mls 330 exam 3

forward typing specimen

pt RBC

forward typing known reagent

Antisera (anti-A,anti-B, anti-D, & DC)

main purpose of forward typing

detect antigens on RBCs

forward type identifies what

unknown antigens

reverse typing specimen

plasma

Reverse typing known reagent

A1 and B cells

Main purpose of reverse typing

Confirm expected ABO antibodies

Reverse typing identifies what?

Unknown antibodies

Antibody screen (IAT) pt specimen

Plasma

Antibody screen (IAT) reagent

Screening cells

Purpose of antibody screen (IAT)

Detect unexpected antibodies

Antibody panel pt specimen

Plasma

Antibody panel reagent

Panel cells

Purpose of antibody panel

Identify antibody specificity

DAT Pt specimen

RBCs / whole blood

DAT Reagent

AHG

Purpose of DAT

Detect in vivo RBC sensitization

Antigen typing pt specimen

RBCs

Antigen typing reagent

Specific antisera (contains Ag)

Purpose of antigen typing

Determine RBC phenotype

Type A+ pt can receive RBCs from

A+/=, O+/=

Type A= pt can receive RBCs from

A=,O=

Type B+ pt can receive RBCs from

B+/=, O+/=

Type B= pt can receive RBCs from

B=, O=

Type O+ pt can receive RBCs from

O+/=

Type O= pt can receive RBCs from

ONLY O= 

Type AB+ pt can receive RBCs from

all blood types

Type AB= pt can receive RBCs from

A= , B= , O= , AB=

How is blood type compatibility determined for transfusions?

A recipient can only receive blood containing antigens they already possess or blood that lacks antigens entirely.

A recipient can only receive blood if it lacks foreign

antigens

Type A contains what antigen

A

Type B contains what antigen

B

Type O contains what antigen

None

Type AB contains what antigen

A and B

what antibodies are in type A plasma

anti-B

what antibodies are in type B plasma

Anti-A

what antibodies are in type AB plasma

none

what antibodies are in type O plasma

anti A, anti B, anti A,B

Which blood type is considered the universal donor for plasma transfusions?

AB+/=

Which blood type is considered the universal recipient for plasma transfusions?

O

Which blood type is considered the universal recipient for RBC transfusions?

AB+

Which blood type is considered the universal donor for RBC transfusions?

O=

What plasma can an AB patient receive?

AB+/=

What plasma can an O patient receive?

All blood types

What plasma can an A patient receive?

A+/=, AB +/=

who can type A donate RBCs to

A and AB

Who can Type B donate Red Blood Cells to?

Type B and Type AB

Who can Type AB donate Red Blood Cells to?

Only Type AB

Who can Type O donate Red Blood Cells to?

All blood types

What plasma can a B patient receive?

B+/=, AB+/=

Who can Type A donate Plasma to?

Type A and Type O

Who can Type B donate Plasma to?

Type B and Type O

Who can Type AB donate Plasma to?

All blood types

Who can Type O donate Plasma to?

Only Type O

RBC transfusion focuses on

Donor RBC antigens

Plasma transfusion focus on plasma

donor plasma antibodies

Why is Type AB blood considered the universal recipient for plasma transfusions?

Plasma lacks both anti-A and anti-B antibodies

What cells are used in an antibody screen?

Group O screening cells with known antigen profiles.

final result of antibody screen

qualitative (+/=)

Why are group O cells used for antibody screening?

To avoid agglutination caused by expected ABO antibodies.

What does a negative antibody screen mean?

No unexpected antibodies were detected.

What happens after a positive antibody screen?

An antibody identification panel is performed.

What is an antigram?

A chart showing the antigen profile of reagent RBCs.

What does a plus sign (+) mean on an antigram?

The antigen is present.

What does a zero (0) or minus sign (-) mean on an antigram?

The antigen is absent.

Why is the lot number important on an antigram?

Antigen profiles are lot-specific.

What is immediate-spin testing?

Testing performed at room temperature without incubation.

Which antibodies commonly react during immediate-spin testing?

Usually IgM or cold-reacting antibodies.

IgM significant or insignificant

insignificant

What is 37°C testing?

Testing in which the sample is incubated at body temperature.

What does the AHG phase detect?

Usually IgG antibodies that react at body temperature.

IgG significant or insignificant

significant

What is the purpose of AHG reagent?

To help IgG-sensitized RBCs form visible agglutination.

What is the purpose of the wash step?

To remove unbound antibodies from the RBCs.

What can happen if RBCs are not washed properly?

Unbound IgG may neutralize the AHG reagent and cause a false-negative result.

What are Check Cells?

IgG-sensitized RBCs used to validate negative AHG results.

What should happen when Check Cells are added to a negative AHG test?

Visible agglutination should occur.

What does a negative Check Cell result mean?

The negative AHG result is invalid.

What are screening cells?

Group O reagent RBCs with known antigen profiles used to detect unexpected antibodies.

What are panel cells?

Group O reagent RBCs with known antigen profiles used to identify unexpected antibodies.

What are examples of enhancement media?

LISS, PEG, and albumin.

What can proteolytic enzymes do?

Enhance or destroy selected RBC antigens.

What is an antibody identification panel?

A test used to identify an unexpected antibody after a positive antibody screen.

How many reagent cells are typically included in an antibody panel?

At least 10 group O reagent cells.

What phases are evaluated during an antibody panel?

Immediate spin, 37°C, and AHG.

What is an autocontrol?

Testing patient plasma with the patient's own RBCs.

What is the purpose of an autocontrol?

To help distinguish an alloantibody from an autoantibody.

What can a positive autocontrol suggest?

An autoantibody or recent transfusion.

What is an alloantibody?

An antibody directed against an antigen the patient does not have.

What is an autoantibody?

An antibody directed against the patient's own RBC antigens.

What is homozygous?

Having two copies of the same antigen.

What is heterozygous?

Having one copy of an antigen.

What is dosage?

Some antibodies may react more weakly when RBCs have only one copy of an antigen.

Why can heterozygous cells cause a problem when ruling out antibodies?

They may express less antigen and produce weak or no reactions.

What is the first step in antibody panel interpretation?

Rule out antibodies using cells that are nonreactive at all phases.

How are antigens ruled out during panel interpretation?

Cross out antigens present on cells that did not react.

What should be considered when ruling out antibodies?

Dosage

What is the second step in antibody panel interpretation?

Consider the usual reaction phase of the antibody.

What is the third step in antibody panel interpretation?

Look for a matching reaction pattern.

What is the Rule of Three?

Three positive cells and three negative cells must support the antibody identification.