1) The document discusses the ABO and Rh blood group systems, which are determined by antigens on red blood cells and the corresponding antibodies found in plasma.
2) The ABO system includes A, B, and H antigens that are synthesized based on inherited genes. The presence or absence of A and B antigens determines the four blood groups - A, B, AB, and O.
3) The Rh system involves the RhD antigen. Most individuals are RhD-positive unless they inherit two copies of the RhD-negative gene.
This document discusses blood group systems, specifically ABO and Rh blood groups. It provides details on:
- The antigens found on red blood cell membranes that determine blood type
- Landsteiner's discovery of the ABO blood group system in 1900 and the four main blood types (A, B, AB, and O)
- The antigens and antibodies present in each blood type
- Rh blood group system including the Rho(D) antigen and typing only for Rho(D) to determine Rh status
- Techniques for blood typing including tube, slide, microplate, and newer gel/cassette methods
- Interpreting and resolving discrepancies in blood typing results
This document discusses various techniques used in blood banking and transfusion medicine, including:
1. Pretransfusion testing involves ABO/Rh typing, antibody screening, and crossmatching to select compatible blood and prevent hemolytic transfusion reactions.
2. Antibody identification uses a panel of red blood cells to identify the specific antibody in a patient's serum through various testing phases including immediate spin, LISS incubation, and antiglobulin.
3. Special techniques like elution, hemagglutination inhibition, and titration are used to further characterize antibodies or quantify their concentration.
Antisera are used to determine which antigens are on the red cells.
The test using antisera and the patient's red cells is called the
front cell group.
The polyclonal antisera used in the front group are obtained from
plasma apheresis of donors stimulated with soluble antigens (A
substance from pig mucosa and B substance from horse mucosa).
Alternatively, monoclonal antisera can be prepared from cultured
cell lines.
The development of monoclonal antibodies obtained from cultures
of cells secreting antibodies called hybridomas has made available
a new source of ABO typing reagents.
This document discusses the ABO blood group system. It notes that there are over 20 known blood group systems that are genetically determined. The ABO and Rh systems are most important for blood transfusions. The ABO system involves antigens on red blood cells and corresponding antibodies in plasma. People are categorized into one of the main blood groups - A, B, AB, or O - depending on which antigens are present on their red blood cells and which antibodies are present in their plasma. The exact genetic basis and inheritance of the ABO system is also described.
Group I discrepancies involve weak or missing antibodies in reverse grouping due to conditions like newborn status, immunosuppression, or subgroups. Group II discrepancies involve weak or missing antigens in forward grouping, which can be caused by subgroups or diseases weakening antigens. Group III discrepancies are due to rouleaux formation or pseudoagglutination from elevated proteins. Group IV involves miscellaneous issues like cold antibodies, mixed field RBCs, or unexpected antibodies. Resolving discrepancies involves investigating patient history, enhancing weak reactions, addressing rouleaux or cold antibodies, determining if multiple RBC populations exist, and following an algorithmic approach.
This example shows mixed field agglutination in the forward grouping. The causes could be a recent blood transfusion of group O cells or a bone marrow transplant. To resolve it, the tests should be repeated on a new sample or the cells washed and retested.
The document summarizes the history and science behind blood grouping and the ABO blood group system. It describes how Karl Landsteiner discovered the major ABO blood groups in 1901. It explains the antigens and antibodies present in each blood group according to Landsteiner's rule. The genetics and biochemistry of the ABO blood group system are covered, including how the H, A, and B antigens are synthesized on red blood cells. Common blood grouping techniques like forward and reverse grouping are also summarized.
This document discusses blood group systems, specifically ABO and Rh blood groups. It provides details on:
- The antigens found on red blood cell membranes that determine blood type
- Landsteiner's discovery of the ABO blood group system in 1900 and the four main blood types (A, B, AB, and O)
- The antigens and antibodies present in each blood type
- Rh blood group system including the Rho(D) antigen and typing only for Rho(D) to determine Rh status
- Techniques for blood typing including tube, slide, microplate, and newer gel/cassette methods
- Interpreting and resolving discrepancies in blood typing results
This document discusses various techniques used in blood banking and transfusion medicine, including:
1. Pretransfusion testing involves ABO/Rh typing, antibody screening, and crossmatching to select compatible blood and prevent hemolytic transfusion reactions.
2. Antibody identification uses a panel of red blood cells to identify the specific antibody in a patient's serum through various testing phases including immediate spin, LISS incubation, and antiglobulin.
3. Special techniques like elution, hemagglutination inhibition, and titration are used to further characterize antibodies or quantify their concentration.
Antisera are used to determine which antigens are on the red cells.
The test using antisera and the patient's red cells is called the
front cell group.
The polyclonal antisera used in the front group are obtained from
plasma apheresis of donors stimulated with soluble antigens (A
substance from pig mucosa and B substance from horse mucosa).
Alternatively, monoclonal antisera can be prepared from cultured
cell lines.
The development of monoclonal antibodies obtained from cultures
of cells secreting antibodies called hybridomas has made available
a new source of ABO typing reagents.
This document discusses the ABO blood group system. It notes that there are over 20 known blood group systems that are genetically determined. The ABO and Rh systems are most important for blood transfusions. The ABO system involves antigens on red blood cells and corresponding antibodies in plasma. People are categorized into one of the main blood groups - A, B, AB, or O - depending on which antigens are present on their red blood cells and which antibodies are present in their plasma. The exact genetic basis and inheritance of the ABO system is also described.
Group I discrepancies involve weak or missing antibodies in reverse grouping due to conditions like newborn status, immunosuppression, or subgroups. Group II discrepancies involve weak or missing antigens in forward grouping, which can be caused by subgroups or diseases weakening antigens. Group III discrepancies are due to rouleaux formation or pseudoagglutination from elevated proteins. Group IV involves miscellaneous issues like cold antibodies, mixed field RBCs, or unexpected antibodies. Resolving discrepancies involves investigating patient history, enhancing weak reactions, addressing rouleaux or cold antibodies, determining if multiple RBC populations exist, and following an algorithmic approach.
This example shows mixed field agglutination in the forward grouping. The causes could be a recent blood transfusion of group O cells or a bone marrow transplant. To resolve it, the tests should be repeated on a new sample or the cells washed and retested.
The document summarizes the history and science behind blood grouping and the ABO blood group system. It describes how Karl Landsteiner discovered the major ABO blood groups in 1901. It explains the antigens and antibodies present in each blood group according to Landsteiner's rule. The genetics and biochemistry of the ABO blood group system are covered, including how the H, A, and B antigens are synthesized on red blood cells. Common blood grouping techniques like forward and reverse grouping are also summarized.
ABO blood group system was decover by Karal landsteine
which contain A, B, and o antigen on the surface of BC, WBC,s platatelet and other body tissue cells except brain cell, and anti A, antiB and Anti Ab natural occuring antibodies in plasma of B,A, and O blood group individual respectively
This document discusses gel card technology used in blood banking tests. It provides details on the history and development of gel cards, how they work, the types of tests they can be used for (including ABO typing, cross-matching, antibody screening), and their advantages over traditional tube-based methods such as improved sensitivity and reproducibility. Gel cards contain a gel matrix in microtubes that allows red blood cells to be separated based on agglutination during centrifugation, providing clear and standardized test results.
