Test Id : IGG
Immunoglobulin G (IgG), Serum
Useful For
Suggests clinical disorders or settings where the test may be helpful
Detecting or monitoring of IgG monoclonal gammopathies and immune deficiencies
Method Name
A short description of the method used to perform the test
Nephelometry
NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.
Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test
Aliases
Lists additional common names for a test, as an aid in searching
Gamma-Globulins, Quantitative
IgG (Immunoglobulin G)
IgG single test
IgG, Serum
Immune Competence
Specimen Type
Describes the specimen type validated for testing
Serum
Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Collection Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial.
Forms
If not ordering electronically, complete, print, and send a Gastroenterology and Hepatology Test Request (T728) with the specimen.
Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the testing laboratory. The minimum volume is sufficient for one attempt at testing.
0.5 mL
Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected
| Gross hemolysis | OK |
| Gross lipemia | Reject |
| Gross icterus | OK |
Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum | Refrigerated (preferred) | 28 days | |
| Ambient | 14 days | ||
| Frozen | 28 days |
Useful For
Suggests clinical disorders or settings where the test may be helpful
Detecting or monitoring of IgG monoclonal gammopathies and immune deficiencies
Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Immunoglobulins are produced by plasma cells as a humoral immune response to contact of the immune system by antigens. The primary reaction after the initial contact is the formation of antibodies of the IgM class, followed later by IgG and IgA antibodies. Quantitative determination of the immunoglobulins can provide important information on the humoral immune status. Decreased serum immunoglobulin concentrations occur in primary immunodeficiency conditions as well as in secondary immune insufficiencies (eg, in advanced malignant tumors, lymphatic leukemia, multiple myeloma, and Waldenstrom disease).
Monoclonal immunoglobulin proliferations in the serum are found in plasmacytomas, Waldenstrom disease, and heavy-chain disease. Monoclonal immunoglobulinemia requires detailed differential diagnostic investigations in addition to the quantitative determination. Local immune reactions result in elevated immunoglobulin levels, particularly IgG, in the cerebrospinal fluid. IgA increases with asparaginase treatment, during pregnancy, with exercise, and in people with alcohol use disorder. It falls with prolonged exposure to benzene and after 1 year's abstinence from drinking alcohol. Diphenylhydantoin, dextran, methyl prednisolone, toluene, xylol, and oral contraceptives may also lower IgA levels. IgM may rise in people with narcotic addiction and after various drug use, as with IgA and IgG.
The gamma globulin band as seen in conventional serum protein electrophoresis consists of 5 immunoglobulins. In normal serum, about 80% is IgG.
Elevations of IgG may be due to polyclonal immunoglobulin production. Monoclonal elevations of IgG characterize multiple myeloma.
Monoclonal gammopathies of all types may lead to a spike in the gamma globulin zone seen on serum protein electrophoresis.
Decreased immunoglobulin levels are found in patients with congenital deficiencies.
Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
0-<5 months: 100-334 mg/dL
5-<9 months: 164-588 mg/dL
9-<15 months: 246-904 mg/dL
15-<24 months: 313-1,170 mg/dL
2-<4 years: 295-1,156 mg/dL
4-<7 years: 386-1,470 mg/dL
7-<10 years: 462-1,682 mg/dL
10-<13 years: 503-1,719 mg/dL
13-<16 years: 509-1,580 mg/dL
16-<18 years: 487-1,327 mg/dL
> or =18 years: 767-1,590 mg/dL
Interpretation
Provides information to assist in interpretation of the test results
Increased serum immunoglobulin concentrations occur due to polyclonal or oligoclonal immunoglobulin proliferation in hepatic disease (hepatitis, liver cirrhosis), connective tissue diseases, acute and chronic infections, as well as in the cord blood of neonates with intrauterine and perinatal infections.
Elevation of IgG may occur in monoclonal gammopathies such as multiple myeloma, primary systemic amyloidosis, monoclonal gammopathy of undetermined significance, and related disorders.
Decreased levels are found in patients with primary or secondary immune deficiencies.
Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
Electrophoresis is usually required to interpret an elevated immunoglobulin class as polyclonal versus monoclonal. Immunofixation is usually required to characterize a monoclonal protein.
If there is a discrete M-peak, the monoclonal protein can be monitored with quantitative immunoglobulins. If immunoglobulin quantitation is used to monitor the size of a monoclonal protein that is contained in a background of polyclonal immunoglobulins, changes in the immunoglobulin quantitation may reflect changes in the background immunoglobulins; therefore, serum protein electrophoresis should be used to monitor the monoclonal protein.
Results determined by assays using different manufacturers or methods may not be comparable.
Quantitation of specific proteins by nephelometric means may not be possible in lipemic sera due to the extreme light scattering properties of the specimen. Turbidity and particles in the specimen may result in extraneous light scattering signals, resulting in variable specimen analysis.
Clinical Reference
Recommendations for in-depth reading of a clinical nature
1. Webster ADB: Laboratory investigation of primary deficiency of the lymphoid system. In: Clinics in Immunology and Allergy. Vol 5. 3rd ed. 1985:447-468
2. Pinching AJ: Laboratory investigation of secondary immunodeficiency. In: Clinics in Immunology and Allergy. Vol 5. 3rd ed. WB Saunders Company; 1985:469-490
3. Dispenzieri A, Gertz MA, Kyle RA. Distribution of diseases associated with moderate polyclonal gammopathy in patients seen at Mayo Clinic during 1991. Blood. 1997;90:353
4. Kyle RA, Greipp PR. The laboratory investigation of monoclonal gammopathies. Mayo Clin Proc. 1978;53:719-739
5. Ballow M, O'Neil KM: Approach to the patient with recurrent infections. In: Middleton Jr E, Reed CE, Ellis EF, et al, eds. Allergy: Principles and Practice. Vol 2. 4th ed. Mosby-Year Book, Inc.; 1993:1027-1058
6. Kyle RA. Detection of quantitation of monoclonal proteins. Clin Immunol Newsletter. 1990;10:84-86
7. Dietzen DJ, Willrich MAV: Amino acids, peptides, and proteins. In: Rifai N, Chiu RWK, Young I, Burnham CAD, Wittwer CT, eds. Tietz Textbook of Laboratory Medicine. 7th ed. Elsevier; 2023:chap 31
Method Description
Describes how the test is performed and provides a method-specific reference
In this Siemens Nephelometer II method, the light scattered onto the antigen-antibody complexes is measured. The intensity of the measured scattered light is proportional to the amount of antigen-antibody complexes in the sample under certain conditions. If the antibody volume is kept constant, the signal behaves proportionally to the antigen volume.
A reference curve is generated by a standard with a known antigen content on which the scattered light signals of the samples can be evaluated and calculated as an antigen concentration. Antigen-antibody complexes are formed when a sample containing antigen and the corresponding antiserum are put into a cuvette. A light beam is generated with a light emitting diode, which is transmitted through the cuvette. The light is scattered onto the immuno-complexes that are present. Antigen and antibody are mixed in the initial measurement, but no complex is formed yet. An antigen-antibody complex is formed in the final measurement.
The result is calculated by subtracting the value of the final measurement from the initial measurement. The distribution of intensity of the scattered light depends on the ratio of the particle size of the antigen-antibody complexes to the radiated wavelength.(Instruction manual: Siemens Nephelometer II, Siemens, Inc.; Version 2.4, 07/2019)
PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information
Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.
Monday through Friday
Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.
Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location
Indicates the location of the laboratory that performs the test
Fees :
Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.
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Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.
This test has been cleared, approved, or is exempt by the US 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
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
CPT codes are provided by the performing laboratory.
CPT codes are provided by the performing laboratory.
82784
LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.
| Test Id | Test Order Name | Order LOINC Value |
|---|---|---|
| IGG | Immunoglobulin G (IgG), S | 2465-3 |
| Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
|---|---|---|
| IGG | Immunoglobulin G (IgG), S | 2465-3 |