<unk>  transfusion Transfusion medicine is a specialized branch of hematology that is concerned with the study of<unk>  groups, along with the work of a<unk>  bank to provide a transfusion service for<unk>  and other<unk>  products. Across the world,<unk>  products must be prescribed by a medical doctor (licensed physician or surgeon) in a similar way as medicines. Main symptoms of acute hemolytic reaction due to<unk>  mismatch. Much of the routine work of a<unk>  bank involves testing<unk>  from both donors and recipients to ensure that every individual recipient is given<unk>  that is compatible and is as safe as possible. If a unit of incompatible<unk>  is transfused between a donor and recipient, a severe acute hemolytic reaction with hemolysis (RBC destruction), kidney failure and shock is likely to occur, and death is a possibility. Antibodies can be highly active and can attack RBCs and bind components of the complement system to cause massive hemolysis of the transfused<unk> . Patients should ideally receive their own<unk>  or<unk> -specific<unk>  products to minimize the chance of a transfusion reaction. It is also possible to use the patient's own<unk>  for transfusion. This is called autologous<unk>  transfusion, which is always compatible with the patient. The procedure of washing a patient's own red<unk>  cells goes as follows: The patient's lost<unk>  is collected and washed with a saline solution. The washing procedure yields concentrated washed red<unk>  cells. The last step is reinfusing the packed red<unk>  cells into the patient. There are multiple ways to wash red<unk>  cells. The two main ways are centrifugation and filtration methods. This procedure can be performed with microfiltration devices like the Hemoclear filter. Risks can be further reduced by cross-matching<unk> , but this may be skipped when<unk>  is required for an emergency. Cross-matching involves mixing a sample of the recipient's serum with a sample of the donor's red<unk>  cells and checking if the mixture agglutinates, or forms clumps. If agglutination is not obvious by direct vision,<unk>  bank technicians usually check for agglutination with a microscope. If agglutination occurs, that particular donor's<unk>  cannot be transfused to that particular recipient. In a<unk>  bank it is vital that all<unk>  specimens are correctly identified, so labelling has been standardized using a barcode system known as ISBT 128. The<unk>  group may be included on identification tags or on tattoos worn by military personnel, in case they should need an emergency<unk>  transfusion. Frontline German Waffen-SS had<unk>  group tattoos during World War II. Rare<unk> s can cause supply problems for<unk>  banks and hospitals. For example, Duffy-negative<unk>  occurs much more frequently in people of African origin, and the rarity of this<unk>  in the rest of the population can result in a shortage of Duffy-negative<unk>  for these patients. Similarly, for RhD negative people there is a risk associated with travelling to parts of the world where supplies of RhD negative<unk>  are rare, particularly East Asia, where<unk>  services may endeavor to encourage Westerners to donate<unk> . Hemolytic disease of the newborn (HDN) A pregnant woman may carry a fetus with a<unk>  which is different from her own. Typically, this is an issue if a Rh- mother has a child with a Rh+ father, and the fetus ends up being Rh+ like the father. In those cases, the mother can make IgG<unk>  group antibodies. This can happen if some of the fetus'<unk>  cells pass into the mother's<unk>  circulation (e.g. a small fetomaternal hemorrhage at the time of childbirth or obstetric intervention), or sometimes after a therapeutic<unk>  transfusion. This can cause Rh disease or other forms of hemolytic disease of the newborn (HDN) in the current pregnancy and/or subsequent pregnancies. Sometimes this is lethal for the fetus; in these cases it is called hydrops fetalis. If a pregnant woman is known to have anti-D antibodies, the Rh<unk>  of a fetus can be tested by analysis of fetal DNA in maternal plasma to assess the risk to the fetus of Rh disease. One of the major advances of twentieth century medicine was to prevent this disease by stopping the formation of Anti-D antibodies by D negative mothers with an injectable medication called Rho(D) immune globulin. Antibodies associated with some<unk>  groups can cause severe HDN, others can only cause mild HDN and others are not known to cause HDN.