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HelpTest ID PEL Electrophoresis, Protein, Serum
Reporting Name
Electrophoresis, Protein, SUseful For
Monitoring patients with monoclonal gammopathies
Diagnosis of monoclonal gammopathies, when used in conjunction with immunofixation
Protein electrophoresis alone is not considered an adequate screen for monoclonal gammopathies
Profile Information
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| TPE | Total Protein | Yes, (order TP) | Yes |
| ELP | Protein Electrophoresis | No | Yes |
Reflex Tests
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| IMFX | Immunofixation | No | No |
Testing Algorithm
If a discrete electrophoresis band is identified, the laboratory will evaluate the serum protein electrophoresis and, if necessary, perform immunofixation at an additional charge.
Specimen Type
SerumNecessary Information
Indicate if multiple myeloma is suspected.
Specimen Required
Patient Preparation: Fasting (12 hour) preferred but not required
Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Specimen Volume: 1 mL
Specimen Minimum Volume
0.5 mL
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Serum | Refrigerated (preferred) | 14 days |
| Ambient | 14 days | |
| Frozen | 14 days |
Reference Values
PROTEIN, TOTAL
≥1 year: 6.3-7.9 g/dL
Reference values have not been established for patients that are <12 months of age.
PROTEIN ELECTROPHORESIS
Albumin: 3.4-4.7 g/dL
Alpha-1-globulin: 0.1-0.3 g/dL
Alpha-2-globulin: 0.6-1.0 g/dL
Beta-globulin: 0.7-1.2 g/dL
Gamma-globulin: 0.6-1.6 g/dL
An interpretive comment is provided with the report.
Day(s) and Time(s) Performed
Monday through Saturday; Continuously until 2 p.m.
Test Classification
This test has been cleared or approved by the U.S. Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.CPT Code Information
84155-Protein, total
84165-Protein, electrophoresis
86334-Immunofixation (if appropriate)
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| PEL | Electrophoresis, Protein, S | 24351-9 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| TPE | Total Protein | 2885-2 |
| 2769 | Albumin | 2862-1 |
| 2770 | Alpha-1 Globulin | 2865-4 |
| 2771 | Alpha-2 Globulin | 2868-8 |
| 2773 | Beta-Globulin | 2871-2 |
| 2774 | Gamma-Globulin | 2874-6 |
| 2785 | A/G Ratio | 44429-9 |
| 22308 | M spike | 33358-3 |
| 22309 | M spike | 33358-3 |
| 15254 | Impression | 12851-2 |
Clinical Information
Serum proteins can be grouped into 5 fractions by protein electrophoresis:
- Albumin, which represents almost two-thirds of the total serum protein
- Alpha-1, composed primarily of alpha-1-antitrypsin (A1AT), an alpha-1-acid glycoprotein
- Alpha-2, composed primarily of alpha-2-macroglobulin and haptoglobin
- Beta, composed primarily of transferrin and C3
- Gamma, composed primarily of immunoglobulins
The concentration of these fractions and the electrophoretic pattern may be characteristic of diseases such as monoclonal gammopathies, A1AT deficiency disease, nephrotic syndrome, and inflammatory processes associated with infection, liver disease, and autoimmune diseases.
Interpretation
Monoclonal Gammopathies:
- A characteristic monoclonal band (M-spike) is often found on protein electrophoresis (PEL) in the gamma-globulin region and more rarely in the beta or alpha-2 regions. The finding of a M-spike, restricted migration, or hypogammaglobulinemic PEL pattern is suggestive of a possible monoclonal protein and should be followed by MPSU / Monoclonal Protein Study, 24 Hour, Urine, which includes immunofixation (IF), to identify the immunoglobulin heavy chain and/or light chain.
- A monoclonal IgG or IgA greater than 3 g/dL is consistent with multiple myeloma (MM).
- A monoclonal IgG or IgA less than 3 g/dL may be consistent with monoclonal gammopathy of undetermined significance (MGUS), primary systemic amyloidosis, early or treated myeloma, as well as a number of other monoclonal gammopathies.
- A monoclonal IgM greater than 3 g/dL is consistent with macroglobulinemia.
- The initial identification of a serum M-spike greater than 1.5 g/dL on PEL should be followed by MPSU / Monoclonal Protein Study, 24 Hour, Urine.
- The initial identification of an IgM, IgA, or IgG M-spike greater than 4 g/dL, greater than 5 g/dL, and greather than 6 g/dL, respectively, should be followed by VISCS / Viscosity, Serum.
- After the initial identification of an M-spike, quantitation of the M-spike on follow-up PEL can be used to monitor the monoclonal gammopathy. However, if the monoclonal protein falls within the beta region (most commonly an IgA or an IgM) quantitative immunoglobulin levels may be more a useful tool to follow the monoclonal protein level than PEL. A decrease or increase of the M-spike that is greather than 0.5 g/dL is considered a significant change.
- Patients suspected of having a monoclonal gammopathy may have normal serum PEL patterns. Approximately 11% of patients with MM have a completely normal serum PEL, with the monoclonal protein only identified by IF. Approximately 8% of MM patients have hypogammaglobulinemia without a quantifiable M-spike on PEL but identified by IF. Accordingly, a normal serum PEL does not rule out the disease and should not be used to screen for the disorder. The MPSS / Monoclonal Protein Study, Serum, which includes immunofixation, and FLCP / Immunoglobulin Free Light Chains, Serum should be done to screen if the clinical suspicion is high.
Other Abnormal PEL Findings:
- A qualitatively normal but elevated gamma fraction (polyclonal hypergammaglobulinemia) is consistent with infection, liver disease, or autoimmune disease.
- A depressed gamma fraction (hypogammaglobulinemia) is consistent with immune deficiency and can also be associated with primary amyloidosis or nephrotic syndrome.
- A decreased albumin (<2 g/dL), increased alpha-2 fraction (>1.1 g/dL), and decreased gamma fraction (<1 g/dL) is consistent with nephrotic syndrome, and when seen in an adult older than 40 years, should be followed by MPSU / Monoclonal Protein Study, 24 Hour, Urine.
- In the hereditary deficiency of a protein (eg, agammaglobulinemia, alpha-1-antitrypsin (A1AT) deficiency, hypoalbuminemia), the affected fraction is faint or absent.
- An absent alpha-1 fraction is consistent with A1AT deficiency disease and should be followed by a quantitative A1AT assay (AAT / Alpha-1- Antitrypsin, Serum).
Clinical Reference
Kyle RA, Katzmann JA, Lust JA, Dispenzieri A: Clinical indications and applications of electrophoresis and immunofixation. In Manual of Clinical Laboratory Immunology. Sixth edition. Edited by NR Rose, RG Hamilton, B Detrick. Washington DC, ASM Press, 2002 pp 66-70
Analytic Time
1 dayMethod Name
TPE: Biuret
ELP: Agarose Gel Electrophoresis
IMFX: Immunofixation and/or Immunodiffusion
Forms
If not ordering electronically, complete, print, and send a General Request Form (T239) with the specimen (http://www.mayomedicallaboratories.com/it-mmfiles/general-request-form.pdf).