IS Crossmatch with Gel IgG Crossmatch

[bduff]

It all just doesn't make sense. You can give blood without an IS crossmatch if they don't have antibodies but if they have antibodies we are suddenly afraid of giving the incorrect type? OYE!!! We have SOFT and it will not allow us to give out an ABO incompatible unit. If you LIS will not let you and you have verified that then there should be nothing wrong with not doing an IS crossmatch with a coombs crossmatch. I would fight any inspector to the bitter end!!!

[KBBB]

In the case when the Gel IgG crossmatch is compatible (performed because the patient has clinically significant antibodies), but the IS crossmatch is incompatible due to clinically INsignificant antibodies, there have been a couple of suggestions. I would like to know what the CMS answer is, but haven't seen anything about this to date.

One person suggested that the IS testing could be prewarmed but another Tech asked whether the prewarmed Immediate Spin procedure detected ABO incompatibility. (no answer given) Since IgM antibodies react best at RT or below, warming the system will decrease the reactivity of the ABO IgM antibodies. That's why I don't think prewarming is a valid answer. Another suggestion is to use group O RBC's. It seems that this would be a valid answer because the concern for ABO incompatibility no longer would be an issue. Just using logic here.

Here in the US, if we order Ag-typed units for a patient with antibodies, the blood supplier will usually have group O available because it is more efficient/cost effective to Ag type O donors for this reason. (I currently work in a small lab that sends all antibody ID's to the Ref. Lab and we don't keep antisera on hand for Ag typing. We also do not have a computer system...all manual.)

Just to clarify for international members, in the US we are required to retype all units that are procured from the blood supplier. ABO on all units, and also IS D on all Rh neg. units.

The Gel IS XM (which I have never actually done) would detect IgM ABO antibodies because there is no incubation time at 37C. The cells and plasma are added to the buffer card and centrifuged immediately...you will get your result...in 10 minutes...which is why we use the tube method.

And finally, just a little information on Electronic "crossmatch" (even though the last lab I worked at didn't have it set up, I investigated the requirements for the computer). The computer algorithm decides whether the patient qualifies based on the requirements set up like...the patient has no historical or current antibodies, ABO/Rh type has been done twice on same or different specimens...& there may be more. Basically, you just aren't doing the actual plasma/RBC crossmatch which saves a lot of time since almost all of the time, the IS XM is negtive. Your crossmatch tags won't print out unless everything is ok. I think that maybe because the 1st rule to use the electronic crossmatch requires the antibody screen to be neg. and historically neg., this is the problem that hasn't been clarified yet.

[Liz]

........ Your crossmatch tags won't print out .......

Hello KBB,

Can you send me a copy of your printed crossmatch tag please: ek01@aub.edu.lb

and what is the brand of your printer?

Thank you,

Liz

[DOGLOVER]

I don't know anything about your system, but in Cerner classic we were able to add a column to answer the IS with the XMG. Works well.

[dawn w]

Thru validation we also proved that gel picked up ABO incompatibility so in order to meet the requirement we stopped doing gel xm all together and just carried our IS thru Coombs when needed.

[Mabel Adams]

Sad to have to do a less sensitive method of AHG xm (and one different than your screen and ID) just because of this silliness. I guess if you use PEG it is probably similar in sensitivity, but LISS or saline are less sensitive. Either way, what do you do with someone with a strong cold agglutinin that will never have a compatible IS xm? Back when we did only tube testing, we skipped the IS phase on such patients and did only AHG in tube. Did anyone ever validate tube AHG as being capable of detecting ABO incompatibility at least as well as IS xm does? Even with weak reverse antibodies? That is, is it any better than gel?

[dawn w]

We do use PEG in place of gel crossmatching. On occasions of strong colds we do skip the IS and go straight to AHG. As to your question regarding validating AHG for detecting ABO incompatibility, we did perform mis-match ABO compatibility validation with a new vendor of PEG to demonstrated that the PEG did catch it. I admit this may not be the perfect solution to the problem, but in order to meet the standard it was the best we could come up with. Any advise would be appreciated.

[Mabel Adams]

Back before gel testing, if we had a strong cold agglutinin we might skip the phases other than AHG (maybe even do pre-warmed). Did anyone ever prove that tube AHG tests detected ABO incompatibility? Or at least did so as well as the IS xm does? After all, no other technique for detecting ABO incompatibility needs to be any more sensitive than the IS xm, right? I see above that those in LISS were questioned at one point. If you warm an IS test, does it still detect ABO incompatibility with adequate sensitivity?

