ABO blood group system roles in cell membrane integrity, cell adhesion, membrane transportation of molecules, and acting as receptors for extracellular ligands, and enzymes. ABO antigens are found having similar roles on epithelial cells as well as red blood cells. The ABO antigen is also expressed on the von Willebrand factor (vWF) glycoprotein, which participates in hemostasis (control of bleeding). In fact, having type O blood predisposes to bleeding, as 30% of the total genetic variation observed in plasma vWF is explained by the effect of the ABO blood group, and individuals with group O blood normally have significantly lower plasma levels of vWF
Jehovah's Witnesses and blood transfusions on blood transfusions has come from both members and non-members. A group of dissident Witnesses known as Associated Jehovah's Witnesses for Reform on Blood (AJWRB) states that there is no biblical basis for the prohibition of blood transfusions and seeks to have some policies changed. In a series of articles in the "Journal of Medical Ethics" US neurologist Osamu Muramoto, who is a medical adviser to the AJWRB, has raised issues including what he claims is coercion to refuse transfusions, doctrinal inconsistency, selective use of information by the Watch Tower Society to exaggerate the dangers of transfusions and the use