Positive blood group
Positive blood group
The entire system of blood group comprises with ABO and Rhesus systems. This decides a person of having positive or negative blood and also decides the compatibility of two different people. The red blood cells surface has many layers among which are the antigens. The two significant antigens are known as the A and B antigen. The A antigen if found on the red blood cells surface, the blood group is considered to be of A group. If the same on the red blood cells surface, B antigen is found, the blood group is determined to be of B group. If the red blood cell surface has both A and B antigen, the blood group is considered to be of the AB group. If the antigens neither A nor B is found on the red blood cell surface, it is considered to be of the O blood group. The antigens are responsible in determining the blood as O, A, AB and B. Blood group having A antigen consist in the plasma B antibodies and the blood having B antigen consist in the plasma A antibodies. Blood with A as well as B antigens on the red cells have no antibodies present in the plasma. But, the same blood with no A and B antigens have in the plasma A and B antibodies. This shows that a blood type certainly has the antibody opposite in the plasma. In case the A or B antigens meet the A or B antibodies respectively, they will destroy the antigens and the red blood cells will get clogged together and block the arteries and veins of a patient. This proves that blood group A cannot be given blood group B as it would attack the antigen of the donor and the veins of the patient would get blocked and turns into a serious condition resulting in death. Therefore, A blood group can be given only to people having A and AB only. Similarly, B blood group can be given to people having B and AB blood group only. The Rhesus factor is very essential to meet the compatibility as the Rh D antigen has a vital role to play. This is an antigen on the red blood cell surface. If the Rhesus antigen is present, it is known as positive and in the absence it is determined as negative. The general rule is that Rh negative can be given to Rh positive, but the Rh positive is nor given to Rh negative patient. However, only during emergencies, Rh positive is given to Rh negative with special drugs and medical supervision. Hence transfusing positive into negative patient is restricted especially among potential mothers. This is avoided as antibodies will form against the Rh D antigen and will cause problems in the pregnancy stages and also to the new born baby.