PRETRANSFUSION TESTING AND DONOR SCREENING

Read the questions carefully. It is recommended to read Harmening kasi hindi to complete pa.

Pre-Transfusion Testing

A series of serologic and non-serologic protocols whose ultimate objective of preventing autoimmune mediated hemolytic transfusion reaction

RA 7719 - National Blood Services Act of 1994

The law regarding blood bank / blood transfusion services.

1. DOH - Department of Health

2. BRL - Bureau of Research and Laboratories

3. PBCC - Philippine Blood Coordinating Council

The regulating agency in blood banking in the Philippines

Clerical error

The greatest threat to safe transfusion therapy

Clerical errors

The most common cause of transfusion-associated fatalities.

Patients must wear wristbands with 2 unique identifiers upon admission to discharge.

This is done to prevent patient misidentification and administration failures.

• Patient’s first and last name

• Date of birth

• Medical record number

What are the examples of unique identifiers?

• Anklebands

• Labels affixed to exposed part of the body (head/ torso)

What are alternatives to wristbands?

Discrepancies

This must be completely resolved prior to collecting the pretransfusion specimen.

Anticoagulated specimens

These specimens are often preferred due to ease of handling.

Red blood cells from anticoagulated sample

It is ideal for preparing a uniform cell suspension for testing.

Anticoagulated specimens

It can inactivate complement binding antibodies due to calcium chelation disrupting cascade.

Clotted red blood cells

These specimens may require additional washing steps.

Serum

It may contain small fibrin clots that can be difficult to distinguish from true agglutination.

• IV line contaminated

• Hemolyzed samples

What specimens are rejected?

True

True or False.

It is recommended that an amount of blood = 3 or more times the dead space of the catheter be discarded.

It can mask antigen-antibody-mediated hemolysis

Why are hemolyzed samples rejected?

Every 3 days

For antibody screening and compatibility testing, how frequent are specimens collected?

3 days

Specimen must be collected every ___ for antibody screening and compatibility testing

Day 3, midnight

When do specimens expire?

2-8 C

Pretransfusion specimen and donor units are stored at what temperature?

7 days

Patient sample and segment from the donor unit must be retained post-transfusion for at least how long?

To investigate any adverse effect

Why are patient sample and segment from the donor unit retained?

• Determining the recipient’s ABO group and Rh type

• Screening for any unexpected antibodies

• Crossmatching the donor unit with the recipient’s plasma.

Compatibility test is done to?

True

True or False.

Between 30% and 35% of antibodies reach undetectable levels within 1 year, and nearly 50% become undetectable after 10 years.

Recipient testing

This must be performed 3 days prior transfusion

• ABO typing

• Rh typing

• Antibody screening of Recipient Testing

Examples of Recipient Testing

ABO Blood Group

This blood group continues to be the most important blood group in transfusion and transplantation due to immunogencity.

• Tubes

• Column-agglutination technology

• Microtiter plates

What instruments are used in ABO grouping?

Forward

• Anti-A

• Anti-B

Reverse

• Known A1 cells

• Known B cells

Reagents used in ABO Grouping

Group O RBC

What should be used if discrepancy cannot be resolved prior to transfusion?

Anti-D reagents

These are monoclonal blends of IgM and IgG components

Room temperature (DAT)

IgM is reactive at what temperature?

Spontaneous agglutination (AB positive)

Rh control is done if there is presence of?

False.

Rh control is tested parallel with anti-D for weak D determination.

True or False.

Rh control is tested inversely with anti-D for weak D determination.

Positive Rh control

What indicates that the Rh typing result is invalid?

Donor units

Weak D testing is optional but required for?

Antibody screening

It is where antibodies to blood group antigens must be assessed for clinical significance.

• RBC destruction

• HTR

• HDFN

Antibody screening is used to assess?

IgG → 37 C

Clinically significant antibodies react at what temperature?

• 2% - 5%

• Multiply transfused populations

• The incidence of alloimmunization in all transfusion recipients is at what percent?

• It is higher in?

Rh-positive

If weak-D is positive, it should be labeled as?

