Test Code IGG Immunoglobulin G (IgG)
Additional Codes
Epic: LAB71
Specimen Required
Specimen Type: Serum
Collection Container/Type
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 3 mL
Collection Instructions: Centrifuge and separate cells after clot formation and within 4 hours of collection.
Specimen Minimum Volume
0.25 mL
Specimen Stability
Room temperature: 4 months
Refrigerated: 8 months
Frozen: 8 months
Reference Range
0 - 1 month: 391 - 1765 mg/dL
1 month - 1 year: 203 - 948 mg/dL
1 - 2 years: 475 - 1226 mg/dL
2 - 150 yers: 540 - 1822 mg/dL
Rejection Due To
nlabeled, mislabeled, wrong tube type, visually lipemic, QNS, exceeds specimen stability requirements.
Report Available
Same day / 1 day
Clinical Significance
IgG is the major immunoglobulin in the blood and is produced in
copious amounts during secondary immune responses. IgG
molecules bind to specific receptors on phagocytic cells, such as
macrophages and polymorphonuclear leukocytes, thereby increasing
the efficiency with which the phagocytic cells can ingest and
destroy infecting microorganisms that have become coated with IgG
antibodies in response to the infection. IgG molecules are
the only antibodies that can pass from mother to fetus. The
ability of IgG to cross the placenta provides a major line of
defense against infection for the first weeks of an infant’s
life. Quantitation of IgG can be used to evaluate humoral
immunity, establish diagnosis and monitor therapy in IgG myeloma,
and evaluate patients, especially children and those with lymphoma,
with propensity to infections. Reduction of IgG, usually less
than 300mg/dL, leads to susceptibility to infection due to
encapsulated bacteria. Elevated IgG levels can be polyclonal,
oligoclonal, or monoclonal.
Elevated polyclonal IgG levels are associated with autoimmune
diseases (systemic lupus erythematosus, rheumatoid arthritis, and
Sjogren’s syndrome), chronic liver disease, some parasitic
diseases, chronic or recurrent infections, and intrauterine
contraceptive devices. Increased oligoclonal IgG levels are
associated with malignancies, infections (especially in the
elderly), some dysgammaglobulinemias, and autoimmune disorders.
Increased monoclonal IgG levels are associated with multiple
myeloma (IgG type), lymphomas, and leukemia.
Method Name
Immunoturbidimetric
Limitations
Samples containing paraproteins (abnormal monoclonal antibodies) may incorrectly fall within the reference range. Samples with elevated total protein concentrations or suspected paraproteinemia can be screened with other methods such as electrophoresis. Turbidity and particles in samples can interfere with the assay. Therefore, particulate matter should be removed by centrifugation prior to running the assay.
Day(s) Performed
Daily
LOINC
2465-3