ABpositiv

ABpositiv, or AB positive, is a blood type within the ABO and Rh blood group systems. It denotes individuals whose red blood cells display both A and B antigens on their surface and the RhD antigen, giving the A+B+ phenotype. Because their plasma contains neither anti-A nor anti-B antibodies, AB positive people do not naturally attack A or B antigens in transfused blood.

Prevalence of AB positive varies by population and region. It is less common than many other types, typically occurring in a minority of people—estimates often place AB positive at around 4 to 7 percent worldwide, with substantial variation by ethnicity. AB negative, by contrast, is rarer, and the distribution of all ABO/Rh types differs across populations.

Clinical implications for transfusion are central to AB positive blood. For red blood cell transfusions, AB positive recipients can receive RBCs from donors of any ABO type under standard safety practices, though Rh compatibility is still considered. In terms of donation, AB positive individuals can donate RBCs to AB positive recipients only. For plasma transfusions, AB type plasma is the universal donor type, meaning it can be given to receivers of any ABO type; Rh status is generally less critical for plasma products, though local guidelines may vary.

Genetics and history: The ABO system was discovered by Karl Landsteiner in 1901. The Rh factor was identified a few decades later, with key work in the 1940s. Inheritance of the AB phenotype involves co-dominant A and B alleles, while the RhD gene determines positive versus negative status. Modern medical practice relies on routine blood typing to ensure compatibility before transfusions and during pregnancy.