Test Catalog

Test Id : IGGS

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IgG Subclasses, Serum

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Overview

Test Catalog

Useful For
Suggests clinical disorders or settings where the test may be helpful

Second-order testing for evaluation of patients with clinical signs and symptoms of humoral immunodeficiency or combined immunodeficiency (cellular and humoral)

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

Testing includes total immunoglobulin G (IgG) as well as the 4 subclasses of IgG.

 

See Celiac Disease Diagnostic Testing Algorithm in Special Instructions

Special Instructions
Library of PDFs including pertinent information and forms related to the test

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.

Yes

Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test

IgG Subclasses, S

Aliases
Lists additional common names for a test, as an aid in searching

IgG (Immunoglobulin G) Subclasses

IgG1, IgG2, IgG3, IgG4 (Immunoglobulins G1, G2, G3, G4)

Immunoglobulin G (IgG)

Subclasses, IgG (Immunoglobulin G)

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

Testing includes total immunoglobulin G (IgG) as well as the 4 subclasses of IgG.

 

See Celiac Disease Diagnostic Testing Algorithm in Special Instructions

Specimen Type
Describes the specimen type validated for testing

Serum

Ordering Guidance

If testing for immunoglobulin (Ig) G4-related diseases, the more appropriate test to order is IGGS4 / Immunoglobulin Subclass IgG4, Serum.

Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing

Patient Preparation: Fasting preferred but not required

Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Specimen Volume: 1 mL

Special Instructions
Library of PDFs including pertinent information and forms related to the test

Forms

If not ordering electronically, complete, print, and send a General Request (T239) with the specimen.

Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the Testing Laboratory

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) 14 days
Ambient 14 days
Frozen 14 days

Useful For
Suggests clinical disorders or settings where the test may be helpful

Second-order testing for evaluation of patients with clinical signs and symptoms of humoral immunodeficiency or combined immunodeficiency (cellular and humoral)

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

Testing includes total immunoglobulin G (IgG) as well as the 4 subclasses of IgG.

 

See Celiac Disease Diagnostic Testing Algorithm in Special Instructions

Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

The most abundant immunoglobulin in human serum is immunoglobulin G (IgG) (approximately 80% of the total). IgG protein is comprised of molecules of 4 subclasses designated IgG1 through IgG4. Each subclass contains molecules with a structurally unique gamma heavy chain. Of total IgG, approximately 65% is IgG1, 25% is IgG2, 6% is IgG3, and 4% is IgG4. Molecules of different IgG subclasses have somewhat different biologic properties (eg, complement fixing ability and binding to phagocytic cells), which are determined by structural differences in gamma heavy chains. Clinical interest in IgG subclasses concerns potential immunodeficiencies (eg, subclass deficiencies) and IgG4-related diseases (eg, IgG4 elevations). This assay is best for deficiency testing, and the IgG4 assay (IGGS4 / Immunoglobulin Subclass IgG4, Serum) is best for IgG4-related disease testing.

 

Diminished concentrations of IgG subclass proteins may occur in the context of hypogammaglobulinemia (eg, in common variable immunodeficiency where all immunoglobulin classes are generally affected) or deficiencies may be selective, usually involving IgG2. Deficiency of IgG1 usually occurs in patients with severe immunoglobulin deficiency involving other IgG subclasses. Deficiency of IgG2 is more heterogeneous and can occur as an isolated deficiency or in combination with deficiency of immunoglobulin A (IgA), or of IgA and other IgG subclasses. Most patients with IgG2 deficiency present with recurrent infections, usually sinusitis, otitis, or pulmonary infections. Children with deficiency of IgG2 often have deficient antibody responses to polysaccharide antigens including bacterial antigens associated with Haemophilus influenzae type B and Streptococcus pneumoniae. Isolated deficiencies of IgG3 or IgG4 occur rarely, and the clinical significance of these findings is not clear.

 

IgG subclass 4-related disease is a recently recognized syndrome of unknown etiology most often occurring in middle-aged and older men. Several organ systems can be involved and encompasses many previous and newly described diseases such as type 1 autoimmune pancreatitis; Mikulicz disease and sclerosing sialadenitis; inflammatory orbital pseudotumor; chronic sclerosing aortitis; Riedel thyroiditis, a subset of Hashimoto thyroiditis; IgG4-related interstitial pneumonitis; and IgG4-related tubulointerstitial nephritis. Each of these entities is characterized by tumor-like swelling of the involved organs with infiltrative, predominately IgG4-positive, plasma cells with accompanying "storiform" fibrosis. In addition, elevated serum concentrations of IgG4 are found in 60% to 70% of patients diagnosed with IgG4-related disease.

 

The diagnosis of IgG4-related disease requires a tissue biopsy of the affected organ demonstrating the aforementioned histological features. It is recommended that patients suspected of having an IgG4-related disease have their serum IgG4 level measured.

 

Testing for IgG subclass levels may be indicated in patients with clinical evidence of a possible immunodeficiency with hypogammaglobulinemic patients or normal concentrations of total serum IgG.

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.

