Major Blood Groups ABO

Although there are over 600 known red blood cell antigens organized into 22 blood group systems, routine blood typing is usually concerned with only two systems: the ABO and Rh blood group systems. Antibody screening helps to identify antibodies against several other groups of red blood cell antigens. Some of the other groups are the Duffy, Kell, Kidd, MNS, and P systems

* * 2 011 YT Cartwright 010 DI Diego 3 009 JK Kidd 6 008 FY Duffy 007 BLOOD GROUP SYSTEMS CONVENTIONAL NAME    ISBT SYMBOL    ISBT NUMBER  ANTIGENS  * 2 011 YT    Cartwright 010 DI    Diego 3 009 JK    Kidd 6 008 FY    Duffy 007 LE    Lewis 21 006 KEL    Kell 18 005 LU    Lutheran 47 004 RH    Rh 1 003 P1    P 37 002 MNS    MNSs 4 001 ABO    ABO *

- - 2 5 10 7 1 9 3 026 JMH JMH 025 RAPH Raph 024 OK Ok 023 IN Indian BLOOD GROUP SYSTEMS   ANTIGENS    ISBT NUMBER    ISBT SYMBOL  CONVENTIONAL NAME  - - 2 5 10 7 1 9 3 026 JMH    JMH 025 RAPH    Raph 024 OK    Ok 023 IN    Indian 022 KN    Knops 021 CROMER    Cromer 020 GE    Gerbich 019 XK    Kx 018 H    Hh 017 CH/RG    Chido/Rogers 016 LW    Landsteiner-Wiener 015 CO    Colton 014 DO    Dombrock 013 SC    Scianna 012 XG0    Xg

ABO blood group antigens present on red blood cells and IgM antibodies present in the serum

Why do we have Anti-A or Anti-B Antibodies??? Viruses transmitted from the respiratory tracts of humans to other humans drag along various antigens including ABO blood group antigens. Prime the newborn’s immune system. Reduces transmissibility of viruses within a population.

Population Distribution of Major Blood Groups O Rh pos 38% O Rh neg 7% A Rh pos 34% A Rh neg 6% B Rh pos 9% B Rh neg 2% AB Rh pos 3% AB Rh neg 1%

Red blood cell compatibility table    AB+ AB- B+ B- A+ A- O+ O- Donor Recipient

Plasma compatibility table Recipient Donor O A B AB AB    A       B       O            

No naturally occurring antibodies Immune response requires Other Blood Groups No naturally occurring antibodies Immune response requires previous exposure Weaker titers of univalent antibodies

Compatibility testing is done to avoid Why do we care? Compatibility testing is done to avoid a hemolytic transfusion reaction If the Host or Recipient recognizes the donor RBC surface antigens as foreign, the host will mount an immune response to the donor RBC’s

The most significant is the Major Blood Groups Rhesus 47 Antigens make up the Rhesus Blood Group The most significant is the D antigen

There is no naturally occurring Anti D Antibodies Production of Anti D in the RH negative recipient requires previous exposure to the D antigen (in utero or by transfusion)

If red cells are administered to an ABO- or D-incompatible recipient, the recipient will mount an antibody response to the foreign RBC surface antigens IgM is polyvalent and fixes complement

Intravascular Clumping of Donor RBC’s

Clumps and extruded RBC stroma result in organ dysfunction and possible death Incidence 1:38,000 – 1:70,000 Mortality 1:30

Intravascular hemolysis of donor RBC’s

Donor RBC’s coated with host antibodies Susceptible to attack by Stiffer RBC membrane Susceptible to attack by splenic macrophages

intravascular clumping But no intravascular clumping

Bits of Donor RBC membrane lost traversing splenic sinusoids (extravascular hemolysis) Spherocytes Decreased RBC survival Delayed anemia Priming for worse reaction

What is compatibility testing? Also called pretransfusion testing Purpose: To select blood components that will not cause harm to the recipient and will have acceptable survival when transfused If properly performed, compatibility tests will confirm ABO compatibility between the component and the recipient and will detect the most clinically significant unexpected antibodies

Patient Identification Must confirm recipient’s ID from bracelet ON the patient Full patient name and hospital number Name of physician http://www.usatoday.com/tech/news/techinnovations/2006-07-17-chips-everywhere_x.htm

COMPATIBILITY TESTING Processing the specimen: ABO Group determined (forward and reverse) D typing determined Antibody screen will be performed ABO/Rh identical or compatible blood will be made available

Sample Identification The sample should also have the full patient name, hospital number, and physician Date and time of collection, phlebotomist’s initials All of this should be on the request form and the sample

Specimen Tubes Pink Top - EDTA Red Top – no additives

Serological Testing 3 tests: ABO/Rh Antibody detection/identification Crossmatch

ABO/Rh Typing In the ABO typing, the forward and reverse MUST match In the Rh typing, the control must be negative Both of these will indicate what type of blood should be given

ABO TYPING Front or forward type using monoclonal anti-A and anti-B (commercial) The sample is diluted to Hct 0.08, the commercial antibodies added & the test tube is centrifuged The RBC’s are then examined for clumping (gross observation, gel suspension)

