Week 7

Immunohematology

A patient has a history of Anti-Fyb in their records, and their current antibody screen is positive in AHG.  What are the appropriate steps to take for crossmatching?

Perform a mini-panel to see if the Anti-Fyb is the only antibody present, or if an additional antibody is present; crossmatch through AHG.

A patient with anti-K and anti-Jka in her plasma/serum needs 2 units of RBCs for surgery.  How many units would need to be screened to find two appropriate units?  (Jka antigen frequency is 77%, and K antigen frequency is 10%)

10

Which of the following will the crossmatch do?

Frequently verify donor ABO compatibility.

A patient types as B negative (by two different technologists), and the antibody screen is negative.  There are no issues present in the patient's history.  How should the technologist proceed with the crossmatch?

An electronic crossmatch is appropriate.

The crossmatch is performed using:

Recipient's serum and donor RBCs

Stopping a crossmatch after the immediate spin phase is appropriate in which of the following situations?

When there is no history of antibodies and the antibody screen is negative.

A patient had a negative antibody screen but all the units (ABO/Rh-matched) chosen from the shelf yield a 1+ or 2+ reaction in immediate spin for the crossmatch.  What is the most likely issue here?

Cold agglutinins

A patient had an anti-c identified in his serum 5 years ago.  His antibody screen is now negative through AHG.  To obtain suitable blood for transfusion, what is the best procedure to use?

Type the donor units for the "c" antigen and crossmatch the c-negative units.

A unit of blood from the Red Cross has arrived to be placed on the shelf in your blood bank.  It is labeled A positive.  Which of the following tests are mandatory to perform on this newly arrived unit?

ABO forward typing only

Antibody screening cells and crossmatch are 2+ positive at immediate spin, but the reactivity goes away in 37 and AHG.  The autocontrol is negative.  What is the most likely problem here?

Cold alloantibody

In an emergency situation where there is no time to ABO/Rh type the recipient, what blood should be transfused?

O negative

A patient's antibody screen is negative, but the immediate spin crossmatch comes up 4+ in immediate spin.  What is the most likely reason for the incompatibility?

Major ABO incompatibility; wrong donor ABO type obtained from the blood bank shelf.

A patient has a positive antibody screen, and a clinically significant antibody is identified using a panel.  What appropriate steps should be taken with the crossmatch?

Carry the crossmatch through AHG and transfuse only antigen-negative units.