This document discusses blood preservatives and the processes involved in preserving blood and its components. It addresses the biochemical changes that occur in stored blood, such as decreasing pH and ATP levels. Preservative solutions aim to minimize these changes by buffering pH and providing nutrients. Common preservatives mentioned are ACD, CPD, and CPDA, which contain ingredients like citrate, dextrose, and adenine. Newer additive solutions provide nutrients to packed red blood cells to extend their shelf life. Methods to rejuvenate stored blood and freezing techniques are also summarized. The document provides an overview of preserving different blood components like platelets, plasma and cryoprecipitate.
This document provides information on three hematology stains:
Leishman's stain, reticulocyte stain, and iron stain. It describes the composition, procedure, and results for Leishman's stain. For reticulocyte stain, it discusses how reticulocytes contain RNA that stains gray-blue and the procedure uses supravital staining. Iron stain demonstrates ferric iron and ferritin using Prussian blue reaction and involves fixation, staining in potassium ferrocyanide and hydrochloric acid, and counterstaining with nuclear fast red.
The document discusses compatibility testing protocols for blood transfusions. It describes how compatibility testing includes ABO and Rh grouping of donor and recipient samples, screening for unexpected antibodies, and a cross-match. Proper identification of donor and recipient samples is critical to avoid errors. The purpose is to select appropriately compatible blood and ensure the best results for the transfusion by preventing hemolysis or antibody-mediated destruction of transfused red blood cells.
Karl Landsteiner discovered the ABO blood group system in 1900. He identified three main blood groups - A, B, and C, which were later renamed to A, B, and O. Von Decastello and Sturli discovered the AB blood group in 1902. The ABO blood group is determined by the presence or absence of antigens A and B on red blood cells, which is controlled by inherited alleles. People universally have antibodies against blood group antigens they lack. This system is important for blood transfusions, as incompatible blood can cause transfusion reactions.
Pretransfusion testing final- ab screening - NAGLAA MAKRAM Naglaa Makram
1. Antibody screening tests patient serum against reagent red blood cells to detect unexpected antibodies that could destroy transfused donor cells.
2. Screening cells must contain many common antigens and include some cells with homozygous antigen expression to detect weakly reacting antibodies.
3. A positive antibody screen requires antibody identification testing to determine the antibody specificity so that antigen-negative blood can be transfused.
Rh typing and its technique , BLOOD TYPING , Rhesus (Rh) typing , procedures of rh typing, process of Rh typing, Test limitations, Sources of Error in Rh Antigen Typing, False positive reactions' reason, False negative reactions' reasons
This document discusses several major blood group systems including Lewis, I, P, MNSs, Kell, Kidd, Duffy, Lutheran, Bg, Sda, and Xg. It provides information on the antigens and genes involved in each system, the clinical significance of associated antibodies, and inheritance patterns. Some key points covered include that Lewis, I, and P antigens produce cold-reacting antibodies while Kell, Kidd, and Duffy produce warm-reacting antibodies. The MNSs, Kell, and Kidd systems can produce clinically significant antibodies implicated in hemolytic transfusion reactions and hemolytic disease of the newborn.
1. Prussian blue staining is used to identify iron stores in bone marrow samples. It detects ferric iron by forming an insoluble blue compound called Prussian blue when iron reacts with potassium ferrocyanide and hydrochloric acid.
2. Iron is primarily stored in the body bound to the protein ferritin or aggregated as hemosiderin. Prussian blue staining results in hemosiderin appearing blue while nuclei counterstain red.
3. The amount of iron stores visualized on bone marrow samples using Prussian blue staining is graded from 0-6, with higher grades indicating increased iron levels and potential iron overload.
This document provides an overview of basic principles of immunohematology. It defines key terms like antigen and antibody. It describes the characteristics of antigens and factors that contribute to antigen immunogenicity. It also discusses the different types of immunoglobulins involved in blood group antibodies, and the differences between naturally occurring versus immune antibodies. Finally, it explains the stages of antigen-antibody reactions including sensitization and agglutination, and factors that can influence these reactions.
1. Karl Landsteiner discovered the main blood group systems (ABO and Rh) in 1900 and 1940 respectively. The ABO system categorizes blood into A, B, AB and O groups based on antigens on red blood cells.
2. Blood typing and cross-matching are important to ensure safe and compatible blood transfusions. Transfusing incompatible blood can cause hemolytic or allergic reactions in the recipient.
3. Other minor blood group systems have been discovered including MNS, Duffy, Kell and Lewis systems which are important for transfusion medicine and anthropological research. Understanding blood groups is crucial for blood banking and preventing diseases like hemolytic disease of the newborn.
special and routine stains in haematology 1Dr.SHAHID Raza
The document discusses various routine and special stains used in hematology. Routine stains like Leishman, Giemsa, and Wright stains are used to stain peripheral blood films and differentiate blood cells. Special stains require additional processing but can identify characteristics not seen with routine stains, such as periodic acid Schiff stain which detects carbohydrates like glycogen by oxidizing glycol groups and producing a red reaction. Proper staining techniques such as fixation, washing, and timing are important for preparing clear blood smears and accurately identifying blood components.
Weak D testing is performed on all prenatal patients, Rh negative blood donors and transfusion candidates to identify those with the weak D phenotype. The procedure involves incubating patient red blood cells with anti-D, and if negative, adding anti-human globulin to look for weak agglutination indicating a weak D positive result. A true weak D will show at least 2+ agglutination; weaker results may be due to prior transfusions and require checking the transfusion history. All results are documented in the grouping register.
The document discusses the ABO blood group system, including its discovery, genetics, biochemistry, antigens, antibodies, and implications for transfusion. Some key points:
- Karl Landsteiner discovered the main ABO blood groups (A, B, AB, O) in 1900. The ABO blood type is determined by alleles at a single gene locus.
- The antigens are carbohydrate structures on red blood cells. People naturally produce antibodies against antigens they lack.
- ABO typing must be accurate to avoid transfusion reactions. Discrepancies can occur due to weak subgroups, diseases, or test issues. Resolving discrepancies helps ensure patient and donor safety.
Osmotic fragility & rbc membrane defects 050916Anwar Siddiqui
This document discusses red blood cell membrane defects and osmotic fragility testing. It begins by introducing the structure and components of the red blood cell membrane, including integral proteins, lipids, and peripheral proteins that make up the cytoskeleton. Key membrane defects are then described, such as hereditary spherocytosis caused by weakened interactions between membrane proteins, and hereditary elliptocytosis caused by defects in spectrin. The document concludes by explaining how the osmotic fragility test measures red blood cell resistance to lysis in saline solutions of varying concentrations to evaluate membrane stability and defects.
This document summarizes the ABO blood grouping system. It describes how Karl Landsteiner discovered the A, B, and O blood groups in 1901. The system is based on the presence or absence of antigens called agglutinogens on red blood cells. People have antibodies against the agglutinogens that are not present on their own red blood cells. The genes that determine the ABO blood groups are located on chromosome 9 and are inherited according to Mendelian genetics. Blood type is determined by mixing blood cells with antisera that cause agglutination based on the antigens present.
