Why test immunoglobulins

In both nephelometry and turbidimetry, a light source is projected through a liquid sample within a transparent container. Turbidimetry measures the decrease in the intensity of light and nephelometry measures scatter of light as it passes through the sample, which is proportional to the concentration of the immunoglobulin in the solution.

Laboratory levels can vary by laboratory due to differences in testing technique. Abnormal test results indicate that there is something affecting the immune system and may suggest the need for further testing. Abnormal Igs are not diagnostic but can, in association with an appropriate clinical history and other tests results, be a strong indicator of a disease or condition. Primary inherited — less common disorders in which the body is not able to produce one or more class of immunoglobulin.

Hypogammaglobulinaemia is more frequently due to secondary rather than primary causes. For patients who have loss of immunoglobulin into the renal tract or gut, the IgM tends to remain normal as it is retained due to its large size. There are a large number of primary humoral immunodeficiencies in which immunoglobulins show a mild or profound alteration usually decreased, sometimes increased.

This finding is often found incidentally, such as when testing for coeliac disease. Most patients are asymptomatic, while some can have recurrent sinopulmonary infections in later childhood. As serum levels of IgA do not reach adult levels until the age of 8 years, a diagnosis of IgA deficiency should not be made in children less than 4 years of age.

IgG levels fall in the first 6 months of life as maternal transplacentally acquired antibody level falls normal physiological hypogammaglobulinaemia. Premature infants have less maternal IgG and may reach a lower nadir. In these patients, the IgM is usually normal. Patients with X-linked agammaglobulinaemia usually have low or undetectable levels of all the major immunoglobulins due to abnormalities of B-cell development, leading to absent or markedly reduced B-cell numbers.

Common variable immunodeficiency is the most common severe antibody deficiency affecting both children and adults. Infections, acute and chronic including HIV, Epstein-Barr virus, cytomegalovirus Connective tissue diseases rheumatoid arthritis, systemic lupus erythematosus, scleroderma Chronic active autoimmune hepatitis IgG Primary biliary cirrhosis IgM Haematologic disorders Non-haematologic malignancies In cord blood of newborns with intrauterine infection IgM to offending pathogen.

An increase in immunoglobulins hypergammaglobulinaemia is usually polyclonal and related to immune activation associated with autoimmune diseases or infection. In these cases, multiple Ig classes tend to be affected. In contrast, monoclonal production is usually associated with a marked increase in one class of immunoglobulin only referred to as a paraprotein or monoclonal protein.

This may be associated with a decrease in the other two classes immunoparesis. Although patients have an increase in total immunoglobulins, they are often relatively immunocompromised because most of the immunoglobulin production is abnormal and does not contribute to the immune response. The presence of hypogammaglobulinaemia should be confirmed on repeat testing. Any underlying secondary causes of hypogammaglobulinaemia should be considered before referral to a consultant immunologist for investigation of hypogammaglobulinaemia.

It is important to analyse urine for protein loss. Medication history may reveal use of medications associated with low immunoglobulin levels Table 1.

Full blood count FBC is important to identify lymphopenia, anaemia, and thrombocytopenia all can occur with hypogammaglobulinaemia and to exclude neutropenia. Lymphocytosis may be seen in CLL or lymphoma. Severe combined immunodeficiency is a medical emergency, and patients should be urgently referred to specialist centres for continuation of diagnosis and treatment as soon as it is suspected ie. There is controversy around measuring IgG subclass levels, as isolated IgG subclass deficiency is rarely significant and, in the absence of specific antibody deficiency, has little clinical relevance.

IgG subclasses should not be routinely ordered. Tests that should be ordered only after discussion with a clinical immunologist include: 8. Values for all immunoglobulin levels for paediatric patients must be compared with normal laboratory values for age. The normal term infant has undetectable levels of IgA and IgM at birth and these levels rise progressively in the first 2—3 years of life.

IgA levels increase with age and are often elevated in the elderly. Patients with immunoglobulin deficiencies may have false negative results from laboratory tests that measure antibodies in the blood. For example, one test for coeliac disease detects the IgA type of anti-tissue transglutaminase antibody anti-tTG.

