To send or not to send (to a reference lab)?

[SMILLER]

Case study:

 

An O pos patient has been developing something over the last few months that always comes out equivocal--we have always been able to get all of the important rule-outs.  Two months ago she was transfused two units. Autocontrol has always been negative.

 

This started out with one or two screening/panel cells coming up weak positive, but now we are seeing about half of the panel cells coming up weak or 1+ positive at coombs --both in gel and tube (all tube cells neg at IS and 37).  The reactions in gel appear to be mixed field.  In the past, occasionally coombs crossmatched units have come up weak positive as well.

 

On this last admission (the patient is not scheduled for OR or a transfusion at this time), we followed our policy for antibody screen positive patients and started crossmatching 2 units to have on hold.  Only 2 out of ten units were found to be compatible at coombs.  Reactions on the others ranged from weak to 3+. 

 

(If we could not find any compatible units and a transfusion was ordered, we would have to have the doc sign a "tranfuse least incompatable" form.)

 

Should this patient be sent to a reference lab for further studies, and why or why not?

 

Thanks, Scott

Edited June 3, 2013 by SMILLER

[Malcolm Needs ☆]

Case study:

 

An O pos patient has been developing something over the last few months that always comes out equivocal--we have always been able to get all of the important rule-outs.  Two months ago she was transfused two units. Autocontrol has always been negative.

 

This started out with one or two screening/panel cells coming up weak positive, but now we are seeing about half of the panel cells coming up weak or 1+ positive at coombs --both in gel and tube (all tube cells neg at IS and 37).  The reactions in gel appear to be mixed field.  In the past, occasionally coombs crossmatched units have come up weak positive as well.

 

On this last admission (the patient is not scheduled for OR or a transfusion at this time), we followed our policy for antibody screen positive patients and started crossmatching 2 units to have on hold.  Only 2 out of ten units were found to be compatible at coombs.  Reactions on the others ranged from weak to 3+. 

 

(If we could not find any compatible units and a transfusion was ordered, we would have to have the doc sign a "tranfuse least incompatable" form.)

 

Should this patient be sent to a reference lab for further studies, and why or why not?

 

Thanks, Scott

 

Hi Scott,

 

I can imagine you (and others) saying, "Well, he would say that, wouldn't he", but the answer is "Yes".

 

The reason I say yes is because this sounds quite an interesting scenario.  By that, I mean that the antibody appears to be strengthening, and it would be best to get the specificity sorted out now, than when the antibody finally decides to show its real muscles, just when the patient requires blood in an emergency.

 

From what you say, the reactions appear to give a sort of "mixed-field" reaction, which suggests either an anti-Sda or something within the Lutheran Blood Group System (neither of which are renowned for being clinically significant), BUT, and it's a big BUT, it may not be.  So you then have the problem that, 1. if it is, how do you know if there is, or is not, another, this time clinically significant antibody lurking under this clinically insignificant antibody or 2. if it isn't, and the patient needs blood urgently, what do you do, as this antibody specificity on its own may be clinically significant?

 

From the Reference Laboratory's point-of-view, I can tell you that there is nothing that makes us bite through 6 inch nails more than a hospital that knows "there is something there", but hasn't sent it to us to identify, and then requires us to identify the antibody specificity in an emergency situation, when we could have identified the specificity (or, at the vey least, had a go at identifying the specificity) as a "cold" case.

 

Just my slant on things!

[SMILLER]

Thanks Malcolm, for your usual succinct and educational response. 

 

In fact, we have sent it out, but mostly to have an additional reference to be able to explain to a physician, should the time come, why we have to have them sign a "release least incompatible form". 

 

But I had not considered the situation that you outlined -- where we could be stuck next time without being able to do our rule-outs and having to dump a STAT specimen on our reference lab!

 

Scott

[Malcolm Needs ☆]

But I had not considered the situation that you outlined -- where we could be stuck next time without being able to do our rule-outs and having to dump a STAT specimen on our reference lab!

 

 

Believe me Scott, neither do some of the hospitals we cover!!!!!!!!!!!!!!!!!!!

[goodchild]

Scott, I can tell you my institution would have sent samples to reference with those kinds of reactions. We actually had a patient extremely similar to that last week (reactions in gel/tube from w+ to 3+ but with no discernable pattern that anyone here could identify, as well as a bunch of negative panel cells with no discernable pattern) but the nurse wouldn't draw any more pink tops for us and the patient was discharged without being transfused.

