Relationship Between Antigens And Antibodies
What is the relationship between antigen and antibody and how does that relationship influence hemolysis?
An antigen is any substance which can provoke an immune response in the body. This immune response results in the production of antibodies, which are immunoglobulin proteins, and which are usually made by immune cells known as plasma cells. The antibodies may float free in the blood plasma, or they may be attached to the outer surfaces of white blood cells known as lymphocytes.
Hemolysis is the lysing (bursting) of red blood cells, also known as erythrocytes. It can happen as a response to several different bacteria and parasites, as well as to the antigen/antibody reaction.
Hemolytic disease of the newborn is the commonest manifestation of hemolysis due to antibodies. It occurs when an Rh postitive infant is born to an Rh negative mother who has Rh antibodies as a result of a previous pregnancy. The maternal antibodies can pass through the placenta and attack the baby's erythrocytes, causing issues that range from mild to very severe.
There is a drug called RhoGam that can be administered to Rh negative women to prevent them from forming anti-Rh antibodies. Since the development of this drug, hemolytic disease of newborns has become much less common.
Think of antigens as the locks (or gates) to a cell, and antibodies as the weapon (or key).
Here are a few comparisons:
- a 'hook' or 'gate' on cell surface
- exists on the surface of most cells
- controls what goes in and out of a cell
- regulates inner functions of cell, whilst protecting interior
- exists due to random mutations - complex in structure
- chemical that attaches to antigen to kill (or sterilise) cell
- needed to destroy pathogens in body
- responds to everyday attacks, like viruses
- are designed to be 'matched' to a particular anitgen
Hemolysis is the process of the break-down of red blood cells, as well as the resulting release of haemoglobin. This can be due to the natural life-span of a red blood cell, or it may be as a result of an antigen-antibody interaction.
Antigens are the microbes that attack the immune system which responds with the production of antibodies. Specific antibodies are produced by lymphocytes, which are a type of white blood cells. These antibodies destroy the antigens, which, once destroyed, are swallowed by macrophages.
Hemolysis happens when red blood cells are destroyed earlier than 120 days. Due to this abnormal red blood cell life span, hemolytic anemia occurs. Usually, Hemolysis can be caused either by disorders of red blood cells or abnormalities of red blood cells.
Immune hemolytic anemia occurs when immune system mistakenly recognizes red blood cells as pathogens, hence producing antibodies to destroy them. Immune hemolytic anemia is usually caused by transfusions of blood from donors whose blood type do not match with the blood type of receptors, infections, toxins, certain drugs, types of cancer.