Patient is group O, rr, K- with slight anaemia.

Patient has a panreactive auto-antibody detected with papain-treated red cells.

The DAT is very weakly positive with anti-IgG monospecific reagent, negative with anti-C3d monospecific reagent.

The patient has what appears to be an anti-D detected by IAT.

BUT the patient is male (so has not been pregnant - well, as far as we know he hasn't!) and has NEVER been transfused.

What is the likely antibody specificity, and how would (easily) you go about proving it (you could also prove it the hard way!)?

:confused::confused:

The antibody could have LW specificity. If so, it should react with Rh Negative cord cells.

The antibody could have LW specificity. If so, it should react with Rh Negative cord cells.

Well, that case study really lasted a long time, didn't it!!!!!!!!!!

Very well done BSIPHERD.

Next time have to find a really evil one.

:slap::slap:

I have to admit I've just recently had to think about LW. We had a patient (Rh positive) with a warm autoantibody that reacted stronger with Rh Pos cells than Rh Neg cells. The DAT was strongly pos and there was Warm Auto in the eluate. However, two adsorptions with ZZAP treated cells had the antibody getting a little stronger rather than weaker. The warm auto being stronger with Rh Pos cells made me consider LW specificity and I knew that LW was destroyed by DTT, and ZZAP cells are of course treated with Papain and DTT. So we did some enzyme only coated autologous cells and were able to do the adsorptions and remove the autoantibody. It was kind of a fun case.

Malcolm

Could you explain the case study in a more simplistic way without me resorting to the textbooks to understand the serology. Thank you in anticipation.

Steve

Malcolm

Could you explain the case study in a more simplistic way without me resorting to the textbooks to understand the serology. Thank you in anticipation.

Steve

Hi Steve,

I'll give it a go anyway!

Almost everyone in the world is positive for the LW(a) antigen (and a few for the LW( antigen. However, auto-anti-LW (I use the generic term, because very few have ever been differentiated into auto-anti-LWa or auto-anti-LWb) is quite a common specificity in AIHA (again, how common, I couldn't say, because most of the time, we don't bother going for the specificity, because it would make no difference to the clinical treatment of the patient), and, in some cases, the patient becomes transiently serologically LW weak or LW-. It is unclear as to whether the red cells are actually LW weak or LW-, or just that the antigen sites are blocked by the auto-antibody, but, again, so what!

Anyway, as you know, anti-LW reacts very much like anti-D, except that D- red cells, like D+ red cells, are also LW+, but have weaken expression of the LW antigen.

This is because the number of LW antigen sites on D- red cells (average 2835) is much less than on D+ red cells (average 4400 sites); hence it can look like anti-D.

Very often, when red cells are treated with papain, the anti-LW will react equally strongly with D+ or D- red cells, BUT by IAT, the anti-LW will react much more strongly with the D+ red cells than the D- red cells (essentially, you get no visible reaction).

Now then, for some reason, the LW antigen is expressed MUCH more stongly on cord red cells, again, because of the number of LW antigen sites (average 5150 for D+ cord blood cells, and 3620 for D- cord blood cells).

AS you can see from these figures, the number of LW sites on a D- cord blood cells (3620) is higher than the number of sites on an adult D- red cell (2835) and, although not as high a number of sites as on an adult D+ red cell (4400), will often react visibly with an anti-LW by IAT. D- cord blood cells will not, of course, react with a true anti-D, therefore, if a group O, D-, DAT- cord blood cell reacts by IAT with an antibody that looks like an anti-D (but anti-D is unlikely, from the patient's history), then there is an excellent chance that the true specificity is anti-LW.

I hope that helps??????????

:whew::whew:

A fantastic explanation Malcolm, I am very grateful - I suppose that could cost me a beer!!

Steve

Certainly not Steve - 2 as a minimum!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Thought you might say that!!!!!!!!!!!!

I'm wondering if I have a similar situation with a patient now. A pregnant woman came to our ER with Abd pain and vaginal bleeding. She was A1 neg with an anti-D and cold auto in plasma. Since she had received antepartum RhIG, our tech assumed the anti-D was passive, and gave her another dose of RhIG. Upon reviewing the case, the reactivity was too strong at IAT (3+) to be passive, so I performed a titer using R1R1 cells and got a titer of 64, score=74. Her DAT was 2+ IgG, neg C3d. An eluate was positive with all cells tested (including cells negative for high incidence antigens - k, Kp(, Js(, Lu( )

I am concerned about the autoantibody in eluate, since she is pregnant. Does this sound like an LW?

After reading that Rh null patients are LW(a-b-) I did a phenotype, but she was c+e+.

Can't you get panreactive eluates shortly after a person begins creating an antibody? Do you use gel?

