blood group systems

Blood group systems are a classification of blood based on the presence or absence of antigens on the surface of red blood cells. An antigen is a molecule that can stimulate an immune response (antibody production).
Types:
ABO Blood Group
A positive(+)
A negative(-)
B positive(+)
B negative(-)
AB positive(+)
Ab negative(-)
O positive(+)
O negative(-)
ABO Blood Groups:
It is the most important blood group system in humans. Austerian scientist Karl Landsteiner first discovered the ABO blood group system. In this system, there are four different blood groups distinct from each other on the basis of specific antigens (antigens A and B) present on the surface of Red Blood Cells. In a person, antigen A has blood group A, Similarly a person having antigen B has Blood Group B, and A person having antigen AB both then its blood group is AB, When a person’s blood has no antigen its blood group is O.
When a child is born, 2 types of antibodies anti-A and anti-B antibodies appear in the blood serum of that child. The presence of these antibodies depends on the corresponding antibodies present in the blood. In a person with blood group A, antigen A is present and antigen B is absent. Their blood will contain anti-B antibodies. In a person with blood group B, antigen B is present and A is absent. So they will contain anti-A antibodies. In a person having blood group AB, both antigens are present A&B. Neither is absent. Their blood contains no antibodies. In a person with blood O, neither antigen A nor antigen B is present. In his blood group, both antigens are absent. So their blood serum contains both anti-A and anti-B antibodies.
Blood Transfusion in ABO Blood Group System:
Blood transfusion is the process of transferring blood or blood-based products from one person into the circulatory system of another. Blood transfusion is life-saving in some situations, such as massive blood loss due to injury, or can be used to replace blood lost during anemia, hemophilia, thalassemia or suckle cell diseases may require frequent blood transfusions.
Transfusion of blood is done after confirming that no agglutination(clumping of cells) results in the blood of the recipient. If agglutination occurs, the clumped cells do not pass easily through capillaries and block the capillaries. For the confirmation of no agglutination, blood samples of the donor and recipient are cross-matched for compatibility. Anti-bodies of the recipient’s blood may destroy the corresponding antigen containing the Red Blood Cells of the donor or antibodies of the donor’s blood may destroy the antigen containing the Red Blood Cells of the recipient. O blood group individuals are called universal donors because they can donate blood to the recipients of every other blood group. AB blood group individuals are called universal accepters because they can receive transfusions from the donors of every other blood group.
Rh blood group system +ve or -ve:
In 1930 Karl Landsteiner discovered the Rh blood group system. In this system are two blood groups Rh positive and Rh negative. These blood groups are distinct from each other on the basis of antigens called Rh factors. Rh factors were first discovered in Rhesus monkeys. A person having Rh factors has a positive blood group. If a person has no Rh factors then its blood group is Rh-negative.
Unlike the naturally occurring anti-A and anti-B antibodies of the ABO system, an Rh-negative person does not produce anti-Rh antibodies unless the Rh factor enters his/her blood.

Blood Cancer:
Blood cancer is a disease that includes leukemia, bleeding disorders, and thalassemia. A change in DNA genes commonly causes blood cancer.
Types of Blood Cancer:
Leukemia:
Leukemia is the production of many immature and abnormal white blood cells. This is caused by a cancerous mutation (change in gene) in bone marrow or lymph tissue cells. It is a serious disorder, and the patient needs to change the blood regularly with normal blood. (got from donors) It can be cured by bone marrow or lymph tissue cells. It is a dire situation and is a very costly treatment.
Thalassemia:
It is caused by a change in the gene of hemoglobin. This change results in defective hemoglobin being produced and the patient cannot transport oxygen properly. With normal blood, the blood of this patient is replaced regularly. It can be cured by bone marrow transplant but it does not give a 100% cure rate.
World Thalassemia Day:
The International Thalassemia is celebrated on 8th May Every Year. This day is dedicated to raise public awareness about thalassaemia and to highlight the importance of the care for thalassaemia patients.