Blood Banking and Transfusion Medicine PDF

## Blood Banking and Transfusion Medicine ### Blood Banking - Encompasses activities, procedures and tests done to ensure blood for transfusion is properly collected, preserved, stored and dispensed for later use in blood transfusion - Transfusion Medicine is a multidisciplinary branch of medicine...

## Blood Banking and Transfusion Medicine ### Blood Banking - Encompasses activities, procedures and tests done to ensure blood for transfusion is properly collected, preserved, stored and dispensed for later use in blood transfusion - Transfusion Medicine is a multidisciplinary branch of medicine that is concerned with the transfusion of blood and blood components - Blood Banks are regulated by FDA and inspected every year - Blood is considered both as a biologic and as a drug. ### Why is blood banking and transfusion medicine important? - RBCs contain antigens - Plasma may contain antibodies - Never allow the antigens to meet antibodies and vice versa - Antigen-Antibody Interactions may trigger RBC destruction via complement activation or by phagocytosis ### Historical Perspective - First recorded blood transfusion recipient: Pope Innocent VII - First successful transfusion was done by: James Blundell - Discovery of ABO blood group system was on 1901 by: Karl Landsteiner ### Serological Principles in Blood banking and transfusion medicine - Serological Tests use antigen and antibody interactions as tools for diagnosis - In serology, antigen or antibody may be detected - Antigens and antibodies may be detected in RBCs and plasma/serum - If you are looking for an Antigen, use Antibody as reagent - If you are looking for an Antibody, use Antigen as reagent ### Antigens - Originated from "antibody generators"; Serve as the target of antibodies - Can be polysaccharide, protein, lipids, nucleic acid, etc - **Epitope (antigenic determinants)** - Specific regions of antigens that are recognized by the immune system ### Characteristics of Antigens - **Monovalent or Univalent Antigen** - Antigen that has a single epitope - **Multivalent Antigen** - Antigen with more than one identical epitope - **Immunogens** - Are antigens capable of stimulating a host's immune system - All immunogens are antigens but not all antigens are immunogens. - **Haptens** - Are small molecules that are not immunogenic by themselves but can be immunogenic when coupled to a carrier - **Carrier** - Macromolecular substance to which a hapten is coupled to in order to produce an immune response. - Examples: RBC, bacteria, charcoal, latex, beads, bentonite - **Soluble antigen** - antigen that does not have a carrier - **Particulate antigen** - antigen that is attached to a carrier ### Forms of Antigens - **Exogenous antigens** - Antigens that enter the body or system and start circulating in the body fluids - Examples: bacteria, viruses, fungi, pollens, drugs, pollutants - **Endogenous antigens** - Refers to antigens that are derived/produced from within the body's own cells - Can be autoantigen, alloantigen, heteroantigen ### Antibodies - Immunoglobulins, proteins (specifically, glycoproteins) - Found in the gamma region during electrophoresis - Part of the Humoral component of adaptive immunity - Responsible for: - Antigen recognition - Opsonization - Complement activation - **Paratope** - Antibody determinants; antigen-binding site - Specific regions of antibody which recognizes and binds to an antigen ### Characteristics of Antibody - **Naturally Occurring abs vs Immune abs** - **Naturally Occurring abs** - Naturally present - Ex: ABO abs - B individuals have: - B Ag in RBCs - Have anti-A in serum - O individuals have: - No A and no B Ag in RBCs - Have anti-A, anti-B in serum - **Immune abs** - Not present initially - Produced only after exposure (transfusion, pregnancy, transplantation) - Ex: Rh abs - Rh positive individuals: - Have D Ag in their RBCs - Have no anti-D in their serum - Rh negative individuals: - Have no