MLT 120: Final - Cram Session REVISED

Extra antigenic reactions in forward typing

Rouleaux, Group A with acquired B antigen, B(A) phenotype

group B individual who acquires reactivity with anti-A reagents in ABO red cell testing; in these individuals the B gene transfers trace amounts of the immunodominant sugar for the A antigen and the immunodominant sugar for the B antigen

B(A) Phenotype

action to take with rouleaux in forward typing

review patient history for disease

action to take with Group A with acquired B antigen in Forward typing

review patient history for transfusions

action to take with B(A) phenotype in forward typing

review patient history and test with additional monoclonal antibodies

missing reactions in forward typing

newbons

weak reactions in forward typing

ABO subgroups and Hodgkins/Leukemia patients

actions to take with newborn missing antigens in forward typing

review reverse typing

actions to take with ABO subgroups in forward typing

repeat testing with increased incubation times

mixed field in forward typing

group A,B or AB individual with transfusion of type O history

actions to take with Group A,B or AB individuals transfused with Type O

research pre-transfusion typing

extra antigens in reverse typing

ABO subgroups (group A2 with anti-A1), cold alloantibodies, cold autoantibodies and Rouleaux

action to take with group A2 with anti-A1 in reverse typing

test with dolichos bifloris

possible cold ALLOantibodies

Anti-P1, Anti-M, Anti-N, Anti-Lea and Anti-Leb

actions to take with cold alloantibodies in reverse typing

test with screening cells

actions to take with autoantibodies in reverse typing

check AC result, if positive then remove/neutralize autoantibody and test again

actions to take with Rouleaux formation in reverse typing

review patient history for multiple myeloma or Waldenstrom's macroglobulinemia; re-wash cells and retest or perform saline replacement technique

missing or weak reaction in reverse typing

newborn or elderly patient

action to take when weak reaction in reverse typing due to newborn or elderly patient

increase incubation times

a crossmatch is good for

3 days

the most clinically significant reactions occur at

37 degrees with IgG antibodies

ideal sample for pretransfusion testing

EDTA

if patient armband is removed, then...

crossmatch needs to be redone

compatibility testing procedure

1. ID patient

2. Review patient history

3. ABO + Rh Typing

4. Antibody Screen ( and ID if necessary)

5. Confirm ABO + Rh of donor units

6. Serological cross match

7. Label products

reasons for positive AC

auto antibodies, passively transfused alloantibodies, medications interferring

AC should be

negative

the sample used for a crossmatch must have been drawn

within the past 3 days

donor cells + patient serum

crossmatch

limitations of crossmatch

- will not detect all antibodies

- will NOT detect ABO mix-ups

- will NOT detect Rh errors

- will NOT detect ID errors

red cells are negative and this is an error. What action must you take?

incubate

Pretransfusion testing must contain

antibody screening by antiglobulin test

In the direct antiglobulin test, the antiglobulin reagent is used to:

detect pre-existing antibodies on erythrocytes

How long must a recipient sample be kept?

7 days

In emergency situations, release

O, Rh-negative red blood cells

A mixed-field reaction at AHG may be...

an antibody such as anti-Sda

Screening cells, major crossmatch, and patient autocontrol are positive in all phases. Identify the problem.

abnormal protein or non-specific auto antibody

When may an IS (abbreviated) crossmatch be performed?

when there is a negative antibody screen and patient has no history of antibodies

What are the pretransfusion requirements for an autologous transfusion?

type and screen

The major crossmatch will detect a(n):

recipient antibody directed against antigens on the donor red cells

may cause a false-negative IAT

too heavy cell suspension

Screening cells and major crossmatch are positive on immediate spin (IS) only, and the autocontrol is negative. Identify the problem.

cold alloantibody

In the direct (DAT) and indirect (IAT) antiglobulin techniques, false-negative reactions may result if the:

addition of AHG is delayed

A unit of RBCs is issued at 9:00 AM. At 9:10 AM the unit is returned to the Blood Bank. The container has NOT been entered, but the unit has NOT been refrigerated during this time span. The best course of action for the technologist is to:

record the return and place back into inventory

AHG (Coombs) control cells:

are coated only with IgG antibody

How would autoantibodies affect compatibility testing?

the DAT would be positive

Which of the following would most likely be responsible for an incompatible major crossmatch?

A. Recipient's red cells possess a low-frequency antigen

B. Recipient's red cells are polyagglutinable

C. Anti-K antibody in serum

D. donor red cells have a positive DAT

D. donor red cells have a positive DAT

Congestive heart failure, severe headache, and/or peripheral edema occurring soon after transfusion is indicative of which type of transfusion reaction?

circulatory overload

What can be done if HDFN is caused by maternal anti-K?

Monitor the mother's antibody level

What is the mechanism for HDFN occurrence?

maternal antibodies react with fetal antigens

True or False

The following will cause a positive DAT on cord cells of a newborn infant. Immune anti-K from a K-negative mother on the cells of a K negative baby.

False

is prevented by the irradiation of blood components

graft vs. host disease

Which blood type would be the BEST choice to transfuse to an ABpos baby who has HDFN caused by anti-D?

A negative or O negative, CMV negative, less than 7 days old, negative for Hgb S

The most frequent transfusion-associated disease complication of blood transfusions is:

hepatitis

Should an A-negative woman who has just had a miscarriage receive RhIg?

YES, but only if she does not have evidence of active Anti-D

is NOT a characteristic of ABO HDFN

strongly positive DAT

An obstetric patient, 34 weeks pregnant, shows a positive antibody screen at the indirect antiglobulin phase of testing. She is group B, Rh-negative. This is her first pregnancy. She has no prior history of transfusions. What is the most likely explanation for the positive antibody screen?

