Hello everyone,

 

So I had an interesting case come in today and since I haven't found too much in my own research I thought I would get the feedback from everyone here.

 

So patient comes in with a Type and Cross for 2 units ordered.  We previously worked on the patient 11 days ago without any issue.  O Positive Negative screen.  When the patient comes in today, we see a 2+ and 3+ for screen cells 1 and 2.  In doing the workup it looks like a D antibody.  In calling the nurse and asking the patient, the last time the patient received WinRho for ITP was in 2005, WAYYYY too long for it to be interfering now.

 

So the main question is what is the chance that this patient developed an Auto Anti-D?  With them not receiving any RhIg product in the last 6 months and nothing inbetween the two visits it kind of has me stumped.  Also, 2 O Pos red cells were given 10 days ago, but we also gave the patient O Pos blood in January and had no issues with subsequent testing when they came in again.

 

Interested in any and all theories to this.  Also for a side note, patient is Caucasion so weak D not suspected either.

 

ANNNNNND GOOOO!!!

What is her auto/DAT?  If either of those are positive, then the chances are it is an auto-anti-D (not as unusual as you may think).  However, it could also be an auto-anti-LW.  Try group O, D-, DAT- red cells against the lady's plasma.

 

Just a couple of theories off the top of my head.

No the DAT was negative in tube, well all testing was negative in tube as a matter of fact, screen with PeG and LISS and DAT all negative in tube.  Screen and ABID positive only on the ECHO. That is why I am hesitant to call an Auto-D, but I didn't think about -LW...

Hmmmmmmmmmmmm. have you thought about ECHO being over-sensitive?????????????!!!!!!!!!!!!!!!  I have.

What is the patient's diagnosis?  Race? Rh phenotype?

Have you considered that she might have a D variant?  Many Dvariants can give 'normal' reactions with most anti-D reagents - and Caucasians can have them too.  Also, did you repeat it on the Echo - could it have been carry-over from a previous sample with anti-D?

Might be useful to have molecular typing done. I've seen a couple of variant Ds in Caucasian patients over the past few years and we are a smaller facility.

 

Is the patient Hispanic by chance? - there is an increased possibility of Rh variants in that population, including uncommon variants, or so I have been told by the reference lab that's done molecular testing for us.

 

The Echo is VERY sensitive to anti-D. The carry over idea is not real likely, but should be considered if your sample was preceded by a really strong anti-D.

Ok, not WinRho D, but what about a large dose of non-specific immunoglobin?  Pharmacy might have data.

Yes, the immunoglobulin theory could explain it.

 

I've also found that you don't always get correct information from the nurse  because sometimes they don't really know what your are asking about. They may see a 'brand' name for something you are referring to generically and not connect the two. If the patient is hospitalized the med list you will most likely get is what the patient is on in the hospital, not the home med list and not what the patient received at the cancer center or doctor's office. Sometimes it pays to dig deeper (if you have the time  ). 

Edited August 7, 201411 yr by AMcCord

Sorry about the delay in responding, was caught up in some other work.  Have I thought about the Echo being over sensitive, YES! But that's the problem we take with advanced technology. For everyone else's questions:

 

Patient was 65 caucasian female with history of ITP.  I forget the current diagnosis, patient was asked about RhIG products and the last one she was given was 9 years ago.  Her last stay with us was an OP stay and there was no medication given.  Patient was not ran after another patient, and she was ran twice with duplicate results.  Did not do molecular testing, and did not phenotype the patient, just issued Rh Neg products that were XM compatible.

 

She was in 7 days prior and received 2 units of blood and screened Negative.  Went with a possible anti-LW all clinically significant antibodies ruled out.  I appriciate all of the insight given to this question. 

She was in 7 days prior and received 2 units of blood and screened Negative. Went with a possible anti-LW all clinically significant antibodies ruled out. I appriciate all of the insight given to this question.

I think the possibility that one of those units of blood was D+, or a Dvariant needs to be examined.  It is also possible that one of the units of blood had enough anti-D left in the remaining plasma for the result you saw to be passive anti-D from the transfusion.

I don't think you can assume that this was an anti-LW without having tested with O- cord blood

 

I also think there is a possibility that the patient might not have known that a medication she was being given was actually RhIG (?)  Unless she really doesn't have ITP any more.  Can it be transient?

Possiblity of it being a -LW is low, but we did not have O Neg cord cells to test against. 

 

Patient was knowledgable of medications given since she was given RhIg for ITP before. That was not her current diagnosis but her last injection, as stated, was years ago so possibility of -RHO is very low.

 

A unit given that was a D Variant could be a good possibliity if there was enough -D in the plasma, but my only thing with that is there was no positive DAT.  Granted in low volume there is a chance it could be positive or negative. But that seems probable.

 

With out send out testing there was no way to determine and since the DR didn't want that, possible -LW with cannot rule out -D was resulted and only Rh Neg products given for safest transfusion for patient.

 

Appriciate all the input.

You can distinguish Anti-LW from Anti-D by using DTT.  Anti-LW is destroyed by DTT and Anti-D is not affected.  Anti-LW more often appears as an autoantibody not by itself too.

Have you talked to Immucor about this patient? If you have specimen available there's a good chance they would investigate this for you.

We recently had a patient, Rh negative who shows a perfect anti-c on the Echo (multiple specimens from different draw dates and multiple panels). When we contacted Tech Support they had us send specimens to investigate including, if necessary, molecular genotyping all at their expense. You are not going to get quick turn around but may give you some anwers down the line.