An immunoglobulin test measures the level of certain immunoglobulins, or antibodies, in the blood. Antibodies are proteins made by the immune system to fight antigens, such as bacteria, viruses, and toxins.
The body makes different immunoglobulins to combat different antigens. For example, the antibody for chickenpox isn't the same as the antibody for mononucleosis. Sometimes, the body may even mistakenly make antibodies against itself, treating healthy organs and tissues like foreign invaders. This is called an autoimmune disease.
The five subclasses of antibodies are:
IgA, IgG, and IgM are often measured together. That way, they can give doctors important information about immune system functioning, especially relating to infection or autoimmune disease.
Once an antibody is produced against a specific antigen, the next time that antigen enters the body, the immune system "remembers" its response and produces more of the same antibodies. In that way, checking for the presence of specific immunoglobulins in the blood can be helpful in diagnosing or ruling out infections or certain other illnesses.
Doctors also rely on the immunoglobulin test as one of the tools to help diagnose immunodeficiencies (when the immune system isn't working properly). A person can be born with an immunodeficiency or acquire it through infection, disease, malnutrition, burns, or as a side effect of medicines. Doctors may suspect an immunodeficiency in a child who experiences frequent or unusual infections.
Your doctor will tell you if any special preparations are required before this test. On the day of the test, it may help to have your child wear a T-shirt or short-sleeved shirt to allow easier access for the technician who will be drawing the blood.
A health professional will usually draw the blood from a vein. For an infant, the blood may be obtained by puncturing the heel with a small needle (lancet). If the blood is being drawn from a vein, the skin surface is cleaned with antiseptic, and an elastic band (tourniquet) is placed around the upper arm to apply pressure and cause the veins to swell with blood. A needle is inserted into a vein (usually in the arm inside of the elbow or on the back of the hand) and blood is withdrawn and collected in a vial or syringe.
After the procedure, the elastic band is removed. Once the blood has been collected, the needle is removed and the area is covered with cotton or a bandage to stop the bleeding. Collecting blood for this test will only take a few minutes.
Either method (heel or vein withdrawal) of collecting a sample of blood is only temporarily uncomfortable and can feel like a quick pinprick. Afterward, there may be some mild bruising, which should go away in a day or so.
The blood sample will be processed by a machine. The results are commonly available within a few days. If results suggest any abnormality, the doctor will likely perform further tests.
The immunoglobulin test is considered a safe procedure. However, as with many medical tests, some problems can occur with having blood drawn, like:
Having a blood test is relatively painless. Still, many children are afraid of needles. Explaining the test in terms your child can understand might help ease some of the fear.
Allow your child to ask the technician any questions he or she might have. Tell your child to try to relax during the procedure, as tense muscles can make it harder and more painful to draw blood. It also may help for your child to look away when the needle is being inserted into the skin.
If you have questions about the immunoglobulin test, speak with your doctor. You also can talk to the technician before the procedure.
Reviewed by: Yamini Durani, MD
Date reviewed: August 2014
|American Medical Association (AMA) The AMA has made a commitment to medicine by making doctors more accessible to their patients. Contact the AMA at: American Medical Association|
515 N. State St.
Chicago, IL 60610
|American Society of Hematology This group provides information relating to blood, blood-forming tissues, and blood diseases.|
|Arthritis Foundation The mission of this group is to support research to find the cure for and prevention of arthritis and to improve the quality of life for those affected by arthritis.|
|Lupus Foundation of America The mission of the Lupus Foundation of America is to educate and support those affected by lupus and find a cure. Call (800) 558-0121 for information.|
|Celiac Disease Foundation The Celiac Disease Foundation provides support, information and assistance to people affected by celiac disease and dermatitis herpetiformis. The site provides information on celiac disease and helps people locate support groups.|
|Celiac Sprue Association This non-profit organization helps people with celiac disease and dermatitis herpetiformis. Find gluten-free products, recipes, support groups, and more.|
|Lab Tests Online This non-commercial site was developed by laboratory professionals to educate caregivers, patients, and patients' families about lab tests.|
|Definition: Immunoglobulin (IgE) Many people have allergy-induced asthma, which means that their asthma symptoms are triggered by allergic reactions.|
|Blood Test (Video) These videos show what's involved in getting a blood test and what it's like to be the person taking the blood sample.|
|Blood Test: Immunoglobulin A (IgA) Checking IgA levels can help doctors diagnose problems with the immune system, intestines, and kidneys. It's also used to evaluate autoimmune conditions, such as rheumatoid arthritis, lupus, and celiac disease.|
|Blood Test: Erythrocyte Sedimentation Rate (ESR) An erythrocyte sedimentation rate test (ESR) detects inflammation that may be caused by infection, some cancers, and certain autoimmune diseases.|
|Getting a Blood Test (Video) A blood test might sound scary, but it usually takes less than a minute. Watch what happens in this video for kids.|
|Life With Lupus Some people have an autoimmune disorder called lupus. Find out more in this article for kids.|
|Living With Lupus Lupus is known as an autoimmune disease in which a person's immune system mistakenly works against the body's own tissues.|
|Lupus Lupus is a disease that affects the immune system. Learn how lupus is treated, signs and symptoms, how to support a friend who has it, and more.|
|Your Immune System The immune system keeps you healthy. How does it work? Find out in this article for kids.|
|Definition: Immunoglobulin (IgE) Immunoglobulin E (IgE) is a type of protein in the body called an antibody.|
|Immune System The immune system is made up of special cells, proteins, tissues, and organs that defend people against germs and microorganisms. It's the body's defense against organisms and substances that invade our systems and cause disease.|
|Blood Test: Immunoglobulin E (IgE) The immunoglobulin E (IgE) test is often performed as part of an initial screen for allergies. High IgE levels also may indicate a parasitic infection.|
|Juvenile Idiopathic Arthritis Juvenile idiopathic arthritis (also called juvenile rheumatoid arthritis) affects some 50,000 kids in the United States. Learn more.|
|Immune System The immune system, composed of special cells, proteins, tissues, and organs that protect against germs and microorganisms, is the body's defense against disease.|
|Celiac Disease People who have celiac disease, a disorder that makes their bodies react to gluten, can't eat certain kinds of foods. Find out more - including what foods are safe and where to find them.|
|Celiac Disease Kids who have celiac disease, a disorder that makes their bodies react to gluten, can't eat certain kinds of foods. Find out more - including what foods are safe and where to find them.|
|Celiac Disease People with celiac disease can't eat gluten, which is found in many everyday foods, such as bread. Find out more by reading this article for kids.|
What to expect when coming to Akron Children's
For healthcare providers and nurses
Residency & Fellowships, Medical Students, Nursing and Allied Health
For prospective employees and career-seekers
Our online community that provides inspirational stories and helpful information.