is it anti-C,D or ant-G

[sdweaver29]

Can someone offer some ideas on this case: 49 yo male. going for back surgery. Sample received for type and screen. patient is O Du positive with positive control. Antibody screen all three cells negative. Panel positve all the way, positive auto control. DAT positive, Igg positive, C3 negative. Eluate shows a WARM with a anti-D. Warm adsortion performe and anti-D and anti-C recovered. Patient antigen typed for C negative. Patient was originally typed as D positive (2+) and transfused 4 units O positive back in 2004.

I thought that anti G was produced by individuals that were D negative. If it C and D how is it possible to have a positive DAT and recover anti-D from the aluate? There is no Winrho or diagosis of Cancer.

[Malcolm Needs ☆]

In this case, I don't think that it is either anti-D+C or anti-G (but I would certainly recommend C Negative blood for the cross-match, and, because the patient may be a Partial, rather than a Weak D, until proved one way or the other by molecular techniques, I would also cross-match D Negative blood).

I am a little confused as to why all three screening cells gave negative results as, with an obvious "warm" auto-antibody being present, as shown by all of the other results, I would have expected the screening cells to be positive with the patient's plasma too.

Anyway, to get back to your question. The overwhelming number, but by no means all, of "warm" auto-antibodies have a specificity within the Rh Blood Group System. Very often, although the "raw" plasma shows a panagglutinin, once differential adsorption has been undertaken, "narrower" specificities within the Rh Blood Group System are detected (such as anti-D - auto-anti-D is more common than many people realise).

If alloadsorption is continued, however, these antibodies of "narrower" specificity can be adsorbed out with cells negative for the corresponding antigen (in this case, rr cells).

It may be that, in fact, in this case, the true specificity may be something like an auto-anti-Rh17, an auto-anti-Rh18, or even an auto-anti-LW, that is mimicking an anti-D+C or anti-G (especially if you are able to elute an apparent anti-C+D from the patient's red cells - or is this being eluted from the cells used for adsorption??? - I'm not quite sure from your post).

The bottom line is though, that it doesn't really matter if the specificity of the antibody is anti-D+C or anti-G in this case. The blood you would give is the same (rr to be on the safe side). The only time that it is really important to differentiate between these two specificities is in the case of a pregnant lady. If an anti-G (or anti-C+G) is mis-interpreted as an anti-D+C in the case of a pregnant lady, she may miss out on being given anti-D immunoglobulin prophylaxis, and then produce a genuine alloanti-D, which is much more clinically significant in pregnancy than is anti-G (or anti-C+G).

In the case of a male, differentiation between anti-G, anti-C+G and anti-D+C may be fun to do as an exercise, but makes absolutely no difference to the way the patient would be treated whatsoever.

[Rh-fan]

Malcolm has given most of the info but as an Rh fan I have some aditions.

This sounds most like a weak D type 2 (ccDEe) with auto anti D. The "anti C" can be an allo anti C or an auto anti G. The only way to make the difference is by absorption/elution. If the "anti C" is in the eluate than it must be an anti G (auto).

You have no real prove that the anti D antibody is an auto antibody, except the fact that the anti D is in the eluate (en thare was no transfusion.

We see these cases almost once a year (weak D type 2 with auto anti D), and most of the times the RhD antigen is weaker because of blocking by the auto antibodies.

[mrmic]

I would agree with Malcolm. If the patient does need transfusion then rr units can be selected. The underlying cause of the autoantibody could be investigated clinically to deternine if treatment is warranted to deal with any anemia the patient may be experiencing. The transfused red cells may or may not have normal survival in the presence of autoantibody, even if the in-vitro crossmatch is compatible. The laboratory investigation of the autoantibody (ies) specificities may be best done at a Immunohematology Reference Lab. They can be complex with very unique specificities or mimicking specificities or may just show preference for certain antigens. That the fun of working in a Reference Lab!

[Malcolm Needs ☆]

They can be complex with very unique specificities or mimicking specificities or may just show preference for certain antigens. That the fun of working in a Reference Lab!

It is mrmic, but we wouldn't go as far as finding the true specificity for an AUTO, as opposed to an ALLO, unless it is likely to make any clinical difference to the patient. It is time consumming (to say the least), and very, very expensive, in terms of reagents - but working in a Reference Laboratory is, without any doubt whatsoever, fun!!!!!!!!!!!!!!!

