immunoelectrophoresis


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Immunoelectrophoresis

 

Definition

Immunoelectrophoresis, also called gamma globulin electrophoresis, or immunoglobulin electrophoresis, is a method of determining the blood levels of three major immunoglobulins: immunoglobulin M (IgM), immunoglobulin G (IgG), and immunoglobulin A (IgA).

Purpose

Immunoelectrophoresis is a powerful analytical technique with high resolving power as it combines separation of antigens by electrophoresis with immunodiffusion against an antiserum. The increased resolution is of benefit in the immunological examination of serum proteins. Immunoelectrophoresis aids in the diagnosis and evaluation of the therapeutic response in many disease states affecting the immune system. It is usually requested when a different type of electrophoresis, called a serum protein electrophoresis, has indicated a rise at the immunoglobulin level. Immunoelectrophoresis is also used frequently to diagnose multiple myeloma, a disease affecting the bone marrow.

Precautions

Drugs that may cause increased immunoglobulin levels include therapeutic gamma globulin, hydralazine, isoniazid, phenytoin (Dilantin), procainamide, oral contraceptives, methadone, steroids, and tetanus toxoid and antitoxin. The laboratory should be notified if the patient has received any vaccinations or immunizations in the six months before the test. This is mainly because prior immunizations lead to the increased immunoglobulin levels resulting in false positive results.
It should be noted that, because immunoelectrophoresis is not quantitative, it is being replaced by a procedure called immunofixation, which is more sensitive and easier to interpret.

Description

Serum proteins separate in agar gels under the influence of an electric field into albumin, alpha 1, alpha 2, and beta and gamma globulins. Immunoelectrophoresis is performed by placing serum on a slide containing a gel designed specifically for the test. An electric current is then passed through the gel, and immunoglobulins, which contain an electric charge, migrate through the gel according to the difference in their individual electric charges. Antiserum is placed alongside the slide to identify the specific type of immunoglobulin present. The results are used to identify different disease entities, and to aid in monitoring the course of the disease and the therapeutic response of the patient to such conditions as immune deficiencies, autoimmune disease, chronic infections, chronic viral infections, and intrauterine fetal infections.
There are five classes of antibodies: IgM, IgG, IgA, IgE, and IgD.
IgM is produced upon initial exposure to an antigen. For example, when a person receives the first tetanus vaccination, antitetanus antibodies of the IgM class are produced 10 to 14 days later. IgM is abundant in the blood but is not normally present in organs or tissues. IgM is primarily responsible for ABO blood grouping and rheumatoid factor, yet is involved in the immunologic reaction to other infections, such as hepatitis. Since IgM does not cross the placenta, an elevation of this immunoglobulin in the newborn indicates intrauterine infection such as rubella, cytomegalovirus (CMV) or a sexually transmitted disease (STD).
IgG is the most prevalent type of antibody, comprising approximately 75% of the serum immunoglobulins. IgG is produced upon subsequent exposure to an antigen. As an example, after receiving a second tetanus shot, or booster, a person produces IgG antibodies in five to seven days. IgG is present in both the blood and tissues, and is the only antibody to cross the placenta from the mother to the fetus. Maternal IgG protects the newborn for the first months of life, until the infant's immune system produces its own antibodies.
IgA constitutes approximately 15% of the immunoglobulins within the body. Although it is found to some degree in the blood, it is present primarily in the secretions of the respiratory and gastrointestinal tract, in saliva, colostrum (the yellowish fluid produced by the breasts during late pregnancy and the first few days after childbirth), and in tears. IgA plays an important role in defending the body against invasion of germs through the mucous membrane-lined organs.
IgE is the antibody that causes acute allergic reactions; it is measured to detect allergic conditions. IgD, which constitutes the smallest portion of the immunoglobulins, is rarely evaluated or detected, and its function is not well understood.

Preparation

This test requires a blood sample.

Aftercare

Because this test is ordered when either very low or very high levels of immunoglobulins are suspected, the patient should be alert for any signs of infection after the test, including fever, chills, rash, or skin ulcers. Any bone pain or tenderness should also be immediately reported to the physician.

