A B AB O In 1900 Dr. Karl Landsteiner identified the four major human blood groups. They are? A, B, AB and O. By mixing plasma and red blood cells taken from himself and five lab assistants he noted that the red cells introduced into foreign plasma either clumped together or they did not. ABO incompatibility is caused by the presence of antigens on the surface of the red blood cells, and antibodies (that react to antigens) in the plasma. Page, Jake. Blood, the River of Life. Torstar Books Inc., New York, NY. 1985.

Blood Type Percentages in the World AB+  O-  A-  B- AB- 36.44% 28.27% 20.59% 5.06% 4.33% 3.52% 1.39% 0.45%

There are 4 major blood groups: A, B, AB and O The blood type depends on the presence of two antigens A or B. Antibodies are part of the immune system, that remains inactive, until the Antigens they are programmed to fight against are introduced into your body. Found in plasma Antigens are what prompt an immune response. Found on RBC cell membrane ABO incompatibility is caused by the presence of antigens on the surface of the red blood cells, and antibodies (that react to antigens) in the plasma.

Antibody Antigen Each blood type has Antigens and Antibodies. Antibodies are part of the immune system that remain inactive until the Antigens they are programmed to fight against are introduced into your body. Antigens what prompt an immune response. Antibodies look like this (a “Y”). At the short end of the Y are Antigen Binding Sites. These site are like unique “keys” that will only fit into the Antigen it was designed for. Antigens are the “locks” that the Antibodies fit into.

Antigen Antigen on the Red Blood Cell Membrane Antibody Antigen What determine the blood types are: Antigens (incorporated into the cell membrane of the red blood cell), and Antibodies (in the Plasma). Antigen on the Red Blood Cell Membrane Antibodies in the Plasma

Draw blood chart on board Blood Type A B AB O Antigen Antibody

Compatible Blood Transfusion Transfusion reaction no clumps, normal blood flow Transfusion reaction red blood cells clump obstruction would occur in capillaries which could lead to death Compatible blood transfusion – no clumps, normal blood flow. Transfusion reaction – red blood cells clump, obstruction would occur in the capillary beds which could lead to death. In 1908 the first blood transfusion was given under the safe conditions Landsteiner made possible. There were no clumps of red blood cells clogging the capillaries, no unexplained deaths and no mysterious reactions.

Antibodies Aggregation Antigen Agglutination Cell (clumping) Antibodies are sitting, waiting to do their work. We introduce Antigens…and they immediately bond to the anitbody. Since each Antibody has 2 binding sites, each one can connect 2 Antigen. Each Antigen can have at least 2 antibodies bound to it… the result is Agglutination (Clumping) Now the foreign body is large enough for the bodies other immune systems to fight them.

Type A Type B Type AB Type O A receives B = Clumping A receives AB = Clumping A receives O = No Clumping B receives A = Clumping B receives AB = Clumping B receives O = No Clumping AB receives A = No Clumping AB receives B = No Clumping AB receives O = No Clumping Discuss If you receive you own blood type… there will be no reaction. Type A receives B, AB, & O… what happens? Type B receives A, AB, & O… what happens? Type AB receives A, B, & O… what happens? Type O receives B, AB, & O… what happens? Point out Type AB never has a reaction when receiving blood! Point out Type O never causes a reaction! O receives A = Clumping O receives B = Clumping O receives AB = Clumping

A ANTI – B B ANTI-A AB NONE O RECIPIENT DONOR A A, O B B,O AB BLOOD TYPE ANTIGENS ON RBC ANTIBODIES IN PLASMA A ANTI – B B ANTI-A AB NONE O ANTI –A & ANTI -B RECIPIENT DONOR A A, O B B,O AB AB, A, B, O O

Blood typing: Rh System Rh factor (Rhesus factor) – 85% of the population have another antigen called Rh on the RBC (Rh+), the other 15% is Rh-. Important to know for pregnancy.

Blood typing: Rh System Rh+ person has Rh antigen on their Red Blood Cell (RBC) Rh- individuals do not have antibodies to the Rh factor

Rh System Problem: when Rh- people are exposed to Rh+ then they produce antibodies.

A person with Rh+ can receive from an Rh- without any problems.                                      A person with Rh+ can receive from an Rh- without any problems. Rh+ can not give to Rh-  

Pregnancy If mother is Rh- and child is Rh+ (inherited from father) The Rh+ fetus blood leaks into mother through placenta The mother produces anti-Rh antibodies In this pregnancy or the next pregnancy the mothers anti-Rh antibodies may cross the placenta and destroy the baby’s RBCs.

Pregnancy RBC leak across the placenta Mother makes anti-Rh antibodies Antibodies attack Rh+ red blood cells in child Child is Rh+ and mother is Rh-

The Rh system. Like the A and B antigens, the Rh antigen, called the D antigen, is located on the surface of the RBCs and is inherited. When the D antigen is present, the person is Rh positive, and when it is absent, the person is classified as Rh negative. Unlike the ABO system, there are no natural antibodies accompanying the Rh system. Anti-D antibodies are produced when an Rh-negative person is exposed to RBCs from an Rh-positive person (that has the D antigen). When RBCs are transfused, Rh-negative patients must receive Rh-negative blood, whereas Rh-positive patients could receive either Rh negative or positive blood. The same reasoning must apply to platelets since they do regularly contain some RBCs.