What are the common types of antibodies?

There are five common types of antibodies, each of which has a different function.  

1. Immunoglobulin G (IgG): Immunoglobulin G (IgG) is the main antibody in blood, accounting for around 70–75% of all antibodies in the human body. IgG plays an important role in the biological defense system because of its strong ability to bind to toxins and bacteria. Depending on the antigen, IgG can promote the release of toxins to destroy the microorganism directly or it can tag a pathogen to help other proteins and immune cells to recognize and destroy it. Immunoglobulin G is the only antibody that is capable of passing through the placenta and providing passive immunity to the fetus and newborn in the first few months of life. 
2. Immunoglobulin M (IgM): Immunoglobulin M (IgM) is one of the first antibodies to be synthesized in response to an antigen or microbe. It accounts for only 5% of all antibodies present in the blood but its population rises rapidly when the body is first faced with an infectious organism. The numbers drop only after IgG antibodies take over. When bound to a pathogen, Immunoglobulin M spurs other immune cells and antibodies into action. 
3. Immunoglobulin A (IgA): Primarily found in mucosal tissues such as those in the mouth, intestines and vagina, as well as in saliva, breast milk, and tears, Immunoglobulin A (IgA) accounts for 15% of all antibodies in the human body. IgA is one of the body's first lines of defense against infections. When confronted with an infection, Immunoglobulin A binds to the invading pathogens and tags them for destruction. It also prevents them from adhering to the epithelium, which lines the tissues of the body. The IgA present in breast milk protects newborns’ gastrointestinal tract against viral and bacterial infections. Immunoglobulin A is associated with hypersensitive reactions in individuals with certain autoimmune disorders including celiac disease.  
4. Immunoglobulin E (IgE): Immunoglobulin E (IgE) is responsible for the allergic responses in the skin, lungs, and mucosal membranes. The least prevalent antibody in the human body under normal circumstances, its concentration increases rapidly in response to allergic conditions or when fighting a parasitic infection. When Immunoglobulin E binds to allergens, it triggers a series of events that results in the release of an inflammatory compound called histamine into the bloodstream. The presence of histamine in the bloodstream is what causes allergy symptoms. 
5. Immunoglobulin D (IgD): Immunoglobulin D (IgD) functions as a signaling antibody and plays a vital role in the early stages of the immune response. Its exact function is still unclear but it is thought to bind to B cells, which triggers the release of front-line Immunoglobulin M to fight infection and disease. Immunoglobulin D makes up only about 0.25% of antibodies in the human body.