Unit #5F – Clinical Laboratory Testing – Basic Immunohematology Cecile Sanders, M.Ed., MLS(ASCP)

Unit #5F – Clinical Laboratory Testing - Basic Immunohematology Immunohematology = Blood Banking In blood banking, technologists and technicians must determine blood groups (types) and other red blood cell antigens before blood transfusions may be given. Blood grouping is also used in organ transplantation, questions of paternity, forensic investigations, and genetic studies.

Unit #5F – Clinical Laboratory Testing - Basic Immunohematology Units or “pints” of blood are “banked” for use in transfusions to patients that need blood either because of a blood loss (accident or surgery, etc.) or because the patient is unable to make his own blood (anemia or leukemia, etc.).

Unit #5F – Clinical Laboratory Testing - Basic Immunohematology Blood from donors is collected in a plastic bag and stored in a special refrigerator until used or until the blood expires, usually in 42 days.

Unit #5F – Clinical Laboratory Testing - Basic Immunohematology Most hospitals obtain donor blood from processing centers, such as the American Red Cross. In Austin, the donor collection and processing center is the Blood and Tissue Center of Central Texas, 4300 N Lamar Blvd, Austin, TX (512) 206-1266 PLEASE DONATE BLOOD IF YOU CAN!

Unit #5F – Clinical Laboratory Testing - Basic Immunohematology Donated blood can be separated into several components, depending on the needs of the medical community. Blood may be left as “whole blood” or separated into red cells, platelets, and plasma. In this way, several patients can benefit from one unit of donor blood. Visit http://www.hhmi.org/biointeractive/vlabs/immunology/index.html for more information on blood processing and storage.

Unit #5F – Clinical Laboratory Testing - Basic Immunohematology The ABO System Group O = 45% Group A = 41% Group B = 10% Group AB = 4% ABO grouping is based on the presence of absence of blood group antigens on red blood cells. (Review “antigens” and “antibodies” in Unit#5C under Basic Serology/Immunology, if needed)

Unit #5F – Clinical Laboratory Testing - Basic Immunohematology Group A individuals have A antigens on their red cells. Group B individuals have B antigens on their red cells. Group AB individuals have A AND B antigens on their red cells. Group O individuals have NEITHER A NOR B antigens on their red cells.

Unit #5F – Clinical Laboratory Testing - Basic Immunohematology Red cell antigens are identified by mixing a person’s red blood cells with typing serum (Anti-A and Anti-B) and looking for agglutination. This is called forward or direct grouping or typing. If a person’s red blood cells agglutinate (clump) when mixed with a typing serum, they have that antigen on their red blood cells.

Unit #5F – Clinical Laboratory Testing - Basic Immunohematology Anti-A and Anti-B serums are purchased like this:

Unit #5F – Clinical Laboratory Testing - Basic Immunohematology Forward or direct blood grouping Anti-A Serum Anti-B Serum Blood Group Agglutination (+) No agglutination (-) A B AB No agglutination(-) O

Unit #5F – Clinical Laboratory Testing - Basic Immunohematology Pictures of ABO Blood Grouping/Typing

Unit #5F – Clinical Laboratory Testing - Basic Immunohematology Humans have naturally occurring antibodies in their plasma or serum against blood antigens they do NOT have. For example: Group A individuals have Anti-B antibodies; Group B individuals have Anti-A antibodies. Detection of these antibodies is called reverse or indirect grouping or typing.

Unit #5F – Clinical Laboratory Testing - Basic Immunohematology Reverse or indirect blood grouping: Blood Group Anti-A Abs Anti-B Abs A No Yes B AB O

Unit #5F – Clinical Laboratory Testing - Basic Immunohematology Blood Group Antigens and Antibodies Summary Blood Group Anti-A Serum Anti-B Serum A Abs B Abs A + - No Yes B AB O

Unit #5F – Clinical Laboratory Testing - Basic Immunohematology Group O packed red blood cells are sometimes referred to as the “Universal Donor”. In an emergency, it can be given to any blood type because the red cells do not have antigens against which the patient’s plasma antibodies might react. Because the blood is “packed”, it does not have plasma antibodies.

Unit #5F – Clinical Laboratory Testing - Basic Immunohematology Group AB is sometimes referred to as the “Universal Recipient”. In an emergency, these patients can receive any blood type because they do not have any plasma antibodies to react against A or B antigens. However, it is always best to give the patient group or type specific blood.

Unit #5F – Clinical Laboratory Testing - Basic Immunohematology Rh is another antigen that individuals may have on their red blood cells. Another name for Rh factor is D antigen. If a person has the Rh factor (D antigen) on their red blood cells, they are called Rh positive. If a person does NOT have the Rh factor (D antigen) on their red blood cells, they are called Rh negative.

Unit #5F – Clinical Laboratory Testing - Basic Immunohematology When a person is blood grouped or typed, Rh is always determined, in addition to ABO grouping. Rh (D) grouping/typing is also performed using anti-serum (anti-D), which is mixed with patient’s blood. If there is agglutination, the person is called Rh positive; if there is NO agglutination, the person is called Rh negative.

Unit #5F – Clinical Laboratory Testing - Basic Immunohematology ABO and Rh

Unit #5F – Clinical Laboratory Testing - Basic Immunohematology Try your hand at working in a Blood Bank! Play the “Blood Typing Game” at this website: http://nobelprize.org/educational_games/medicine/landsteiner/index.html (Hint: Use the syringe to draw blood from patients’ arms; then move the syringe over the blood typing reagents to add it to the tubes. Once you decide on the correct blood type, click on the right bag of blood and move it to the IV pole to start the transfusion.)