5.12.20241
Blood types.
Budínská Xenie
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Functions of the RBC
̶ Transport of respiratory gases
̶ Buffering system
̶ Maintaining blood viscosity
̶ Immune function
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Blood groups
̶ Is a classification of blood, based on the presence and absence of
antigenic substances on the surface of red blood cells.
̶ Antigens (depending on the blood group system):
̶ proteins
̶ carbohydrates
̶ glycoproteins
̶ glycolipids
̶ Some of these antigens are also present on the surface of other
types of cells of various tissues.
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Blood groups
̶ 45 human blood group systems are recognized by the International
Society of Blood Transfusion:
̶ ABO System (Antigens: A, B, O).
̶ MNS System (Antigens: M, N, S, s, U).
̶ Rh System (Antigens: D, C, c, E, e).
̶ Lutheran System (Antigens: Lua, Lub).
̶ Kell System (Antigens: K, k).
̶ Lewis System (Antigens: Lea, Leb).
̶ Duffy System (Antigens: Fya, Fyb).
̶ Kidd System (Antigens: Jka, Jkb).
̶ Landsteiner-Wiener (Antigens: LWa, LWb).
̶ Chido/Rodgers System (Antigens: Ch, Rg).
̶ H System (Antigens: H).
̶ …
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Blood groups
H antigen
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Agglutinogen
̶ The ABO gene is located on chromosome 9
and exists in three allelic forms:
̶ The A allele encodes an enzyme that adds Nacetylgalactosamine
to the H antigen.
̶ The B allele encodes an enzyme that adds galactose to the H
antigen.
̶ The O allele does not produce a functional enzyme, so the H
antigen remains unchanged.
A type
0 type
B type
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"Bombay phenotype"
̶ in 1 of 10,000 individuals in India
̶ 1 in a million people in Europe
̶ H antigen deficiency
̶ Hemolytic disease of the newborn???
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Agglutinin
̶ γ-globulin (IgM)
̶ after births almost zero concentration in blood
̶ production of agglutinins begins 2-8 months after birth:
̶ stimulation by antigens similar to agglutinogens – in food, in GIT bacteria
̶ maximal concentration of antibodies is reached in 8-10 years,
decreases gradually with age
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AB0 system
̶ Antigens on the surface of RBCs (agglutinogens): A, B
̶ Antibodies in the blood (agglutinins): anti-A, anti-B (IgM)
Immunization against A and
B happens during the first
months of life (these antigens
are also in the diet) –
agglutinins are then in the
blood for the rest of the life
AB0 system
0 (-, anti AB) A (A, anti B) B (B, anti A) AB (AB,-)
RBC
0 (-) V V V V
A (A) - V - V
B (B) - - V V
AB (AB) - - - V
Plasma
0(anti AB) V - - A(anti
B) V V - B(anti
A) V - V AB(-)
V V V V
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Rh factor
̶ Antigens D, d (also C,c, E, e, which are weaker) are only on RBCs
̶ The strongest one is an antigen D – if present → Rh+ blood group
̶ In recessive homozygotes (dd) → blood group Rh- (17% in Europe, <1% elsewhere)
̶ in Rh- blood, antibodies (anti-D, IgG) develop only after immunization
̶ The first reaction is weaker, the next encounter with Rh+ blood will trigger a stronger immune
response → hemolysis
I. Rh- + Rh+ => N
II. Rh- + Rh+ => hemolysis
Rh+
Rh+
Rh+
Anti-D
(IgG)
Anti-D
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Blood products for transfusion
̶ Whole blood contains red cells, white cells, and platelets
suspended in blood plasma:
̶ Trauma, Surgery
̶ RBCs
̶ Anemia, Any blood loss, Blood disorders, such as sickle cell
̶ Platelets
̶ Cancer treatments, Organ transplants, Surgery
̶ Plasma
̶ Burn patients, Shock, Bleeding disorders
̶ Cryoprecipitated Antihemophilic Factor (Cryo)
̶ Hemophilia, Coagulation abnormality
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Tests conducted before a transfusion:
̶ Blood Typing (ABO and Rh Typing).
̶ Antibody Screen (Indirect Coombs Test).
̶ Crossmatching:
̶ Immediate Spin Crossmatch.
̶ Full/Extended Crossmatch.
̶ Complete Blood Count (CBC)
̶ Coagulation Tests.
̶ Infectious Disease Screening (Usually performed on donor blood):
̶ HIV
̶ Hepatitis B & C
̶ Syphilis
̶ Direct Coombs Test (Direct Antiglobulin Test - DAT)
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Blood transfusion. Early Complications.
̶ Hemolytic reactions (immediate and delayed)
̶ Non-hemolytic febrile reactions
̶ Allergic reactions
̶ Reactions secondary to bacterial contamination
̶ Circulatory overload
̶ Air embolism
̶ Thrombophlebitis
̶ Hyperkalemia
̶ Hypothermia
̶ Clotting abnormalities (after massive transfusions)
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Blood transfusion. Late complications.
̶ Transmission of infection
̶ Viral (hepatitis A, B, C, HIV, CMV)
̶ Bacterial (Salmonella)
̶ Parasites (malaria, toxoplasma)
̶ Graft-vs-host disease
̶ Iron overload (after chronic transfusions)
̶ Immune sensitization (D antigen)