See also ABO blood group typing
Hemagglutination is a general term applied to any agglutination test in which clumping of red blood cells indicates a positive reaction.
Human blood can vary from one individual to the next. The phrase “blood group” is used to identify any one of the nermerous types into which an individual’s blood may be classified, based upon the presence or abasence of certain antigens located on the surface of a person’s erythrocytes (i.e., red blood cells). Each specific blood group contains, or many contain, antibodies within the serum which react against the cells of other groups.
conversion of Type A, B and AB blood to Type O blood:
Extra-corporal blood treatment using sacharides: Nilsson (US 2002/0146814) discloses an apparatus which contains a saccharide such as N-Acetylgalactosamine (GalNAc) which is a terminal carbohydrate forming the antigen of blood group A covalently bound by a spacer to a cross linked matrix which which can be used to remove blood group A and/or blood group B antibodies from blood.
Extra-corporal blood treatment using enzymes:
Clausen (WO 03/027245 A2) teaches the enzymatic removal of type A and B antigens from blood group A, B, and AB in blood products uisng α-N-acetylgalactosaminidases and α-galactosidases for removing the immunodominant monosaccharides of the blood group A and B antigens.
Nilsson (US 12/597192) also discloses a column which can be used for the reduction and or removal of blood group A and/or B specific antibodies combined with the use of enzymes such as N-acetyl-alpha-D-galactosaminidase which cleaves GalNAc form blood group A erythrocytes and alpha-D-galactosidasewhich cleaves galactose (Gal) from blood group B erythrocytes resulting in glood group O erythrocytes. In a separate embodiment, Nilsson (US 12/597192) also discloses a column which can be used to remove anti-A/B antibodies and also hydrolyse IgG and/or IgM molecules in connection with extra-corporal blood treatment of a graft recipient before and/or after transplantation of a blood group incompatible graft such as a donor kidney using at least one proteolytic enzymes bound to the matrix as for example IdeS or EndoS which hydrolyize saccharides from IgG.
Rheus blood group antigens:
Rheus blood group antigens are located on transmembrane erythrocyte proteins. The include the so-called “C, c, E, e and D antigens. Aobut 16% of the Caucasion porpulation is Rehsus D negative (RhD(-)) due to an inherited polymorphism. In addition, multiple genetic and serological variants of RhD exist (divided into category II-VII) of which RHDVI is the most clinically relevant. Since category VI positive red blood cells carry fewer of the various epitopes of the D protein than RBC of otehr categoreies, RhDVI+ individuals may form alloantiboides agaisnt RBC form other rhD positive inidivduals.
RhD negativity in itself is not assocaited with any medical conditions, but has important medical implications wehn a RhD(-) femals carries a RhD(+) or RhDVI(+) fetus or a RhDVI(+_ female carries a RhD(+) fetus. Fetomaternal RhD alloimmuizaiton may then occur if fetal erythrocytes enter the maternal circulation and thereby cause the induction of a amternal anti-RhD anitobdy response.
Rh factor: Individuals having the D antigen are called “Rh-positive”. Antibodies of the specifity anti-D are the most common irregular rhesus antibodies and arise above all during rhesus-incompatible pregnancies and following transfusion of rehsus-incompatible blood.
Polyclonal immunoglobulin preprations against RhD are used to prevent alloimmunization of pregnant RhD()-) and RhD(VI)+ women, thereby preventing hemolytic disease of the newborn. Rasmussen (WO2006/007850) describe a method for manufacturing an anti-RhD recombinant polyclonal antibody composition where cell lines are capable of expreesing from a VH and VL comprising nucleic acid segment from one membrne of a library of anti-RhD antibodies.