gagpinks

Hi Amy
Feel free to ask questions.  This is very good sites to share BT knowledge. The best person for this topic is Malcolm Needs as you can see in threads. 
Good luck 

It is most unlikely to be anti-f, as this specificity will not react with either R1R1 or R2R2 red cells (I presume that you are using both antibody screening cells and antibody identification panel cells that have these phenotypes represented).

Anti-f reacts with red cells where the c and e antigens are the result of an RHCE*ce haplotype where, for want of a better way of putting it, the c and e antigens are the result of the RHc and RHe genes being in the cis position - NOTE THAT THIS TERMINOLOGY IS (KNOWINGLY) WRONG!

Like all Rh antibodies, anti-f reacts most strongly with its cognate antigen on red cells that have been treated with a proteolytic enzyme (such as papain or ficin), but will very often react with untreated red cells by IAT.

Hi Amy
Feel free to ask questions.  This is very good sites to share BT knowledge. The best person for this topic is Malcolm Needs as you can see in threads. 
Good luck 

A little bit late into the forum, but I am currently completing the HSD in transfusion and also in the process of trying to find others that have or are completing this course to keep in touch, as I am the first within my department to complete this! 

Aah okay, I guess you answered your own question. The mixed field C result is perhaps due to the dual population of blood transfused. Some may have been C+ and some C-. c+ is a common antigen, almost 80% of Caucasians have it.  That could explain the strong c 4+.  Most place don't do phenotyping after multiple transfusions because of possible dual rbc population , so yes, Townsend is right, "honor the genotyping and provide E-, c-, and K- red cells for this patient moving forward"(Townsend). 

I wouldn't bother, to be honest.
Apart from the fact that the Lutheran antigens vary in strength of expression, making it difficult to ensure that the recorded titres would "match up" one to another, but the expression of the Lutheran antigens on foetal and cord erythrocytes is known to be weak.  On top of that, of course, there is the problem of finding a regular source of adult erythrocytes with heterozygous expression.
In addition, anti-Lua and anti-Lub can be either IgG or IgM but are more commonly IgM.  It might be worth your while treating the maternal plasma/serum with a reducing agent such as 0.01M dithiothreitol, 2-mercaptoethanol or ZZAP to see how much, if any, IgG is present.
Even if the antibodies are IgG, they are thought to be adsorbed on to foetal Lutheran glycoprotein on the placental tissue.
Lastly, as you so rightly say, clinically significant HDFN caused by anti-Lub is incredibly rare, and so, all in all, you could be giving yourself an awful lot of work for very little return.  If you do decide to test the maternal plasma/serum with reducing agent, and you find that there is an element of IgG present, it might be worthwhile just performing a titre once, in order to see that you have not got one of these incredibly rare examples that might cause clinically significant HDFN, and, as lone as the titre isn't massive. I would rest easy.

If you want, I can cite references to back up what I have written above, but I haven't done so straightaway, as actually finding some of these papers to read is equally hard work!!!!!!!!!!
I hope that helps.

We also inculed documents owner documents authorised by and effective date. 

My two pennies worth... I did measurement of uncertainty on KB - 47%. Shocking sensitivity... We changed our policy that any foetal cells required follow up by flowm while we were addressing the issue.
We solved it by requiring all staff to take part in each EQA session and following up any discrepancy of >10%. We also introduced scoring for our controls and required all staff to do a count before moving onto the patient ones. Any discrepancies in the control scoring or EQA resulted in retraining.
What actually happened was that because staff were required to do an actual count, rather than an eyeball, for every kleihauer, they organically became more proficient. We also were able to identify the staff member who was counting lymphocytes as foetal cells...
For anyone who is interested - there is a modified KB that I have developed (sadly I never published before leaving the labs) that has a counter stain for the white cells - makes the foetal cells ping

Hello 
Patient has developed antiD in first pregnancy at around 32 weeks and her quantification level was 1.0 IU/ml.
In 2nd pregnancy her booking blood at (12 weeks) antibody screening was negative.  At 15 weeks sample sent for fetal genotype (FDS). On this Report received inconclusive due to all Anti D.
Because patients was on file for historical antibody therefore sample sent for quantification  in 2nd pregnancy and Report received antibody not quantified since it reacted weakly in enzyme IAT only. 
My understanding standing is if patients once developed Allo antiD her titre level does not go down. Why was her antibody screen was negative in 2nd pregnancy at 12 weeks?

The simple answer is gagpinks, but this is the answer I have just received from my friend at the IBGRL (who shall remain anonymous for now).

The question I put was as follows:

"Sorry to bother you yet again, but I have had a query from a friend. I think I know the answer, but I wanted to check with an expert. If a pregnant lady has an allo-anti-D, can this affect cffDNA harvesting from the mother's circulation? I don't think it does unless the anti-D knocks out all of the foetal red cells. Best wishes from this bloody nuisance, Malcolm"
Answer below.