Immunofluorescence is a technique that uses fluorescent-labeled antibodies or antigens to visualize tissues or cells under a fluorescence microscope. There are two main types - direct immunofluorescence labels antibodies directly while indirect immunofluorescence uses a secondary antibody labeled with a fluorescent dye. Direct immunofluorescence is useful for detecting autoantibodies bound directly to a patient's own tissue sample.
The document discusses ABO and Rh blood group systems. It provides details on the antigens and antibodies involved, including their reciprocal relationship. It explains how the ABO blood groups are inherited based on codominance and gives examples of inheritance patterns. The synthesis of ABO antigens is described, showing how genes code for enzymes that add specific sugars to produce the A, B, or H antigens. Practical aspects of blood grouping techniques like the tube method and microplate method are also covered.
This document provides information about ABO and Rh blood grouping and typing. It discusses the antigens and antibodies involved in these two major blood group systems, including their inheritance, development, expression, and clinical significance. The key points covered include the reciprocal relationship between ABO antigens and antibodies, development of ABO antigens at birth, subgroups within the ABO system, inheritance of ABO blood groups, anti-A and anti-B antibody production, and Rh (D) antigen properties and typing. Practical aspects of ABO and Rh blood grouping using tube, gel, and microplate methods are also described.
ABO blood group system was decover by Karal landsteine
which contain A, B, and o antigen on the surface of BC, WBC,s platatelet and other body tissue cells except brain cell, and anti A, antiB and Anti Ab natural occuring antibodies in plasma of B,A, and O blood group individual respectively
This document discusses gel card technology used in blood banking tests. It provides details on the history and development of gel cards, how they work, the types of tests they can be used for (including ABO typing, cross-matching, antibody screening), and their advantages over traditional tube-based methods such as improved sensitivity and reproducibility. Gel cards contain a gel matrix in microtubes that allows red blood cells to be separated based on agglutination during centrifugation, providing clear and standardized test results.
This document discusses blood preservatives and the processes involved in preserving blood and its components. It addresses the biochemical changes that occur in stored blood, such as decreasing pH and ATP levels. Preservative solutions aim to minimize these changes by buffering pH and providing nutrients. Common preservatives mentioned are ACD, CPD, and CPDA, which contain ingredients like citrate, dextrose, and adenine. Newer additive solutions provide nutrients to packed red blood cells to extend their shelf life. Methods to rejuvenate stored blood and freezing techniques are also summarized. The document provides an overview of preserving different blood components like platelets, plasma and cryoprecipitate.
This document provides information on three hematology stains:
Leishman's stain, reticulocyte stain, and iron stain. It describes the composition, procedure, and results for Leishman's stain. For reticulocyte stain, it discusses how reticulocytes contain RNA that stains gray-blue and the procedure uses supravital staining. Iron stain demonstrates ferric iron and ferritin using Prussian blue reaction and involves fixation, staining in potassium ferrocyanide and hydrochloric acid, and counterstaining with nuclear fast red.
The document discusses compatibility testing protocols for blood transfusions. It describes how compatibility testing includes ABO and Rh grouping of donor and recipient samples, screening for unexpected antibodies, and a cross-match. Proper identification of donor and recipient samples is critical to avoid errors. The purpose is to select appropriately compatible blood and ensure the best results for the transfusion by preventing hemolysis or antibody-mediated destruction of transfused red blood cells.
Karl Landsteiner discovered the ABO blood group system in 1900. He identified three main blood groups - A, B, and C, which were later renamed to A, B, and O. Von Decastello and Sturli discovered the AB blood group in 1902. The ABO blood group is determined by the presence or absence of antigens A and B on red blood cells, which is controlled by inherited alleles. People universally have antibodies against blood group antigens they lack. This system is important for blood transfusions, as incompatible blood can cause transfusion reactions.
Pretransfusion testing final- ab screening - NAGLAA MAKRAM Naglaa Makram
1. Antibody screening tests patient serum against reagent red blood cells to detect unexpected antibodies that could destroy transfused donor cells.
2. Screening cells must contain many common antigens and include some cells with homozygous antigen expression to detect weakly reacting antibodies.
3. A positive antibody screen requires antibody identification testing to determine the antibody specificity so that antigen-negative blood can be transfused.
Rh typing and its technique , BLOOD TYPING , Rhesus (Rh) typing , procedures of rh typing, process of Rh typing, Test limitations, Sources of Error in Rh Antigen Typing, False positive reactions' reason, False negative reactions' reasons
This document discusses several major blood group systems including Lewis, I, P, MNSs, Kell, Kidd, Duffy, Lutheran, Bg, Sda, and Xg. It provides information on the antigens and genes involved in each system, the clinical significance of associated antibodies, and inheritance patterns. Some key points covered include that Lewis, I, and P antigens produce cold-reacting antibodies while Kell, Kidd, and Duffy produce warm-reacting antibodies. The MNSs, Kell, and Kidd systems can produce clinically significant antibodies implicated in hemolytic transfusion reactions and hemolytic disease of the newborn.
1. Prussian blue staining is used to identify iron stores in bone marrow samples. It detects ferric iron by forming an insoluble blue compound called Prussian blue when iron reacts with potassium ferrocyanide and hydrochloric acid.
2. Iron is primarily stored in the body bound to the protein ferritin or aggregated as hemosiderin. Prussian blue staining results in hemosiderin appearing blue while nuclei counterstain red.
3. The amount of iron stores visualized on bone marrow samples using Prussian blue staining is graded from 0-6, with higher grades indicating increased iron levels and potential iron overload.
This document provides an overview of basic principles of immunohematology. It defines key terms like antigen and antibody. It describes the characteristics of antigens and factors that contribute to antigen immunogenicity. It also discusses the different types of immunoglobulins involved in blood group antibodies, and the differences between naturally occurring versus immune antibodies. Finally, it explains the stages of antigen-antibody reactions including sensitization and agglutination, and factors that can influence these reactions.
1. Karl Landsteiner discovered the main blood group systems (ABO and Rh) in 1900 and 1940 respectively. The ABO system categorizes blood into A, B, AB and O groups based on antigens on red blood cells.
2. Blood typing and cross-matching are important to ensure safe and compatible blood transfusions. Transfusing incompatible blood can cause hemolytic or allergic reactions in the recipient.
3. Other minor blood group systems have been discovered including MNS, Duffy, Kell and Lewis systems which are important for transfusion medicine and anthropological research. Understanding blood groups is crucial for blood banking and preventing diseases like hemolytic disease of the newborn.
special and routine stains in haematology 1Dr.SHAHID Raza
The document discusses various routine and special stains used in hematology. Routine stains like Leishman, Giemsa, and Wright stains are used to stain peripheral blood films and differentiate blood cells. Special stains require additional processing but can identify characteristics not seen with routine stains, such as periodic acid Schiff stain which detects carbohydrates like glycogen by oxidizing glycol groups and producing a red reaction. Proper staining techniques such as fixation, washing, and timing are important for preparing clear blood smears and accurately identifying blood components.
Weak D testing is performed on all prenatal patients, Rh negative blood donors and transfusion candidates to identify those with the weak D phenotype. The procedure involves incubating patient red blood cells with anti-D, and if negative, adding anti-human globulin to look for weak agglutination indicating a weak D positive result. A true weak D will show at least 2+ agglutination; weaker results may be due to prior transfusions and require checking the transfusion history. All results are documented in the grouping register.
