Immunohematology + Transfusion Medicine

benefits/reasons for transfusion

maintaining oxygen carrying capacity

restoring blood volume

replacing coagulation factors

restoring leukocyte functions

whole blood, blood components, and derivatives for transfusion

packed RBCs

irradiated RBC

frozen RBC

fresh frozen plasma

cryoprecipitate

blood donation: donors, collection, storage, and processing

donor selection and identification

collection of RBCs

• anticoagulants

• labeling

• storage of blood

standard ISBT 128 End Label Format

blood group

expiry date

special testing/characteristics (optional)

routine blood screening tests for blood processing

syphilis

hepatitis

HIV/AIDS

Human T-Cell Lymphotropic Virus

West Nile

Trypanosoma cruzi

autologous transfusions

directed transfusions

other types of blood donations

antigen

a foreign (different from self) substance that, when introduced into the body of a person lacking the antigen, results in an immune response —> formation of a corresponding antibody

antibody

a protein found in plasma that is formed as a result of antigenic stimulation and is specific for an antigen

isoantibodies

naturally occurring ABO antibodies

unexpected/immune antibodies

result from specific antigenic stimulation from RBCs

anti-sera

a highly purified solution of antibody, and is named based on the antibody it contains

agglutination

clumping of RBCs caused by the reaction of a specific antibody and antigen on the cells

means of detecting antigen-antibody reactions

antisera

agglutination

hemolysis

hemolysis

destruction of RBCs by activation of complement

a reagent used in blood banks

all samples must be free of this when tested

blood banking techniques

gel technology

traditional tube method

positive reaction for solid-phase RBC adherence methods

well coated with red cell stroma + serum containing antibodies —> antibody in serum bound to red cell stroma + indicator red cells coated with anti-IgM —> indicator red cells bound to antibodies —> ? (red cells dispersed throughout the wall)

negative reaction for solid phase RBC adherence methods

well coated with red cell stroma + serum containing no antibodies —> antibodies and therefore indicator red cells not bound —> ? (red cells buttom at the bottom of the well)

type A

Anti-A serum —> agglutination

anti-B serum —> none

type B

anti-A serum → none

anti-B serum —> agglutination ty

type AB

agglutination in both anti-A and anti-B serum

type O

no agglutination occurs in neither anti-A or anti-B serum

Landsteiner’s Rule

reciprocal antibodies are consistently and predictably present in the sera of normal people whose RBCs lack the corresponding antigens

type O

approximately 45% of the population

No A or B antigens are present

these individuals form potent anti-A and anti-B antibodies which circulate in the blood plasma at all times

type A

approximately 40% of the population

no B antigens present

these individuals form potent anti-B antibodies that circulate in the blood plasma at all times

type B

approximately 11% of the population

no antigens present

these individuals form potent anti-A antibodies that circulate in the blood plasma at all times

type AB

approximately 4% of the population

both A and B antigens present

these individuals possess no ABO antibodies

Rh (D) antigen

blood group system with many antigens

prefers to the presence or absence of D antigen on the RBC

individuals who lack this antigen do not naturally make it

agglutination (hemagglutination)

RBCs have antigens that combine with serum antibodies (either patient or reagent) —> antibody bridges from with antigens on adjacent cells —> ?

4+

one large aggregate

3+

a few medium to large aggregates

2+

several medium sized aggregates

1+

many small aggregates

0

no visible agglutination

front type

testing for the presence of antigens on RBCs using anti-sera and patient cells

type A

anti-A sera = positive (3-4+)

anti-B sera = negative (0) t

type B

anti-A sera = negative (0)

anti-B sera = positive (3-4+)

type O

anti-A sera = negative (0)

anti-B sera = negative (0)

type AB

anti-A sera = positive (3-4+)

anti-B sera = positive (3-4+)

back type

testing for the presence of antibodies in plasma using reverse group cells and patient plasma

type A

reagent A cells = negative (0)

reagent B cells = positive (3-4+)

type B

reagent A cells = positive (3-4+)

reagent B cells = negative (0)

type O

reagent A cells = positive (3-4+)

reagent B cells = positive (3-4+)

type AB

reagent A cells = negative (0)

reagent B cells = negative (0)

Rh+

presence of D antigen

Rh-

absence of Rh antigen

Rh+

anti-D sera = positive (3-4+)

Rh-

anti-D sera = negative (0)