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| Serum
Protein Electrophoresis (SPE) |
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Indications for SPE:
- The most common reason for doing the SPE is to
check for the presence of a monoclonal gammopathy (suspect multiple myeloma...bone lesions...back pain, Waldenstrom's, amyloidiosis).
- It may also helpful
in liver disease detection & evaluation: in cases of hyperproteinemia with hypoalbuminemia, for example.
- work-up of peripheral neuropathy of undetermined etiology.
- anemia of uncertain etiology in a renal insufficiency and/or bone-pain patient.
- hypercalcemia of uncertain etiology.
- rouleaux formation noted on CBC peripheral smear.
- renal insufficiency with elevated serum protein.
- unexplained pathologic fracture or lytic bone lesion on X-ray.
- Bence Jones proteinuria.
Interpretation is enhanced by having
knowledge of the serum total protein and albumin levels...then
an A/G ratio can be checked (normal being 1.0 or slightly
higher).
A sample of serum (with known albumin determination
value) is placed on the moist electrophoretic membrane to
which an electric charge is applied. The charge causes various
proteins to reliably migrate certain distances in certain amounts
of time. The membrane is then stained and submitted for a densitometer
tracing of the variable degrees of protein staining along the protein
migration line. The clinical pathologist then has:
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the analytic value for serum albumin,
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the visible membrane pattern, and
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the densitometer tracing quantitation in order
to make a screening-level diagnosis.
Should there be any suggestion of monoclonal gammopathy
among the above three lines of evidence, then immunofixation
electrophoresis (IFE...IFX) can be carried out on the same sample.
We do this at no additional charge so that an abnormal protein
workup can be expeditiously finalized.
Suspicion of monoclonal gammopathy...presence of "M-protein"...is
most commonly noted on the membrane in the "gamma" region.
But, "M-protein" can be present in the beta or beta-gamma
zone, too (it may be problematic to discern in those locations). And,
one occasionally notes pseudo-M-proteins. [serological
methods]
Hypogammaglobulinemia will indicate primary (see
Michigan Immunodeficiency Foundation list of
primary disorders) or secondary immunodeficiency disorders. |
ALBUMIN ZONE:
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CONSTITUENTS:
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ELEVATIONS: DEHYDRATION
OR THERAPEUTIC OVERDOSE of
albumin
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DECREASES:
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DECREASED SYNTHESIS:
- LIVER DISEASES (implies
reduced hepatocyte capacity)
- STARVATION OR MALNUTRITION
- CONGENITAL ANALBUMINEMIA
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LOSS:
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RENAL: NEPHROTIC SYNDROME
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GUT: PROTEIN-LOSING GASTROENTEROPATHY
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SKIN: SEVERE ECZEMA/MARKED
VESICULAR OR BULLOUS; BURN WOUNDS
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INCREASED CATABOLISM:
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ACUTE PHASE REACTIONS
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PREGNANCY
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ILLNESS & RECOVERY
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THYROTOXICOSIS
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WISKOTT-ALDRICH SYNDROME
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FAMILIAL INCREASED CATABOLISM
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ALPHA-1 ZONE:
-
CONSTITUENTS:
-
ELEVATIONS:
- DECREASES:
ALPHA-2 ZONE:
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CONSTITUENTS:
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ELEVATIONS:
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DECREASES:
BETA ZONE:
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CONSTITUENTS:
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ELEVATIONS:
-
PSEUDO-M: HYPERTRANSFERRINEMIA
(OF CHRONIC IDA, PREGNANCY, BIRTH CONTROL PILLS)
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TRUE M-PROTEIN: IgA
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DECREASES:
BETA-GAMMA ZONE:
-
PRESENCE/ELEVATIONS:
-
PSEUDO-M:
-
"Beta-gamma bridging " IS
HIGHLY ASSOCIATED WITH CHRONIC LIVER DISEASE and is...as visble on the membrane or tracing...the reduction of the valley (tracing) or clear zone (membrane) between the beta peak and the gamma peak. Since the liver disease might be occult as to other liver function tests, decisions must be made about the sensitivity level of "calling" a beta-gamma bridge.
- ABSENT: normal.
- "Stair-step" PATTERN: the alpha 1, alpha 2, and gamma zones on the tracing form peaks with blunting of the beta-gamma valley and the successive peaks visually remindful of upward stairsteps; think of sarcoidosis and/or chronic liver disease.
GAMMA ZONE:
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CONSTITUENTS:
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ELEVATIONS:
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PSEUDO-M:
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fibrinogen spike in someone
on heparin
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minimonoclonals within
a polyclonal zone ["MGUS"]
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broad increases might indicate
autoimmune disease
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DECREASES:
POST-GAMMA ZONE:
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PRESENCE/ELEVATIONS: HYPERLYSOZYMEMIA
ASSOCIATED WITH RENAL INSUFFICIENCY OR MONOCYTIC LEUKEMIA
References:
- American Family Physician SPE file.
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| (posted about 2001; latest addition 17 July 2006) |
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© Copyright
1999 - 2006, all rights reserved, Pathology Associates Of Lexington,
P.A. |
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