<unk>  products To provide maximum benefit from each<unk>  donation and to extend shelf-life,<unk>  banks fractionate some whole<unk>  into several products. The most common of these products are packed RBCs, plasma, platelets, cryoprecipitate, and fresh frozen plasma (FFP). FFP is quick-frozen to retain the labile clotting factors V and VIII, which are usually administered to patients who have a potentially fatal clotting problem caused by a condition such as advanced liver disease, overdose of anticoagulant, or disseminated intravascular coagulation (DIC). Units of packed red cells are made by removing as much of the plasma as possible from whole<unk>  units. Clotting factors synthesized by modern recombinant methods are now in routine clinical use for hemophilia, as the risks of infection transmission that occur with pooled<unk>  products are avoided. Red<unk>  cell compatibility *<unk>  group AB individuals have both A and B antigens on the surface of their RBCs, and their<unk>  plasma does not contain any antibodies against either A or B antigen. Therefore, an individual with<unk>  AB<unk>  can receive<unk>  from any group (with AB being preferable), but cannot donate<unk>  to any group other than AB. They are known as universal recipients. *<unk>  group A individuals have the A antigen on the surface of their RBCs, and<unk>  serum containing IgM antibodies against the B antigen. Therefore, a group A individual can receive<unk>  only from individuals of groups A or O (with A being preferable), and can donate<unk>  to individuals with<unk>  A or AB. *<unk>  group B individuals have the B antigen on the surface of their RBCs, and<unk>  serum containing IgM antibodies against the A antigen. Therefore, a group B individual can receive<unk>  only from individuals of groups B or O (with B being preferable), and can donate<unk>  to individuals with<unk>  B or AB. *<unk>  group O (or<unk>  group zero in some countries) individuals do not have either A or B antigens on the surface of their RBCs, and their<unk>  serum contains IgM anti-A and anti-B antibodies. Therefore, a group O individual can receive<unk>  only from a group O individual, but can donate<unk>  to individuals of any ABO<unk>  group (i.e., A, B, O or AB). If a patient needs an urgent<unk>  transfusion, and if the time taken to process the recipient's<unk>  would cause a detrimental delay, O negative<unk>  can be issued. Because it is compatible with anyone, O negative<unk>  is often overused and consequently is always in short supply. According to the American Association of<unk>  Banks and the British Chief Medical Officer's National<unk>  Transfusion Committee, the use of group O RhD negative red cells should be restricted to persons with O negative<unk> , women who might be pregnant, and emergency cases in which<unk> -group testing is genuinely impracticable. Red<unk>  cell compatibility chartIn addition to donating to the same<unk>  group;<unk>  O<unk>  donors can give to A, B and AB;<unk>  donors of<unk> s A and B can give to AB. + Red<unk>  cell compatibility table Recipient1 Donor1 O− O+ A− A+ B− B+ AB− AB+ O− O+ A− A+ B− B+ AB− AB+ Table note 1. Assumes absence of atypical antibodies that would cause an incompatibility between donor and recipient<unk> , as is usual for<unk>  selected by cross matching. An Rh D-negative patient who does not have any anti-D antibodies (never being previously sensitized to D-positive RBCs) can receive a transfusion of D-positive<unk>  once, but this would cause sensitization to the D antigen, and a female patient would become at risk for hemolytic disease of the newborn. If a D-negative patient has developed anti-D antibodies, a subsequent exposure to D-positive<unk>  would lead to a potentially dangerous transfusion reaction. Rh D-positive<unk>  should never be given to D-negative women of child-bearing age or to patients with D antibodies, so<unk>  banks must conserve Rh-negative<unk>  for these patients. In extreme circumstances, such as for a major bleed when stocks of D-negative<unk>  units are very low at the<unk>  bank, D-positive<unk>  might be given to D-negative females above child-bearing age or to Rh-negative males, providing that they did not have anti-D antibodies, to conserve D-negative<unk>  stock in the<unk>  bank. The converse is not true; Rh D-positive patients do not react to D negative<unk> . This same matching is done for other antigens of the Rh system as C, c, E and e and for other<unk>  group
Blood type
Hh blood group
Human blood group systems
Functional symptom
History of pathology
Vel blood group
Rh blood group system
Vegetative symptoms