blood bank exam 1

most blood group antibodies are of what immunoglobulin classes

IgM and IgG

Bombay (Oh) individuals can be differentiated from normal group O person because

Bombay (Oh) individuals

the hh genotype

What are the possible ABO phenotypes of the offspring from the mating of a group A

to a group O individual

phenotypes: A or O

Genotypes: AO or OO

What ABH substance(s) would be found in the secretions of a group B secretor

B and H

You are working on a specimen in the laboratory that you believe to be a Bombay

phenotype. Which of the following reactions would you expect to see in a Bombay

phenotype

no agglutination with anti-A, anti-B, anti-AB, and anti-H

Naturally occurring antibodies that react at room temperature, activate complement and can be hemolytic are of which class

IgMfor

In newborns only this test is performed to determine ABO

forward grouping

Which ABO group contains the least amount of H substance

Bombay (Oh), then type A

What is the worst complication of transfusing someone with the wrong ABO group?

Intravascular hemolysis, can result in death

What class of immunoglobulin is capable of crossing the placenta

IgG

A woman with blood group A marries a man with blood group O. Their firstborn child

has blood group O. The mother's most probable genotype is:

AO

The B gene will elicit the production of an enzyme which transfers which sugar to

the terminal end of the H substance

D-galactose

In a person who demonstrates A, B and H substances in their saliva, which genes

must he/she possess

AB

Differentiate alloantibodies versus autoantibodies

alloantibodies- directed vs. non-self antigens

autoantibodies- directed against self-antigens

Terminal sugars for H, A and B

H: L-fucose

A: N-acetyl-D-galactosamine

B: D-galactose

If a person with the Bombay phenotype needs a blood transfusion, what blood type

would be most compatible

another bombay phenotype person’s blood

What is the only possible phenotype of an offspring produced from two group O

parents

OO

How do you resolve rouleaux in the laboratory

wash patient’s cells several times with saline. cord cells must be washed six to eight times to remove Wharton’s jelly

An elderly patient is documented as being type O. The forward grouping is negative

with anti-A and anti-B. The reverse grouping shows no reactivity with A1 cells and B

cells. What can be done to correct the discrepancy

it is possible that their antibodies may be undetectable during reverse grouping due to lower levels of anti-A and anti-B antibodies in the blood

At what age to infants begin to produce their own ABO antibodies

6 months after birth

The ABO group antibodies are primarily what type of antibodies

IgM

What is the source of anti-B lectin

Bandeiraea simplicifolia

Which type of cancer is most often associated with acquired B phenomenon

colon cancer

An example of a technical error that can occur during ABO typing is

• cell supension too heavy of light

• failure to add reagent

• failure to follow instructions

• uncalibrated centrifuge

• contaminated reagents

• warming during centrifugation

Examples of Group I, II and III discrepancies

group I: newborns, elderly, leukemia patients, patients on immunosuppressive drugs, congenital agammaglobulinemia, bone marrow transplant patients, and patients whose existing ABO antibodies are diluted by plasma transfusion or exchange

group II: subgroups of A, leukemias may yield weak A or B antigens, Hodgkin’s diseases, Acquired B phenomenon

group III: elevated globulin levels (multiple myeloma, waldenstrom’s macroglobulinemia, some cases of hodgkin’s), elevated levels of fibrinogen, plasma expanders, wharton’s jelly in cord blood samples

An antigen-antibody reaction alone does not cause hemolysis. Which of the following

is required for red blood cell lysis

complement

Where are ABH substances detected in secretors

the antigens present in a persons blood that is secreted

What percentage of individuals inherit the secretor gene

80%

An example of a technical error that can result in an ABO discrepancy is

failure to add reagents

What percentage of the white population has type O blood

45%

In transfusion medicine most clinically significant antibodies that react at body

temperature and are capable of causing transfusion reactions are of which class

IgG

The use of known commercial antisera (anti-A, anti-B) to detect antigens on

individual red blood cells is called

forward grouping

The use of known reagent red blood cells (A1 and B cells) to detect ABO

antibodies in the patient’s serum is called:

reverse grouping

What percentage of type A population is A2

20%

Why is reverse grouping not performed on cord blood specimens

most antibodies present will be from the mother and will not be an accurate reflection of the baby’s ABO group

Which phenotype(s) will give rise to the Bombay phenotype

hh only

What blood type is not possible for an offspring of AO and BO mating

AA and BB

What is the source of anti-A1 lectin

Dolichos biflorus, sometimes Ulex europaeus depending on the amount of H antigen available

What antibodies are formed by a Bombay individual

Anti-A, anti-B, and H

Which blood group has the greatest amount of H antigen

type O