Indications for SPE:

1. Myeloma search: 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).
2. Liver disease: It may also helpful in liver disease detection & evaluation, mostly in cases of hyperproteinemia (especially if there is beta-gamma bridging) with hypoalbuminemia, for example.
3. Neurology: work-up of peripheral neuropathy of undetermined etiology.
4. Anemia: anemia of uncertain etiology in a renal insufficiency and/or bone-pain patient.
5. Weakness and/or fatigue workup.
6. Immunoglobulin deficiency cases.
7. Recurrent infections cases.
8. Abnormal lab values :
• hypercalcemia of uncertain etiology
• elevated ESR of uncertain etiology
• hypergammaglobulinemia of uncertain etiology (reversed A/G ratio)
• heavy proteinuria in patient >40 y/o & look for Bence Jones proteinuria
9. CBC smear review: rouleaux formation noted on CBC peripheral smear.
10. Nephrology: unexplained renal insufficiency, especially if with elevated serum protein.
11. ER & Orthopedic: unexplained bone pain or pathologic fracture or lytic bone lesion on X-ray.

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).

•  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.

Since the clinical lab usually has no idea when/whether a monoclonal spike (M protein) has known significance, a lab-based terminology for small spikes has often been "mini-monoclonal" gammopathy. Though the term MGUS (monoclonal gammopathy of uncertain significance) is usually applicable to any new monoclonal gammopathy of as-yet-undetermined etiology, it sort of tends to be synonymous with "mini-monoclonal". It is these small ones that often elude specific identification of an etiology. Some can be so small that it is not absolutely certain that it is even a "minute" mini-monoclonal

• 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

• CONSTITUENTS: alpha-1 antitrypsin.
• ELEVATIONS:
  • abnormal alpha-1 AT type (MGUSs rarely if ever migrate as far as the alpha-1 zone)
  • PSEUDO-M: HYPER-ALPHA-2
• DECREASES:

• CONSTITUENTS: haptoglobin, alpha-2 macroglobulin, HDL.
• ELEVATIONS:
  • PSEUDO-M:
• DECREASES:

• CONSTITUENTS:
• ELEVATIONS:
  • PSEUDO-M: HYPERTRANSFERRINEMIA (OF  CHRONIC IDA, PREGNANCY, BIRTH CONTROL PILLS) 
  • High LDL.
  • Elevated C3
  • TRUE M-PROTEIN: IgA
  • increases in IgA or IgM².
• DECREASES:

• PRESENCE/ELEVATIONS:
  • PSEUDO-M: fibrinogen or CRP.
  • "Beta-gamma bridging" IS MOST IMPORTANTLY TENDS TO BE ASSOCIATED WITH CHRONIC LIVER DISEASE and is a technical, visual phenomenon...as visble & best discerned on the electrophoretic membrane (tracing gives a "heads up" but is too sensitive)...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 (we have rarely seen the bridge when the SPE pattern & quantities are all otherwise normal). 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.

• CONSTITUENTS:
• ELEVATIONS:
  • PSEUDO-M:
  • fibrinogen spike in someone on heparin
  • minimonoclonal: small M-spike within a polyclonal zone ["MGUS"] determined to be monoclonal by immunofixation. If it goes away on subsequent testing a few weeks or so later, it might be referrd to as an "evanescent 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, it being a nonspecific reflection of active autoimmunity⁴. But, modern electrophoretic plates sometimes detect seeming bands due to higher-precision separation.
  • broad increases might indicate autoimmune disease vs. active chronic inflammation of non-autoimmune type.
• DECREASES:

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

References:

1. American Family Physician SPE file.
2. Ritzmann SE & Daniels JC, Serum Protein Abnormalities, Diagnostic and Clinical Aspects, about 1982, Alan R. Liss, Inc., New York. [JBC's office]
3. Wikipedia HERE.
4. Carter JB, personal communication.
5. British Columbia Society for Laboratory Science web file on SPE with many membrane examples