She received RhIg at 28 weeks gestation

Current testing on all donor blood must include:

(serological testing for) syphillis

What should be done if a mother types as an O and the baby types as an AB?

AB baby is not possible from O mother so check samples and identification.

The principle of the Kleihauer-Betke stain is that:

Adult hemoglobin is more soluble in acid buffer than fetal hemoglobin. Fetal cells are more resistant to acid and stain darker.

How many milliliters of whole blood from an FMH is covered with a 300-mg dose of RhIG?

30 ml

Anti-E is detected in the serum of a woman in the first trimester of pregnancy. The first titer for anti-E is 32. Two weeks later, the antibody titer is 64 and then 128 after another 2 weeks. Clinically, there are beginning signs of fetal distress. What may be done?

perform plasmapheresis to remove anti-E from the mother

Irradiation of transfusion products is primarily carried out to eliminate _____________________ disease.

graft versus host disease

List at least two treatments for HDFN

phototherapy and intrauterine exchange

______________ is the plasma protein that functions to bind hemoglobin following intravascular hemolysis?

haptoglobin

Coughing, cyanosis, and difficulty breathing are symptoms of _____________ _____________ (transfusion reaction)

TRALI, anaphylactic or circulatory overload

In performing a DAT, agglutination occurs after the addition of IgG sensitized cells (check cells.) What is true of this situation?

The antiglobulin reagent was functional.

Hemoglobinuria, hypotension and generalized bleeding are symptoms of which of the following transfusion reactions?

hemolytic

What test is most commonly used to demonstrate antibodies that have become attached to a patient's red cells in vivo?

DAT

An O-negative mother with no record of any previous pregnancies gives birth to her first child, a B-positive baby. The DAT is weakly positive (+/-). The DAT negative control is negative. The antibody screen is negative. The baby appears healthy but develops mild jaundice after two days, which is treated with phototherapy. The baby goes home after 4 days in the hospital without complications. What is the most likely explanation for the weakly positive DAT?

immune anti-b from the mother

An antibody shows strong reactions in all test phases. All screen and panel cells are positive. The serum is then tested with cord cell and the reaction is negative. What antibody is suspected?

Anti-I

The ____________Blood Group System's antibodies are commonly associated with delayed HTRs?

Kidd

True or False

The following is a part of the preliminary evaluation of a transfusion reaction. Do a DAT on the post-transfusion sample

true

Which type of transfusion reaction occurs in about 1% of all transfusions, results in a temperature rise of 1oC or higher, is associated with blood component transfusion, and is not related to the patient's medical condition?

febrile, non-hemolytic

Which of the following conditions are the most serious immediate consequences of HDFN?

hyperbilirubinemia and anemia

The process of separation of an antibody from its associated antigen on the RBC is known as:

an elution

What is the cause of transfusion-induced hemosiderosis?

iron overload

What is done to prevent HDFN caused by maternal anti-K antibody formation?

monitor the mother's antibody level

In the direct antiglobulin test, the antiglobulin (AHG) reagent is used to:

detect pre-existing antibodies on erythrocytes

Four units of blood are ordered for a patient. Blood bank records are checked and indicate that 5 years ago this patient had an anti-Jkb. What is the next course of action?

Antigen type units for the Jkb antigen and only crossmatch units negative for Jkb

Listeria grows in the cold but another bacteria often associate with sepsis from a blood component might be _____________ enterocolitica.

yersinia

A trauma patient had a severe hemolytic reaction just minutes after receiving a blood transfusion. What is the most likely cause?

immediate, immunologic; ABO incompatibility

_______ is the class of immunoglobulin generally associated with hemolytic disease of the newborn?

IgG

GIve the formula from the Kleihauer-Betke test that is used to determine the volume of FMH in mL of whole blood.

cells counted/1000 or 2000 = %

% x 50 = FMH ml

What would be the result of group A blood being given to a group O patient?

acute hemolytic transfusion reaction

The most appropriate laboratory test for quick, early detection of acute hemolysis is:

visual inspection

When Warton's Jelly is contained in a cord blood sample, it may cause a(n):

incorrect cell typing results

Anti-K anti-k are usually of the ________ class of antibodies.

IgG

is destroyed by proteolytic enzymes

M

The most common antigenic phenotype for the Lutheran system is:

Lu (a-,b+)

is the most immunogenic blood group

K

characteristics that are true of all 3 of the following antibodies: anti-Fya, anti-Jka, and anti-K?

detected at IAT phase (AHG) and may cause hemolytic disease of the fetus and newborn (HDFN) and transfusion reactions.

Which is the class of immunoglobulin uniquely associated with hemolytic disease of the newborn (HDN)?

IgG

Which system is associated with resistance to Malaria?

duffy

Unexpected antibodies formed to antigens on red cells of other humans but not on cells of the person forming the antibody are referred to as:

alloantibodies

Anti-S, Anti-s, and Anti-U are usually of the __________ class of antibodies.

IgG

Enzymes enhance the reactivity of red cell antigens with some antibodies by:

exposing additional antigen sites

The following antibody reacts optimally at WARM temperatures:

anti-jka

What is one possible genotype for a patient who develops anti-C antibody?

Rr

Which of the following phenotypes will react with Anti-f?

A. R2R2

B. R1R1

C. R1R2

D. rr

D. rr

The optimum phase to detect Kell, Kidd, and Duffy antibodies is:

AHG