Blood type Blood Transfusion in addition to the common ABO and Rh systems. Thus, in addition to the ABO antigens and Rh antigens, many other antigens are expressed on the RBC surface membrane. For example, an individual can be AB, D positive, and at the same time M and N positive (MNS system), K positive (Kell system), Le or Le negative (Lewis system), and so on, being positive or negative for each blood group system antigen. Many of the blood group systems were named after the patients in whom the corresponding antibodies were initially encountered. Transfusion medicine is a specialized branch of
Jehovah's Witnesses and blood transfusions place patients at heightened risk for reduced long-term survival." The study also stated that "Survival estimates of Witnesses were 86%, 69%, 51%, and 34% at 5, 10, 15, and 20 years after surgery, respectively, vs 74%, 53%, 35%, and 23% among non-Witnesses who received transfusions." Bloodless medical and surgical techniques have limitations, and surgeons say the use of various allogeneic blood products and pre-operative autologous blood transfusion are appropriate standards of care for certain patient presentations. The Watch Tower Society states that in medical emergencies where blood transfusions seem to be the only available way to save a life, Jehovah's