The document discusses the ABO blood group system, including its discovery, genetics, biochemistry, antigens, antibodies, and implications for transfusion. Some key points:
- Karl Landsteiner discovered the main ABO blood groups (A, B, AB, O) in 1900. The ABO blood type is determined by alleles at a single gene locus.
- The antigens are carbohydrate structures on red blood cells. People naturally produce antibodies against antigens they lack.
- ABO typing must be accurate to avoid transfusion reactions. Discrepancies can occur due to weak subgroups, diseases, or test issues. Resolving discrepancies helps ensure patient and donor safety.
Osmotic fragility & rbc membrane defects 050916Anwar Siddiqui
This document discusses red blood cell membrane defects and osmotic fragility testing. It begins by introducing the structure and components of the red blood cell membrane, including integral proteins, lipids, and peripheral proteins that make up the cytoskeleton. Key membrane defects are then described, such as hereditary spherocytosis caused by weakened interactions between membrane proteins, and hereditary elliptocytosis caused by defects in spectrin. The document concludes by explaining how the osmotic fragility test measures red blood cell resistance to lysis in saline solutions of varying concentrations to evaluate membrane stability and defects.
This document summarizes the ABO blood grouping system. It describes how Karl Landsteiner discovered the A, B, and O blood groups in 1901. The system is based on the presence or absence of antigens called agglutinogens on red blood cells. People have antibodies against the agglutinogens that are not present on their own red blood cells. The genes that determine the ABO blood groups are located on chromosome 9 and are inherited according to Mendelian genetics. Blood type is determined by mixing blood cells with antisera that cause agglutination based on the antigens present.
Immunofluorescence is a technique that uses fluorescent-labeled antibodies or antigens to visualize tissues or cells under a fluorescence microscope. There are two main types - direct immunofluorescence labels antibodies directly while indirect immunofluorescence uses a secondary antibody labeled with a fluorescent dye. Direct immunofluorescence is useful for detecting autoantibodies bound directly to a patient's own tissue sample.
The document discusses ABO and Rh blood group systems. It provides details on the antigens and antibodies involved, including their reciprocal relationship. It explains how the ABO blood groups are inherited based on codominance and gives examples of inheritance patterns. The synthesis of ABO antigens is described, showing how genes code for enzymes that add specific sugars to produce the A, B, or H antigens. Practical aspects of blood grouping techniques like the tube method and microplate method are also covered.
This document provides information about ABO and Rh blood grouping and typing. It discusses the antigens and antibodies involved in these two major blood group systems, including their inheritance, development, expression, and clinical significance. The key points covered include the reciprocal relationship between ABO antigens and antibodies, development of ABO antigens at birth, subgroups within the ABO system, inheritance of ABO blood groups, anti-A and anti-B antibody production, and Rh (D) antigen properties and typing. Practical aspects of ABO and Rh blood grouping using tube, gel, and microplate methods are also described.
The document discusses blood grouping methodology and focuses on the ABO and Rh blood group systems. It provides details on:
- The ABO blood group system is the most clinically important and is determined by the presence or absence of A and B antigens on red blood cells. The Rh system involves the D antigen.
- Karl Landsteiner discovered the ABO system in 1901 and was awarded the Nobel Prize for his work. Inheritance of blood groups follows genetic patterns.
- Common techniques for blood grouping include slide tests, tube tests, microplates, and gel cards. Proper sample collection and testing procedures must be followed.
- Understanding blood groups is essential for safe blood transfusions and preventing issues like hemolytic
This document provides an overview of immunohematology, focusing on blood group systems. It discusses key concepts including antigens, antibodies, and the major blood group systems like ABO and Rh. The ABO system is described in detail, including the antigens (A, B, H), antibodies (anti-A, anti-B), inheritance patterns, common subtypes, frequencies in different populations, and routine testing methods involving direct and indirect agglutination. Causes of discrepancies in ABO testing are also reviewed. Overall, the document serves as an introduction to immunohematology and blood group systems from an immunological perspective.
The ABO blood group system is the most important for transfusion medicine. It includes four main groups - A, B, O, and AB - determined by the presence or absence of antigens on red blood cells. ABO incompatibility between donor and recipient blood can cause hemolytic transfusion reactions. Resolving discrepancies in ABO typing results is important and may be due to technical errors, subgroups, or medical conditions affecting antibody production.
The ABO blood group system is one of the most important blood group systems for transfusions. It is determined by the ABO gene which has three alleles - IA, IB, and i - that encode for the A, B, and O antigens, respectively. The ABO blood types are determined by which alleles are present: IAIA or IAi produce type A blood, IBIB or IBi produce type B, IAIB produces AB, and ii produces O. The Rh system, specifically the D antigen, is the second most important blood group and sensitization to the D antigen in Rh-negative pregnant women can cause hemolytic disease of the newborn if not prevented.
The document discusses ABO blood group inheritance and antigen formation. It can be summarized as:
1. ABO blood groups are determined by inherited genes that code for glycosyltransferase enzymes adding specific sugars to precursor substances on red blood cells, forming A, B, or H antigens.
2. The H gene produces fucosyltransferase, adding a fucose to form the H antigen. The A gene adds galactosamine and the B gene adds galactose.
3. Inheriting one A, B, or O gene from each parent determines presence of A or B antigens and naturally occurring antibodies, establishing a person's blood group.
This document discusses the history and science behind blood typing and blood transfusions. It covers the following key points:
- Karl Landsteiner discovered the ABO blood group system in 1901 and was awarded the Nobel Prize for this work. The Rh factor was discovered in 1930.
- Blood types are determined by the presence or absence of antigens on red blood cells and the presence of corresponding antibodies in the plasma. The major blood group systems are ABO and Rh.
- Incompatible blood groups can cause blood clotting during transfusions. Type O negative blood is the "universal donor" as it lacks A, B and Rh antigens, while type AB positive is the "universal receiver."
- Not following blood
This document discusses the history and science behind blood typing and blood transfusions. It covers the following key points:
- Karl Landsteiner discovered the ABO blood group system in 1901 and was awarded the Nobel Prize for this work. The Rh factor was discovered in 1930.
- Blood types are determined by the presence or absence of antigens on red blood cells and the presence of corresponding antibodies in the plasma. The major blood group systems are ABO and Rh.
- The ABO system includes four blood types - A, B, AB, and O - based on whether the red cells have A antigens, B antigens, both, or neither. Compatibility for transfusion depends on this.
- The Rh system
The document summarizes key information about major blood group systems including ABO, Rh, Lewis, Kell, Duffy, and Kidd. It describes the antigens and genes involved in determining blood group types, frequencies in different populations, clinically significant antibodies, and associations with diseases.
The document discusses the inheritance and genetics of blood group systems, focusing on the ABO and Rh blood group systems. The key points are:
1) The ABO and Rh blood group systems are the most important for blood transfusions. The blood group you belong to depends on what antigens you inherited from your parents.
2) The ABO system involves A, B, and O blood types which are determined by the presence or absence of A and B antigens. The Rh system involves Rh+ and Rh- blood types determined by the presence or absence of the Rh antigen.