No, sorry, this one doesn't sound like an anti-LW to me.

Thanks Malcolm. I learned a lot from this one

anti LWa, treat panel cells with DTT and retest.

great explanation, in a simpler way

We just this week had an A pos patient with what looks like and Anti-D. She has never been given Win -Rho so they say. I tried the O Neg cord blood to see if it was Anti- LW. Much to my dismay it came up negative. I have never wanted a positive test so much in my life! lol

We just this week had an A pos patient with what looks like and Anti-D. She has never been given Win -Rho so they say. I tried the O Neg cord blood to see if it was Anti- LW. Much to my dismay it came up negative. I have never wanted a positive test so much in my life! lol

What about the DAT result, if it is neg,Maybe the patient is partial D. If you can't do PCR on her, maybe try to react her serum with her siblings or parents is a method.

Does her been transfused before?

Edited November 7, 201014 yr by shily

We just this week had an A pos patient with what looks like and Anti-D. She has never been given Win -Rho so they say. I tried the O Neg cord blood to see if it was Anti- LW. Much to my dismay it came up negative. I have never wanted a positive test so much in my life! lol

It would be nice to know a few more details please bduff.

As shily asks, is the DAT positive or negative?

What reactions do you get when using an enzyme treated panel of red cells?

Is the reaction her red cells give with your anti-D grouping reagents strong or weak?

What is her ethnic origin?

Has she been transfused in the past, or has she ever been pregnant?

What is the underlying pathology?

Sorry, loads of questions, and no answer as yet!

:faq::faq:

The DAT was negative. We do not have any enzyme treated panels. We are not in any way a reference lab... we usually send the difficult stuff out. I got a little excited when I saw the cord blood experiment I could try. Her red cells reacted with a 3+ in the biotest tube reagent. She is registered as "White". We have not ever transfused her but we already know that means nothing. She has breast cancer as her diagnosis and she is 73. We did the TS because she was to receive platelets so we didn't HAVE to go any further. My supervisor has put in a note to transfuse Rh neg cells for now. I believe she is thinking mosaid or partial D.

oops forgot the pregnancy one... I am not sure but I would assume she has been.

The DAT was negative. We do not have any enzyme treated panels. We are not in any way a reference lab... we usually send the difficult stuff out. I got a little excited when I saw the cord blood experiment I could try. Her red cells reacted with a 3+ in the biotest tube reagent. She is registered as "White". We have not ever transfused her but we already know that means nothing. She has breast cancer as her diagnosis and she is 73. We did the TS because she was to receive platelets so we didn't HAVE to go any further. My supervisor has put in a note to transfuse Rh neg cells for now. I believe she is thinking mosaid or partial D.

oops forgot the pregnancy one... I am not sure but I would assume she has been.

Sorry about all the questions, but thanks for the prompt (and thorough) answers.

As the DAT is negative, I would tend to agree with the other posters that this lady may well have a partial D and an alloanti-D.

However, as she is 73-years-old, and has breast cancer, the other explanation could be (although it is rare) that she is losing her D antigenicity and is producing an "alloanti-D" because of this (although, in such a case, I would expect a transient positive DAT).

Is 3+ your strongest reaction? Strength of reaction varies around the world (we, for example, use from 0 to 5+). If you use something similar, then that is even more evidence on the side of a partial D.

4+ is our strongest reaction but with the biotest reagents we don't see 4+ too often. The reagent seems to be a little weak. So a 3+ would be considered a strong reaction. With that being said would you think then it is more likely she is losing her D antigenicity? That is interesting! Thank you by the way for the guidance I am glad to have "met" you!

4+ is our strongest reaction but with the biotest reagents we don't see 4+ too often. The reagent seems to be a little weak. So a 3+ would be considered a strong reaction. With that being said would you think then it is more likely she is losing her D antigenicity? That is interesting! Thank you by the way for the guidance I am glad to have "met" you!

Frankly, no, I think it is less likely that she is losing her D antigen.

Your answers have made it much more likely that it is a partial D with an alloanti-D, as the other posters have said.

It is certainly an inertesting case.

Thank you for your kind comments.

:cuddle::cuddle:

Thank you Malcolm and the gang! I appreciate it!

On 06/10/2010 at 7:32 PM, BSIPHERD said:

The antibody could have LW specificity. If so, it should react with Rh Negative cord cells.

How can you differentiate between anti-LW and auto anti-D ?

 

On 07/11/2010 at 5:50 PM, Malcolm Needs said:

Frankly, no, I think it is less likely that she is losing her D antigen.

Your answers have made it much more likely that it is a partial D with an alloanti-D, as the other posters have said.

It is certainly an inertesting case.

Thank you for your kind comments.

How can we differentiate between  anti-LW and auto anti D?

It is interesting nice share!!