D Ag in their RBCs - Have no anti-D in their serum ### Alloantibodies vs Autoantibodies - **Alloantibodies** - Are produced after exposure to genetically different, or non-self, antigens of the same species - Can be detected in the Screening cells (during ab screen) in and Panel cells (during ab identification) - **Autoantibodies** - Are produced in response to self-antigens - Detected using Autocontrol (autocontrol contains patient serum + patient RBCs) ### Complement-activating abs vs Non-complement activating abs - **Complement-activating abs** - Results to intravascular hemolysis - Leads to immediate hemolytic transfusion reaction - **Non-complement activating abs** - Results to extravascular hemolysis - Leads to a delayed hemolytic transfusion reaction ### How are immune antibodies produced? - In transfusion - In pregnancy ### Characteristics of Antigen-Antibody Interactions - Antigen-Antibody Reactions are REVERSIBLE - Antigen-Antibody Reactions are usually sensitive and specific - Antigen-Antibody Reactions can be described as: - No reaction - Specific reaction - Cross reaction ### Cross-reactivity or Cross-reaction or Cross-immunity - Is a phenomenon where some antibodies secreted by one plasma cell can bind a similar but not identical epitope - Although an antibody may react with a similar antigen, the strength of the binding differs ### Strength of Binding - **Affinity** - Refers to the association constant between antibody and a univalent antigen - **Avidity** - Refers to the measure of the overall binding between antigen-binding sites and multivalent antigen ### Serological Techniques Applied in Blood Banking: Agglutination vs Precipitation - **Precipitation** - Refers to interaction of an antibody with a soluble antigen. This occurs since antibodies can be cross-linked by multivalent antigens to form immune complexes. - **Agglutination** - Refers to interaction of an antibody with a particulate antigen - Stages of Agglutination - **Sensitization or coating** - Refers to the combination of antibody with a single antigenic determinant on the surface of a cell without agglutination - **Lattice Formation** - Formation of large aggregates and visible clumping ### Non-agglutinating or incomplete antibodies - Antibodies that can perform sensitization but not the lattice formation - Usually IgG - Remedy: use AHG (Coombs Reagent or antiglobulin) ### Factors that affect Antigen-Antibody Interactions - **Antigen-Antibody Ratio** - **Zone of equivalence** - Ideal reactive condition where the number of multivalent sites of antigen and antibody are approximately equal - Optimum Serum to Cell Ratio in Blood Banking procedures = 2:1 - **Prozone vs Postzone** - **Prozone** - Antibody excess - Sample Case: patient who is in the height or in the peak of infection - Causes false negative - Remedy: subject specimen to serial dilution - **Postzone** - Antigen excess - Sample Case: patient who is in the window period - Causes false negative - Remedy: wait for patient to produce antibody - **pH** - Optimum pH for antigen-antibody binding: 6.5-7.5 - **Antibody in blood banking that is enhanced by acidic pH (6.5): anti-M** - **Centrifugation/Rotations** - Enhances physical contact between antigen and antibody - Immediate Spin/Saline phase in blood banking: 20 secs. ### Addition of Colloids and enhancement Media - **22% albumin** - Increases the dielectric constant, which then reduces the zeta potential - **Polyethylene Glycol (PEG)** - Brings RBCs closer together and concentrates antibodies by removing water molecules from the testing sample - **Low Ionic Strength Saline Solution (LISS)** - Decreases the ionic strength/ionic cloud, which then reduces the zeta potential ### Length of Incubation - A certain amount of contact time must occur for antibody to bind the antigen - 22% albumin = 30-60mins - PEG = 10-30mins - LISS = 10-15mins ### Number of Available Antigens on the Carrier - Lattice formation becomes faster if more antigens are