BB lab final

given results of forward and reverse type, determine the blood type

Test	Reaction Strength

Anti-A

0

Anti-B

4+

A1 Cells

4+

B Cells

0

Type B blood

• B ag, Anti-A present

• A ag, Anti-B not present

Compatibility in RBC

• Blood Type B, what type can receive if compatible?

Type B

Type O

Compatibility in Plasma

• Plasma Type A, what plasma can be received?

Type A

Type AB

Type of Ig, IgG & IgM, which Ab associated with

• IgG: Rh, Duffy, Kidd, Kell, MNs (S,s), Lu^b

• IgM: Lewis, P, I, MNs (M,N), Lu^a

Transfusion Reactions, which blood group system are responsible for it:

• HTR

• HDFN

• GVHD

• HTR: incompatibility bw ABO blood group

• HDFN: incompatibility bw Rh mom and fetus

• GVHD: incompatiblity bw graft ABO and host ABO

Types of sugars associated w/ blood groups (ABO)

• Type A

• Type B

• Type O

• Type A: N-acetyl-D-galatosamine (GalNac)

• Type B: D-galactose (Gal)

• Type O: lacks either sugar, only has H precursor w/ Fucose (Fuc) attached to end

Direct Antiglobulin Test

• what samples used to test

• detects in-vivo sensitization of RBCs w/ IgG or complement components

• clinical conditions that result in in-vivo coating of RBCs w/ Ab or complement

  • Hemolytic disease of fetus and newborn (HDFN)

  • Hemolytic transfusion reaction (HTR)

  • Autoimmune and drug induced hemolytic anemia (AIHA)

• DAT includes testing 1 drop of 3-5% suspension of washed RBCs w/ polyspecific (anti-IgG, anti-C3d) reagent

• positive results are monitored by a DAT panel using monospecific anti-IgG and anti-C3d to determine specific type of protein sensitizing

what type of test is Weak D typing?

Indirect Antiglobulin Test (IAT)

How is weak D test performed?

• perform Rh₀(D) test

  • add Anti-D reagent to “D” labeled tubel add Rh control reagent to “C” tube (Rh control reagent is a “negative” control and must remain negative throughout testing)

  • add patient’s RBC (3-5%); mix

  • spin, read, grade reaction

    • if D tube is positive & Rh control is negative: Rh positive

    • if D tube is negative & Rh control is negative: continue testing - perform “Du test”

• Du test

  • incubate both tubes 37C for 15 mins

  • spin, read, grade reaction

    • if D tube is positive: Rh positive

    • if D tube is negative: continue testing

  • wash both tubes 3x saline

  • add AHG, spin & read, grade reaction

  • if D tube is positive & Rh control is negative: Du positive = Rh positive

  • if D tube is negative & Rh control is negative: Rh negative

  • if D tube is positive & Rh control is positive: Rh is undetermined

    • perform additional test to determine Rh phenotype: DAT, Elution

Given specific phenotype, tell Wiener Phenotype

R_{1 =} DCe

R_{2 =} DcE

R_{0 =} Dce

R_{z =} DCE

r = ce

r^’= Ce

r” = cE

r^y = CE

Given specific reaction when it comes to Rh Ab & tell what Wiener phenotype is

• Example:

  Antigen	Reaction
  D	+
  C	+
  E	0
  c	0
  e	+

DCe : R₁R₁, R₁r’

which Wiener phenotype is less common or considered rare to have?

R_z, r’, r”, r^y

Given scenario where mom is type O and baby is Type A, what is cause for weakly positive DAT

• cause: maternal IgG anti-A Ab reaction w/ baby’s A red cells

• condition: HDFN

Monospecific vs polyspecific (for DAT)

• Polyspecific AHG sera contain Ab to BOTH human IgG & C3d component of human complement

  • initial screening

• Monospecific AHG sera contain only 1 Ab specificity

  • either anti-IgG or anti-C3b/C3d

  • ID/confirmation, specific test

Which test is used to demonstrate antibodies that have been attached to patient RBCs?

Antiglobulin Test (Coombs Test)

Given antigram, tell what most likely antibodies are

Multiple choice, answers can be obvious

Familiarize self w/ fetal screen test and what those results mean

a. Forward blood typing only, reverse typing unreliable

• aka Rosette test : Detects Rh-positive fetal red cells in an Rh-negative mother’s blood.

  • Negative:

    • No/low fetal bleed → Give 1 dose of RhIG (300 µg)

  • Positive:

    • Fetal cells detected → Do Kleihauer-Betke test to calculate bleed → Adjust RhIG dose

What conditions are associated with positive DAT

a. HDFN (Hemolytic Disease of Fetus & Newborn)

b. HTR (Hemolytic Transfusion Reaction)

c. AIHA (Autoimmune and Drug Induced Hemolytic Anemia)

What is principle of antiglobulin test

• Antihuman globulins obtained from immunized non-human species bind to human globulins, such as IgG or complement, either free in serum or attached to antigens on red blood cells

• detect RBCs sensitized by IgG alloantibodies, IgG autoantibodies, complement components

  • Antibody molecules and complement components are globulins

  • Injecting an animal with human globulin stimulates the animal to produce antibody to the foreign protein (i.e., AHG)

  • AHG reacts with human globulin molecules, either bound to RBCs or free in serum. Washed RBCs coated with human globulin are agglutinated by AHG

In class, check cells, what does it mean if check cells are not working (in professional setting)

If check cells are not working, then antibodies were not detected properly. Check cells negative means there was an error in the procedure and the test should be repeated.

Which antibody is most commonly associated with HDFN?

Rh antibody

What antibodies can cross the placenta?

IgG: small = can cross placenta

• Ab: Rh, Kidd, Kell, Duffy, MNs (Ss), Lutheran (Lu^b)

Scenario, baby born as stillborn, what is the likely cause

HDFN

Given specific type of plasma, can it be transfused to patient who is group ____

Example: Plasma type A given to type AB?

Example: Plasma type AB given to type O?

• no

• yes

After ABO and Rh antibodies what is next most commonly seen antibody

Kell antibodies (anti-K)

how are weaker expressions of anti-D categorized

Categorized as positive for D antigen

extra credit

• most important thing in blood bank?

compatibility — ensuring that blood from a donor is compatible with the recipient’s blood group