Anti-Diego b in an OB patient

[butlermom 28]

Our Reference Lab has informed us that a patient's sample we sent to them has anti-Dib (Diego b), anti-Fya, and anti-Jka! The patient is pregnant and due the end of July. All 3 antibodies are capable of causing HDFN, although usually mild from what I have read. My concern is if we have to transfuse the mother. The prospect of getting blood is problematic. Most likely the units would be frozen and our local supplier would have them shipped in already thawed and deglycerolized, plus the time of flying them here is a challenge with flight schedules to our area. From my reading the Diego antibodies are more commonly associated with HDFN than transfusion reactions, and anti-Dib typically causes mild HDFN.  Therefore, my strategy is to have units that are at least antigen negative for Fya and Jka for the mom in case we cannot obtain units that are negative for all 3 antigens. If we can get units that are antigen negative for all 3 that's great, but the patient is not a scheduled C-section so the timing will be next to impossible. Any thoughts or ideas for a different strategy?

Thanks for any input!

[Malcolm Needs ★ 4,405]

 

This may help (or may not, of course!).

[Bb_in_the_rain 98]

On 7/8/2019 at 4:03 AM, butlermom said:

Our Reference Lab has informed us that a patient's sample we sent to them has anti-Dib (Diego b), anti-Fya, and anti-Jka! The patient is pregnant and due the end of July. All 3 antibodies are capable of causing HDFN, although usually mild from what I have read. My concern is if we have to transfuse the mother. The prospect of getting blood is problematic. Most likely the units would be frozen and our local supplier would have them shipped in already thawed and deglycerolized, plus the time of flying them here is a challenge with flight schedules to our area. From my reading the Diego antibodies are more commonly associated with HDFN than transfusion reactions, and anti-Dib typically causes mild HDFN.  Therefore, my strategy is to have units that are at least antigen negative for Fya and Jka for the mom in case we cannot obtain units that are negative for all 3 antigens. If we can get units that are antigen negative for all 3 that's great, but the patient is not a scheduled C-section so the timing will be next to impossible. Any thoughts or ideas for a different strategy?

Thanks for any input!

We usually try to

• collect autologous unit if she can donate. 
• If mom cannot donate, you can also send out the sample for monocyte mono layer assay (MMA) to see if anti-Dib is clinically significant or if you can transfuse this patient Di(b+), had she bleed during her C section. (This test is a test that predict hemolytic potential, just like reminiscence assay performed in Europe as the journal that Malcolm has describe above. Here in the US, we used MMA assay instead of CLT).
• We also perform titer on the antibodies to predict potential HDFN, which is supervised by our Medical Director. (titer value more than 2 tubes difference in consecutive sample collected within a month is considered critical value here). 

Hope this is helpful. 

[butlermom 28]

Malcolm, thanks so much for the article. It was very helpful. As it turned out, we sent mom's sample to our reference lab for MMA testing, and we also antigen typed her 2 brothers and her father. One of the brothers matched her Duffy and Kidd antigen types and was Coombs crossmatch compatible with her. He donated two units of packed red cells (at one donation) and was also confirmed to be Diego b negative. The patient's anti-Dib came back as clinically significant based on the MMA test. She did have a C-section after all and did not require any blood! The baby had a negative direct coombs so there were no issues there either!