Explain the importance of antibody testing, the RhD results obtained and if the results of the antibody testing in table 2 should have been used.

Pathological science 2 Blood Transfusion SAA coursework

This case study concerns a female patient of 26 years of age. The case study follows this patient through a two-week period. You must describe how improper testing contributed to the outcome of the case and what actions could have prevented the case from worsening.

Event 1:

A 26-year-old female attends her local maternity hospital. She is 38 weeks pregnant with her third child and is in labour. She is known to have anti-D. Paternal samples are Rh D Positive and both her children are also RhD positive. The patient appears healthy and is in physical distress. Within six hours of first attending the hospital, the patient has given birth although suffers a significant postpartum bleed. The patient’s blood group is reported below (table 1):

Table 1. Patient’s blood group

ABO group	Rh D status	Rh C status	Rh E status	Rh c Status	Rh e status	Antibody screen
A	Negative	Positive	Negative	Negative	Positive	Negative

 

Below is a table of how various antibody screens and panels were performed and how they should have been performed (Table 2). All tests were incubated for 15 minutes at 37°C.

Table 2. Table of how patient’s testing was performed versus how it should have been performed and relevant obtained versus expected results.

Test	ACTUAL APPROACH			FOLLOWING MANUFACTURER’S INSTRUCTIONS
	Used testing consumable	Used red cell reagent and plasma volume	Result	Expected testing consumable	Expected red cell reagent and plasma volume	Expected test result.
Antibody screen	LISS gel card	3% (red suspension) NISS cells (50 µL) + 25 µL patient plasma	All 3 wells negative	LISS gel card	0.8% (red cell suspension) LISS cells (50 µL) + 25 µL patient plasma	Positive in first 2 wells
Antibody panel	LISS gel card	3% (red cell suspension) NISS cells (50 µL) + 25 µL patient plasma	All wells negative	LISS gel card	0.8% (red cell suspension) LISS cells (50 µL) + 25 µL patient plasma	Positive in first 3 wells (4+) (Anti-D specificity)
Enzyme treated antibody panel	LISS gel card	0.8% (enzyme treated red cell) suspension LISS cells (50 µL) + 25 µL patient plasma	All wells weakly positive 1-2 + Non-specific pan-reactive antibody	NISS gel cards	0.8% (enzyme treated red cell suspension) NISS cells (50 µL) + 25 µL patient plasma	Positive in first 3 wells (4+) (Anti-D specificity)

 

Due to the severity and speed of the bleed, the patient is administered three units of red cells. Below is the table of Blood groups for those red cells that were transfused (Table 3).

Table 3: Transfused red cell list for patient

Red cell unit number	ABO group	Rh D status	Rh C status	Rh E status	Rh c Status	Rh e status
Unit 1	A	Negative	Negative	Negative	Positive	Positive
Unit 2	A	Negative	Negative	Negative	Positive	Positive
Unit 3	A	Positive	Positive	Positive	Positive	Positive

 

After a three day stay in hospital the patient and baby were discharged home.

Event 2:

Approximately 10 days after the initial admission to the maternity hospital, the patient attends her local GP surgery complaining of fatigue, light-headedness and pallor. Upon her insistence, the GP sends her to the blood collection clinic to have blood taken for suspected anaemia of unknown origin. Observation of centrifuged patient sample is either suggestive that the patient was under bled or that she has a low RBC content. Her plasma appears very icteric.

When the FBC results are received, the patient is admitted to the local general hospital where the patient’s blood group and antibody screen was tested again in preparation for another potential transfusion. The results are as follows in Table 4:

Table 4: Patient’s subsequent blood grouping result from event 2

ABO Group	Rh D status	Rh C status	Rh E status	Rh c Status	Rh e status	Antibody screen
A	Positive	Positive	Negative	Negative	Positive	Positive

 

The next table shows how the tests were set up and interpreted. All tests were incubated for 15 minutes at 37°C.

Table 5 is a table showing how the antibody screens and panels were setup and read.

Test	ACTUAL APPROACH			FOLLOWING MANUFACTURER’S INSTRUCTIONS
	Used testing consumable	Used red cell reagent	Result	Expected testing consumable	Expected red cell reagent	Expected test result.
Antibody screen	LISS gel card	0.8% (red cell suspension) LISS cells (50 µL) + 25 µL patient plasma	Positive in first 2 wells	LISS gel card	0.8% (red cell suspension) LISS cells (50 µL) + 25 µL patient plasma	Positive in first 2 wells
Antibody panel	LISS Gel card	0.8% (red cell suspension) LISS cells (50 µL) + 25 µL patient plasma	Positive in first 3 wells (4+) (Anti-D specificity)	LISS Gel card	0.8% (red cell suspension) LISS cells (50 µL) + 25 µL patient plasma	Positive in first 3 wells (4+) (Anti-D specificity)
Enzyme treated antibody panel	NISS gel cards	0.8% (enzyme treated red cell suspension) NISS cells (50 µL) + 25 µL patient plasma	Positive in first 3 wells (4+) (Anti-D specificity)	NISS gel cards	0.8% (enzyme treated red cell suspension) NISS cells (50 µL) + 25 µL patient plasma	Positive in first 3 wells (4+) (Anti-D specificity)

 

Following this case study, you must answer the following. (5% will be contributed through accuracy of spelling good use of grammar and punctuation. 10 marks for any additional knowledge demonstrated).

1. Explain the difference between LISS and NISS reagents. Why does the concentration of red cell suspension affect test results?
2. Explain the presence of the historical antibody in the maternal sample ahead of testing and the speed and type of transfusion reaction.
3. Explain the importance of antibody testing, the RhD results obtained and if the results of the antibody testing in table 2 should have been used.
4. What blood type should have been selected for the three red cell units transfused and comment on the types of blood that should be administered for subsequent transfusion.