TOTAL IgG

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

 

IgG1

0-<5 months: 56-215 mg/dL  

5-<9 months: 102-369 mg/dL

9-<15 months: 160-562 mg/dL

15-<24 months: 209-724 mg/dL

2-<4 years: 158-721 mg/dL

4-<7 years: 209-902 mg/dL

7-<10 years: 253-1,019 mg/dL

10-<13 years: 280-1,030 mg/dL

13-<16 years: 289-934 mg/dL

16-<18 years: 283-772 mg/dL

> or =18 years: 341-894 mg/dL

 

IgG2

0-<5 months: < or =82 mg/dL

5-<9 months: < or =89 mg/dL

9-<15 months: 24-98 mg/dL

15-<24 months: 35-105 mg/dL

2-<4 years: 39-176 mg/dL

4-<7 years: 44-316 mg/dL

7-<10 years: 54-435 mg/dL

10-<13 years: 66-502 mg/dL

13-<16 years: 82-516 mg/dL

16-<18 years: 98-486 mg/dL

> or =18 years: 171-632 mg/dL

 

IgG3

0-<5 months: 7.6-82.3 mg/dL

5-<9 months: 11.9-74.0 mg/dL

9-<15 months: 17.3-63.7 mg/dL

15-<24 months: 21.9-55.0 mg/dL

2-<4 years: 17.0-84.7 mg/dL

4-<7 years: 10.8-94.9 mg/dL

7-<10 years: 8.5-102.6 mg/dL

10-<13 years: 11.5-105.3 mg/dL

13-<16 years: 20.0-103.2 mg/dL

16-<18 years: 31.3-97.6 mg/dL

> or =18 years: 18.4-106.0 mg/dL

 

IgG4

0-<5 months: < or =19.8 mg/dL

5-<9 months: < or =20.8 mg/dL

9-<15 months: < or =22.0 mg/dL

15-<24 months: < or =23.0 mg/dL

2-<4 years: 0.4-49.1 mg/dL

4-<7 years: 0.8-81.9 mg/dL

7-<10 years: 1.0-108.7 mg/dL

10-<13 years: 1.0-121.9 mg/dL

13-<16 years: 0.7-121.7 mg/dL

16-<18 years: 0.3-111.0 mg/dL

> or =18 years: 2.4-121.0 mg/dL

Interpretation
Provides information to assist in interpretation of the test results

Diminished concentrations of all immunoglobulin G (IgG) subclasses are found in common variable immunodeficiency, combined immunodeficiency, ataxia telangiectasia, and other primary and acquired immunodeficiency diseases. 

 

A diminished concentration of IgG2 protein may be clinically significant in the context of recurrent sinopulmonary infection and may occur with or without concomitant immunoglobulin A deficiency.

 

Elevated levels of IgG4 are consistent with, but not diagnostic of, IgG4-related disease.

 

Slightly diminished concentrations of 1 or more IgG subclass proteins are not uncommon, and usually have little clinical significance.

 

Conversely, some individuals with deficient specific antibody responses to polysaccharide antigens may have normal serum levels of IgG subclasses.

Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Measurement of immunoglobulin G (IgG) subclass proteins is not a first-order test in patients suspected of having an immunodeficiency disease. Quantitation of IgG, immunoglobulin A, and immunoglobulin M levels, along with other first-order tests for immunodeficiency, should be performed first.

 

Elevations in serum IgG4 concentrations are not specific to IgG4-related disease; they are also found in disorders such as multicentric Castleman disease, allergic disorders, Churg-Strauss syndrome, sarcoidosis, and a large number of other conditions.

Clinical Reference
Recommendations for in-depth reading of a clinical nature

Umetsu DT, Ambrosino DM, Quinti I, et al: Recurrent sinopulmonary infection and impaired antibody response to bacterial capsular polysaccharide antigen in children with selective IgG-subclass deficiency. N Engl J Med 1985;313:1247-1251

Special Instructions
Library of PDFs including pertinent information and forms related to the test

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 (LED), 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 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, Newark, DE, Version 3, 2008; Schauer U, Stemberg F, Rieger CH, et al: IgG subclass concentration in certified reference material 470 and reference values for children and adults determined with The Binding Site Reagents. Clin Chem 2003;49[11]:1924-1929)

PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information

No

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.

Same day/1 to 3 days

Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

14 days

Performing Laboratory Location
Indicates the location of the laboratory that performs the test

Rochester

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.

  • Authorized users can sign in to Test Prices for detailed fee information.
  • Clients without access to Test Prices can contact Customer Service 24 hours a day, seven days a week.
  • Prospective clients should contact their Regional Manager. For assistance, contact Customer Service.

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.

82784

82787 x 4

Test Setup Resources

Setup Files
Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.

Excel | Pdf

Sample Reports
Normal and Abnormal sample reports are provided as references for report appearance.

Normal Reports | Abnormal Reports

SI Sample Reports
International System (SI) of Unit reports are provided for a limited number of tests. These reports are intended for international account use and are only available through MayoLINK accounts that have been defined to receive them.

SI Normal Reports | SI Abnormal Reports