You may be asked not to eat or drink anything for 4 hours before the test.
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 slight bruising. This soon goes away.
Why the Test is Performed
The test provides a rapid and accurate measurement of the amounts of the immunoglobulins IgM, IgG, and IgA.
Normal results for the three immunoglobulins are:
IgG: 650 to 1600 milligrams per deciliter (mg/dL), or 6.5 to 16.0 grams per liter (g/L)
IgM: 54 to 300 mg/dL, or 540 to 3000 mg/L
IgA: 40 to 350 mg/dL, or 400 to 3500 mg/L
The examples above show the common measurements for these test results. Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results. Some labs use different measurements or test different samples.
Other tests are needed to confirm or diagnose any of the conditions above.
There is 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:
Fainting or feeling lightheaded
Multiple punctures to locate veins
Hematoma (blood accumulating under the skin)
Infection (a slight risk any time the skin is broken)
Abraham RS. Assessment of functional immune responses in lymphocytes. In: Rich RR, Fleisher TA, Shearer WT, Schroeder HW, Few AJ, Weyand CM, eds. Clinical Immunology: Principles and Practice. 5th ed. Philadelphia, PA: Elsevier; 2019:chap 93.
McPherson RA. Specific proteins. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 23rd ed. St Louis, MO: Elsevier; 2017:chap 19.
Todd Gersten, MD, Hematology/Oncology, Florida Cancer Specialists & Research Institute, Wellington, FL. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.