present in the surface of cell/carrier ### Location of the Antigen - Binding occurs faster if the antigens are accessible to the antibody's reach ### Rouleaux Formation vs True Agglutination - Rouleaux formation (pseudoagglutination) may be confused with true agglutination - **Add NSS** - When clumping is dispersed = ROULEAUX FORMATION - When clumping remains intact = TRUE AGGLUTINATION - **Causes of Rouleaux Formation** - Monoclonal gammopathy (multiple myeloma, Waldenstrom's macroglobulinemia) - Plasma or Volume Expanders (i.e. Colloids such as dextran) - Wharton's Jelly in cord blood specimen - **Remedy:** Wash cord blood specimen before using: 6-8x (5x from Turgeon) washing with NSS ### Type of Antibody and the Temperature of the Reaction - IgM = usually Cold-reactive - IgG = usually Warm-reactive ### Who should receive blood? | Blood Product | Purpose/Major Indications | |-------------------------|---------------------------------------------------------------------------------------------------| | Whole Blood | Symptomatic anemia with large volume deficit | | Packed Red Blood Cells | Symptomatic anemia | | Washed Red Blood Cell | Symptomatic anemia on patients with history of severe allergic or anaphylactic reactions | | Leuko-reduced/Leuko-poor components | Prevents febrile transfusion reaction and transfusion-related acute lung injury (TRALI) caused by antibodies | | Irradiated blood components | Against WBCs, to reduce CMV transmission | | Neocyte-enriched red blood cells | To prolong time between transfusions in chronically transfusion-dependent patients | | Random Donor Platelets | Bleeding due to quantitative or qualitative platelet defect | | Single Donor Platelets | Bleeding due to quantitative or qualitative platelet defect, prevention of HLA alloimmunization | | Fresh Frozen Plasma | Multiple coagulation factor deficiency | | Cryoprecipitate | Treatment of patients with von Willebrand's disease, hemophilia A (factor VIII deficiency), or | | Granulocyte Concentrates | To elevate the leukocyte count in patients with neutropenia or granulocyte dysfunction | | Factor Concentrates | Specific coagulation factor deficiencies | | Immune Serum Globulin (ISG) | Patients with congenital hypogammaglobulinemia | ### What is in the blood? | Blood Components | Standards and Quality Control | Storage and Shelf Life | Storage Lesions | |----------------------|-----------------------------------------------------------------------|---------------------------------------------------------------|-------------------------------------------------------------| | Whole blood | Hct approx.. 40% | 1-6 degC: ACD, CPD or CP2D = 21 days; CPDA1 = 35 days | Decrease pH | | Packed red blood cells | Hct ≤80% | 1-6 degC: ACD, CPD or CP2D = 21 days; CPDA1 = 35 days | Decrease in glucose | | Frozen red blood cells | 80% RBC recovery; <1% glycerol; <300mg Hgb; Hct 70-80% | Open Sys. = 24 hours; ≤-65degC = 10 years | Decrease in ATP | | Washed red blood cells | | 1-6 degC = 24 hours | Decreased 2, 3 DPG | | Irradiated components | 25 Gy to the center of the canister | 1-6 degC = 24 hours | Decreased plasma sodium | | Leuko-reduced components| RBCs <5 x 106; ≥85% RBC recovery; Platelets pH ≥6.2; SD <5 x 106; RD <8.3 x 105 | Original outdate or 28 days from irradiation; Closed: same; Open: 24 hours | Increased plasma hemoglobin | | Platelet concentrate (RDP) | pH ≥6.2; ≥5.5 x 1010 | 20-24degC; 5 days | Increased plasma potassium | | Single Donor Platelet (SDP) | pH ≥6.2; ≥3.0 x 1011 | 20-24degC; 5 days; Pooled: 4 hours | Increased plasma ammonium | | Fresh Frozen Plasma (FFP) | Should be prepared within: 6 hours after collection for ACD; 8 hours after collection for CPD, CP2D, CPDA1 | -18degC = 1YR; -65degC = 7YRS | Increase in lactic acid | | Cryoprecipitate | FVIII:C = 80IU; Fibrinogen of at least 150mg per unit | Frozen: -18degC, 1yr; Thawed: 20-24degC, 6hrs; Pooled: 20-24degC, 4hrs | | | Granulocytes | ≥1.0 x 1010 PMNs/unit | 20-24degC 24 hours | |