Blood Bank and Blood Group Systems - SLLE 2023

BLOOD BANK Presented by: Haya Mansour SLLE Exam 2023  Major Blood Groups Systems. - ABO blood group system. - Rh Blood Group System. Minor Blood Group System. - Lewis, I, P, MNSs. Outline - Kell, Kidd, Duffy, Lutherean....

BLOOD BANK Presented by: Haya Mansour SLLE Exam 2023  Major Blood Groups Systems. - ABO blood group system. - Rh Blood Group System. Minor Blood Group System. - Lewis, I, P, MNSs. Outline - Kell, Kidd, Duffy, Lutherean. ABO Discrepancy. Antibody Screening. Antibody identifications. Techniques used in blood bank. Hemolytic disease of the newborn HDN. Blood donation. Blood components. Major Blood Groups Systems  ABO Blood group system. 1. This system called ABO system. 2. One position, or locus on each chromosome 9 is occupied by an A, B, or O gene. 3. Each person has one blood group A, AB, B or O. 4. They are carbohydrates attached proteins or lipids (glycoproteins, glycolipids). 5. They called antigens when they inter to other body. 6. They called protein when they are inside the body as part of RBC structure. 7. ABO Abs are mostly IgM class They most important systems which contain antigens that can provoke the most severe transfusion reactions are: - ABO system. (ABO blood group system - first described by Karl - O is the Universal donor. Landsteiner in 1900). - AB is the Universal recipient. - Rhesus system - Other blood group systems (Kell,Kidds, Duffy etc).  ABO system Antigens Existing normally 1. As solid on RBC. 2. As soluble antigens in plasma, saliva, semen, and other secretions. 3. There is no ABO antigens in CSF. 4. They are also expressed on various body tissues.  Maybe existing on T, B cells and platelets when they adsorbed from the plasma. Antigens blood group importance They are: 1. Most immunogenic. 2. Because the most common cause of death from a blood transfusion. 3. Different ABO blood types vary among different populations. 4. ABO antigens are also important in organ transplantation  Inheritance of ABO antigens One A,B,O gene is inherited from each parent Phenotypes Genotypes - A genes  Dominant A AA or AO - B gene  Dominant B BB or BO - A & B genes  Co- Dominant AB AB - O gene  An recessive O OO  Genotype of group A individual? Genotype vs. Phenotype: - AA/AO. - The phenotype: is the result of the reaction between the red cells and antisera.  Father is A, Mother is O, baby blood - The genotype: is the genetic makeup and can be predicted using the group is O, the father pattern is? phenotype. - Heterozygous.  Parents are A group, offspring blood group? - A or 0.  Father is AB, Mother is B, the possibilities? - A, B, AB.  Percentage possibility of child for O father, AB mother? - А (50%). В (50%).  AB parents, the possibilities? - A (25%), B (25%), AB (50%). ABO Blood group system.  ABO Blood group system.  Subgroups.  Antibodies properties. Rules must be known: ▪ A person does not have antibody to his own antigens. ▪ Each person has antibody to the antigen he lacks (only in the ABO system)  Subgroups of A and B antigens: They are inheritance conditions. This subgroup has fewer H chains converted to A or B antigen. The most common are subgroups of A antigen : A1, A2, A3, Ax, A.int, A.m, A.el, A1B, A2B. The most common subgroups of B antigen: B3, Bx, B.m, B.cl  ABO Subgroups. Subgroup Differ in the amount of the antigen expressed on the RBCs. Blood group A divided into: Al and A2: - 80% of group A people are Al. - 20% of group A people are A2. - A1 antigen has five times sites more than on A, and few H antigen. - A2 has more free H antigen and antibodies anti-A1 that is usually clinically insignificant.  Formation of A, B, and H Red Cell Antigens ABH genes code for produce specific glycosyltransferases that add sugars to a basic precursor substance. A, B, and H antigens are formed from a basic precursor material (called glycan) to which sugars are attached in response to specific enzyme transferases. The H antigen is the precursor of A and B antigens. Inheritance of the H gene results in the formation of the H antigen, H and Se genes influence A and B antigen expression. The H gene must be inherited to form the ABO antigens on the RBCs, and the Se gene must be inherited to form the ABO antigens in secretions. When L-fucose sugar attaced to an oligosaccharide chain on the terminal galactose of type 2 chains H substance is formed. When N-acetyl-D-galactosamine sugar transfer to the H substance the blood group A is formed. The blood group B is formed if D-galactose sugar transfer to the H substance. Genotype hh (Bombay), no production of α-2-L-fucosyltransferase no L-fucose, no A, B, O Ags produced.  Donor Nucleotides & Immundominant Sugars responsible for H, A, and B Ags specificity GENE Glcosyltransferase Immunodominant Immunodominant sugar sugar H L- fucosyl trnsferas L-fucose H A N N-acetyl-D A acetylglucosaminyl galactoseamine transferase B D- galactosyl D-galactose B transferase H: O > A2 > B > A2B > A1 > A1B Glycan and RBCs ABO-Antibodies characteristic are: Formed naturally, they arise without immune stimulation. They are IgM for A and B blood group. IgG for blood group O. They can fix the complement. Existing in the plasma. They are absent at birth or they are very weak. They are not detectable in the blood of newborn infants. Why? due to their underdeveloped immune system Start to appear at age 4 months; They are stable by ages 5-6 years They reach adult levels at age 10,  What means the presence of natural antibodies at birth? - If anti-A and/or anti-B are present at birth, they are of maternal ABO Antibodies origin(IgG). 1. Naturally: formed without prior exposure for foreign antigen. 2. Autoantibody: antibody formed May disappear with elderly age. against patient own antigens. Older agein. 3. Alloantibody: formed to foreign Bone marrow transplantation. antigens.  Blood group antibodies -clinical significance Disease Explanation Haemolytic transfusion reaction (HTR) in case of ABO-mismatched blood transfusion. New born Haemolytic transfusion reaction in case of the embryo A or B the mother O (NB-HTR) blood group. Acute graft rejection in case of ABO-incompatible solid organ transplantation Haemolysis of donor red cells following ABO-incompatible bone marrow transplantation.  Lectins and Subgroup A identification Lectins are extracts of seeds of plants that react specifically with certain antigens on the RBC.  They act like antibodies. Lectins in blood banking: 1- Ulex europaeus, or “lectin H” which agglutinates RBC cells that have H substance. 2- Dolichos biflouros, or ‘lectin A1”, which agglutinates RBC cells with A₁. Lectin-H Reactions. Lectin-H reacts strongest with O cells, which has a high concentration of H antigen. And weakest with A, cells, which have a low concentration of H Lectin O cell A1 cell A2 cell Lectin-H 4+ 0 3+  Lectin-A Reactions. Lectin-A1 Reactions: Lectin-A reacts strongest with Al cells, and A, B cells which has a low concentration of H antigen. And negative the other RBC cells cells, which have high concentration of H. A1 and A2 subgroups: Anti- A Anti- A1 Anti-H lectin ABO Antibodies in serum A1 4+ 4+ 0 Anti-B A2 4+ 0 3+ Anti-B & anti-A1  Bombay phenotype – Oh “H null”. The designation "Bombay" phenotype was assigned to those whose cells lack A, B, and H antigen. H antigen: - Is not expressed on RBCs. - H antigen is not found in saliva - Genotype: h/h se/se, no production of a-2-L-fucosyl-transferase (H- enzyme) no fucose, no A, B, O Ags produced. - They are also referred to as having the "Oh“ - Represent