Protein electrophoresis pdf

Moving toward the negative portion of the gel i. The alpha 1 -protein fraction is comprised of alpha 1 -antitrypsin, thyroid-binding globulin, and transcortin. Malignancy and acute inflammation resulting from acute-phase reactants can increase the alpha 1 -protein band. A decreased alpha 1 -protein band may occur because of alpha 1 -antitrypsin deficiency or decreased production of the globulin as a result of liver disease. Ceruloplasmin, alpha 2 -macroglobulin, and haptoglobin contribute to the alpha 2 -protein band.

The alpha 2 component is increased as an acute-phase reactant. The beta fraction has two peaks labeled beta 1 and beta 2. Beta 1 is composed mostly of transferrin, and beta 2 contains beta-lipoprotein. IgA, IgM, and sometimes IgG, along with complement proteins, also can be identified in the beta fraction.

Much of the clinical interest is focused on the gamma region of the serum protein spectrum because immunoglobulins migrate to this region. It should be noted that immunoglobulins often can be found throughout the electrophoretic spectrum. C-reactive protein CRP is located in the area between the beta and gamma components.

Serum protein electrophoresis commonly is performed when multiple myeloma is suspected. Unexplained peripheral neuropathy not attributed to longstanding diabetes mellitus, toxin exposure, chemotherapy, etc.

Hypercalcemia attributed to possible malignancy e. Information from references 2 through 4. Often, there are associated decreases in the albumin and transferrin levels. Information from reference 6. In the interpretation of serum protein electrophoresis, most attention focuses on the gamma region, which is composed predominantly of antibodies of the IgG type.

The gamma-globulin zone is decreased in hypogammaglobulinemia and agammaglobulinemia. Although many conditions can cause an increase in the gamma region, several disease states cause a homogeneous spike-like peak in a focal region of the gamma-globulin zone Figure 2. Abnormal serum protein electrophoresis pattern in a patient with multiple myeloma. Note the large spike in the gamma region. It is extremely important to differentiate monoclonal from polyclonal gammopathies.

Monoclonal gammopathies are associated with a clonal process that is malignant or potentially malignant. In contrast, polyclonal gammopathies may be caused by any reactive or inflammatory process, and they usually are associated with nonmalignant conditions.

The most common conditions in the differential diagnosis of polyclonal gammopathy are listed in Table 3. Viral infections, especially hepatitis, human immunodeficiency virus infection, mononucleosis, and varicella Focal or systemic bacterial infections, including endocarditis, osteomyelitis, and bacteremia Tuberculosis Connective tissue diseases Systemic lupus erythematosus Mixed connective tissue Temporal arteritis Rheumatoid arthritis Sarcoid Liver diseases Cirrhosis Ethanol abuse Autoimmune hepatitis Viral-induced hepatitis Primary biliary cirrhosis Primary sclerosing cholangitis.

Information from references 8 and 9. An M protein is characterized by the presence of a sharp, well-defined band with a single heavy chain and a similar band with a kappa or lambda light chain. A polyclonal gammopathy is characterized by a broad diffuse band with one or more heavy chains and kappa and lambda light chains.

Once a monoclonal gammopathy is identified by serum protein electrophoresis, multiple myeloma must be differentiated from other causes of this type of gammopathy. The quantity of M protein can help differentiate multiple myeloma from monoclonal gammopathy of undetermined significance. Definitive diagnosis of multiple myeloma requires 10 to 15 percent plasma cell involvement as determined by bone marrow biopsy.

Characteristic differentiating features of the monoclonal gammopathies are listed in Table 4. M protein appears as a narrow spike in the gamma, beta, or alpha 2 regions. M-protein level is usually greater than 3 g per dL. Skeletal lesions e. Diagnosis requires 10 to 15 percent plasma cell involvement on bone marrow biopsy.

Anemia, pancytopenia, hypercalcemia, and renal disease may be present. There is less than 10 percent plasma cell involvement on bone marrow biopsy. Affected patients have no M protein in their urine, no lytic bone lesions, no anemia, no hypercalcemia, and no renal disease. There is greater than 10 percent plasma cell involvement on bone marrow biopsy.

Affected patients have no lytic bone lesions, no anemia, no hypercalcemia, and no renal disease. M-protein levels are low.

Affected patients have few bone lesions and few hematologic disturbances. This monoclonal gammopathy occurs in younger patients. Affected patients have only one tumor, with no other bone lesions and no urine or serum abnormalities. Affected patients have hyperviscosity and hypercellular bone marrow with extensive infiltration by lymphoplasma cells. Multiple myeloma: recognition and management. Am Fam Physician ; In some patients with a plasma cell dyscrasia, serum protein electrophoresis may be normal because the complete monoclonal immunoglobulin is absent or is present at a very low level.

The remainder had hypogammaglobulinemia or a normal-appearing pattern. Consequently, urine protein electrophoresis is recommended in all patients suspected of having a plasma cell dyscrasia. An additional point to consider is the size of the M-protein spike. Although this spike is usually greater than 3 g per dL in patients with multiple myeloma, up to one fifth of patients with this tumor may have an M-protein spike of less than 1 g per dL.

If multiple myeloma still is considered clinically in a patient who does not have an M-protein spike on serum protein electrophoresis, urine protein electrophoresis should be performed. Monoclonal gammopathy is present in up to 8 percent of healthy geriatric patients. Patients with monoclonal gammopathy of undetermined significance require close follow-up because about 1 percent per year develop multiple myeloma or another malignant monoclonal gammopathy.

