Overview
This lecture introduces immunohematology, focusing on the principles of blood banking, transfusion medicine, and the immunological basis of blood compatibility.
Introduction to Immunohematology
- Immunohematology studies the immune response to blood components.
- Blood banking involves collecting, storing, processing, and distributing blood and its components.
- Transfusion medicine refers to administering matched blood components to patients in medical settings.
Blood Components and Their Uses
- Whole blood donations can be separated into packed red cells, fresh frozen plasma, cryoprecipitate, platelets, and factor VIII concentrate.
- Each blood component serves different therapeutic purposes.
Importance of Accuracy in Transfusion Medicine
- Errors in transfusion medicine can result in fatal hemolytic transfusion reactions.
- Proper patient identification and labeling at every step are critical to prevent life-threatening mistakes.
Antigens and Antibodies in Blood Banking
- An antigen is a substance capable of inducing antibody formation; found on cell surfaces or pathogens.
- An antibody (immunoglobulin) is a protein produced in response to an antigen and is highly specific to its epitope (part of an antigen).
- Antigens contain multiple epitopes; different antibodies can target different epitopes on the same antigen.
- Proteins are the most common and potent antigenic molecules.
Blood Group Antigens and Compatibility
- Human red blood cells express species- and individual-specific antigens.
- The major blood group antigens include ABO (A and B) and Rh (D, E, C, and variants).
- Other blood group systems include Kell, Duffy, and Lewis.
- Individuals form antibodies only to antigens they do not possess.
Mechanism and Consequences of Transfusion Reactions
- Transfusing blood with foreign antigens can cause the recipient to form antibodies against those antigens.
- Once antibodies are present, future transfusions with that antigen can cause severe transfusion reactions.
- Symptoms include chills, fever, back pain, nausea, vomiting, low blood pressure, and rapid pulse; monitoring is required during transfusions.
Key Terms & Definitions
- Immunohematology — study of immune responses to blood components.
- Blood banking — procedures for collecting, storing, and distributing blood.
- Transfusion medicine — clinical practice of administering blood or blood components.
- Antigen — substance that induces antibody formation.
- Antibody (Immunoglobulin) — protein that binds specifically to an antigen.
- Epitope — specific region on an antigen recognized by an antibody.
- Transfusion reaction — adverse immune response to incompatible blood transfusion.
Action Items / Next Steps
- Review the major blood group systems (ABO, Rh, Kell, etc.).
- Understand the process and importance of proper patient and sample identification in transfusion medicine.