Doctors sometimes treat low immunoglobulin levels with an intravenous (IV) immunoglobulin infusion. Read on to learn more about immunoglobulins, including how they help your body mount a defense against infections and why doctors use tests to measure your immunoglobulin levels.
What are immunoglobulins
Immunoglobulins are Y-shaped molecules made up of sugar and protein produced by plasma cells, a type of white blood cell.
They have three main functions:preventing foreign invaders from entering cells by neutralizing themcoating foreign invaders to tag them for destruction by white blood cells called macrophagestriggering destruction of foreign invaders by stimulating other immune responses
The tip of immunoglobulins contains a highly variable region called a paratope. The paratope binds to sections of foreign molecules called epitopes like a lock and key. The tip of the paratope contains a highly variable region that allows for your body to produce millions of types of antibodies.
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Daniel Kumar 2 minutes ago
Each antibody only binds with one particular type of foreign molecule.
What are plasma cells
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Hannah Kim 8 minutes ago
They have the capacity to generate mass quantities of immunoglobulins that are programmed to recogni...
Each antibody only binds with one particular type of foreign molecule.
What are plasma cells
Plasma cells are activated B cells.
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Scarlett Brown 3 minutes ago
They have the capacity to generate mass quantities of immunoglobulins that are programmed to recogni...
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Brandon Kumar 2 minutes ago
Lymphoid stem cells can become three types of white blood cells that play critical roles in your ada...
They have the capacity to generate mass quantities of immunoglobulins that are programmed to recognize a specific epitope (foreign molecule). Your blood consists of three types of blood cells:red blood cells that carry oxygen around your bodyplatelets that help your blood clot after an injurywhite blood cells that protect your body from foreign invaders and cancers
All blood cells come from special cells called hematopoietic stem cells found in your bone marrow. These cells can become two other types of cells called myeloid stem cells or lymphoid stem cells.
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Chloe Santos 11 minutes ago
Lymphoid stem cells can become three types of white blood cells that play critical roles in your ada...
Lymphoid stem cells can become three types of white blood cells that play critical roles in your adaptive immunity:Natural killer cells: contain enzymes to destroy cancer cells or virusesT cells: destroy infected cells and activate other immune cellsB cells: become plasma cells when activated by foreign invaders and produce Immunoglobulins
What are the most common types classes of immunoglobulin
Immunoglobulins are made up of two molecules called light chains and two called heavy chains. Five types of immunoglobins are found in humans. They’re named after the type of heavy chain they contain:IgM: Provides rapid defense against infectious diseases.IgG: Provides most of the immunoglobin-based immunity against foreign molecules but has a slower effect than IgG.IgA: Provides defense against infectious agents and is found mostly in your mucus membranes.
It protects the surfaces of your respiratory, digestive, and urinary systems.IgE: Provides protection against parasites. It also triggers histamine release from white blood cells called mast cells and basophils to trigger allergic reactions.IgD: Has a largely unknown function.
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Joseph Kim 9 minutes ago
It may serve as a receptor on B cells that haven’t been previously exposed to foreign molecules. <...
It may serve as a receptor on B cells that haven’t been previously exposed to foreign molecules.
How are immunoglobulins used in the field of medicine
Immunoglobulin levels are useful biomarkers for monitoring many different diseases, including immunodeficiencies and autoimmune diseases.
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Charlotte Lee 25 minutes ago
Your doctor may recommend testing your immunoglobulin levels if immunodeficiency runs in your family...
Your doctor may recommend testing your immunoglobulin levels if immunodeficiency runs in your family or if you have symptoms of a condition associated with atypical immunoglobulin levels like persistent diarrhea or unexplained weight loss.
Low immunoglobulin levels
Low immunoglobulin levels suggest that your immune system is not functioning optimally.
Conditions associated with low immunoglobulin levels include:serious infectionsmedication side effectskidney diseaseburnsmalnutrition
Some people are born with lower-than-normal immunoglobulin levels. IgA deficiency occurs in about 1 in 700 people, according to the National Health Service.
High immunoglobulin levels
Elevated immunoglobulin levels are seen in people with conditions such as:autoimmune diseasehepatitiscirrhosischronic infectionsome cancers like multiple myelomaallergiesinflammatory bowel disease
Antibody deficiency disorders
Some people do not produce immunoglobulins or do not produce as many immunoglobulins as they typically should.
These conditions are called antibody deficiency disorders. They may present shortly after birth with recurrent infections.
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Sophia Chen 22 minutes ago
These conditions are often treated with intravenous immune globulin (IVIG) where immunoglobulins are...
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Lucas Martinez 9 minutes ago
This happens through a process called molecular mimicry. In molecular mimicry, the paratopes of circ...
These conditions are often treated with intravenous immune globulin (IVIG) where immunoglobulins are infused through a vein. Other people have autoimmune conditions where they produce immunoglobulins against their own cells.
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Audrey Mueller 19 minutes ago
This happens through a process called molecular mimicry. In molecular mimicry, the paratopes of circ...
This happens through a process called molecular mimicry. In molecular mimicry, the paratopes of circulating immunoglobulins that are primed against an earlier infection closely resemble innocent epitopes on the surface of healthy cells.
IVIG is often used to treat these conditions, which include:ConditionDescriptionimmune thrombocytopeniaautoimmune destruction of plateletsautoimmune hemolytic anemiaautoimmune destruction of red blood cellsGuillain-Barré syndromeautoimmune destruction of nerves that control breathingchronic inflammatory demyelinating polyneuropathyautoimmune destruction of your nerves’ protective coating
What do immunoglobulin blood tests measure
Doctors often order tests to check circulating levels of IgA, IgG, and IgM to measure your immune function. IgD isn’t routinely tested, and its function isn’t fully understood. Here’s a look at immunoglobulin tests and what a low or high score could indicate.
