Tests
& Imaging > Labs
> Immunoglobulins
Last Update: 02/29/2008
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Immunoglobulins - a large family of proteins, also known as
antibodies, that protect the body from foreign pathogens.
"Antibody
proteins are often called immunoglobulins ( Ig). All
immunoglobulin molecules have many common structural features…The
antibodies are made of protein "chains" linked together by
chemical bonds. There are "heavy" chains and
"light" chains. ... there are
five different classes of heavy chains termed G, M, A, E, and D.
Based on the differences in their heavy chains, immunoglobulin
molecules are divided into five major classes: IgG, IgM, IgA, IgE,
and IgD. ..." See Immunoglobulin
Explanation by Guy Sherwood
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IgA
Immunoglobulin A
Est. Normal Range:
80 - 350 mg/dl
Lab-specific
Varies by age
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Immunoglobulin
A (IgA) is a type of antibody that protects against infections of the
mucous membranes lining the mouth, airways, and digestive tract.
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SELECTIVE IgA DEFICIENCY - merck.praxis.MD
"Selective IgA deficiency is defined as less than 5 mg/dL of
serum IgA in the presence of normal concentrations of IgM and IgG.
Among the B-cell disorders it is the most commonly identified
deficiency. It occurs in one in every 500 to 1000 individuals in
Europe and the United States. It is less common in those of
African-American or Asian descent ... "
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IgD
immunoglobulin D
Est. Normal Range:
.3 - 3.0 mg/dl
Lab-specific
Varies by age
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IgD, immunoglobulin D is
mainly found on the surface of B-cells and may help regulate B-cell
function. The function of circulating IgD is unknown.
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IgE
immunoglobulin E
Normal Range:
.002 - .2 mg/dl
Lab-specific
Varies by age
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IgE, immunoglobulin E - the
protective role is not clear. IgE is frequently increased in parasitic infestations and atopic individuals. IgE myeloma is extremely rare and should be sought after abnormal protein electrophoresis (restriction) and/or abnormal kappa/lambda ratio unexplained by IgG, IgA, or IgM. IgE is elevated 4-30 times normal in various diseases, among which atopic disorders and parasitic disorders are most prominent. The principal limitation of this test is the wide overlapping range of IgE values between atopic and nonatopic disease states.
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IgG
immunoglobulin G
Est. Normal Range:
620 - 1400 mg/dl
Lab-specific
Varies by age
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IgG, immunoglobulin G - the major antibody found in the blood that can enter tissues. It coats germs, helping other cells to seek and destroy
them.
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IgG subclasses in healthy children and adults xs4all.nl
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IgG subclasses and humoral immunity - xs4all.nl
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IgM
immunoglobulin M
Est. Normal Range:
45 - 250 mg/dl
Lab-specific
Varies by age
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IgM, immunoglobulin M - an antibody that remains in the bloodstream where it can kill bacteria that enter the blood stream.
Elevated levels of IgM are associated with Waldenström’s
Macroglobulinemia
"IgM in normal serum is often found to bind to specific
antigens, even in the absence of prior immunization. For this reason
IgM has sometimes been called a "natural antibody". This
phenomenon is probably due to the high avidity of IgM that allow it to
bind detectably even to weakly cross-reacting antigens
that are naturally occurring in nature" 1
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Test info
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Immunoelectrophoresis
serum/urine
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Detects the
presence or absence of Immunoglobulins in the urine and assesses the
qualitative character (polyclonal vs. monoclonal) of the
immunoglobulins [1]
Normal Values: No, or small amount, of protein in the urine.
Abnormal: Immunoglobulin (antibodies) in the urine.
Possible indications: Kidney disorders,
multiple myeloma, Macroglobulinemia of Waldenstrom's, chronic lymphocytic
leukemia, a single clone of lymphocytes produces one type of immunoglobulin -- a monoclonal immunoglobulin. This is identifiable as monoclonal by
immunoelectrophoresis. You can have monoclonal immunoglobulins,
without it being a cancer, however.
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