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 are now permitted by the WTS." He says the objection to blood transfusions on the basis of biblical proscriptions against eating blood is similar to the refusal of a heart transplant on the basis that a doctor warned a patient to abstain from eating meat because of his high cholesterol level. David Malyon, chairman of the English Hospital Liaison Committee in Luton, England, has claimed that Muramoto's discussion of the differences between consuming blood and alcohol is pedantic and says blood laws in the Bible are based upon the reverence for life and its association with blood, and that laws