[SMILLER]

Follow-up: 

 

Our reference lab did indeed identify a HTLV -- Csa.  Probably will get stronger with each transfusion unitl we can only supply "least incompatible" -- but at least we will know what to tell the physicians...

 

Scott

[Malcolm Needs ☆]

Nice one Scott.  Anti-Cs^a is pretty uncommon - but you can see now why I say it should go to the Reference Laboratory before it gets urgent.

 

Just to illustrate what I mean, we have been dealing with a sickle cell disease patient (no name, no pack drill) for a while.  We couldn't work out what specificity was there (although we knew there was an anti-M and an anti-Fy^a.  We asked for further samples (several months ago) to send to the International Blood Group Reference Laboratory (IBGRL), but none arrived.

 

Late last week, we received a further couple of samples on the patient, who had an Hb of 69 g/L, and we still couldn't work out what was there.  They needed blood urgently (fortunately, the patient settled) because we then had to send the sample down to the IBGRL as urgent.  NOW, they are GOOD!  But, even they took a bit of time over this one.

 

The provisional report from the IBGRL is that this patient has a (papain) enzyme auto-antibody, an anti-M reacting at 37oC, an anti-s, an anti-Fya and an anti-HrB!!!!!!!!!!

 

Now, we have to get -D-/-D-, ^.D^./^.D^. or Rh_null blood (rare enough in itself), that is also M-, s- and Fy(a-).  oh, and he is group O as well, so that cuts things down too!  We have none in the UK.

 

The patient has had no transfusions since the last time we saw him (so all of these antibodies were probably present the last time we saw him).  If our request for further samples had been acted upon, then we would not be in this position now, because we could have got it all worked out before his latest crisis.  Now, we are working as "crisis management".

 

Can you tell that I'm not happy?  Humph!!!!!!!!!!!!!!!!!!!

 

       

[pstruik]

Sorry you're unhappy Malcolm (grumpy old so and so that you are)

 

On the wall of the laboratory where I started my career (many years ago now) there was a cartoon with a doctor laughing and explaining to the laboratory 'If I wanted the result tomorrow I would have sent the sample tomorrow'

 

It doesn't appear anything has changed in the intervening 'X+lots' years.

 

As someone who worked at a hospital served by Malcolm's excellent laboratory I can't say we ever found a complex case that became easier to resolve after further treatments and/or transfusions - early involvement of a reference laboratory is worthwhile*

 

(* even if only so you can sit back with a feeling of unbearable smugness when they fail to reveal anything you hadn't detected, completely forgetting to express any gratitude for the feeling of security that you are doing the right thing with that patient thus engendered)

Edited June 6, 2013 by pstruik

[David Saikin]

The way you describe your ab in gel  (mf rxs) and 2/10 compatibles - sounds like it could be an anti-M (to me).   This is a tough nut - to send or not to send.  Like Malcolm says, you don't want to get caught needing to transfuse and then having to send away.  I'd send it if you can not identify to your satisfaction.

[Liz0316]

If given the opportunity, I will send specimens like this to reference even when no transfusion is ordered. Get it to reference, have them ID the culprit when there is no rush. That way you can be prepared when the patient shows up on your door step in a blizzard on Sunday morning! I had a similar case about a year ago, turned out to be a JK3! 

[Malcolm Needs ☆]

If given the opportunity, I will send specimens like this to reference even when no transfusion is ordered. Get it to reference, have them ID the culprit when there is no rush. That way you can be prepared when the patient shows up on your door step in a blizzard on Sunday morning! I had a similar case about a year ago, turned out to be a JK3! 

 

NASTY!!!!!!!!!!!!!!!!!!!

[Mabel Adams]

When something like that is happening I would send it in because I would suspect some HTLA-like antibody which only our reference lab can ID.  Then I will probably feel OK if we have to give least incompatible blood later.

[AMcCord]

"If given the opportunity, I will send specimens like this to reference even when no transfusion is ordered. Get it to reference, have them ID the culprit when there is no rush. That way you can be prepared when the patient shows up on your door step in a blizzard on Sunday morning! .............." 

 

Me too! Saves a lot of stress for everyone involved.

[tupton]

We would have also sent to the IRL.  The incompatible crossmatches are a dead give-away something is formed or forming.