-1. Increased beta-1 protein due to the increased level of free transferrin is typical of iron deficiency anemia
Iron deficiency anemia
Iron-deficiency anemia is a common anemia that occurs when iron loss occurs, and/or the dietary intake or absorption of iron is insufficient...
, pregnancy
Pregnancy
Pregnancy refers to the fertilization and development of one or more offspring, known as a fetus or embryo, in a woman's uterus. In a pregnancy, there can be multiple gestations, as in the case of twins or triplets...
, and oestrogen
Estrogen
Estrogens , oestrogens , or œstrogens, are a group of compounds named for their importance in the estrous cycle of humans and other animals. They are the primary female sex hormones. Natural estrogens are steroid hormones, while some synthetic ones are non-steroidal...
therapy. Increased beta-1 protein due to LDL elevation occurs in hypercholesterolemia
Hypercholesterolemia
Hypercholesterolemia is the presence of high levels of cholesterol in the blood. It is not a disease but a metabolic derangement that can be caused by many diseases, notably cardiovascular disease...
.
Beta-2 comprises C3 (Complement protein 3). It is raised in the acute phase response. Depression of C3 occurs in autoimmune disorders as the complement system is activated and the C3 becomes bound to immune complexes and removed from plasma. Fibrinogen, a beta 2 protein, is found in normal plasma but also absent from normal serum. Occasionally, blood drawn from heparinized patients does not fully clot, resulting in a visible fibrinogen band between the beta and gamma globulins.
Gamma Zone
The immunoglobulins (IgA, IgM, IgG, IgE and IgD) are the only proteins present in the normal gamma region, but note that immunoglobulins may be found in th alpha and beta zones. If the gamma zone shows an increase (or spike), the first step in interpreting the graph is to establish if the region is narrow or wide. If it is elevated it could be elevated in a single narrow "spike-like" manner indicating monoclonal gammopathy or a broad "swell-like" manner (wide) indicating polyclonal gammopathy.- Monoclonal Gammopathy - A narrow spike indicates a monoclonal gammopathy, also known as an "M-spike". Typically, a monoclonal gammopathy is malignant or clonal in origin, Myeloma being the most common cause of IgAIGAIga or IGA may stand for:-Given name:* a female given name of Polish origin. The name originates from the female given name Jadwiga and stands for gia,or gina in the USA....
and IgG spikes. chronic lymphatic leukaemia and lymphosarcoma are not uncommon and usually give rise to IgMIGMIGM as an acronym or abbreviation can refer to:* Immunoglobulin M , the primary antibody against A and B antigens on red blood cells* International Grandmaster, a chess ranking* intergalactic medium* Intragroup medium - see: Intracluster medium...
paraproteins. Note that up to 8% of healthy geriatric patients may have a monoclonal spike. Waldenstrom's macroglobulinaemia (IgM), monoclonal gammopathy of undetermined significanceMonoclonal gammopathy of undetermined significanceMonoclonal gammopathy of undetermined significance , formerly benign monoclonal gammopathy, is a condition in which a paraprotein is found in the blood during standard laboratory tests...
(MGUS), amyloidosis, plasma cell leukemia and solitary plasmacytomas also produce an M-spike. - Polyclonal Gammopathy - A "swell-like" elevation in the gamma zone indicates a polyclonal gammopathy, and this typically points to a non-malignant condition (although is not exclusive to non-malignant conditions). The most common causes of polyclonal hypergammaglobulinaemia detected by electrophoresis are severe infectionInfectionAn infection is the colonization of a host organism by parasite species. Infecting parasites seek to use the host's resources to reproduce, often resulting in disease...
, chronic liver disease, rheumatoid arthritis, systemic lupus erythematosusLupus 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...
and other connective tissue diseases. LysozymeLysozymeLysozyme, also known as muramidase or N-acetylmuramide glycanhydrolase, are glycoside hydrolases, enzymes that damage bacterial cell walls by catalyzing hydrolysis of 1,4-beta-linkages between N-acetylmuramic acid and N-acetyl-D-glucosamine residues in a peptidoglycan and between...
may be seen as a band cathodal to the slowest gamma in myelomonocytic leukaemia in which it is released from tumour cells. FibrinogenFibrinogenFibrinogen is a soluble plasma glycoprotein, synthesised by the liver, that is converted by thrombin into fibrin during blood coagulation. This is achieved through processes in the coagulation cascade that activate the zymogen prothrombin to the serine protease thrombin, which is responsible for...
from plasmaBlood plasmaBlood plasma is the straw-colored liquid component of blood in which the blood cells in whole blood are normally suspended. It makes up about 55% of the total blood volume. It is the intravascular fluid part of extracellular fluid...
samples will be seen in the fast gamma region. - Hypogammaglobulinaemia - This is easily identifiable as a "slump" or decrease in the gamma zone. It is normal in infants. It is found in patients with X-linked AgammaglobulinemiaX-linked agammaglobulinemiaX-linked agammaglobulinemia is a rare X-linked genetic disorder that was discovered in 1952 which affects the body's ability to fight infection. XLA is an X-linked disorder, and therefore is more common in males...
. IgA deficiency occurs in 1:500 of the population, as is suggested by a pallor in the gamma zone.
C-Reactive Protein
C-reactive protein
C-reactive protein is a protein found in the blood, the levels of which rise in response to inflammation...
:is found in between the beta and gamma zones producing beta/gamma fusion.
IgA
IGA
Iga or IGA may stand for:-Given name:* a female given name of Polish origin. The name originates from the female given name Jadwiga and stands for gia,or gina in the USA....
: This immunoglobulin has the most anodal mobility and migrates in the region between the beta and gamma zones also causing a beta/gamma fusion in patients with cirrhosis, respiratory infection, skin disease, or rheumatiod arthritis (increased IgA).