"Hi, that's right, anti-D makes no difference to the cffDNA test. The two biggest problems are false negatives due to insufficient RHD gene in the test sample and mums with a RHD gene (despite pheno typing as D-) leading to strong positive results. Take it easy."

As I said, the friend will remain anonymous for now, but, suffice it to say, he/she is one of the people who do the test, so I think the answer can be trusted!
 

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Follow this in comments.

Thanks Malcolm.  
I checked it she was not given large dose of anti -D in her first pregnancy.   However in her first pregnancy she developed anti D at 32 weeks where her level was 0.5Iu/ml then at end of her first pregnancy level was 1.0IU/ml. 
As per routine antenatal sample if booking blood is Rh negative we send sample for FDS for Rh D prediction. 
Could it be because lady had Allo antiD? When lady has Allo anti D do they use different techniques? 
 
 

Yes.  
Another thought do you think in 1st pregnancy anti-D could be in IgM nature and therefore level might  be slightly raised? 
 

ISBT has an excellent podcast I have been listening too. You can listen and subscribe here:https://www.isbtweb.org/resource/announcing-our-new-podcast-transfusion-practitioners-across-the-world.html 

I would thoroughly recommend that you contact Rachel Moss Hibbttt at Imperial College Healthcare NHS Trust.

Pre delivery sample going for urgent c-section. 

Pre delivery sample going for urgent c-section. 

Pre delivery sample going for urgent c-section. 

I agree that such an antibody formed late in pregnancy does not usually cause severe HDFN, BUT, you cannot state that it is a non-specific antibody.  It may well be an antibody directed against a low prevalence antigen that just happens, by coincidence, to be expressed on the screening cells, but not on the panel cells.  Once a person makes an antibody of such a specificity, they often make more than one specificity directed against more than one low prevalence antigen.  It could well be that such an antibody had been madee earlier in the pregnancy (or even an earlier pregnancy) and you may not be aware.
I agree with both Ensis01 and exlimey that more work needs to be done, just to be on the safe side.
By the way, I am aware of what the Guidelines say, having been one of the writers!

Is the buffer used for preparing the RBC suspension for X-Match the same as for the AC? If not, this patient may have an additional Ab to a buffer component? 

Yes, it will be available as a recording after the event, but I don't know for how long.

I just saw this seminar being offered by Bio-Rad with our own, infamous, Malcolm Needs as the presenter. I registered and thought I'd pass the word to all of us here. Here is the link:https://info.bio-rad.com/ww-IHD-transfusion-w-registration-lp2.html?elq_mid=48765&elq_cid=10201434&elqCampaignId=30837&utm_campaign=30837&utm_source=eloquaEmail&utm_medium=email&utm_content=Email 13ER EM-R-CM-385201-FY21-TCHS-AWEN_BR-JRNL-TRF News 19 Nov&elqTrackId=6ecbbea5f2bb46849981687404578a8e&elq=7c5f74470efa434dbd4351e512f7ae7a&elqaid=48765&elqat=1&elqCampaignId=30837

Please let me know if you would like me to do more "mock-up cases" with RHCE variants. I can look for some good ones.  I think it is fun to interact with case studies here. (I mean it is quite fun to pick Malcolm's brain and learn from him... cough cough). 

Anti-Cob has rarely caused a clinically significant haemolytic transfusion reaction, and, even then, the antibody was, in both cases, extremely potent.
An anti-Cob, only detected by papain-IAT is certainly not going to be clinically significant, although when the antibody can be detected by IAT, using red cells that have not been treated with a proteolytic enzyme, then Co(b-) units should be transfused.  In your case, it would be quite safe to transfuse units that are found to be compatible by IAT with untreated red cells.
Geoff Daniels says in his book (Daniels G.  Human Blood Groups.  3rd edition, 2013, Wiley-Blackwell) that anti-Cob is quite a rare antibody and, while I am ALWAYS wary about gainsaying anything written by Geoff, I think that may be more to do with the Co(b) antigen not being expressed on most screening red cells and even on most panel cells because, when they were, anti-Cob was a comparatively common finding in the samples submitted to NHSBT-Tooting Centre's RCI Laboratory when I was Reference Service Manager there.
As you are working in the UK, you might find it useful to read the specification (SPN214/4), issued by NHSBT, "The Clinical Significance of Blood Group Alloantibodies and the Supply of Blood for Transfusion.", written by my good friend Nicole Thornton, Head of Red Cell Reference at the IBGRL.  You can find it on line.

Thanks everyone 
Clinician hasn't suspected transfusions reaction and hasn't asked for any investigations. This is something we noticed the results when they requested further blood unit.   just wanted to know causes of DAT to be positive in C3d therefore shared on discussions board.