Warm auto titers??

[Jives]

Have any of you ever performed titers on a mom with a warm auto antibody??

If so, what kind of titer results do you get?? i have a mom now whose auto (i thought) was MI with no enhancement so i titered it and it titered out to 1:8 all with MI reactions!! kinda sounds like what used to be called an HTLA?!?!

thanks, jane (just another blood bank nerd )

[David Saikin]

I have had a few Moms with autoabs . . . never titered them. I asked on this website and responses were that the child is rarely, if ever, affected. All my babes had negative DATs at birth and no problems.

[Malcolm Needs ☆]

Have any of you ever performed titers on a mom with a warm auto antibody??

If so, what kind of titer results do you get?? i have a mom now whose auto (i thought) was MI with no enhancement so i titered it and it titered out to 1:8 all with MI reactions!! kinda sounds like what used to be called an HTLA?!?!

thanks, jane (just another blood bank nerd )

Hi Jane,

We regularly see pregnant ladies with auto-antibodies (and positive DATs), but have never seen a case that has resulted in clinically-significant HDFN.

We would never titrate such an antibody. For one thing, the concentration of free antibody within the mother's plasma would vary as the auto-antibody is adsorbed onto, and

dissociate from her own red cells.

What is MI incidentally? I am unfamiliar with this term - except as myocardial infarction - and I just know that you don't mean that!

[bmarotto]

Hi Jane,

What is MI incidentally? I am unfamiliar with this term - except as myocardial infarction - and I just know that you don't mean that!

Just a guess...but microsopic reactions?

[Malcolm Needs ☆]

Thanks bmarotto. If that is the case, then I must declare an interest, shared with Peter Issitt, that microscopes should be banned from Blood Banks, except for use on things like a Kleihauer!

[Mabel Adams]

Issitt says that autoantibodies are about as bad in the baby as the mom. All that I have seen have not caused hemolytic anemia in the mom and were likewise benign in the baby. If you ever see a case of severe hemolytic anemia in a pregnant mom then that baby might be at risk too (beyond the obvious problems of a severely anemic mom).

[sshel55]

Titers may be helpful in discerning allo vs auto antibodies when there is apparent blood group specificity. Also, keep in mind that some apparent auto-anti D may in fact be allo if the mom is a D variant.

[Malcolm Needs ☆]

Titers may be helpful in discerning allo vs auto antibodies when there is apparent blood group specificity. Also, keep in mind that some apparent auto-anti D may in fact be allo if the mom is a D variant.

Agreed that a titre may be helpful in such a case, as the alloantibody tends to have a higher titre than the auto-antibody, BUT, that implies that you are doing multiple tests on the titrated plasma to ensure that you test to ensure that the antigen against which the auto-antibody is directed is NOT present on the titration red cells and that the antigen against which the alloantibody is directed IS expressed on the red cells. I would prefer to perform alloadsorptions and test the adsorbed plasma against the panel.

Partial D types that express the D antigen quite strongly, require an IAT. In such a case, of course, you could try treating the red cells with chloroquine diphosphate (CPD) to dissociate the auto-antibody (to make them DAT negative), but, it has to be remembered that CPD also weakens the Rh antigens, thus you are in a "Catch 22" situation. Then, of course, there is the problem of Partial D III, which will react with all anti-D reagents, but such individuals are more than capable of producing quite a strong alloanti-D. Again, to be certain, you would have to resort to molecular techniques.

[sshel55]

Agreed that a titre may be helpful in such a case, as the alloantibody tends to have a higher titre than the auto-antibody, BUT, that implies that you are doing multiple tests on the titrated plasma to ensure that you test to ensure that the antigen against which the auto-antibody is directed is NOT present on the titration red cells and that the antigen against which the alloantibody is directed IS expressed on the red cells. I would prefer to perform alloadsorptions and test the adsorbed plasma against the panel.

Partial D types that express the D antigen quite strongly, require an IAT. In such a case, of course, you could try treating the red cells with chloroquine diphosphate (CPD) to dissociate the auto-antibody (to make them DAT negative), but, it has to be remembered that CPD also weakens the Rh antigens, thus you are in a "Catch 22" situation. Then, of course, there is the problem of Partial D III, which will react with all anti-D reagents, but such individuals are more than capable of producing quite a strong alloanti-D. Again, to be certain, you would have to resort to molecular techniques.