3) Incompatible blood groups can cause agglutination if mixed, so it is important to understand blood group inheritance and compatibility for safe blood transf
There are over 30 known blood group systems that contain around 400 antigens. The most important systems for blood transfusions are ABO and Rh. The ABO system contains A, B, and H antigens. People are type A, B, AB, or O based on which antigens are present. Naturally occurring antibodies are directed against antigens not present on one's own red blood cells. The Rh system contains D and other antigens. Most people are Rh+ or Rh-. Rh incompatibility can cause hemolytic disease of the newborn.
A blood type (also called a blood group) is a classification of blood based on the presence or absence of inherited antigenic substances on the surface of red blood cells (RBCs). These antigens may be proteins, carbohydrates, glycoproteins, or glycolipids, depending on the blood group system.
Karl Landsteiner discovered the main human blood group systems in 1901 which allowed safer blood transfusions. He found that mixing blood from two individuals can cause clumping if they have incompatible blood types due to antigens and antibodies. There are four main blood types - A, B, AB and O based on the presence or absence of A and B antigens on red blood cells and the corresponding antibodies in plasma. The Rh system further divides blood into Rh+ and Rh- based on the presence of the Rh antigen. Understanding blood groups is crucial to ensure compatibility during transfusions.
This presentation aims to help medicine undergraduates and post graduates in the department of Pathology and Department of transfusion medicine for better understanding of various blood grouping systems, sub groups, RBC antigens and corresponding antibodies. It also covers the practical aspect of blood grouping and cross matching.
Karl Landsteiner discovered the main human blood groups (A, B, AB and O) in 1901. He found that mixing blood from two individuals can cause clumping of red blood cells. This occurs due to the presence of antigens on red blood cells and corresponding antibodies in plasma. Landsteiner's discovery made blood transfusions safer by allowing blood typing. There are over 20 blood group systems but ABO and Rh (Rhesus) are most important. ABO blood groups are determined by inheritance of A, B or O alleles while Rh status depends on presence/absence of the D antigen. Compatibility between donor and recipient blood is crucial to avoid dangerous immune reactions.
This document discusses the genetics and inheritance of blood groups, focusing on the ABO system. It explains that the ABO system is determined by three genes - A, B, and O - located on chromosome 9. These genes encode glycosyltransferase enzymes that add specific sugars to a basic oligosaccharide chain on red blood cells, producing the A, B, and H antigens. The presence or absence of these antigens determines the individual's blood group type. Proper understanding of blood group genetics is important for blood transfusions to avoid immune reactions between incompatible blood types.
The document summarizes the ABO blood group system, which was discovered in 1901 by Karl Landsteiner. It describes the antigens and antibodies present in the four main blood groups (A, B, AB, and O) based on the presence or absence of the A and B antigens. The genes that code for the A, B, and H antigens are explained, as well as how they produce specific enzymes that add sugars to precursor structures on red blood cells. Forward and reverse blood grouping tests are outlined to determine a person's blood group.
Karl Landsteiner discovered the main human blood groups (A, B, AB, and O) in 1901. This discovery allowed safer blood transfusions by preventing fatal reactions between incompatible blood groups. The presence or absence of antigens (proteins) and antibodies on red blood cells and in plasma determines a person's blood group. The ABO and Rh blood group systems are most important for transfusions. A person can only receive blood from a donor with compatible or identical blood groups to prevent dangerous clumping of red blood cells.
8 Surprising Reasons To Meditate 40 Minutes A Day That Can Change Your Life.pptxHolistified Wellness
We’re talking about Vedic Meditation, a form of meditation that has been around for at least 5,000 years. Back then, the people who lived in the Indus Valley, now known as India and Pakistan, practised meditation as a fundamental part of daily life. This knowledge that has given us yoga and Ayurveda, was known as Veda, hence the name Vedic. And though there are some written records, the practice has been passed down verbally from generation to generation.
Does Over-Masturbation Contribute to Chronic Prostatitis.pptxwalterHu5
In some case, your chronic prostatitis may be related to over-masturbation. Generally, natural medicine Diuretic and Anti-inflammatory Pill can help mee get a cure.
Local Advanced Lung Cancer: Artificial Intelligence, Synergetics, Complex Sys...Oleg Kshivets
Overall life span (LS) was 1671.7±1721.6 days and cumulative 5YS reached 62.4%, 10 years – 50.4%, 20 years – 44.6%. 94 LCP lived more than 5 years without cancer (LS=2958.6±1723.6 days), 22 – more than 10 years (LS=5571±1841.8 days). 67 LCP died because of LC (LS=471.9±344 days). AT significantly improved 5YS (68% vs. 53.7%) (P=0.028 by log-rank test). Cox modeling displayed that 5YS of LCP significantly depended on: N0-N12, T3-4, blood cell circuit, cell ratio factors (ratio between cancer cells-CC and blood cells subpopulations), LC cell dynamics, recalcification time, heparin tolerance, prothrombin index, protein, AT, procedure type (P=0.000-0.031). Neural networks, genetic algorithm selection and bootstrap simulation revealed relationships between 5YS and N0-12 (rank=1), thrombocytes/CC (rank=2), segmented neutrophils/CC (3), eosinophils/CC (4), erythrocytes/CC (5), healthy cells/CC (6), lymphocytes/CC (7), stick neutrophils/CC (8), leucocytes/CC (9), monocytes/CC (10). Correct prediction of 5YS was 100% by neural networks computing (error=0.000; area under ROC curve=1.0).
- Video recording of this lecture in English language: https://youtu.be/kqbnxVAZs-0
- Video recording of this lecture in Arabic language: https://youtu.be/SINlygW1Mpc
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Muktapishti is a traditional Ayurvedic preparation made from Shoditha Mukta (Purified Pearl), is believed to help regulate thyroid function and reduce symptoms of hyperthyroidism due to its cooling and balancing properties. Clinical evidence on its efficacy remains limited, necessitating further research to validate its therapeutic benefits.
Here is the updated list of Top Best Ayurvedic medicine for Gas and Indigestion and those are Gas-O-Go Syp for Dyspepsia | Lavizyme Syrup for Acidity | Yumzyme Hepatoprotective Capsules etc
Basavarajeeyam is an important text for ayurvedic physician belonging to andhra pradehs. It is a popular compendium in various parts of our country as well as in andhra pradesh. The content of the text was presented in sanskrit and telugu language (Bilingual). One of the most famous book in ayurvedic pharmaceutics and therapeutics. This book contains 25 chapters called as prakaranas. Many rasaoushadis were explained, pioneer of dhatu druti, nadi pareeksha, mutra pareeksha etc. Belongs to the period of 15-16 century. New diseases like upadamsha, phiranga rogas are explained.
Histololgy of Female Reproductive System.pptxAyeshaZaid1
Dive into an in-depth exploration of the histological structure of female reproductive system with this comprehensive lecture. Presented by Dr. Ayesha Irfan, Assistant Professor of Anatomy, this presentation covers the Gross anatomy and functional histology of the female reproductive organs. Ideal for students, educators, and anyone interested in medical science, this lecture provides clear explanations, detailed diagrams, and valuable insights into female reproductive system. Enhance your knowledge and understanding of this essential aspect of human biology.
