What Blood Type Is "Panda Blood"? A Guide to Rh-Negative Blood
"Panda blood" is the common name for the Rh-negative blood type. Human red blood cell blood types are made up of more than twenty blood group systems, and the ABO and Rh blood groups are the two most closely related to human blood transfusion. When a person's red blood cells carry a D blood group substance (antigen), the blood is called Rh-positive; when the D antigen is absent, it is Rh-negative. Rh-negative blood is relatively rare and is a very uncommon blood type, so it is also called "panda blood," and among these, AB Rh-negative blood is even rarer.
The Rh-negative blood type is one type within the Rh blood group system. Most people know that the four types A, B, O and AB all belong to the ABO blood group system. In fact, there are more than these four blood types; there are dozens of types or systems, vast and complex. Because blood group antigens other than A, B, O and AB are mostly not strongly antigenic, clinical physicians consider that, in addition to the four blood types above, the Rh blood group system is the most widely used and most important blood group in clinical practice.
Blood types are determined according to the differences in blood group antigens, which are glycoproteins, on the structure of the red blood cell membrane, and different blood types cannot be transfused into one another at will. For example, besides the B antigen, the red blood cells of a person with type B blood also contain anti-A antibodies against type A blood, which can trigger an immune agglutination reaction with red blood cells carrying the type A blood antigen. If the blood of a type A donor is mistakenly transfused to a type B recipient, the A antigen on the type A red blood cells will react immunologically with the A antibody of the type B recipient, causing the type A red blood cells to agglutinate and triggering a hemolytic reaction, which is extremely dangerous. To avoid immune and hemolytic reactions, the blood types of the donor and the recipient must be the same.
In China, more than 99% of people with the Rh blood type are positive, so hemolytic reactions caused by Rh blood type incompatibility during transfusion are relatively uncommon, but uncommon does not mean nonexistent. If a recipient with Rh-negative blood receives blood of the Rh-positive type, it will cause an immune hemolytic reaction. The correct approach is that the blood types of the recipient and the donor must be the same, that is, both must be Rh-negative.
The Rh-negative blood type differs from the A, B, O and AB blood types; the latter are distributed relatively evenly among the population, and blood sources for these several blood types are easy to find. The Rh-negative blood type, however, is a rare blood type, accounting for less than 1% of people with ABO blood types. It is understood that among the 3 million people who donated blood in a certain city, only 3,300 were of the Rh-negative blood type. And the probability of Rh-negative appearing among clinical surgery patients is 5-7/1000. By comparison, Rh-negative blood is extremely precious.