Risks

Risks for this test are minimal, but may include slight bleeding from the blood-drawing site, fainting or feeling lightheaded after venipuncture, or bruising.

Normal results

Reference ranges vary from laboratory to laboratory and depend upon the method used. For adults, normal values are usually found within the following ranges (1 mg = approximately 0.000035 oz. and 1 dL = approximately 0.33 oz.):
  • IgM: 60-290 mg/dL
  • IgG: 700-1,800 mg/dL
  • IgA: 70-440 mg/dL

Abnormal results

Increased IgM levels can indicate Waldenstroöm's macroglobulinemia, a malignancy caused by secretion of IgM at high levels by malignant lymphoplasma cells. Increased IgM levels can also indicate chronic infections, such as hepatitis or mononucleosis and autoimmune diseases, like rheumatoid arthritis.
Decreased IgM levels can be indicative of AIDS, immunosuppression caused by certain drugs like steroids or dextran, or leukemia.
Increased levels of IgG can indicate chronic liver disease, autoimmune diseases, hyperimmunization reactions, or certain chronic infections, such as tuberculosis or sarcoidosis.
Decreased levels of IgG can indicate Wiskott-Aldrich syndrome, a genetic deficiency caused by inadequate synthesis of IgG and other immunoglobulins. Decreased IgG can also be seen with AIDS and leukemia.
Increased levels of IgA can indicate chronic liver disease, chronic infections, or inflammatory bowel disease.
Decreased levels of IgA can be found in ataxia, a condition affecting balance and gait, limb or eye movements, speech, and telangiectasia, an increase in the size and number of the small blood vessels in an area of skin, causing redness. Decreased IgA levels are also seen in conditions of low blood protein (hypoproteinemia), and drug immunosuppression.

Resources

Books

Fischbach, Frances T. A Manual of Laboratory Diagnostic Tests. Philadelphia: Lippincott Williams & Wilkins, 1999.
Pagana, Kathleen D., and Timothy J. Pagana. Mosby's Manual of Diagnostic and Laboratory Tests. St. Louis, MO: Mosby, Inc., 1999.

Key terms

Antibody — A protein manufactured by the white blood cells to neutralize an antigen in the body. In some cases, excessive formation of antibodies leads to illness, allergy, or autoimmune disorders.
Antigen — A substance that can cause an immune response, resulting in production of an antibody, as part of the body's defense against infection and disease. Many antigens are foreign proteins not found naturally in the body, and include germs, toxins, and tissues from another person used in organ transplantation.
Autoimmune disorder — A condition in which antibodies are formed against the body's own tissues; for example, in some forms of arthritis.

immunoelectrophoresis

 [im″u-no-e-lek″tro-fo-re´sis]
a method of distinguishing proteins and other materials on the basis of their electrophoretic mobility and antigenic specificities.
rocket immunoelectrophoresis electrophoresis in which antigen migrates from a well through agar gel containing antiserum, forming cone-shaped (rocket) precipitin bands.

im·mu·no·e·lec·tro·pho·re·sis

(im'yū-nō-ē-lek'trō-fō-rē'sis),
A kind of precipitin test in which the components of one group of immunologic reactants (usually a mixture of antigens) are first separated on the basis of electrophoretic mobility in agar or other medium, the separated components then being identified, by means of the technique of double diffusion, on the basis of precipitates formed by reaction with components of the other group of reactants (antibodies).

immunoelectrophoresis

/im·mu·no·elec·tro·pho·re·sis/ (-e-lek″tro-fah-re´sis) a method of distinguishing proteins and other materials on the basis of their electrophoretic mobility and antigenic specificities.
rocket immunoelectrophoresis  electrophoresis in which antigen migrates from a well through agar gel containing antiserum, forming cone-shaped (rocket) precipitin bands.

immunoelectrophoresis

(ĭm′yə-nō-ĭ-lĕk′trə-fə-rē′sĭs, ĭ-myo͞o′-)
n.
The separation and identification of proteins based on differences in electrical charge and reactivity with antibodies.