ABDOMINAL TRAUMA in pediatrics part one.drhasanrajab
Abdominal trauma in pediatrics refers to injuries or damage to the abdominal organs in children. It can occur due to various causes such as falls, motor vehicle accidents, sports-related injuries, and physical abuse. Children are more vulnerable to abdominal trauma due to their unique anatomical and physiological characteristics. Signs and symptoms include abdominal pain, tenderness, distension, vomiting, and signs of shock. Diagnosis involves physical examination, imaging studies, and laboratory tests. Management depends on the severity and may involve conservative treatment or surgical intervention. Prevention is crucial in reducing the incidence of abdominal trauma in children.
2. Teaching Aim
Understanding inheritance, synthesis, various
antigens and antibodies and their clinical
significance in ABO & Rh blood group systems
Understanding practical aspects of ABO & Rh blood
grouping
3. Human Blood Groups
Red cell membranes have antigens (protein /
glycoprotein) on their external surfaces
These antigens are
o unique to the individual
o recognized as foreign if transfused into another individual
o promote agglutination of red cells if combine with antibody
o more than 30 such antigen systems discovered
Presence or absence of these antigens is used to
classify blood groups
Major blood groups – ABO & Rh
Minor blood groups – Kell, Kidd, Duffy etc
4. ABO Blood Groups
Most well known & clinically important blood group system.
Discovered by Karl Landsteiner in 1900
It was the first to be identified and is the most significant for
transfusion practice
It is the ONLY system that the reciprocal antibodies are
consistently and predictably present in the sera of people
who have had no exposure to human red cells
ABO blood group consist of
o two antigens (A & B) on the surface of the RBCs
o two antibodies in the plasma (anti-A & anti-B)
5. Reciprocal relationship between ABO
antigens and antibodies
Antigens on
RBCs
Antibody in plasma /
serum
Blood
group
A Anti-B A
B Anti-A B
AB None AB
None Anti-A, Anti-B O
6. All the ABH antigens develop as early as day 37 of fetal
life but do not increase very much in strength during
gestational period
Red cell of newborn carry 25-50 % of number of antigenic
sites found on adult RBC
Although cord red cells can be ABO grouped, the
reactions may be a bit weaker than expected
A or B antigen expression fully developed at 2-4 yrs of age
and remain constant throughout life
7. Although the ABO blood group antigens are regarded as
RBC antigens, they are actually expressed on a wide variety
of human tissues and are present on most epithelial and
endothelial cells
ABH antigens are not only found in humans, but also in
various organisms such as bacteria, plants, and animals
Present both on red blood cells and in secretions only in
humans and some of the apes (chimpanzee, gorilla)
In all other mammalian species these substances are found
only in secretions
8. Not present in the newborn, appear in the first years of life (4-6
months usually), reach adult level at 5-10 years of age, decreases in
elderly
Naturally occurring as they do not need any antigenic stimulus
However, some food & environmental antigens (bacterial, viral or
plant antigens) are similar enough to A and B glycoprotein antigens
and may stimulate antibody development
Immunocompetent person react to these antigens by producing
antibodies to those absent from their own system
Usually IgM, which are not able to pass through the placenta to the
fetal blood circulation
Anti-A titer from group O > Anti-A titer from group B
Anti-A titer from group B > Anti-B titer from group A
10. 'Landsteiner's law :-
the plasma contains natural antibodies
to A or B, if these antigens are absent
from the red cells of that person
11. Inheritance of ABO Blood Groups
Follows Mendelian principles
Blood group antigens are “codominant”- if the gene
is inherited, it will be expressed.
There are three allelic genes -A, B & O
Some aberrant genotypes do occur but they are
very rare.
Understanding of basic inheritance important.
12. Two genes inherited, one from each parent.
Individual who is A or B may be homozygous or
heterozygous for the antigen.
o Heterozygous: AO or BO
o Homozygous: AA or BB
Phenotype is the actual expression of the genotype, ie,
group A
Genotype are the actual inherited genes which can only
be determined by family studies, ie, AO.
Inheritance of ABO Blood Groups
13. Example of Determining Genotype
Mother’s phenotype is group A, genotype AO
Father’s phenotype is group B, genotype BO
B O
A AB 25% (Group AB) AO 25% (Group A)
O BO 25% (Group B) OO 25% (Group O)
14. Other Examples
Mother Father Offspring Blood Group
AA BB 100% AB
BO OO 50% each of B or O
OO OO 100% O
OO AO 50% each of A or O
15. ABO Antigen Synthesis
Blood group antigens are actually sugars attached
to the red blood cell.
Antigens are “built” onto the red cell.
Individuals inherit a gene which codes for specific
sugar(s) to be added to the red cell.
The type of sugar added determines the blood
group.
16. ABO and H Antigen Genetics
Genes at three separate loci control the occurrence
and location of ABO antigens
Presence or absence of the ABH antigens on the
red cell membrane is controlled by the H gene
Presence or absence of the ABH antigens in
secretions is indirectly controlled by the Se gene
o H gene – H and h alleles (h is an amorph)
o Se gene – Se and se alleles (se is an amorph)
o ABO genes – A, B and O alleles
17. H Antigen
The H gene codes for an enzyme (fucosyltransferase) that
adds the sugar fucose to the terminal sugar of a precursor
substance
The precursor substance (proteins and lipids) is formed on
an oligosaccharide chain (the basic structure)
The H antigen is the foundation upon which A and B
antigens are built
A and B genes code for enzymes that add an
immunodominant sugar to the H antigen
Immunodominant sugars are present at the terminal ends of the
chains and confer the ABO antigen specificity
19. Formation of the H antigen
Glucose
Galactose
N-acetylglucosamine
Galactose
H antigen
RBC
Fucose
20. A and B Antigen
The “A” gene codes for an enzyme (transferase)
that adds N-acetylgalactosamine to the terminal
sugar of the H antigen
o N-acetylgalactosaminyltransferase
The “B” gene codes for an enzyme that adds D-
galactose to the terminal sugar of the H antigen
o D-galactosyltransferase
21. Formation of the A antigen
Glucose
Galactose
N-acetylglucosamine
Galactose
RBC
N-acetylgalactosamine
Fucose
22. Formation of the B antigen
Glucose
Galactose
N-acetylglucosamine
Galactose
RBC
D-Galactose
Fucose
23. Immunodominant sugars responsible for
antigen specificity
Gene Glycosyltransferase Immunodominant
sugar
Antigen
H L-fucosyltransferase L-fucose H
A N-acetylgalactosaminyltransferase N-acetyl-D-
galactosamine
A
B D-galactosyltransferase D-galactose B
24.
25. Secretor Status
A, B, H substances are found in all body secretions
(except CSF) in 80% of individuals
Ability to secrete these substances is determined by the
presence of secretor gene (Se) in either homozygous
(SeSe) or heterozygous (Sese) state.
Blood Group Substances Secreted
O H
A A & H
B B & H
AB A, B, & H
Oh Nil
26. Characteristics of Bombay Phenotype
First reported by Bhende et al in Bombay in 1952.
Frequency estimated to be about 1 in 7600 in Bombay.
Absence of H, A & B antigens. No agglutination with anti-A,
anti-B or anti-H
Presence of anti-H, anti-A and anti-B in the serum
No A, B or H substances present in saliva
Incompatible with any ABO blood groups, compatible with
Bombay phenotype only
A recessive mode of inheritance (identical phenotypes in
children but not in parents)
27. ABO Subgroups
ABO subgroups differ in the amount of antigen present
on the red blood cell membrane
o Subgroups have less antigen
Subgroups are the result of less effective enzymes.
