Warm auto antibody crossmatch / testing frequency

[tkakin]

When crossmatching for Warm Auto patient's we have it in our procedure to AHG crossmatch with the neat plasma and the adsorbed plasma.  When the adsorption works this is a great tool, but when the adsorption does not work it seems redundant and useless.  Am I missing something if I change the procedure to state that we do not have to perform the AHG crossmatch with adsorbed plasma if the adsorption did not work?

I was also wondering what other labs are doing for workups for frequently transfused warm autos...I know they shouldn't transfuse, but they don't listen to me. 

We do the adsorption workup every 3 days.  Our reference lab will not do the adsorption if the DAT has no significant change every 2 weeks. What do you do?

Thanks for your time and knowledge

 

[Malcolm Needs ☆]

10 hours ago, tkakin said:

When crossmatching for Warm Auto patient's we have it in our procedure to AHG crossmatch with the neat plasma and the adsorbed plasma.  When the adsorption works this is a great tool, but when the adsorption does not work it seems redundant and useless.  Am I missing something if I change the procedure to state that we do not have to perform the AHG crossmatch with adsorbed plasma if the adsorption did not work?

I was also wondering what other labs are doing for workups for frequently transfused warm autos...I know they shouldn't transfuse, but they don't listen to me. 

We do the adsorption workup every 3 days.  Our reference lab will not do the adsorption if the DAT has no significant change every 2 weeks. What do you do?

Thanks for your time and knowledge

 

In NHSBT Red Cell Reference Laboratories in the UK, we used to cross-match with neat and adsorbed plasma too, but I could never see the sense of cross-matching with the neat plasma, when we knew before we started that the cross-match would be incompatible due to the warm auto-antibody.  It seemed to me to be a complete and utter waste of expensive reagents and even more expensive time.  We no longer perform a cross-match with the neat plasma (one of my few victories!).

We would adsorb an absolute maximum of eight cycles, and if these multiple cycles did not result in success, we would telephone our own Consultant Clinician and discuss the matter.  Almost every time, this would result in them advising us to give ABO, Rh and K matched blood, following an immediate spin cross-match (and, of course, negative for any antigen against which the patient had already produced a clinically significant antibody, such as an anti-Fy^a), and our own Consultant Clinician would contact the patient's physician at the hospital and tell them what we were doing and why.  Following such an instance, we would discuss with our own Consultant Clinician how we would approach subsequent samples (including how many cycles of adsorption we would try before "giving up"), so that we did not waste precious time and reagents in the future.  Unless there was evidence of the need for more frequent transfusions (suggesting the formation of a possible new antibody specificity), we would often go seven days between adsorptions, however, we would certainly NOT gauge this on the strength of the DAT, as variations in the strength of the DAT are no guide whatsoever as to whether a new antibody is present or not.

[mrmic]

Warm autos are a curious bunch.  Are antibodies present truly auto or are the allo?  Are they really allo or mimicking specificities of the autoantibody(ies) present.  Once you start transfusions you should be doing allo-absorptions since transfused red cells may be present.  Do multiple adsorptions have a dillutional effect with the absorbed serum which may cause a weak significant allo antibody be missed?   Maybe the crossmatch is of little use in these situations so whatever you do is ok?  In these situations the focus is on the cause and resolution of the warm autoantibody production by the patient and the determination of the benefits/risks of transfusion.  We had seen little differences with utilizing "absorbed" sera crossmatchs vs "least incompatible" crossmatches with regards to patient outcome.     However, it is a technically challenging/interesting when we get these cases sent to us and then to try to follow up of the patients as long as we can.

[Ensis01]

tkakin; you said that you crossmatch with "the adsorbed plasma and the neat plasma". Your post also indicates that the reference lab does the adsorptions/workup. To me doing both makes sense if the reference lab does the workup and crosmatches with the adsorbed plasma, sends you the units and report. You then crossmatch using the neat plasma of the current specimen (also ensuring reactions less than or equal to the auto control). If however you are doing the adsorbtions in-house I can see no reason to crossmatch with adsorbed and neat plasma.

[tkakin]

12 hours ago, Ensis01 said:

tkakin; you said that you crossmatch with "the adsorbed plasma and the neat plasma". Your post also indicates that the reference lab does the adsorptions/workup. To me doing both makes sense if the reference lab does the workup and crosmatches with the adsorbed plasma, sends you the units and report. You then crossmatch using the neat plasma of the current specimen (also ensuring reactions less than or equal to the auto control). If however you are doing the adsorbtions in-house I can see no reason to crossmatch with adsorbed and neat plasma.

