Because they have no antibodies to A, B, or Rh in their blood, people with type AB+ blood can get red blood cells from any blood type donor. To avoid A and B antibodies in the transfused plasma attacking the recipient's red blood cells, plasma transfusions are matched. That is, donors who offer only A-positive or B-positive plasma would not be suitable donors for an individual who needs a plasma transfusion because they would likely produce antibodies that would attack the recipient's red blood cells. Individuals with type AB+ blood can get plasma from anyone whose blood types are known. Thus, they do not need to find a donor who is a perfect match; they can obtain enough plasma from several different donors to fill their requirement. This is why individuals with type AB+ blood are called "universal recipients" for blood transfusions. The AB+ blood group is one of the most common human blood groups. It occurs with a frequency of about 1 in 50 individuals. People with AB+ blood may not know it, but they are able to receive plasma from any other person whose blood types are known. In fact, this ability is what makes them good candidates for plasma donations. As plasma comes in single units rather than whole blood, finding compatible donors is easier for individuals with AB+ blood than for those with other blood types. However, even people with AB+ blood cannot always find suitable donors among friends and family members.