Packed red blood cells red cells with both are called AB. Except in unusual cases like infants or seriously immunocompromised individuals, all people will have antibodies to any ABO blood type that isn't present on their own red blood cells, and will have an immediate hemolytic reaction to a unit that is not compatible with their ABO type. In addition to the A and B antigens, there are rare variations which can further complicate transfusions, such as the Bombay phenotype. The Rh blood group system consists of nearly around 50 different antigens, but the one of the greatest clinical interest is the "D" antigen,
Jehovah's Witnesses and blood transfusions eating blood to prohibit the medical transfusion of human blood. Osamu Muramoto has argued that the refusal by Jehovah's Witnesses of "life-saving" blood treatment creates serious bio-medical ethical issues. He has criticized the "controlling intervention" of the Watch Tower Society by means of what he claims is information control and its policy of penalising members who accept blood transfusions or advocate freedom to choose blood-based treatment. He says the threat of being classified as a disassociated Witness and subsequently shunned by friends and relatives who are members coerces Jehovah's Witnesses to accept and obey the prohibition on blood transfusions. In