Suggested algorithm for follow-up of a monoclonal gammopathy. If the serum M-protein spike is 1. If these examinations are normal, serum protein electrophoresis should be repeated in three to six months; if that examination is normal, serum protein electrophoresis should be repeated annually. The alpha-2 peak consists of alpha-2 macroglobulin, haptoglobin, and cerulo- plasmin. Because of the variable migration of the haptoglobin types, a2-macroglobu- lin is often adjacent to, or co migrating with, haptoglobin and is therefore not seen as a discrete band.

A distorted pattern of alpha-2 region in electrophoresis is seen commonly in conditions of hemolysis, including in vivo and in vitro. The pathophysiology behind this pattern is the formation of hemoglobin-haptoglobin complexes in these condi- tions. This is a physiological adaptive response by human physiology to conserve hemoglobin released as a result of RBC breakdown into circulation and hemoglobin being a smaller globular protein is bound to be lost in urine.

Hence to preserve it, haptoglobin is consumed to form complex with hemoglobin which results in the formation of a macromolecular protein which is retained in circulation making hemoglobin available for the production of RBCs and prevention of anemia. Haptoglobin and ceruloplasmin are acute-phase reactants, and hence increased in acute inflammatory states. Alphamacroglobulin is increased in nephrotic syndrome and cirrhosis of the liver. Ceruloplasmin is an important copper-binding transport protein produced by the liver.

The disadvantage of serum protein electrophoresis is that it will not aid in the detection of a decreased ceruloplasmin. Beta-1 zone comprises proteins like transferrin and low-density lipoprotein LDL. Transferrin functions to transport non-heme ferric iron from the gastroin- testinal tract. Each Transferrin molecule can bind two molecules of free iron. An increased beta-1 band is observed in iron deficiency anemia due to an increased level of free transferrin and also in pregnancy.

Determinations of the transferrin levels are useful in distinguishing between iron deficiency anemia inadequate intake or chronic hemorrhage with loss of iron stores and hemolytic anemia, in which transferrin levels are low resulting in a beta-1 peak of low amplitude. Transferrin is usually decreased in alcoholic cirrhosis. Transferrin is also decreased during renal disease and thermal injuries. The beta-2 band is mostly composed of complement proteins, C3 and C4.

Elevated beta-2 zone can be caused in inflammatory states due to activation of complement cascade which include C3 and C4 too. A reduced beta-2 peak intensity can be encountered in an aged sample, since the immune complexes are used up and low serum levels of complements are evidenced.

Fibrinogen is a protein with molecular weight of kDa protein. Sometimes a small fibrinogen band can be seen in serum protein electrophoresis due to the insuffi- cient clotting or failure to remove the serum from the clot. This fibrinogen band is seen between beta-1 and beta-2 regions. This band is also seen in patients who are receiving heparin therapy.

It is also an important indicator of the sample type being analyzed. When plasma is used in the place of serum for protein electrophoresis, fibrinogen present in plasma appears in the beta-2 region, and this has the potentiality to interfere with the detection of monoclonal gammopathies in such patients Figure 4. Gamma region comprises mainly of serum immunoglobulins.

The immunoglobulins are characterized by the presence of two protein moieties named as heavy chain and light chain. The classifica- tion of immunoglobulin had been made based on the composition of heavy chains, while the light chains are of two types including kappa or lambda. Physiologically, kappa forms the major light chain fraction among the two. Various clinical conditions are associated with alteration of gamma globulins including: a.

Hypergammaglobinemia increased serum gamma globulin levels b. Fibrinogen producing a peak in beta 2 region from a plasma sample. Hypergammaglobinemia gammopathies : Gammopathy is defined as abnormal proliferation of the lymphoid cells produc- ing immunoglobulins. There are four types of gammopathies: polyclonal, monoclo- nal, biclonal, and oligoclonal. Polyclonal gammopathies are defined as heterogeneous increase in immu- noglobulins involving more than one cell line, commonly caused by a variety of inflammatory conditions chronic inflammation , infections, chronic liver diseases cirrhosis , chronic kidney diseases, etc.

Monoclonal gammopathies are characterized by a homogenous increase produced by clonal population of mature B cells, most commonly plasma cells. Monoclonal immunoglobulins seen in these conditions are also known as Para proteins. Biclonal gammopathies are characterized by a double peak in the gamma region. This electrophoretic pattern is seen when there is a biclonal proliferation of immu- noglobulins encountered in multiple myeloma. A biclonal pattern is also seen in monoclonal gammopathies associated with IgA and IgG.

In such scenarios, these immunoglobulins appear as polymerized and monomerized forms which elute as biclonal peaks in gamma region or in beta region, respectively Figure 5. The oligoclonal pattern of gamma region is characterized by more than two peaks evident in the gamma region. This pattern is commonly seen in autoimmune disorders, light chain myelomas characterized by clonal proliferation of light chains , amyloidosis, etc. Figure 5. Apart from serum immunoglobulin, C-reactive protein CRP also is evident in the gamma region.

C-reactive proteins levels usually increase during inflammatory responses. Abnormal electrophoretic patterns of gamma zone.

Role of SPE in multiple myeloma work-up According to the International Myeloma Foundation, plasma cell dyscrasias are group of plasma cell disorders involving a wide spectrum of pathologies including: 1. MGUS—monoclonal gammopathy of undetermined significance 2. MGRS—monoclonal gammopathy of renal significance 3.

Syed R. Haider, Helen J. Reid, Barry L. Marta P. Pereira Morais, John S. Fossey, Tony D. James, Jean M. Kim Y. Page 1 Navigate to page number of 3. About this book Introduction Proteins are the functional units of the cellular machinery and they provide significant information regarding the molecular basis of health and disease.

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