M5-8 BB LAB

Secretors

Individuals who express blood group substances (A,B,H antigens) in soluble forms detectable in secretions such as saliva.

(A,B,H antigens)

Secretors are individuals who express blood group substances (—) in soluble forms detectable in secretions such as saliva.

Neutralize or inhibit

Secretors are water soluble substances are readily detected in small quantities

- —or —- the capacity of antibodies to agglutinate specific red cells

Hemagglutination-Inhibition or Neutralization

• Evaluates the relative strength/potency of water-soluble substances

Principle of Secretors

• different from ABO typing with direct agglutination of red cell

A

Secretors Phenotype

Example: Type A individual

AO

Secretors Genotype

Example: Type A individual

Saliva

Secretors

• commonly used sample since it is easily collected, unlike other bodily fluids with invasive procedures

Secretors Reagent

1:4

Secretors Reagent

• reagents are diluted with — ratio of dilution since the antigens detected are much weaker/lesser, thus, less antibodies are also used = zone of equivalence

Secretor Status Determination

Secretor Status Determination

Secretor Status Determination

Secretor Status Determination

ABO Discrepancy

an unexpected result which can indicate incorrect procedure or something unique with the patient (e.g. gene, blood type)

• forward and reverse typing doesn’t correlate

• there is a weak reaction (e.g. Anti-A in Patient X); problem depends on where it lies:

  • forward - antigens

  • reverse - antibodies

ABO Discrepancy

to know if there is discrepancy:

ABO Discrepancy

Resolution/s:

ABO Discrepancy

ABO Discrepancy

ABO Discrepancy

Rh Typing

Rh Typing

Rh ANTIGENS

D Status Determination

• characterized as nonglycosylated proteins on red cell membrane

D antigen

D Status Determination

• is the most clinically significant of all non-ABO antigens, It is so highly immunogenic.

D antigen

D Status Determination

• The only Rh antigen that undergoes routine testing, except in the case of investigation of unexpected antibodies.

D antigen

D Status Determination

• can trigger Hemolytic Transfusion Reaction (HTR) and Hemolytic Disease of Fetus and Newborn (HDFN) = more severe and deadly with — compared to ABO

Du phenotype

weakened expression of the D antigen/ weak D

Mechanisms for Du phenotype occurrence:

• weak D antigen expression occurs due to (3) causes of problem with the patient’s Rh antigen:

Mechanisms for Du phenotype occurrence:

• weak D antigen expression occurs due to (3) causes of problem with the patient’s Rh antigen:

Mechanisms for Du phenotype occurrence:

• weak D antigen expression occurs due to (3) causes of problem with the patient’s Rh antigen:

Rh Null Syndrome

Anti-Rh:29

– the antibody of broadest specificity

- described as anti-total Rh

- can be produced by Rh null individuals

Positive DAT

False Positive reactions are due to:

most common cause of Rh-typing (Du typing) discrepancies.

Rouleaux

False Positive reactions are due to:

- occurs due to high plasma proteins in blood; reason why samples are washed (red cell suspension)

Cold Autoagglutinins

False Positive reactions are due to:

antibodies that are innate to patient; since they are cold-reacting, place the sample in incubator to stop their reaction