Immunoglobulin G (IgG), Serum

CPT CODE:

USEFUL FOR:

Detecting or monitoring of monoclonal gammopathies and immune deficiencies

SPECIMEN REQUIRED:

Draw blood in a plain, red-top tube(s) or a serum gel tube(s). Spin down and send  1 mL of serum refrigerated.

TRANSPORT TEMPERATURE:

Refrig\Ambient <14 days OK\Frozen <14 days OK

CLINICAL INFORMATION:

The gamma globulin band as seen in conventional serum proteinelectrophoresis consists of 5 immunoglobulins. In normal serum, about 80% is IgG.
Elevations of IgG may be due to polyclonal immunoglobulin production.  Monoclonal elevation of IgG characterize multiple myeloma.
Monoclonal gammopathies of all types may lead to a spike in thegamma globulin zone seen on serum protein electrophoresis.
Decreased immunoglobulin levels are found in patients with congenitaldeficiencies.

CLINICAL INTERPRETATION:

Increased serum immunoglobulin concentrations occur due to polyclonal or oligoclonal immunoglobulin proliferation in hepaticdisease (hepatitis, liver cirrhosis), connective tissue diseases, acuteand chronic infections, as well as in the cord blood of neonates withintrauterine and perinatal infections.
Elevation of IgG may occur in monoclonal gammopathiessuch as multiple myeloma, primary systemic amyloidosis, monoclonalgammopathy of undetermined significance, and related disorders.
Decreased levels are found in patients with primary or secondaryimmune deficiencies.

REFERENCE VALUES:

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