Deactivation of Insignificant Cold antibodies

[tnbloodbank]

I have looked for a source to base an addition to the procedure manual for deactivating insignificant cold antibodies and can not find anything in AABB.

 

Does anyone have a source I can use to refer to in the procedure when I make the change.

[applejw]

I'll be the curious mind for today - what addition are you wanting to add to your procedure to "deactivate insignificant cold antibodies"?  

[Neil Blumberg]

Could you define what you mean by deactivating, please? Not familiar with the meaning of this term.

[Malcolm Needs ☆]

38 minutes ago, Neil Blumberg said:

Could you define what you mean by deactivating, please? Not familiar with the meaning of this term.

I agree Neil.  I hope the "deactivation" does not involve the denaturation of IgM molecules by, for example, dithiothreitol.  This would be a great way to miss most examples of anti-Vel - a VERY clinically significant antibody!

[tnbloodbank]

Taking out of the computer system so it no longer flags is what i meant by deactivating, Sorry.

[Malcolm Needs ☆]

Okay, so as long as the said antibody is tested each and every time, to ensure that the antibody specificity has not "broadened", but also that the thermal amplitude has not changed, so that, "this time" it may be a clinically significant "cold-reacting antibody", rather than a clinically insignificant "cold reacting antibody".

Sadly, it is not even THAT simple (if only), but it depends upon the specificity of the antibody and, to a certain extent, the ethnicity of the patient.  "Cold-reacting" anti-M, for example, is known to be much more clinically significant in people from the Far East (particularly Japan) than in any other ethnic group, as far as I know.

However, if you take the "antibody" out of the computer system, so that it no longer flags, there is the very real possibility that a formally clinically insignificant "cold-reacting antibody", that has developed into a clinically significant "cold-reacting antibody" may be ignored - not "not detected" (far from it) but ignored, because "it was okay last time"!

All that having been said, I have NEVER understood why time and money is spent on determining the specificity of a genuine cold-reacting antibody, rather than just determining the thermal amplitude, to determine the clinical significance, and bothering to provide antigen negative blood, when there is zero chance of a haemolytic transfusion reaction!

Edited March 29, 2023 by Malcolm Needs

[Bet'naSBB]

Sorry - no reference to share - but, for the most part, we only "report" cold autos if the DAT is pos with anti-C3D and they interfere with IS testing(XM or Reverse)......OR if the patient has evidence of hemolysis.  That being said - once reported, we repeat the a full DAT profile (gel for Poly/IgG; tube for complement) at each visit.  Once the DAT's are negative and there's no evidence of cold remaining in the IS testing on TWO successive visits, our techs can remove the "Cold".  We then replace it with a comment stating "Pervious Warm/Cold" antibody.  (So, that  being said, we treat Warm's the same way)

We also do Thermal Amplitude testing when we have C3D pos DAT and pos reactions @ IS.  Our Medical Director considers "colds" reactive at 28-30C clinically significant.

Edited March 30, 2023 by Bet'naSBB

[AMcCord]

It is possible to designate a cold reactive antibody as not clinically significant in our BB LIS system. We report them as we would any other antibody. We can add a 'special needs' requirement for an AGT crossmatch to the patient profile, if appropriate/necessary for the antibody in question, when a 'clinically insignificant' antibody is reported. Our system is also set up to flag all red cell units issued for patients with antibodies, including clinically insignificant, if antigen screening was not performed. That flag is included in the daily system review report. We don't remove a cold antibody ID from the LIS, but can inactivate the AGT crossmatch requirement if the antibody is no longer detectable. I have no references for that.

[jayinsat]

Same as @AMcCord. We use MEDITECH and cold antibodies are listed as clinically insignificant in our rules table for determining if EXM will be allowed. For those who are panicking, note:

1. EXM will be rejected if the CURRENT antibody screen is positive
2. EXM will be allowed only if the CURRENT antibody screen is negative and THE ONLY antibody listed in the patient's history is a cold antibody.
3. EXM will be rejected if any other clinically significant antibody is present, regardless of the current antibody sreen.

That's how we handle it.

[Malcolm Needs ☆]

Another idea.  Not mine, but I wish it was!

 

[JJSPLAYHOUSE]

Deactivating them from where? Your LIS? Policy?