[KBBB]

We need to think about which class of antibodies are being tested. When doing a gel or tube AHG crossmatch using anti-IgG we are looking for reactions between the antigen and an IgG antibody. When doing the IS crossmatch at Rm Temp, the phase favors the reaction between the antigen and an IgM antibody. The percentage of IgM vs IgG and the titer of anti-A, anti-B, and anti-A,B varies from sample to sample. We generally think of ABO antibodies as IgM, but they may be a variable mixture of IgM, IgG, & IgA.

So only doing an AHG crossmatch, or prewarming, which decreases the possibility of IgM antibodies reacting, will not always detect an ABO incompatibility especially if the sample only contains IgM ABO antibodies.

This is also why I don't think "validating" a system to detect ABO incompatibility makes sense since the samples are so variable.

Thus the conundrum! It seems the only way to avoid doing the required IS crossmatch to detect ABO incompatibility is to take away any possibility of an ABO incompatibility in the first place...Use group O.

[carolyn swickard]

Quote - "It seems the only way to avoid doing the required IS crossmatch to detect ABO incompatibility is to take away any possibility of an ABO incompatibility in the first place...Use group O."

I hope you were not really serious about that suggestion. We are already having trouble keeping up with O blood for O users in this region. Any sustained use of O blood for non-O users just for something like this seems an unjustified waste of O blood resources. Speaking as an O blood donor and an O blood user - I just can't agree with any trend like this at all. What are you going to do for your O blood users on the day you have given your last unit of O blood to an A user for a reason like this? Our donor center is already reeling from recent increases in O blood usage that they are having to investigate the reasons for - I hope they don't find a lot of new policies like this. The region is already trying to accomodate the newer CAP requirement to "make transfusion safer" where all the hospitals are getting and resulting 2 separate specimens on patients before they will release type specific blood. If they don't have the specimens they give, guess what? - O blood! When we can "make" all O blood maybe this will all make sense, but right now - I would like to be assured that that O blood will be there for my O users, myself included.

[David Saikin]

Blood suppliers are now starting to evaluae the number of group O red cells transfused/purchased in order to keep group O on the shelf. Some also have a significantly higher fee for group O red cells - to reach the same end.

I saw some earlier comments about using LISS or PeG crossmatches vs gel ahg . . . gel is so much more sensitive - how can you be certain your ahg xms done in tube correlate with gel ab detections?

[Brenda K Hutson]

So I noticed a couple of people asking about the ability (and/or validity) of charging for 2 crossmatches if this is required; both I.S. and Coombs. For some, it may not be a huge issue (i.e. they perform tube coombs crossmatches) while for others (i.e. my Institution) who use GEL, the I.S. Crossmatch is a totally separate test then. According to our I.S. guru with regard to our Blood Bank LIS (HCLL) when I asked her about the ability to charge for both, her response was:

HCLL has logic to send out a charge for the actual type of crossmatch test performed – IS or Coombs

But the question (for me) still remains; can we (legally) charge 2 separate crossmatch charges? Would love to hear what the rest of you have decided on that aspect of this issue.

Thanks,

Brenda Hutson

[Deny Morlino]

At this point I am playing it conservative and not charging for the I.S. crossmatch. If not before, when our technical meeting with the blood supplier occurs this fall I will bring the question up to the Medicare specialist. My suspicion is billing for only one will be reimbursed. I am in the same boat as you Brenda with GEL and tube I.S. If I find anything out I will certainly post here.

[Liz]

In addition to gel IS or the gel major crossmatch it is routine for us to repeat the forward blood group on the already confirmed types of the donor and the patient. We do not charge for that. I sleep well.

[khalidm3]

In addition to gel IS or the gel major crossmatch it is routine for us to repeat the forward blood group on the already confirmed types of the donor and the patient. We do not charge for that. I sleep well.

A few of our staff practice the same though it is not according to our SOP. Long ago I was on the bench and was practicing the same; My supervisor objected that I was wasting the reagents and I replied to him that if he not allow, I may buy the reagents from pocket but will not changethe practice. He kept silent and never objected again.

[Brenda K Hutson]

Same for us; but doing a 2nd, different type of crossmatch (GEL vs Tube) seems to warrant a charge in my opinion.

Brenda Hutson

In addition to gel IS or the gel major crossmatch it is routine for us to repeat the forward blood group on the already confirmed types of the donor and the patient. We do not charge for that. I sleep well.

[Mabel Adams]

There is a CPT code for "incubation of xm" (or at least there used to be). Since none of us would ever have done only an incubation (I assume they mean reading at 37) I always had interpreted that as allowing us to charge for all phases of tube xms performed. I think I have since heard that was not what was intended, but whatever the answer was to that, it should apply here. Maybe someone that is still doing tube xms through AHG has the answer to that.