Quantitative immunoglobulins

Definition

The quantitative immunoglobulins test measures the levels of proteins called gamma globulins in the fluid part of a blood sample. This fluid is called serum.

How the Test is Performed

A blood sample is needed.

In the lab, the technician places the blood sample on special paper and applies an electric current. The proteins move on the paper and form bands that show the amount of each protein.

How to Prepare for the Test

Follow instructions on whether or not you need to fast before this test.

Certain medicines may affect the results of this test. Your health care provider will tell you if you need to stop taking any medicines. Do not stop any medicine before talking to your provider.

How the Test will Feel

When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging. Afterward, there may be some throbbing or a slight bruise. This soon goes away.

Why the Test is Performed

This test is done to look at gamma globulin protein levels in the blood. Identifying the levels of gamma globulins can help diagnose certain medical issues.

Gamma globulins include various types of antibodies such as immunoglobulins (Ig) M, G, and A.

Certain diseases are associated with producing too many immunoglobulins. For example, Waldenström macroglobulinemia is a cancer of certain white blood cells. It is linked with producing too many IgM antibodies. Other diseases are associated with low levels of one or more immunoglobulins.

Normal Results

Normal value ranges are:

• IgM component: 40 to 230 milligrams per deciliter (mg/dL) or 0.4 to 2.3 g/L
• IgG component: 700 to 1600 mg/dL or 7 to 16 g/L
• IgA component: 103 to 501 mg/dL or 1.0 to 5.0 g/L

Normal value ranges may vary slightly among different labs. Some labs use different measurements or test different samples. Talk to your provider about the meaning of your specific test results.

What Abnormal Results Mean

Increased gamma globulin proteins may indicate:

• Acute infection
• Blood and bone marrow cancers including multiple myeloma, and some lymphomas and leukemias
• Long-term (chronic) inflammatory disease (for example, rheumatoid arthritis and systemic lupus erythematosus)
• Waldenström macroglobulinemia

Risks

There is very little risk involved with having your blood taken. Veins and arteries vary in size from one person to another, and from one side of the body to the other. Taking blood from some people may be more difficult than from others.

Other risks associated with having blood drawn are slight, but may include:

• Excessive bleeding
• Fainting or feeling lightheaded
• Multiple punctures to locate veins
• Hematoma (blood buildup under the skin)
• Infection (a slight risk any time the skin is broken)

References

Cunningham-Rundles C. Primary immunodeficiency diseases. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 231.

McPherson RA, Riley RS, Massey HD. Laboratory evaluation of immunoglobulin function and humoral immunity. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 24th ed. Philadelphia, PA: Elsevier; 2022:chap 47.