Monoclonal elevations of IgM occur in macroglobulinemia. Increased serum immunoglobulin concentrations occur due to polyclonal or oligoclonal immunoglobulin proliferation in hepatic disease hepatitis, liver cirrhosis , connective tissue diseases, acute and chronic infections, as well as in the cord blood of neonates with intrauterine and perinatal infections.

Elevations of immunoglobulin G IgG , immunoglobulin A IgA , or immunoglobulin M IgM may occur in monoclonal gammopathies such as multiple myeloma IgG, IgA , macroglobulinemia IgM , primary systemic amyloidosis, monoclonal gammopathy of undetermined significance, and related disorders. Electrophoresis is usually required to interpret an elevated immunoglobulin class as polyclonal versus monoclonal. Immunofixation is usually required to characterize a monoclonal protein.

If there is a discrete M-peak, the monoclonal protein can be monitored with quantitative immunoglobulins. If immunoglobulin quantitation is used to monitor the size of a monoclonal protein that is contained in a background of polyclonal immunoglobulins, changes in the immunoglobulin quantitation may reflect changes in the background immunoglobulins.

In these situations, serum protein electrophoresis should therefore be used to monitor the monoclonal protein. In Clinics in Immunology and Allergy. Why do I need an immunoglobulins blood test? What happens during an immunoglobulins blood test? Will I need to do anything to prepare for the test? You don't need any special preparations for an immunoglobulins blood test.

Are there any risks to the test? What do the results mean? If your results show lower than normal levels of immunoglobulins, it may indicate: Kidney disease Severe burn injury Complications from diabetes Malnutrition Sepsis Leukemia If your results show higher than normal levels of immunoglobulins, it may indicate: An autoimmune disease Hepatitis Cirrhosis Mononucleosis A chronic infection A viral infection such as HIV or cytomegalovirus Multiple myeloma Non-Hodgkin lymphoma If your results are not normal, it doesn't necessarily mean you have a medical condition needing treatment.

Is there anything else I need to know about an immunglobulins blood test? References Hinkle J, Cheever K. Johns Hopkins Medicine [Internet]. Washington D. Quantitative Immunoglobulins [updated Jan 15; cited Feb 17]; [about 3 screens]. IgD antibodies are found in small amounts in the tissues that line the belly or chest. How they work is not clear. Why It Is Done A test for immunoglobulins antibodies in the blood is done to: Find certain autoimmune diseases or allergies.

Find certain types of cancer such as multiple myeloma or macroglobulinemia. See whether recurring infections are caused by a low level of immunoglobulins especially IgG. Check the treatment for certain types of cancer affecting the bone marrow. Check the treatment for Helicobacter pylori H. Check the response to immunizations to see if you are immune to the disease. Check to see if you have an infection or have had it in the past.

How To Prepare You do not need to do anything before you have this test. How It Is Done The health professional drawing blood will: Wrap an elastic band around your upper arm to stop the flow of blood. This makes the veins below the band larger so it is easier to put a needle into the vein.

Clean the needle site with alcohol. Put the needle into the vein. More than one needle stick may be needed. Attach a tube to the needle to fill it with blood. Remove the band from your arm when enough blood is collected. Put a gauze pad or cotton ball over the needle site as the needle is removed. Put pressure on the site and then put on a bandage.

How It Feels The blood sample is taken from a vein in your arm. Risks There is very little chance of a problem from having a blood sample taken from a vein. You may get a small bruise at the site. You can lower the chance of bruising by keeping pressure on the site for several minutes. In rare cases, the vein may become swollen after the blood sample is taken. This problem is called phlebitis. A warm compress can be used several times a day to treat this.

Results An immunoglobulins test is done to measure the level of immunoglobulins, also known as antibodies , in your blood. Normal The normal values listed here—called a reference range—are just a guide. Levels of IgA also get higher in some autoimmune diseases , such as rheumatoid arthritis and systemic lupus erythematosus SLE , and in liver diseases, such as cirrhosis and long-term chronic hepatitis. In multiple myeloma, tumor cells make only one type of IgG antibody monoclonal ; the other conditions cause an increase in many types of IgG antibodies polyclonal.

High levels of IgM can mean macroglobulinemia , early viral hepatitis, mononucleosis , rheumatoid arthritis, kidney damage nephrotic syndrome , or a parasite infection is present.

Because IgM antibodies are the type that form when an infection occurs for the first time, high levels of IgM can mean a new infection is present.