• HBV DNA

• HBsAG

• HBc antibodies

• HCV antibodies

• HCV RNA

• HIV1/2 antibodies

• HIV-1 RNA

• HTLV I/II antibodies

• WNV RNA

• Serologic test for syphilis

• Antibodies to Trypanosoma cruzi

Test for infectious disease markers

Bleeding

What is the term used for collecting blood for donation?

Segments

Access to the donor unit is obtained through?

Blood typing

Segments can be tested for?

16 gauge

The bore size used in blood bank

• ABO / Rh compatible

• Antigen-negative

• Platelets, thawed plasma, cryoprecipitate

What are the selection criteria for blood transfusion?

• Males

• Menopausal women

Rh positive blood can be given to Rh negative recipients, but only in cases of?

Rh, Kell, Duffy RBC matching

What should be done to decrease rate of alloimmunization in Sickle Cell Disease?

• False positive

• Positive IAT, Negative DAT

• DTT or Trypsin

• Multiple myeloma displays what result in AHG?

• In what way does it create this result?

• How to resolve?

Daratumumab (causes false positive)

Multiple myeloma is treated using?

It binds to CD38 on RBCs, where in turn the Coomb’s reagent binds to

Why does daratumumab cause false positive agglutination?

• Platelets

• Thawed Plasma

• Cryoprecipitate

What components do not require compatibility testing?

Compatibility testing

If there is antigen or RBC in platelet concentrate or cryoprecipitate, what must be done?

Group A thawed plasma → lack of group AB plasma

If an emergency or trauma patient with unknown blood type requires blood, what can be given?

Serologic Crossmatch

It indicates the donor unit is safe and compatible for transfusion. It is also called compatibility testing.

PSDR

• Patient Serum

• Donor RBC

• Patient antibodies (tested)

What are collected and tested in Major Groups in Serologic Crossmatching?

PRDS

• Patient RBC

• Donor Serum

• Donor Antibodies

What are collected and tested in Minor Groups in Serologic Crossmatching?

1. Immediate Spin Crossmatch

2. Antiglobulin Crossmatch

What are the phases in Serologic Crossmatch?

• Immediate spin crossmatch

• Antiglobulin crossmatch

• This is performed when no clinically significant antibodies or history of antibodies are detected.

• This is performed if a clinically significant antibody is detected.

Serologic test - Immediate Spin

If no clinically significant antibodies are detected and there is no history of antibody, this is sufficient.

• Recipient plasma

• Cells → donor

In immediate spin crossmatch, recipient ___ is mixed with ___ from the donor unit, immediately centrifuged, and observed for agglutination and/or hemolysis.

• Incorrect ABO Grouping of recipient / donor

• Cold-reactive alloantibody or autoantibody

• Abnormalities in the plasma (rouleaux)

What are the possible reasons for incompatibility in immediate spin crossmatch?

• Antibody screening

• Antibody identification at room temperature

• Autocontrol

If there is cold-reactive alloantibody or autoantibody in the plasma that is not detected in antibody detection tests, what must be done?

Room (temperature)

If the antibody screen was negative, perform antibody identification at ___ temperature since the incompatibility is detectable at that phase of testing.

Inclusion of autocontrol

In antibody detection (immediate spin), how are cold-reactive alloantibodies distinguished from autoantibodies?

Prewarming of test system

It circumvents the reactivity in the presence of a cold-reactive antibody.

Inclusion of A1, A2, B cells

This is useful to include when testing the plasma to rule out the presence of immune-mediated or passively acquired ABO antibodies.

Plasma

Rouleaux is detectable only when ___ is present.

True agglutination

In Saline Replacement (Immediate Spin), rouleaux will disap- pear while ___ ___ will not.

Antiglobulin crossmatch

It is required if clinically significant antibody was detected.

False.

The antiglobulin crossmatch consists of an immediate spin crossmatch with the recipient’s plasma and cells from the donor unit.

True or False.

The antiglobulin crossmatch should not include the immediate spin crossmatch with the recipient’s plasma and cells from the donor unit.

