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Clinical Pathology Laboratory - Available
Test
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Total Protein Electrophoresis
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| This procedure separates the proteins in serum and body
fluids (e.g. peritoneal fluid, urine) into the component immunoglobulins.
Electrophoresis is indicated for determination of the underlying nature
of a hyperglobulinemia or if multiple myeloma is suspected in a patient.
The types of immunoglobulin comprising a hyperglobulinemia can provide
useful diagnostic information. It is less useful for evaluation of
immunodeficiencies; individual immunoglobulin quantification provides
more information in these disorders. Currently at Cornell University,
we are using agarose gel electrophoresis for our protein electrophoresis.
This is a very sensitive technique and splits the proteins into multiple
fractions, which are species-dependent. For simplicity of reporting,
we do not report out results for individual fractions, but those for
combined fractions, e.g. albumin, a1, a2,
total a, b1,
b2, total b
and g. We provide interpretative comments
on our electrophoretograms as well. |
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Serum protein electrophoresis |
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Serum is the preferred sample for electrophoresis. Fibrinogen
(in heparinized samples) produces a monoclonal peak in the b-region,
which affects interpretation in plasma samples. We have established
our own reference intervals for dogs, cats, horses, and cattle. Therefore,
abnormal results in these species will be flagged. In addition, we
always provide the electrophoretogram scan itself, not just the written
report (click on the image below for examples).
Click on the image below, to obtain more information about the individual
components of the electrophoretogram. Note that the ag in front of
each test result indicates that agarose gel electrophoresis was performed
on the sample. |
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Body fluid protein electrophoresis |
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| Electrophoresis can be performed on body
fluids, such as peritoneal fluid. This is usually done in cats with
abdominal effusions to support the diagnosis of feline infectious
peritonitis virus infection. In this disorder, an exudative effusion
can develop in the abdomen. The electrophoretic characteristics of
the fluid is similar to the serum results as the effusion is due to
a vasculitis. Therefore, serum and fluid should be submitted concurrently
for electrophoresis. Both usually show an increase in a-globulins
(acute phase response) and a polyclonal gammopathy (broad-based increase
in g-globulins). An increase in g-globulins in the fluid is quite
specific for FIPV infection. Electrophoresis can also be done on CSF
samples, however this is not done routinely because large volumes
of CSF are required. The protein in CSF is usually too low to run
on ELP without concentration. We need a minimum of 600 mg/dL of protein
to perform electrophoresis. Concentrating CSF requires at least 5
to 10 ml of fluid, which cannot be obtained from many animals. |
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Urine protein electrophoresis |
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| Electrophoresis can be performed on urine, but similar
to CSF, this requires concentrating because protein values are usually
quite low in urine (we need a minimum of 600 mg/dL of protein to perform
electrophoresis). Luckily, we can obtain sufficient urine (10 ml minimum)
from most animals to perform electrophoresis. Electrophoresis on urine
is the preferred technique for identification of Bence Jones proteins
in patients with suspected multiple myeloma. It should always be done
in conjunction with serum, so the results can be compared directly.
Other people have performed urine electrophoresis to distinguish between
hemoglobinuria and myoglobinuria (however the distinction is subjective
and fraught with complications) and to gain insight on mechanisms
of proteinuria. |
Serum and urine electrophoretograms from a cat with
multiple myeloma. A monoclonal peak
is seen in the g-region in serum. A similar monoclonal peak with little
albumin is seen in urine.
This confirms Bence Jones proteinuria. The monoclonal protein was
IgG. |
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