O-negative blood group is reasonably unusual compared to other blood groups. An individual with O-negative blood group is a universal donor as O-negative blood can be transfused to any blood group.
Blood group is determined by the existence of antigen(s) on the membrane of red cell. The “antigens” are special particles that can elicit an immune response. Body acknowledges its own antigens and the immune system normally will not attack own antigens (and hence the cells bearing these antigens). Nevertheless, any foreign antigen will not be recognized as native and an immune response will be created to remove the foreign antigens. One of the parts of this attack is antibodies (special class of particles that bind to antigens and assists immune system get rid of foreign antigens and the cells bearing them).
ABO and Rh Blood Group System
ABO blood group and Rh blood group is figured out by the existence of 3 antigens (“A” and “B” for ABO system, “Rh” for Rh system). These 2 are the most vital blood collection systems and are based upon the three essential antigens, i.e. A, B and Rh. It is very important to keep in mind that the two are 2 various blood group systems that are quoted in combination. ABO blood group system is determined by the presence of A and B antigen. Rh antigen determines the Rh blood group system category. There many other less important antigens and therefore various other blood collection systems.
An individual with “A” blood group will have “A” antigen on the red cell and anti-B antibody in the plasma. Likewise, an individual with “B” blood group will have “B” antigen on the red cell and anti-A antibody in the plasma. A person with “AB” blood group will have both “A” and “B” antigens on the red cell and none of the above discussed antibodies in the plasma(neither anti-A nor anti-B antibody). Blood group “O” means absence of both “A” and “B” antigens and both anti-A and anti-B antibody in the plasma.
The positive or negative in the blood group describes the Rh antigen. A “positive” blood group implies that the person has Rh antigen on the red cell whereas a “damaging” blood group suggests that the Rh antigen is missing on the red cell. Unlike ABO system, an Rh -ve person will not have anti-Rh antibody in the blood unless he/she has been previously exposed to Rh +ve blood. Right after birth, newborns develop anti-A and/or anti-B antibodies but not the anti-Rh antibody.
|Blood Group||Antigen (A,B)||Rh Antigen||Antibodies|
Keep in mind: Anti-Rh is not typically present in an Rh negative individual. It only establishes after a direct exposure to Rh positive blood in a person with Rh damaging blood group.
Importance of Blood Group Matching
Blood group matching is necessary so that the transfused blood is not attacked by the body immune system of the recipient. The body will attack any foreign antigen. For e.g., An individual with blood group B will be having B antigen on the red blood cells and for that reason “A” antigen will be foreign. If any blood type with A antigen (A or AB blood group) is transfused, the immune system will attack such cells and this will result in the breakdown of the freshly transfused red blood cells.
A person with AB+ blood group will have all 3 antigens (A, B, and Rh) on his/her red cell. For that reason, he can be transfused with any blood group (described a “universal recipient”). An individual with O-negative blood group will have none of the 3 antigens, and therefore can only receive O-negative blood group (any other blood group will lead to immune attack on the “foreign” antigen). Nevertheless, this person can contribute blood to any blood group person as none of the three antigens is present on the red blood cells.
O-negative Blood Group and Possible Problems
As currently mentioned, the O-negative blood group suggests absence of all of the three significant antigens (“A”, “B” and “Rh”) on the red blood cells. It is important to keep in mind that there is no “O” antigen on the blood cells. The absence of antigens A and B is described as O blood group.
O-negative blood group is reasonably unusual and its occurrence varies among various races. Around 7-8 % of the Caucasian population will have O-negative blood group. Nevertheless, just 1 % of the Asian population will have O-negative blood group. In general, around 5 % of the world’s population will have O-negative blood group.
O-negative Blood Group and Pregnancy
A female with O-negative blood group might have Rh incompatibility concerns if she is pregnant with an Rh positive fetus. Issues are most likely to happen in 2nd pregnancy with an Rh favorable fetus if appropriate preventive procedures are not taken.
Nevertheless, sufficient prophylactic treatment is available and it usually avoids the problems if taken at appropriate schedule. The treatment involves injecting the mom with antibodies against the Rh antigen (RhoGHAM) throughout pregnancy and at the time of delivery of baby.
O-negative Blood Group and Blood Donation
O-negative blood group is the “universal donor” blood group. This implies that an individual with any blood group can receive O-negative blood. This is essential in emergency situation situations when a person requires instant blood transfusion and there is no time at all to test his/her blood group. Such person can be transfused an O-negative blood.
People with O-negative blood group can only get O-negative blood. For that reason, sometimes it may be tough to discover O-negative blood for transfusing an O-negative individual.