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Hannah Kim 27 minutes ago
Reference ranges are based on the 2.5th and 97.5th percentiles. Each laboratory establishes its own ...
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Ava White 51 minutes ago
Higher than normal levels may indicate Graves’ disease
Takeaway
Immunoglobulins are mole...
Reference ranges are based on the 2.5th and 97.5th percentiles. Each laboratory establishes its own reference range, so these values are estimates.Immunoglobulin testApproximate reference rangesConditions associated with a low scoreConditions associated with a high scoreIgA test0.8 to 3.0g/L• some types of leukemia
• kidney damage
• intestinal problems
• ataxia-telangiectasia,
• increased risk of severe reaction after blood transfusion
• low or lack of IgA production from birth• monoclonal gammopathy of unknown significanc (MGUS)
• multiple myeloma
• some autoimmune diseases like rheumatoid arthritis
–cirrhosisIgD test0.003 to 0.03g/L• researchers are still trying to understand the significance of low IgD• may rarely suggest multiple myelomaIgE test0.0002 to 0.002g/L• can occur with a rare disease called ataxia-telangiectasia• parasitic infection
• allergic reactions
• asthma
• atopic dermatitis
• some cancers
• some autoimmune diseases
• rarely multiple myelomaIgG test6.0 to 16.0g/L• Waldenstrom’s macroglobulinemia
• leukemia
• kidney damage
• rarely, people are born without IgG immunoglobulin• chronic infections like AIDS
• MGUS
• multiple myeloma
• chronic hepatitis, multiple sclerosisIgM test0.4 to 2.5g/L• multiple myeloma
• leukemia• MGUS
• Waldenstrom’s macroglobulinemia
• early viral hepatitis
• mononucleosis
• rheumatoid arthritis
• kidney damage
• parasitic infection
• new infectionThyroid-stimulating immunoglobulin (TSI) hormoneUnder 0.54 IU/LTSI is a type of IgG that tells the thyroid to release more thyroid hormones.
Higher than normal levels may indicate Graves’ disease
Takeaway
Immunoglobulins are molecules produced by plasma cells following B cell activation due to exposure to a foreign agent. B cells are white blood cells of lymphoid lineage. Many different health conditions are associated with high or low immunoglobulin levels.
A doctor may recommend testing your immunoglobulin levels if you have a family history of immunodeficiency or symptoms of a condition associated with atypical immunoglobulin levels. Last medically reviewed on October 14, 2022
How we vetted this article
SourcesHistoryHealthline has strict sourcing guidelines and relies on peer-reviewed studies, academic research institutions, and medical associations. We avoid using tertiary references.
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Victoria Lopez 37 minutes ago
You can learn more about how we ensure our content is accurate and current by reading our editorial ...
You can learn more about how we ensure our content is accurate and current by reading our editorial policy.Anatomy and Physiology (Boundless). (2020).
med.libretexts.org/Bookshelves/Anatomy_and_Physiology/Book%3A_Anatomy_and_Physiology_(Boundless)/00%3A_Front_Matter/02%3A_InfoPageAntibody.
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Victoria Lopez 13 minutes ago
(2022).
genome.gov/genetics-glossary/AntibodyBlood tests explained: Immunoglobulins. (n.d.).
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Harper Kim 32 minutes ago
(2019). Antibody structure and function: The basis for engineering therapeutics.
ncbi.nlm.nih.go...
(2022).
genome.gov/genetics-glossary/AntibodyBlood tests explained: Immunoglobulins. (n.d.).
iwmf.com/wp-content/uploads/2020/10/bloodcharts_ig.pdfImmunoglobulins. (2022).
ouh.nhs.uk/immunology/diagnostic-tests/tests-catalogue/immunoglobulins.aspxChiu ML, et al.
(2019). Antibody structure and function: The basis for engineering therapeutics.
ncbi.nlm.nih.gov/pmc/articles/PMC6963682/Khan SR, et al. (2021).
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Grace Liu 35 minutes ago
Determinants of serum immunoglobulin levels: A systematic review and meta-analysis.
ncbi.nlm.nih...
Determinants of serum immunoglobulin levels: A systematic review and meta-analysis.
ncbi.nlm.nih.gov/pmc/articles/PMC8058410/Natural killer cell. (n.d.).
cancer.gov/publications/dictionaries/cancer-terms/def/natural-killer-cellRojas M, et al.
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Brandon Kumar 52 minutes ago
(2018). Molecular mimicry and autoimmunity.
sciencedirect.com/science/article/pii/S0896841118305...
(2018). Molecular mimicry and autoimmunity.
sciencedirect.com/science/article/pii/S0896841118305365Thyroid stimulating immunoglobulin (TSH receptor antibodies).
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Victoria Lopez 12 minutes ago
(2020).
healthcare.uiowa.edu/path_handbook/handbook/test1829.htmlVaillant AAJ, et al. (2022)....
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Lucas Martinez 8 minutes ago
Immunoglobulin.
ncbi.nlm.nih.gov/books/NBK513460/Our experts continually monitor the health and ...
(2020).
healthcare.uiowa.edu/path_handbook/handbook/test1829.htmlVaillant AAJ, et al. (2022).
Immunoglobulin.
ncbi.nlm.nih.gov/books/NBK513460/Our experts continually monitor the health and wellness space, and we update our articles when new information becomes available. Current Version
Oct 14, 2022
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Daniel Yetman
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Share this articleMedically reviewed by William C Lloyd III, MD, FACS — By Daniel Yetman on October 14, 2022
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