immunoelectrophoresis

[-ilek′trōfôrē′sis]
Etymology: L, immunis + Gk, elektron, amber, pherein, to bear
a technique that combines electrophoresis and immunodiffusion to separate and allow identification of complex proteins. The proteins in the test serum are spread out in agar and separated by electrophoresis. Wells or troughs are then cut into the agar, and parts of antibody are placed in the troughs and allowed to diffuse toward the separated proteins. A visible precipitin will form in a series of arcs in the agar when an antigen-antibody reaction occurs. The shape and location of each arc are specific for known proteins. Unusual arcs are representative of abnormal or unknown protein. Although the density of the precipitation corresponds to the concentration of protein in each electrophoretic band, immunoelectrophoresis does not accurately quantify the amount of protein in the test serum. immunoelectrophoretic, adj.

im·mu·no·e·lec·tro·pho·re·sis

(im'yū-nō-ĕ-lek'trō-fŏr-ē'sis)
A kind of precipitin test in which the components of one group of immunologic reactants are first separated on the basis of electrophoretic mobility; the separated components then being identified on the basis of precipitates formed by reaction with components of the other group of reactants.

immunoelectrophoresis

the use of ANTIBODY-ANTIGEN reactions to identify PROTEINS that have been separated by ELECTROPHORESIS.

im·mu·no·e·lec·tro·pho·re·sis

(im'yū-nō-ĕ-lek'trō-fŏr-ē'sis)
Precipitin test in which the components of one group of immunologic reactants are first separated on the basis of electrophoretic mobility.

immunoelectrophoresis (im´ūnō-ilek´trəfərē´sis),

n a technique that combines eletrophoresis and immunodiffusion to separate and allow identification of complex proteins.

immunoelectrophoresis

separation, usually in an agar gel, of complex mixtures of antigens which then combine, following immunodiffusion, with antibody to form precipitation lines for each separated antigen.

counter immunoelectrophoresis
antigen and antibody are placed in separate wells, close together and electric current is applied first in one direction then in the other. When they migrate and meet, a line of precipitin is formed.
rocket immunoelectrophoresis
electrophoresis in which antigen migrates from a well through agar gel containing antiserum, forming cone-shaped (rocket) precipitin bands; the area under the cone is used to calculate the amount of antigen.
References in periodicals archive ?
6) C3 conversion was assayed by immunoelectrophoresis.
Fibrinogen can be quantitated by various methods including precipitation or denaturation methods, turbidimetric or fibrin clot density method, coagulable protein assays, as well as immunologic assays, which utilize antibodies to fibrinogen in assays, such as radial immunodiffusion, measurement of turbidity or rocket immunoelectrophoresis and the modified thrombin clotting time, which is the most widely performed clinical fibrinogen assay.
The diagnosis is confirmed by serum and/or protein immunoelectrophoresis, which reveals an increased amount of immunoglobulin [Gamma] heavy chain not associated with light chain.
In brief, K-typing was conducted by counter current immunoelectrophoresis (CCIE) with a modified version of the method described by Palfreyman (17).
In 1957, he adopted the agar gel immunoelectrophoresis (IEP) procedure of Grabar and Williams (42) into a CA-membrane format.
Immunoelectrophoresis of red blood cell membrane proteins from patients with AD demonstrates a different pattern of proteins cross-reacting with antibodies against band 3 in comparison to age-matched controls.
This observation is in line with the report of a proportion of false-negative results in a [beta]-trace assay using Lauren rocket immunoelectrophoresis (34).
Normal laboratory studies included erythrocyte sedimentation rate, serum creatinine phosphokinase, serum immunoelectrophoresis, antinuclear antibody, vitamin [B.
The analytical anomalies (total proteins, [gamma]-globulins, serum immunoelectrophoresis, fibrinogen, and ESR) disappeared 6 months after surgery.
Serum electrophoresis revealed polyclonal gammopathy, and urine immunoelectrophoresis was normal.
Four years ago, we used the five-band approach and sent out our immunoelectrophoresis testing.
2]-microglobulin molecule presumably could lead to design specifications for devices to remove it: Does its different mobility on crossed immunoelectrophoresis imply a need to use charged-membrane hemodialysis, which improves removal of glycated [[beta].

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