[sdweaver29]

thanks Malcom, I am honored by seen you respond to my post. I have visited this site regularly fo r a couple of years and have learned soo much just by reading everyone's post and reponses. I did decide to place a message on patient;s chart to transfuse compatible Rh negative , C negative packed cells. I am just very puzzle by the fact that this patient is actually weak Du, has developed a anti-D and that has also sensitized his cells. The eluate show the anti-D and C pattern but also the rest of the cells were very weakly positve caused by the warm.

I would like to also share another case that I encountered today. Patient was previously identified with anti-K andanti-E. Since patient has received K,E negative units. Last transfusion was 11/2011. Patient returned yesterday for a another transfusion. The panels showed the previously identified antibodies with a positive autp control. DAT's were performed and reported as positive. The eluate, according to tech performing testing indicates anti-K recovered. Is this possible? I am very incomfortable with all this as the staff that work the off hours are generalists.

[Rh-fan]

you have found it, therefore it is possible. In serology eberthing is possible we say.

Did you make an acid eluate (elu-kit Immucor). With this eluate we see this very often, the presence of an allo antibody in the eluate while there is no transfusion in the last 3 months (most often with anti K). I think we are dealing with a combination of thing first of all the fact that the specificity of the anti K (in this case) is not htat narrow. Or as Malcolm says "mimick specificity" in his first reply. And the fact that in elu-kit bovine albumine is added in the buffer. This is used to enhance the reaction strength of antibodiesin the aluate but also from antibodies yoy dont expect in the eluate.

Peter

[JOANBALONE]

I agree with Rh Fan - If you use Elu Kit read the Limitations section (#9)of package insert.

JB

thanks Malcom, I am honored by seen you respond to my post. I have visited this site regularly fo r a couple of years and have learned soo much just by reading everyone's post and reponses. I did decide to place a message on patient;s chart to transfuse compatible Rh negative , C negative packed cells. I am just very puzzle by the fact that this patient is actually weak Du, has developed a anti-D and that has also sensitized his cells. The eluate show the anti-D and C pattern but also the rest of the cells were very weakly positve caused by the warm.

I would like to also share another case that I encountered today. Patient was previously identified with anti-K andanti-E. Since patient has received K,E negative units. Last transfusion was 11/2011. Patient returned yesterday for a another transfusion. The panels showed the previously identified antibodies with a positive autp control. DAT's were performed and reported as positive. The eluate, according to tech performing testing indicates anti-K recovered. Is this possible? I am very incomfortable with all this as the staff that work the off hours are generalists.

[mrmic]

what?

While it is not uncommon to find autoantibodies with non-Rh specificities it is also not common. As long as the last wash from the washing of the patient's rbcs for the eluate is tested for the presence of antibody, then the eluate represents what is eluted from the red cells. It may be an autoantibody showing preference for K1 or it may be one of the units were actually Kell positive. Transfused rbcs may last longer in the circulation than 3 months. Thoroughly check the transfusion history and recheck K1 typings. Would the patient have been transfused elswhere? There was a abstract written in the past about red cell and HLA antibody development due to sharing needles for drugs. History is important documentation. Colaboration is nice too. Some labs check to see if actually more than one cell population is present and if the "autoantibody" is actually an "alloantibody" coating transfused cells. Orrrrr it could just be a new autoantibody problem starting. You should be able to discuss specifics with your Immunohematology Reference Lab and get some answers.

These are interesting and fun things to investigate!

[galvania]

I am going back to your patient who is Du. You state that he is Du positive control positive. How exactly are you doing this test, and why did you do it? What I am thinking is that if the Du test is carried out using an IAT then this and the control will be positive as his DAT is positive. It is possible that he is actually ccddee (RH:-1,-2,-3,4,5) and always was, and has simply made an ALLO-anti-C+D in response to the blood he received in 2004. There is also something very fishy about the fact that the antibody screen is negative and the panel positive with everything. I can buy into this ONLY if the two sets of screening cells come from a different manufacturer and/or are used by a different technique. Then it could be something to do with different dilution medium. If this is not the case, then I would be willing to say I am sure there is a pipetting error.