So I was answering the question. About titering an auto-antibody in a pregnant female. My concern is discerning an auto-D from an allo-D in a pregant female. I wasn't trying to cover every feasible option and lecture on partial and weak D phenotypes and resolving warm autos although our reference lab does all these techniques but we prefer EGA to CPD (yes it denatures Kell group antigens). Unfortunately, it seems that new opinions are not welcome here so I will refrain from posting and those of you who own the board can have at it.

[Malcolm Needs ☆]

Unfortunately, it seems that new opinions are not welcome here so I will refrain from posting and those of you who own the board can have at it.

You are SO far from the truth, when you say that new opinion are not welcome; everyone's opinion is welcome, as far as I know, and nobody, particularly me, would profess to be the "expert" in all aspects of blood transfusion (maybe I know a bit more than some about blood group serology - but, then I should; it is my job). I learn from other people on this site on an almost daily basis.

I would honestly say that you really should continue to post (and I sincernely aoplogise if you took offence to my post - it was in no way meant to be offensive to you; just my opinion as an experienced Reference Laboratory Manager.

Lastly, I in no way "own the board"; like others, I am just a member, and those who do actually run the site (such as Cliff) could take away my membership at the drop of a hat, if they so desired, or if I really did post offensive (and by that, I mean deliberately offensive) comments.

PLEASE DO NOT STOP POSTING sshel55; I am certain that I, and other people, would value your views.

Am I correct members?

:surrender:surrender:surrender:surrender:surrender

[PAWHITTECAR]

sshel55 please don't leave....Malcolm is not really that bad you just have to get used to him....

[Eagle Eye]

agree 100%. Please continue posting, we learn something new from each other.

& Malcolm please do not STOP posting...

[Malcolm Needs ☆]

sshel55 please don't leave....Malcolm is not really that bad you just have to get used to him....

I'm not sure how I should take that!!!!!!!!!!!!!!!!!!!!

:paranoid::paranoid:

[aafrin]

Agreed that a titre may be helpful in such a case, as the alloantibody tends to have a higher titre than the auto-antibody, BUT, that implies that you are doing multiple tests on the titrated plasma to ensure that you test to ensure that the antigen against which the auto-antibody is directed is NOT present on the titration red cells and that the antigen against which the alloantibody is directed IS expressed on the red cells. I would prefer to perform alloadsorptions and test the adsorbed plasma against the panel.

Partial D types that express the D antigen quite strongly, require an IAT. In such a case, of course, you could try treating the red cells with chloroquine diphosphate (CPD) to dissociate the auto-antibody (to make them DAT negative), but, it has to be remembered that CPD also weakens the Rh antigens, thus you are in a "Catch 22" situation. Then, of course, there is the problem of Partial D III, which will react with all anti-D reagents, but such individuals are more than capable of producing quite a strong alloanti-D. Again, to be certain, you would have to resort to molecular techniques.

I am sorry to bother you Malcolm, but I am lost on the above explanation. Can you please explain it again a little more simply? I am a newbie where antibody screening & identification are concerned. My adsorption is a little primeval:confused:.

Thanks and please keep posting, we are learning new things and getting updated everyday.

[Malcolm Needs ☆]

I'll do my best aafrin, but this may be a bit of a long post (and I'm still totally hyper from watching England smash the All Blacks at rugby)!

When an auto-antibody is present, it is often difficult to tell if there is an alloantibody present as well, as the auto-antibody tends to mask the presence of the alloantibody. The auto-antibody will react with all cells by IAT and with papain-treated red cells, apart from some very rare cells, such as Rhnull and other Rh deletion cells, such as D--/D--, or with Wr(b-) red cells. However, although the autoantibody reacts with (almost) all red cells (and, often, this reaction looks incredibly strong), it is often true to say that the titre of a masked alloantibody is higher than that of the auto-antibody. Therefore, if you titrate the patient's plasma, to the "extinction" of the auto-antibody (say a dilution of 1 in 16), you can usually detect a masked alloantibody in plasma that is diluted 1 in 16. BUT, there are several problems associated with this method.

