30 year-old female with menorrhagia case study
Overview
An immunohematology teaching case with questions. For use or adaption with teaching/examination resources for transfusion medicine, immunohematology, and blood banking.
Case Study Question
Can use multiple choice or write open ended questions to resolve the case.
Detailed solutions for the published questions are below.
- From the results above what can be determined about the patient’s blood type?
A: a The patient’s front and back type both indicate that the patient’s cells have the A and D antigens present with anti-B antibodies present in the plasma. This correlates with a type A Pos and matches the patient’s historical type.
- Based on the patient’s condition, type and antibody screen results, which of the following would be the next best step for this patient?
A: b. The patient appears to have an previously unknown alloantibody. Best practices indicate that at minimum, performance of an antibody panel, potential need to test selected cells, antigen typing, and a complete crossmatch through AHG will delay availability of crossmatched blood for transfusion 45-90 minutes or more than is expected for a patient without unexpected antibodies. Early communication of this expected delay can allow for best patient care as evaluated by the care team at the patient bedside and the patient blood management team.
- Based on the results of the panel which of the following is most likely?
A: a. The panel pattern of reactivity matches up with a single antibody with anti-c specificity, with all other clinically significant antibodies able to be ruled out. The autocontrol or testing of patient plasma with patient cells at the bottom of the panel indicate that the patient has an alloantibody and not an autoantibody. The rule of three is met for an anti-c antibody with three reactive and three non-reactive cells.
- What is the likely specificity of the alloantibody in the patient’s plasma?
A: b. The panel indicates an anti-c antibody.
- Approximately how many units will you need to antigen-type to find 1 compatible unit for this patient?
A: b. The c antigen is present in approximately 80% of donors, therefore, antigen testing 5 random ABO compatible units should yield at least 1 c-negative unit.
- Which of the following strategies could best aid in identifying compatible blood?
A: b. The c antigen is present in approximately 98% of donors of African decent and r’ or ry genes are extremely rare in any type making Rh-negative donors unlikely to be c-negative. While use of patient plasma to screen for rare antigens can be useful when anti-sera is scarce or expensive causing need to conserve the antisera, monoclonal anti-c antisera is generally readily available commercially and FDA cleared for donor testing. Additionally, anti-C is typically an IgG antibody therefore, the units would need to be screened at AHG phase as IS testing is expected to yield false negative results. The father is unlikely to be a match (see below).
- Based on the patient history given which of the following is most likely?
A: c. The mother was likely immunized to the c antigen though transfusion or pregnancy since her last record 4 years ago indicated a negative antibody screen. It is likely that the father of the child was the source of the c gene inherited and expressed by the child and the mother was likely immunized to the c antigen through fetomaternal hemorrhage.
Blood Bank Case Study: 30 year-old bleeding female of child-bearing potential[1]
A 26 year-old female patient, Candi Cameroon was typed as Type A positive with a negative antibody screen during an uncomplicated pregnancy four years ago. Today she is admitted for shortness of breath, fatigue, and menorrhagia. The patient’s hemoglobin is 6.5 and hematocrit of 21%. The physician orders 1 unit of RBCs for STAT transfusion. The patient’s initial blood typing, antibody screen and panel are included in the attached document.
[1] Disclaimer: This case is fictitious and for teaching and learning purposes only. Resemblance to any real patient is coincidental.