Pathology Associates Of Lexington, P.A.

Serum Protein Electrophoresis (SPE)

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 (especially if there is beta-gamma bridging) 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:

the analytic value for serum albumin,
the visible membrane pattern, and
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:

CONSTITUENTS:
TWO BANDS = bisalbuminemia, an insignifcant hereditary situation.
ELEVATIONS: DEHYDRATION OR THERAPEUTIC OVERDOSE of albumin
DECREASES:
- DECREASED SYNTHESIS:
  - LIVER DISEASES (implies reduced hepatocyte capacity)
  - STARVATION OR MALNUTRITION
  - CONGENITAL ANALBUMINEMIA
- LOSS:
  - RENAL: NEPHROTIC SYNDROME
  - GUT: PROTEIN-LOSING GASTROENTEROPATHY
  - SKIN: SEVERE ECZEMA/MARKED VESICULAR OR BULLOUS; BURN WOUNDS
- INCREASED CATABOLISM:
  - PSEUDO-M: BISALBUMINEMIA
  - ACUTE PHASE REACTIONS
  - PREGNANCY
  - ILLNESS & RECOVERY
  - THYROTOXICOSIS
  - WISKOTT-ALDRICH SYNDROME
  - FAMILIAL INCREASED CATABOLISM

ALPHA-1 ZONE:

CONSTITUENTS:
ELEVATIONS:
- PSEUDO-M: HYPER-ALPHA-2
DECREASES:

ALPHA-2 ZONE:

CONSTITUENTS:
ELEVATIONS:
- PSEUDO-M:
DECREASES:

BETA ZONE:

CONSTITUENTS:
ELEVATIONS:
- PSEUDO-M: HYPERTRANSFERRINEMIA (OF CHRONIC IDA, PREGNANCY, BIRTH CONTROL PILLS)
- TRUE M-PROTEIN: IgA
- increases in IgA or IgM².
DECREASES:

BETA-GAMMA ZONE:

PRESENCE/ELEVATIONS:
- PSEUDO-M:
- "Beta-gamma bridging" IS MOST IMPORTANTLY ASSOCIATED WITH CHRONIC LIVER DISEASE and is a technical, visual phenomenon...as visble on the membrane or tracing...denoting the reduction of the depth of the valley (tracing) or distinctness of the 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. The zone "blurrs" or "bridges" due to an increase in the polyclonal, anodally migrating portion of the total polyclonal IgG plus increased IgA & IgM which migrate between beta & gamma; it is sometimes alternatively called "beta-gamma fusion" or "beta gamma linking"². This polyclonal increase may be also be due to a variety of other clinical situations: chronic infections, autoimmune or collagen disorders, metastatic carcinoma, cystic fibrosis and some stages of thermal burns. We had a case in Oct. 2009 with bridging but negativity for hypoalbuminemia that was Hashimoto's thyroiditis. So, maybe bridging is related to oprgan-based diseases with lots of plasma cells. In truth, it is a nonspecific finding that must be looked at in conjunction with the clinical situation and possibly followed by specific Ig testing and disease specific profiles.
- 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, though some say this pattern has no definite diagnostic significance².

GAMMA ZONE:

CONSTITUENTS:
ELEVATIONS:
- PSEUDO-M:
- fibrinogen spike in someone on heparin
- minimonoclonal: small M-spike within a polyclonal zone ["MGUS"]
- Oligoclonal gammopathy: there can be a significant increase in a narrow, tightly peaked, spike-like polyclonal zone (a compact gamma-globulin band) as revealed by increases of both kappa & lambda & referred to as an oligoclonal gammopathy (seen more commonly in lupoid & auto-immune hepatitis & diseases with high levels of circulating immune complexes such as rheumatoid arthritis with high RF levels)².
- broad increases might indicate autoimmune disease
DECREASES:

POST-GAMMA ZONE:

PRESENCE/ELEVATIONS: HYPERLYSOZYMEMIA ASSOCIATED WITH RENAL INSUFFICIENCY OR MONOCYTIC LEUKEMIA

References:

American Family Physician SPE file.
Ritzmann SE & Daniels JC, Serum Protein Abnormalities, Diagnostic and Clinical Aspects, about 1982, Alan R. Liss, Inc., New York. [JBC's office]
Wikipedia HERE.

(posted about 2001; latest addition 8 September 2010)