Firstly, you have to "guess" that the red cell you are using to test the "extinction" of the auto-antibody does not express the antigen that corresponds to the alloantibody that is masked by the auto-antibody. For example, if there is an alloanti-Fya being masked by the auto-antibody, and the red cells you use to test the titrated plasma containing the auto-antibody is Fy(a+), you will not detect the anti-Fya, because the apparent end point of the auto-antibody will actually be the titration end point for the anti-Fya. So, unless you use several different red cells of various different phenotypes for testing the titration end point of the auto-antibody, you may not detect a masked alloantibody.

Secondly, the alloantibody may have a lower end point titration than the auto-antibody, so that, even if you use a whole raft of different red cells against the titrated plasma, you still will not detect the alloantibody. In the example I gave, suppose the auto-antibody has a titre of 16, but the anti-Fya only has a titre of 8, you will not detect the anti-Fya.

So, in my opinion (and it is only an opinion), it is safer to try to adsorb out the auto-antibody by alloadsorption (one cannot use auto-adsorption, as there is the danger that foetal red blood cells may be present in the maternal circulation that expreess an antigen encoded by a gene inherited from the father, and so an alloantibody may be adsorbed out by the foetal red cells).

In the UK, we tend to use three papain-treated red cell samples for alloadsorption, each of which is used to adsorb an aliquot of the maternal antibody. One of these cells will be R1R1, one will be R2R2 and the third rr. So, if there happens to be an alloanti-C present, which is being masked by the auto-antibody, the alloanti-C and the auto-antibody will be adsorbed out by the R1R1 red cells, but not by the R2R2 or rr red cells; only the auto-antibody will be adsorbed out, leaving the alloanti-C still detectable.

Equally, one of these adsorption cells will be, for example S+s-, whilst one or other of the other two adsorption cells will be S-s+, so either an alloanti-S, or an alloanti-s will still be detectable in the adsorbed plasma.

One cell will be Jk(a+b-), whilst one or both of the other cells will be Jk(a-b+), so that all three cells will adsorb out the auto-antibody, whilst, when testing the three aliquots of adsorbed plasma will reveal the presence of either an anti-Jka or a Jkb.

And so on and so forth.

Of course, there is always the danger that the alloantibody may be directed against a high-frequency antigen, such as k or Vel, in which case, the anti-k or anti-Vel will be adsorbed out by all three adsorption cells; but this would just be unlucky (and unlikely).

I hopr that helps, but if it is still not clear, please do not hesitate to say so.

[PAWHITTECAR]

Malcolm,

I just meant that it can take a while to get used to how you think but you are usually a well of knowledge and that you really are just trying to share that knowledge with all of us. I know that I have definately learned my share from you.

Trish

[Malcolm Needs ☆]

Malcolm,

I just meant that it can take a while to get used to how you think but you are usually a well of knowledge and that you really are just trying to share that knowledge with all of us. I know that I have definately learned my share from you.

Trish

Don't worry Trish; my reply was entirely tongue in cheek!

[David Saikin]

I think that everyone who posts on this site realizes that posters are posting based on their experience and knowledge . . . I, for one, have had my ignorance pointed out, been disagreed with on any number of occasions, been just plain wrong AND I am grateful to any and all who have pointed out my shortcoings . . . This site, and its posters, is enormously helpful to me professionally. Never has anyone been anything but professional in discussions on the myriad topics expounded upon here. THANKS TO ALL OF YOU and keep up the good work. I learn a lot here from everyone. If I knew you personally I would be glad to call you all my friends.

[Malcolm Needs ☆]

I think that everyone who posts on this site realizes that posters are posting based on their experience and knowledge . . . I, for one, have had my ignorance pointed out, been disagreed with on any number of occasions, been just plain wrong AND I am grateful to any and all who have pointed out my shortcoings . . . This site, and its posters, is enormously helpful to me professionally. Never has anyone been anything but professional in discussions on the myriad topics expounded upon here. THANKS TO ALL OF YOU and keep up the good work. I learn a lot here from everyone. If I knew you personally I would be glad to call you all my friends.

I feel the same way David.

[tbostock]

Yeah, what David said!

[Deny Morlino]

Agreed