They are not as efficient in converting H antigens to A or
B antigens (fewer antigens are present on the RBC)
Subgroups of A are more common than subgroups of B
28. Subgroups of A
Two principle subgroups of A are: A1 and A2
Both react strongly with reagent anti-A
To distinguish A1 from A2 red cells, the lectin Dolichos
biflorus is used (anti-A1)
80% of group A or AB individuals are A1 and A1B
20% are A2 and A2B
29. A2 phenotype
Clinical significance of A2 phenotype
o 8% of A2 and 25% of A2B individuals may produce anti-A1 in the
serum
o This may result in discrepancy in blood grouping or
incompatibility in cross match
o However, these anti-A1 antibodies are cold reacting & therefore
may not cause problems routinely.
Difference between A1 and A2
o It is quantitative
o The A2 gene doesn’t convert the H to A very well resulting in
fewer A2 antigen sites compared to the many A1 antigen sites
30. A1 and A2 Phenotypes
Anti-A Anti-A1 Anti-H Antibody
in serum
Antigens /
RBC
A1 4+ 4+ 0 Anti-B 9 x 105
A2 4+ 0 3+ Anti-B &
Anti-A1
2.5 x 105
31. Subgroups of A
Pheno
type
Reaction with antisera Antibodies Substance
in Saliva
(secretors)
AntiA Anti B Anti AB Anti A1 Anti H Common Unexpected
A1 +4 0 +4 +4 0 Anti-B - A and H
A2 +4 0 +4 0 +2-3 Anti-B
Sometimes
Anti-A1
A and H
A3 +2 mf 0 +2 mf 0 +3 Anti-B
Sometimes
Anti-A1
A and H
Ax
Weak
Or 0
0 +2 0 +4 Anti-B
Always
Anti-A1
H
Am 0 0 0 0 +4 Anti-B
No
Anti-A1
A and H
Ael 0 0 0 0 +4 Anti-B
Sometimes
Anti-A1
H
Aend
Weak
Mf
0
Weak
Mf
0 +4 Anti-B
Sometimes
Anti-A1
H
32. B Subgroups
B subgroups occur less than A subgroups
B subgroups are differentiated by the type of
reaction with anti-B, anti-A,B, and anti-H
B3, Bx, Bm, and Bel
33. Practical aspects of ABO grouping
Routine ABO grouping must include both cell & serum testing as
each test serves as a check on the other
Test should be done at room temperature or lower; testing at
37oC weakens the reactions
Tubes, slides should be dry and labeled properly
Serum should always be added before adding cells
Results should be recorded immediately after observation
Hemolysis is interpreted as positive result
34. Blood Grouping
There are 2 components to blood typing:
o Test unknown cells with known antibodies
o Test unknown serum/plasma with known red
cells
The patterns are compared and the blood
group is determined.
35. Blood Sample for Blood Grouping
Blood sample
Clearly labeled blood samples in sterile tubes (plain & EDTA)
Test should be performed on the fresh sample for best results. In
case the test can not be performed immediately, sample can be
stored at 4oC & should be tested with in 48 hours
No signs of hemolysis should be there
If serum is not completely separated, centrifuge tube at 1000-3000
rpm fro 3 min
Preferably use saline washed red cells and make 2-5% suspension
36. Red Cell Suspensions for Blood Grouping
50%: Slide Method
5%: Test Tube Method
1%: Gel technology
1%: Microplate
37. Not recommended as a routine method
Very rudimentary method for determining blood groups.
CANNOT be used for transfusion purposes as false
positives and negatives do occur. Drying of reaction
mixture can cause aggregation - false positive
Less sensitive, not reliable for weakly reactive antigens
and antibodies
Can only be used for emergency ABO grouping or for
selection of plateletpheresis donors
Slide Method for ABO Grouping
38. Slide Method for ABO grouping
Put 1 drop anti-A & anti- B
separately on slide
Add 1 drop of 40-50%
suspension of test red cells to
each drop of typing antisera
Mix & spread each mixture
evenly on the slide over an
area of about 15 mm diameter
Leave the test for 2 min at
room temp (20-24oC)
Record the results immediately
39. 5 % cell suspension
for
Tube grouping
0.8 % cell suspension
for
Gel card grouping
40. Test Tube Method of ABO Grouping
Recommended method
Allows longer incubation of antigen and antibody
mixture without drying
Tubes can be centrifuged to enhance reaction
Can detect weaker antigen / antibody
Two steps in ABO grouping
Cell grouping (Forward grouping)
Tests the patients red cells with known Anti-A & Anti-
B to determine the antigen expressed
Serum grouping (Reverse grouping)
Test the patients serum with known A & B cells to
determine the presence of antibody
42. 1 vol of 2-5% red
cell suspension
2 vol of anti- A /
anti-B/ Anti-AB
Forward
Grouping
Incubate at room temp
(20-24oC) for 5 min
Centrifuge at 1000 rpm for
1 min
Check for agglutination
against well lighted
background
43. 2 vol of test
serum/plasma
1 vol of 5%
suspension of
reagent red cells in
respective tubes
Reverse
Grouping Centrifuge at 1000 rpm for 1
min
Centrifuge & record the
results similarly as for
cell grouping
Shake & leave at room
temp (20-24oC) for 5 min
45. Recording results of ABO grouping
Reaction of red cells
with
Reaction of serum
with pooled cells
Interpretation
Anti-A Anti-B Anti-AB Ac Bc Oc
+ + + 0 0 0 AB
+ 0 + 0 +/H 0 A
0 + + +/H 0 0 B
0 0 0 +/H +/H 0 O
0 0 0 +/H +/H + Oh
+ = agglutination, 0 = no agglutination H = hemolysis
46. Microplate Method
It is ideal for testing large number of blood samples.
More sensitive to detect weaker antigen-antibody
reactions
Results can be photographed for archival storage
Microplate can be incubated & centrifuged
There is significant saving in time and in the cost of
disposables and reagents.
Microplates are intended to be disposable however
they can be reused after cleaning them properly
making sure that all foreign protein are removed.
Microplates can be adapted for automation
47. Reaction in the microplate after 1 hour incubation at room temperature
Microplate Method
48. Column Agglutination Technology
One card is basically a set of 6
microtubes
Microtubes contain either Sephadex
Gel or glass microbeads
impregnated with antisera
Antigen-antibody reaction takes
place in the reaction chamber of
microtube
Gel matrix or glass beads act as
sieve and allow free cells (un-
agglutinated) to pass through and
settle at the bottom of microtube
while agglutinated cells are trapped
in the matrix
50. Sources of errors resulting in ABO
discrepancies
Inadequate identification of sample, test tubes or
slides
Cell suspension either too heavy or too light
Clerical errors
Missed observation of hemolysis
Failure to add reagents
Uncalibrated centrifuge
Contaminated / expired reagents
Failure to follow manufacturer’s instructions
51. Technical problems
• Glassware, Reagents, Equipment
o Dirty glassware, contaminated or outdated reagent,
temperature not proper
• Cell concentrations
o Too high or too low concentration
• Centrifugation
• Carelessness –
o patient identification,
o sample identification,
o reading and recording results
52. Obtain fresh sample
Rule out clerical error
Rule out technical error
Obtain clinical history
o age, diagnosis, pregnancy, drug & transfusion
Repeat test using
o Washed RBC
o Incubate at different temperatures (4oC, RT, 37oC)
o Put up auto control
o Antisera from different lot no.
o Antisera from different manufacturer
Resolution of Blood Group Discrepancies
53. Resolution of ABO group discrepancies
….contd.