Anti A Anti B Anti A Anti B A B Anti A Anti B Anti A Anti B AB O

ABO TYPING Back or reverse type with A and B cells Commercially available A and B cells are added to two tubes of plasma AB B A O A B A B A B A B

How do we know whether or not the host (or recipient) has antibodies to minor blood group antigens? Add commercial RBC’s with known important minor antigens on their surface to host (or recipient) plasma and centrifuge. Then incubate at body temperature for 15-30 minutes Then add rabbit antiglobulin

Antibody screen Also called the indirect Coombs test or the indirect antiglobulin test The antibody screen will detect the presence of any unexpected antibodies in patient serum If antibodies are detected, identification should be performed using panel cells (with an autocontrol) IS 37° (LISS) AHG

If recipient antibodies have coated commercial RBC surfaces

Rabbit antiglobulin will bind to the Antibodies and the RBC’s will clump

ANTIBODY SCREENING Detection of unexpected clinically significant antibodies against the minor blood group system antigens Positive in between 0 - 8% of samples depending on the population

Possibly significant minor blood groups 2 011 YT    Cartwright 010 DI    Diego 3 009 JK    Kidd 6 008 FY    Duffy 007 LE    Lewis 21 006 KEL    Kell 18 005 LU    Lutheran 47 004 RH    Rh 1 003 P1    P 37 002 MNS    MNSs    *

SCREENING TEST RESULTS A negative antibody screen allows blood to be dispensed using an immediate spin X-match or an electronic X-match, either of which confirms ABO compatibility A positive antibody screen requires a full antiglobulin phase X-match

Crossmatching Purpose: Prevent transfusion reactions Increase in vivo survival of red cells Double checks for ABO errors Another method of detecting antibodies

Crossmatches According to the AABB Standards: The crossmatch “shall use methods that demonstrate ABO incompatibility and clinically significant antibodies to red cell antigens and shall include an antiglobulin phase”

Crossmatch No agglutination ~ compatible Agglutination ~ incompatible Donor RBCs (washed) Patient serum

The procedure Donor cells are taken from segments that are attached to the unit itself Segments are a sampling of the blood and eliminate having to open the actual unit

Crossmatch Procedure if antibodies are NOT detected: Only immediate spin (IS) is performed using patient serum and donor blood suspension This fulfills the AABB standard for ABO incompatibility This is an INCOMPLETE CROSSMATCH If antibodies ARE detected: Antigen negative units found and X-matched All phases are tested: IS, 37°, AHG This is a COMPLETE CROSSMATCH

Crossmatches… Will Will Not Verify donor cell ABO compatibility Detect most antibodies against donor cells Will Not Guarantee normal survival of RBCs Prevent patient from developing an antibody Detect all antibodies Prevent delayed transfusion reactions

Approaches Requiring Less Than a Complete Crossmatch

Type and Screen Determines the ABO-Rh of the patient and the presence of the most commonly found unexpected antibodies(elimination of the crossmatch ).

Type and Screen If an emergency transfusion is required after type and screen alone, an immediate-phase crossmatch is performed. Blood given in this manner is more than 99% effective in preventing incompatible transfusion reactions due to unexpected antibodies.

Is the Crossmatch Really Needed? If the correct ABO and Rh blood type is given, the possibility of transfusing incompatible blood is less than 1 chance in 1000. ABO-Rh typing alone results in a 99.8% chance of a compatible transfusion, The addition of an antibody screen increases the safety to 99.94%, and A crossmatch increases this to 99.95%.

Physician responsibility in ordering uncrossmatched blood In an emergency (ER or OR), there may not be enough time to test the recipient’s sample It is your judgment that the risk of the patient dying from from anemia is greater than the risk of transfusing the patient without pre-transfusion testing

What can be given in an emergency? Type-Specific, Partially Crossmatched Blood An ABO-Rh typing and an immediate-phase crossmatch An abbreviated format Macroscopic agglutination. This takes 1 to 5 minutes

What can be given in an emergency? Type-Specific, Uncrossmatched Blood The ABO-Rh type Most ABO type-specific transfusions are successful. Caution should be used for patients who have previously received transfusions or have had pregnancies.

What can be given in an emergency? Type O Rh-Negative (Universal Donor), Uncrossmatched Blood Type O blood lacks the A and B antigens Type O Rh-negative, uncrossmatched packed RBCs should be used in preference to type O Rh-negative whole blood. More than two units of type O Rh-negative, uncrossmatched whole blood, the patient probably cannot be switched to his or her blood type .

Specific Recommended Protocol Infuse crystalloids or colloids. Draw a blood sample for typing and crossmatching. If crossmatched blood is not ready to give, use type-specific or type O Rh-negative cells or type O Rh-positive cells for males or postmenopausal females without a history of transfusions.

Summary The crossmatch “shall use methods that demonstrate ABO incompatibility and clinically significant antibodies to red cell antigens If an emergency transfusion is required after type and screen alone, an immediate-phase crossmatch is performed before transfusion (an abbreviated format ) If crossmatched blood is not ready to give, use type-specific or type O Rh-negative cells