Adaptive immunity and blood group types

Adaptive Immunity & Blood groups/Types

Adaptive immunity: An overview

One of the great advantages of the human immune system is its capacity to respond to changes in the environment. The immune system possesses the ability to develop adaptive as well as innate immunity to pathogens. Innate, as opposed to adaptive immunity "is an antigen-nonspecific defense mechanisms that a host uses immediately or within several hours after exposure to almost any microbe. This is the immunity one is born with and is the initial response by the body to eliminate microbes and prevent infection" (Kaiser 2007). But the fact that the immune system is adaptive is the reason that "once you've had the chickenpox, it's extremely unlikely that you'll ever catch it again. This is because your body, when exposed again, will recognize the disease and fight it off" (Hoyt 2010). The immune system identifies foreign or 'non-self' substances such as viruses and bacteria, known as antigens, and once the antigens are identified, the immune system develops proteins called antibodies. Antibodies "fight the infection by killing the antigens. Antibodies are made by white blood cells called lymphocytes, also known as B cells. The main purpose of B cells is to create antibodies to fight infection" (Hoyt 2010).

"The body stockpiles these antibodies so they are available to fight off the disease if exposed later on. Unfortunately, antibodies are disease-specific, so previously acquired chickenpox antibodies will be useless if faced with other diseases" that are not extremely similar in nature (Hoyt 2010). For example, exposure to cow pox had an inoculating capacity for individuals that could protect them from smallpox, which was a devastating epidemic in the 19th century -- but not scarlet fever.

Adaptive immunity is what makes inoculation, or vaccinations possible -- through slight exposure to a killed form of a virus, for example, enough immunity is built up within the individual's body to resist an onslaught from the actual illness. "The vaccine provides just enough of these antigens for the body to recognize them and complete the immune response process, therefore protecting them from exposure to the disease in the future" (Hoyt 2010).

Blood groups and types: Antigens and antibodies

While almost everyone is aware of the fact that different people have different blood types, few are aware that the differences in human blood types are due to the presence or absence of certain protein molecules called antigens and antibodies (Blood group, 2010, Nobel Prize). "The antigens are located on the surface of the red blood cells and the antibodies are in the blood plasma. Individuals have different types and combinations of these molecules" (Blood group, 2010, Nobel Prize).

The ABO and Rh classifications of blood type are the most important systems of differentiation from a medial perspective. The mismatching of these types can cause the immune system to attack the cells in a hostile fashion during a transfusion. "Mixing incompatible blood groups leads to blood clumping or agglutination, which is dangerous for individuals. The clumped red cells can crack and cause toxic reactions. This can have fatal consequences" (Blood group, 2010, Nobel Prize).