Additional test
A2, O or cord cells if required may be used
Anti AB antisera
Lectins (anti A1, anti H)
Increasing serum : cell ratio
Increasing incubation time
Decreasing incubation temperature
Including autocontrol
Saliva secretor status
Adsorption elution test
56. Rh (D) Antigen
Of next importance is the Rh type.
o Rh is a blood group system with many antigens, one of which is D.
Rh refers to the presence or absence of the D antigen on the
red blood cell.
Unlike the ABO system, individuals who lack the D antigen do
not naturally produce anti-D.
Production of antibody to D requires exposure to the antigen.
The D antigen is very immunogenic, ie, individuals exposed to it
will very likely make an antibody to it.
For this reason all individuals are typed for D, if negative must
receive Rh (D) negative blood.
57. Rh (D) Antigen (continued)
Rh antigens are an integral part of the red cell
membrane.
They are protein in nature with an active phospholipid
component
Rh antigens do not exist in the soluble form and,
therefore are not excreted in body fluids.
Unlike ABO antigens, Rh antigens are present only on
red blood cells. These antigens are not found on other
blood cells including platelets and leukocytes
58. Rh (D) Antigen (continued)
A very potent antigen (50% may form antibody to exposure)
Frequency in Indian population
o 95% Rh positive
o 05% Rh negative
The most important patient population to consider is females
of child-bearing age.
If immunized to Rh (D) antigen the antibody can cross the
placenta and destroy Rh (D) positive fetal cells resulting in
death.
This is why Rh negative women are given anti-D (Rhogam)
after birth of Rh positive baby.
59. Various antigens in Rh system
Rh antigens Frequency % in India
D 95
d (absence of D) 05
C 70
E 15
c 90
e 98
60. Rh Antibodies
• All Rh antibodies are immune in nature, developed
after immunizing event
• React at 37oC and require anti globulin test to
demonstrate the reaction
• Generally do not react at room temperature in saline
• Most are IgG in nature and therefore can cross the
placenta
• Generally, do not fix complement and cause
extravascular hemolysis
• All are important in HDN and delayed HTR
61. Rh typing
Normal typing for Rh antigens only includes typing
for Rh (D).
The result of this typing determines the Rh status of
the cells (Rh - positive or Rh - negative).
Some Rh typing sera is diluted in high protein
solutions and may require a negative control.
It is recommended to use two monoclonal anti-D
sera from two different manufacturers labeled as D1
and D2, especially to confirm all Rh negatives
62. 1. Polyclonal high protein – obsolete
2. Saline acting
3. Monoclonal antibody – mostly used now
Types of anti- D
63. Anti-D reagents
Prepared from pooled human sera to which high concentration of
protein (20-24% albumin) is added.
Albumin, being a dipolar molecule, increases the dielectric
constant and decreases the zeta potential, allowing the red cells to
come closer
Reaction with D positive red cells at IS & weak D at 37°C/AHG test
False positives are common when RBCs are coated with
Immunoglobulins - spontaneous aggregation
Use control reagent & follow manufactures’ directions
It is now almost obsolete
Polyclonal high protein
64. Anti-D for saline test
Two kind of saline active anti –D sera :
1. Traditionally from raw material containing predominantly
IgM antibodies that agglutinates D + cells in saline
2. Saline acting reagents prepared from IgG antibodies
that have been chemically modified to convert them to
agglutinate in the saline medium
These agents split the inter-chain disulphide bonds that hold
the heavy chains together and allow the two Fab fragments to
span a wider distance
65. Monoclonal Anti-D
Three types
1. IgM anti-D monoclonal reagent
2. Blend of IgM and IgG monoclonal antibodies reagent
3. Blend of monoclonal IgM and Polyclonal (human) IgG anti-D
IgM antibodies are highly specific and saline reacting
equally at RT and 370 C but unreliable for detection of
weak D
Blended antibodies are now routinely used and can
be used for detecting weak D
66. Tube Technique for Rh Typing
Prepare 5% washed red cell suspension of test sample.
Take three clean test tubes and label tubes 1 & 2 as “test” and
tube 3 as “control”.
Place 1 drop of anti-D (D1) in tube 1 and 1 drop of anti-D (D2) in
tube 2.
Place 1 drop of 22% bovine albumin / control in tube 3.
Add 1 drop of 5% test cell suspension to each tube.
Mix well, centrifuge at 1000 rpm for 1 min.
Resuspend cell button & look for agglutination
Control tube should show no agglutination
For all RhD negative test on blood donor, Du test recommended
67. Method for Rh Typing
1 2 3
1 drop
anti-D1
1 drop
anti-D2
1 drop 22%
albumin
1 drop 5%
red cells
1 drop 5%
red cells
1 drop 5%
red cells
+ + +
Mix well and centrifuge at 1000 RPM x 1 min
Look for agglutination
68. RBC with normal
expression of D antigen
Decreased number of
D antigens in Du
Weak D
Inheritance of D genes which result in lowered densities of
D Antigens on RBC membranes, gene codes for less D.
69. Partial D
Absence of a portion of the total material that
comprises the D antigen (qualitative defect)
If the partial D patient is transfused with D positive red
cells, they may develop an anti-D alloantibody to the
part of the antigen (epitope) that is missing
Missing
portion
RBC RBC
All epitopes in
normal D antigen
70. Method for Weak D Testing
Add 1 drop of 10% suspension of D negative red cells to a
test tube and add 2 drops of Anti D (blend of IgG + IgM)
Incubate at 37C for 30 minutes.
Wash three times with normal saline.
Make dry red cell button and add polyspecific AHG reagent.
Look for agglutination.
Results:
If there is agglutination Du Positive.
If there is no agglutination Du Negative.
71. Significance of Weak D
Donors
Weak D testing on donors required.
Labeled as D positive
Weak D substantially less immunogenic than normal D
Weak D has caused severe HTR in patient with anti-D
Patients
If weak D due to partial D can make antibody to portion they lack.
If weak D due to suppression, theoretically could give D positive
Weak D testing on patients not required.
Standard practice to transfuse with D negative
72. Significance of Weak D (Du)
Weak D is much less antigenic in comparison to D,
however, such red cells may be destroyed if transfused to a
patient already having anti-D. Hence, weak D donor units
are labeled as Rh postive.
The weak D poisive recipients are classified as Rh negative
and safely transfused with Rh negative blood
Du positive infant can suffer from HDN if the mother
possess anti-D antibodies
Rh immunoprophylaxis is recommended for the Rh
negative mother if the newborn is Du positive.
73. Learning Outcome
You should now be able to perform ABO & Rh
grouping on the donor and recipients sample
You should be able to resolve discrepancies in the
blood grouping
You should be able to perform weak D testing if
required