• New alloantibody in recipient’s plasma

• Low-incidence alloantibody on donor RBCs

• Warm-reactive autoantibody in recipient’s plasma

• Positive DAT

Reasons for positive results in Antiglobulin Test

Perform antibody identification

If there is new alloantibody is present in recipient’s plasma, what is the remedy?

Perform more extensive antibody identification

If there is alloantibody to a low-incidence antigen present on donor unit RBC, what should be done?

Perform adsorption

If there is warm-reactive autoantibody is present in the recipient’s plasma, what should be done?

Adsorptions

Autoantibodies present in the plasma will require ___ to circumvent reactivity.

• Donor RBCs are ABO incompatible. (ABO is IgM)

• Donor RBCs are polyagglutinable. (Reacts with normal sera)

• Anti-A1 is the serum of an A2 or A2B individual.

• Alloantibodies reactive at room temperature (anti-M).

• Rouleaux formation.

• Cold autoantibodies (anti-I).

• Passively acquired anti-A or anti-B.

Give the cause(s) of the result as many as you possibly can.

• Negative Antibody Screen

• Incompatible Immediate Spin Crossmatch

• Donor RBCs have a positive DAT.

• Antibody reacts only with RBCs having strong expression of a particular antigen (dosage) or variation inantigenstrength(e.g.,P1). • Antibodytoalow-incidenceantigenonthedonorredbloodcells.

  • Passivelyacquiredanti-Aoranti-B.

Give the cause(s) of the result as many as you possibly can.

• Negative Antibody Screen

• Incompatible Antiglobulin Crossmatch

Computer Crossmatch

ABO compatibility can be verified electronically via a validated, on-site computer system provided acceptable criteria have been met.

• St Luke’s

• Asian Hospital

Hospitals in the PH with computer Crossmatch

Computer Crossmatch

It requires no detectable clinically significant antibodies or history of antibodies.

Electronic crossmatching

It eliminates need for serologic crossmatch, reduces sample volume requirements and testing time.

• 1 from historical records

• 1 from current records

2 determinations of recipient’s ABO in Computer Crossmatch requires?

• Group O red blood cells

• Group A thawed plasma

If the blood type of the recipient in need of emergent transfusion is unknown, what blood (component) can be given?

• Readily available

• Initial resuscitation has no increase in mortality

Advantage of Group A thawed plasma

• 8 to 10 units → less than 24 hours

• 4 to 5 units → within 1 hour

Massive transfusion is defined as the administration of ___ to ___ RBC units to an adult, or ___ to ___ units within ___.

1:1:1

The American College of Surgeons recommends transfusion of red blood cells, thawed plasma, and platelets in what ratio for effective resuscitation?

• Red blood cells

• Thawed plasma

• Platelets

The American College of Surgeons recommends transfusion of these components in 1:1:1 ratio for effective resuscitation.

• Restore blood volume

• Maintain hemostasis

• Maintain oxygen-carrying capacity

• Oncotic pressure

• Biochemical parameters

The goal of treatment in massive transfusions

Neonatal transfusions

It is done in infants less than 4 months of age.

True

True or False.

Either the infant’s or mother’s plasma may be used for antibody screening and any necessary compatibility testing.

False.

If an infant has a negative antibody screen and will only receive group O red blood cell transfusions, repeat testing may be omitted for the remainder of the hospital admission.

True or False.

If an infant has a negative antibody screen and will only receive group O red blood cell transfusions, repeat testing is needed.

Antiglobulin test

What test is used to detect passively acquired maternal anti-A and/or anti-B?

Intrauterine Transfusions

These are indicated in severe cases of fetal anemia.

• Umbilical vein

• Sonography

Intrauterine transfusions are performed by inserting a needle into the ___ ___ using high-resolution ___ to guide the procedure.

• Blood typing

• DAT

• Antigen typing

• Bilirubin levels

In Intrauterine Transfusions, fetal samples are obtained to perform what tests?

• Fresh (less than 7 days old)

• Leukocyte reduced

• Irradiated (prevent GVHD)

Requirements for units to be used in intrauterine transfusions

• Donation identification number / pool number

• Interpretation of compatibility

A form or label must be attached to the unit that contains the intended recipient’s two unique identifiers, which are?