Different types of antibodies are produced by your immune system.
Each has distinct methods of defending your body against disease and infection.
Harmful infectious organisms are identified as invaders due to their antigens (distinct molecules on their surface).
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Immunoglobulin Isotypes
Antibodies are also known as immunoglobulins (Ig).
Your body can produce an infinite number of binding sites to bind to antigens.
IgA is one of the body’s first-line defenses against infection.
IgA is also associated with hypersensitive reactions in people withceliac diseaseand several other autoimmune disorders.
What Are Autoantibodies?
An autoantibody is an antibody directed against the bodys cells.
Antibodies are designed to attack invading pathogens, like viruses and bacteria.
Autoantibodies occur when the immune system becomes confused and mounts an assault on the body’s own proteins.
It is histamine that is responsible for many of the most commonsymptoms of allergy.
IgE also helps to protect the body from parasitic infections, including helminths (parasitic worms).
As a signaling antibody, IgD helps incite the release of front-line IgM to fight disease and infection.
IgD accounts for only around 0.25% of antibodies in the human body.
As with naturally occurring antibodies, monoclonal antibodies stimulate the immune system to act against disease-causing agents.
In addition to their origin, they fundamentally differ in specificity and utilization.
Antibody tests are used to detect disease-specific antibodies in a blood sample.
A positive result means “yes,” the test has detected the antibody or antigen.
A negative result means “no,” while borderline results are considered inconclusive.
Depending on the disease, it may take time for enough antibodies to be produced to reach detectable levels.
Some disorders are associated with a deficiency, but not from a specific IgG.
For example,primary immunodeficiency disease (PID)is diagnosed with a deficiency of total IgG.
Sometimes, immunoglobulin levels can be used to characterize the stage of an infection.
For example, herpes simplex is an infection for whichIgMandIgGtests can help determine the timing of the infection.
In people with allergies, IgE tests can be used to confirm that an allergic response has occurred.
Summary
The body has five different types of antibodies, also known as immunoglobulins.
IgA, IgD, IgG, IgE, and IgM are different immunoglobulin isotypes.
Immunoglobin A (IgA) defends against infection by binding to pathogens to tag them for destruction.
IgD binds to B cells to kick-start the immune response.
IgG binds to a pathogen or activates antibodies to destroy it.
IgE fights parasitic infections and binds to allergens.
Antibodies are produced in response to a disease or infection; they are not the disease or infection.
Some antigen tests can detect an actual pathogen by its signature antigen.
Some diseases can be diagnosed with either an antibody or antigen test.
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