Thank you for your response, yes we do warm auto adsorptions in hours only if they have not been transfused.  If they have been transfused we then send it to the reference lab for the differential adsorption.  If the reference lab does the workup, we then have reference lab to the crossmatches.

[dragonlady97213]

When we come up against a warm autoantibody, we will run a saline panel (in addition to enzyme and PEG/LISS) and if the warm autoantibody isn't reactive in saline, we recommend using saline technique for crossmatches.  If there is reactivity in the saline panel, we'll do an adsorption, auto or allo depending on transfusion status, to identify any underlying alloantibodies.  If we find none, we communicate that back to the submitting lab.  We don't provide guidance to crossmatch with adsorbed serum/plasma as that can give the clinician a false sense of security that the crossmatch is compatible; it won't be because of the warm autoantibody.

[tkakin]

On ‎4‎/‎28‎/‎2017 at 5:45 PM, dragonlady97213 said:

When we come up against a warm autoantibody, we will run a saline panel (in addition to enzyme and PEG/LISS) and if the warm autoantibody isn't reactive in saline, we recommend using saline technique for crossmatches.  If there is reactivity in the saline panel, we'll do an adsorption, auto or allo depending on transfusion status, to identify any underlying alloantibodies.  If we find none, we communicate that back to the submitting lab.  We don't provide guidance to crossmatch with adsorbed serum/plasma as that can give the clinician a false sense of security that the crossmatch is compatible; it won't be because of the warm autoantibody.

This is a great idea.  How long do you incubate your saline test for?

[dragonlady97213]

1 hour ago, tkakin said:

This is a great idea.  How long do you incubate your saline test for?

We incubate for 30 minutes.  I have to add a caveat to this.  Keep in mind that I work in a reference lab so shaking tubes is what we do 90-95% of the time and my techs are very skilled at it.  We also require non-reactivity with at least one double dose red cell for rule out when using saline technique.

Chapter 17, AABB TM, 18th edition states;

Quote

It is the exclusion of newly formed alloantibodies that is of concern.  Because of the presence of autoantibodies, all crossmatches are incompatible.  This is unlike the case of clinically significant alloantibodies, without autoantibodies, where a compatible crossmatch with antigen-negative red cells is possible.

This is why we don't provide guidance to crossmatch with absorbed serum/plasma.

[Yanxia]

On 2017/4/29 at 6:25 AM, tkakin said:

 

 

Edited May 3, 2017 by yan xia

[Yanxia]

On 2017/4/29 at 8:45 AM, dragonlady97213 said:

When we come up against a warm autoantibody, we will run a saline panel (in addition to enzyme and PEG/LISS) and if the warm autoantibody isn't reactive in saline, we recommend using saline technique for crossmatches.  If there is reactivity in the saline panel, we'll do an adsorption, auto or allo depending on transfusion status, to identify any underlying alloantibodies.  If we find none, we communicate that back to the submitting lab.  We don't provide guidance to crossmatch with adsorbed serum/plasma as that can give the clinician a false sense of security that the crossmatch is compatible; it won't be because of the warm autoantibody.

i am sorry if my understanding is wrong.

Do you mean if the salin panel result is neg, you will not do adsorption test even the enzyme and PEG/LISS panel results is pos?

I think it is not safe, because most allo -antibodies are IgG, they are non reactive in saline.

[Malcolm Needs ☆]

51 minutes ago, yan xia said:

i am sorry if my understanding is wrong.

Do you mean if the salin panel result is neg, you will not do adsorption test even the enzyme and PEG/LISS panel results is pos?

I think it is not safe, because most allo -antibodies are IgG, they are non reactive in saline.

I could be wrong, but what I think dragonlady97213 means is that, when they test by IAT (which will, of course, detect an IgG antibody), the red cells are suspended in saline prior to and during incubation, rather than in a potentiating agent, such as LISS.  Is that right dragonlady97213?

[mrmic]

If I remember from many moons ago, there was a reference paper indicating the optimal time for antibody-antigen complexes in saline was 60 minutes.  I believe there were subsequent papers/abstracts suggesting that shorter incubation times using saline and "pre-warm" methods allo-antibodies were being missed, however, the warm reactive autoantibody was not interfering and the crossmatches were "compatible".

Hence, once allo-antibodies are ruled out through other immunohematological testing methods, issuing "least incompatible" crossmatches are ok as well thereby reflecting what is really happening.

[dragonlady97213]

@Malcolm Needs  Yes, you are correct.  Enhancement is not added to the system and the tubes are incubated at 37C for 30 minutes, washed and AHG added.  This is only done once we've established we're working with a warm autoantibody.